65
Comparison of Myectomy Alone or in Combination with Mitral Valve Repair for Hypertrophic Obstructive Cardiomyopathy D. Fritzsche. R. Krakor, H. Goos, K.-F Lindenau, and L. will-Shahab » Clin ic of Card iac a nd Vascu lar Su rge ry, University of Leipzig * Institute of Heart a nd Circu latio n Rese a rch , Berli n Su ch , Germany
Betw een 1184 a nd 6/91 56 pati en ts were tr eated for hypertrophi c obstructive ca rdiomyopathy (Ha eM): th e Morr ow techniqu e alone wa s performed on 40 patients (group 1), in 16 pati ent s (group 2) an additional repl a ceme nt (0 = 13 ) or reconst ruction (0 = 3) of the mitral valve wa s indi cated. In a total of14 cas es corona ry artery bypass gr afting and aortic va lve replacement was per form ed in add ition . Postop eratively (mean follow-up 4.2 yrs, 14 1 patient-years) left-ventricular diastolic and systolic fun ction parameters , heart muscl e mass , ECG find ings, and symptomatology wer e recorded and the ratios of .a-adrenoreceptor density to density of the calcium chan ne l were measured . Result s: Pres sur e gradient decreas ed from 69 .2 ± 5.2 (grou p 1) and 75.1 ± 4.8 (group 2)\0 23.3 ± 2.7 and 11.7 ± 2.2 mm llgpostoperatively. Likewise Sokolow - Lyon ind ex decreas ed from 3.5 ± 0.2 / 3.7 ± 0.2 to 2.9 ± 0.2/2 .8 ± 0.3. The quotient tim e-to-peakvelocity/left -ventricular-ejectlon-time decreased significantl y in group 2 from 58 .6 ± 6.3 10 4 1.9 ± 5.8 (p < 0.051. The heart muscle mass, determined echo cardiographically, decreas ed from 680 g to 43 0 g (p < 0.0 5). Isovolumet ric ten sion time , isovolume tric relaxation time , and E/A ra tio at rest and after stre ss showed typica l characteristics. Ca'"-ch anne l density was clea rly rai sed in all pati ents, with no differences between th e two groups being obs ervable. We conclude from our results : - The most marked improvements in clinical and left-ventricular functional pa ram eter s we re experi enced by pat ients in group 2 (myectom y + MVR) . - Myectom y alone ac hieved good results, but did not influen ce th e severity of a concomita nt low-grade mitral insufficiency: only in one patient of th is gro up did we register a progression of the mitr al insufficiency. - This obse rva tion allows us to conclude that deterioration in left-ventric ula r ar chitecture, rather than a high intracavitary pres sure gradient, is responsible for the devel opment of mitral insufficienc y in HOCM. Prognostic crit eria for th e development of accompa nying mitral valve dysfunction could not be found . Thus, on the basis of a ca reful risk-benefit a nal ysis. there appears to us to be no au tomatic justificat ion for perform ing a combined myectom y and MVR, or MVR alon e , in cases of HOCM gene rally. Keywords
Verg leich zwi sche n a lle inige r Myek to mie un d Myektomie kombinie rt mit 1\1it ralklappen ersatz bei IIOCM Von Januar 1984 bis Juli 1991 wurde am Herzzentrum Leipzig (HZL) unter 4 970 EingrifTen am ofTenen Herze n bel 56 Pati enten die Myektomi e nachMorrow ausgeftih rt. 16 Patienten (28 %) erforderten einen zusatzlichen Mitralklapp enei ngrifT (MVR: n = 13; plastische Rekonstruktion: n = 3). Bei 14 (25 %) waren a ndere Kombinatio nse ingriffe (Aortenklappenersatz. aortoko ro nare Bypas ses) indiziert. Die Hospitalletalitat betrug 7,1 %, es trat ein Spat todesfal l a uf. In der Nach beoba chtungsz eit (bis 7 Jahre ; 141 Patlentenja hre; mea n follow-up 4,2 Jahre) wurde n Angaben tiber subjektlve Beschwerde n, EKG·Veranderungen , linksv entrikulare Funktionsparam eter sowi e die lI er zmuskelmasse erfaBt. Die Myektomi e bewi rkte eine Verschiebungdes NYHA-Sta diums von III zu I postoperativ (p < 0.05). Oer ven triku loaortale Druckg radient sank in der Gruppe . Myektomie " (Gruppe I) von 69 ,2 ± 5,2 auf 23,3 ± 2,7 mm Hg. In der Grup pe . Myektomie + Mitralklappenei ngrtff" (Gruppe II) wurde der intrakavitare Druckgradient auf 11 ,7 ± 2,2mmHg gesenkt (p < 0,05). Der Sokolov-Lyon Index betrug praoperativ 3,7 ± 0,2 un d sank postoperativ auf2 ,8 ± 0,16 . Das Verha ltnis der a -edrenoreceptor- zu Kalziumkanaldicht e von 0,5 ± 0,1 irn Vergleieh zu einer Kontrollgru ppe (n = 6) von 0,9 ± 0,08 bew eist die hohere Anza hl von Kalziumkan alrezeptoren bei HOCM·Patienten , Die aus echokard lographis chen Daten ermittelte Herzmuskelma sse reduzierte sich von 680 g auf 430 g (p < 0,05). Aus unseren Untersuchungen geht hervor, daB in der Gru ppe 2 die deutli che re Verbesserung der klinischen un d linksventrikularen Parameter zu ver zeichnen war. Mit der Myektomie alleine erzielt man zwa r ein gutes Resultat. der Schwe regrad der begleitenden Mitra linsuffizienz wird dadurch je doch nieht beeinflullt . In dies erGruppe 1 fand sieh ein Patient, bei dem es zu einer Zunahme der Mitralin suffizienz kam . Nach uns ere r Mein ung ist wen iger der h ohe intrakavitare Oru ckgradie nt als vielrnehr die Ver schlechterung der links ven tri kularen Architektur flir die Entwi cklung der Mitrali nsu ffizien z bei der HOCM verantwortlich . Es konn ten keine prognostischen Kriterien ftlr die Entwieklung der begleitenden Mitralinsuffizienz gefund en werd en . Aufgru nd eine r sorgfelngen Ris lkoa bwagung er schei nt es uns nlcht ger echt fer tigt , bei der IIOCMgen er ell eine Myektomie zusammen mit einem Mitralkla ppeneingrifT ode r n ur eine n Mitralklappeneingriff alleine vorzunehmen.
Hypertrophic ca rdiomyopathy - Myectom y - Mitral valve replacement - Morrow procedure
Thorae. cardiovasc. Surgeon 40 (992) 65 -69 © Geo rg Thieme Verlag Stuttgart- New York
Received for Publication : Septem ber 9, 1991
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Summa ry
Thorac. cardiovas c. Surgeon 40 (1992)
Introduction The hypertrophic obstructive cardiomy opathi es (HOCM) display a numbe r of special morphological and functional featu res . The etiology of these featu res , and their relation to the individual prognosis, has not yet been explained. HOCM thus rep resents a problem with both scientific and hea lthpolicy as pects (1). Common to all forms of HOCM is the formation of an intracavitary pressure grad ient, for which a num ber of factors are responsible: 1. asymmetrical hypert rophy of the se ptum, 2. hypertrophy and dislocation of the papillary muscles, 3. altera tion of the tiss ue texture in the hypertrophied portion of the se ptum, 4. convex arc hed form of the left ventricle . The mechanism s unde rlying the outflow tract obst ruc tion are comp lex , and their individual significance is
un known . In addition to the hypertrophy of the septum and of the papillary muscle , the systolic anterior movement (SAM) phenomenon and the Ventu ri effect a re also involved in the obstruction of the left-ventricular outflow tra ct. Approxima tely 85% of patie nts show symptoms; the symptoms are not, however, disease-specific. The disease can man ifest itselfat any stage in the life of an individual and displays a progressive cours e. The patients die of acute left cardiac insufficiency, experience sudde n cardiac death , or develop a myocardial insufficiency. Thera py continues to be hamp ered by considerable uncert ainties. which are above all based on the unexplained pathogenesis and the considerable functional variability of the symptoms. These factors are difficulty to record, and their relevance often cannot be judged with certainty at present. Anothe r source of difficulty is the rar eness of the disease an d, as a result, the relative lack of thera peutic expe rience on the part of the doctor in att endance. Two particu lar problems which remain completely uns olved are the estimation of individual progn oses and the ability oftherapeutic intervention to influence the individual prognosis (4, 9, 20). In our own thinking on this matte r we began with the assumption that the intracavitary gra dient has an essential effect on disease progression and patient prognos is. On this basis we would expect that reduction of a hemodynamically significant pressure gradi ent via myectomy would influenc e the course of the disease , part ly rever se the functional disturban ces, redu ce the symptoms, and improve the individual prognosis. The goal of the pr esent study was to compare the Morrow procedu re (17) alone or in combination with mitral valve repair with respect to the hemodynamic an d clinical results.
D. Fritzsche. R. Kraker. H. Goos. K..F. Lindenau. and L. Will·Sha hab Table 1 Patient details number ofpatients operatedon: 56 (m/f = 1.7) Age: 42.3 (t4 -68) y Time span between first appearance 4.3 y of symptoms anddiagnosis: 141patient y Postoperative follow-up: 4.2 y Mean follow-up:
- patients with an intracavitary pressu re gradient were to undergo cardiac surgery for other heart diseases .
We perform ed replacem ent or re pair oft he mitr al valve when patients showed an hemodynam ically significant mitral valve insufficiency preoperatively.
All patients were examin ed regularl y pre- a nd postope ratively in our outpatient department. Case notes provided the following parameters which were includ ed in our asse ssment: clinical investigation
dyspnea , angina pectoris, dizziness and syncopes, a rrhythmias, NYHAclass
ECG rhythm, conduction disturbances . signs of hypertroph y echocardiography diameter of the left vent ricle in the parast ernal short axis internal diamete r of the left vent ricle in diast ole and systole (LVEDD, LVESD) diam eter of the ventr icular septum in diastole and systole (lVSD, IVSS) diameter of the posterior wall in diastole an d systole (PWD,PW S) determi nation of left ventric ular volumes (LVEDV, LVESV) and of ejection fraction (EF) according to Sandler and Dodge from the apical 4-cham ber view calculation of cardia c output semiquan titative evaluation oft he systolic anterior move -
ment of the mitral vale (SAM phenomen). Dopplersonographic param eters mitr al valve: early and late diastole peak velocity (A, E) - filling time - time to peak velocity aorta: pea k velocity, calculation of the left-ventr icular outflowtr act pressure gradi ent (LVOT) left-ventricular ejection time (LVET) time to peak velocity (TPVS) isovolumetr ic relaxation time (lVRT) isovolumetric tens ion time (lVIT )
The Doppler echoca rdiogra phic meas urem ents were repeated after intravenous application oforciprenalin .
Mat erials and ~I ethods During the period J. J. 1984-30. 6. 1991 a total of 93 patients with the sympt oms of hypertrophic cardiomyopathy (HCM) were referred to our clinic and admitted as outpatients. 56 patients were opera ted on in this period for muscular outflow-tract obstruction (Table 1). Myectomy was indicated when : patients with an intracavitary press ure gra dient 2: 50 mm Hg at rest or under stress rem ained symptomatic despite ad equate dru g thera py;
Calculation ofheart muscle mas s (Devereux meth od [8]) Measurement oj l3-adrenoreceptor and calcium-channel densiti es 13 tissu e sampl es obtained by myectomy wer e investigated for l3-adrenoreceptor- (BAR) as well as calcium cha nnel density (dihydrop yridin e receptor; DHP). The control group (n - 6) consisted ofseptum myocardium biopsies from healthy hea rts. Invasive investigations included meas urement of left-ventricular outflow-t ract pressure
gradient at rest and under st ress [Valsa lva mano euvre , orciprenalin, Brockenb rough sign ) measurement ofleft-ventricular pressure
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66
Thome. cardiovasc. Surg eon 40 (1992)
Compa rison ofMy ectomy Alone or in Combination with Mitra l Valve Repair
Results The NYHA class was III pr eop eratively for most patients. A postoperative improvement of NYHA class to was gen erally ac hieved (p < 0.05). Th e improvement in symptoms of angina pectoris, dyspnea. dizziness . and syncopes was , as expec te d, ana logous to th e improvement in NYHA class (Tabl e 2). No significant differen ces were observ ed between th e two gro ups . When ask ed for their subjective evalua tion of th e success of the operation, 48 % of the gr oup I patien ts describ ed th eir condition as "much impro ved ", 37% as "improved" , 10 % noted no change, 5% we re free of symptoms . No patients reported a worsening of their condition. Th e subje ctive result s for the group II patients were signific antly better: 38 % claim ed to be free of symptoms , 12 % described the ir condition as "much improved" and 50% claimed an "improvement". The operation resulted in a significant decrease in the intracavitary pr essure gr ad ient (p < 0.005) . Th e remaining pr essure gr adient was sign ificantly lower in the pati ents with accompan ying mitral valve rep lacem ent (Fig. 1). A comparison of pre- and postoperative echocardiographic data for ejection frac tion rEF), stroke volume (SV) as well as LVEDV and LVESV showed a tend en cy towards normalization of the hyperc ontractility, but no statistical significance could be esta blishe d (Tab le 3). Particularly noti ceable was a shortening of the tim e to peak velocity (TPVS) and of left ventricular ejection time (LVET). The quotien t TPVS/LVET decrea sed fro m 60 .2 pr eop erati vely to 54. 2 postoper at ively ac ross both groups. Thi s shortening was stati stically significan t in group II (Fig. 2). An int eresting obs ervati on whi ch spea ks for a func tional rever sab ility of the diseas e is that we were able to calculate a sign ificant reduction of heart muscl e mass from our echocardiographical da ta . Th is is confirmed by th e red uction of th e Sokolov-Lyon ind ex (SL) (Fig. 3). Th e cor rectn ess of the calculat ed heart mass in comparison to th e actual heart weigh t was checked by weighing the hearts of pati ents who died . The average pe rcentage error in the calculation of th e heart muscle weight from echocardiographi c dat a in our study was 7.7% (-1 3.5 % to +3.2%). Of les s assi stance in the assessm ent of operative success was th e eva lua tion of electrocardiogra phic findings (with the exce ption of SLindex) and those ech ocardiographic find ings not disc uss ed in thi s paper (13 ,1 5). Whereas the ratio of ,6-adre norece ptor- to calcium channe l den sity (DHP-re ceptor) wa s 0.9 (± 0.08) in normal
Table 2
Alteration insymptomatology
angina pectoris dyspnea
preoperative
SG
postoperative
SG
72%(n = 40) 79%(n ~ 44)
2.2
3.1
35%(n ~ 19) 26%(n ~ 14)
2
1.2
dizziness/
70%(n ~ 39)
syncopes
26%(n ~ 14)
SG: average degree of severity Table 3
Average values for echocardiographic data(both groups)
EF SV LVEDV LVESV
preoperative
postoperative
76.5 (± 85.9 (± 112.7 (± 26.0 (±
72.5 (± 85.6 (± 117.8 (± 33.4 (±
1.84) 9.2)
13.1) 5.01
1.95) 6.8) 8.8) 3.5)
Ef: ejection fraction; SV: stroke volume; LVEDV: left-ventricular end-diastolic volume; LVESV: left-ventricular end-systolic volume
preoperative
postoperative
- - - - -- ---
group 1 group II
69.2 (± 5.2) 75.1 (± 4.8)
---
- --- .-
I_
23 .3 (± 2. 7) 11.7 (± 2.2)
group I
_
grou p II
~
Fig. 1 Alteration inintracavitary pressure gradient
TPVSILVET 60. --
55
-
-
-
-,-----
-- - -
-
-
-
-
,.._+ grou p I group II
-- -
-
-
-
-,
~--- --p , 0.05 - -
46
40
-
- -- + - - ---,-,----- - - -1 poatoperathlfl...-_
pre.aperative 59 .3 58.6
1 - group I
53.6 41 .9
-+-
group II
I
Fig. 2 Significant decrease of ratiottme-tc-peak-velocity/left-verrtrlculerejection-time (TPVS/LVETj ingroup II
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levograp hy in the standa rd positions, calculation of end systolic and enddiastolic volume s (EDV, ESV) (San dler and Dodge) corona rog ra phy The pati ents were divided into two group s: group I: tran saor tic subvalvular myectomy n ~ 40 gro up II: myectomy and mitral valve replacem ent n ~ 13 or reconstructive mitral valve surgery n = 3 Furthermore, a tota l of 10 pati ents across both groups required an aortic valve replacement and/or myocardial rev asc ula rization (on average 2.1 aortocoronary bypa sses). Tbe r esu lts were chec ked statistically usin g the X' test for alte rn ative features. Th e significance threshold was set at p < 0.05.
67
D. Fritzs che. R. Kraker. H. Goos. K.-F. Ltnd enau. and L. Will-Shahab
Thorae_cardiovase. Surgeon 40 (I 992) (Ig)
-..
200
--. -
20
2
.. _.-
--
- ~-
peetepererlve
preoperative
SL-Index (mV) PG (mm Hg)
2.9 (± 0.16) 19.5 (± 2.7) 430 (± 39 .2)
3.7 (±0.19) 72.1 (± 4.3) 680 (± 43.5)
muscle mass (g)
---
•
~ PO (mm Hg}
•
Slo.ind'll (mY)
o
mu. c:t, ma.. (g)
Fig.3 Significant decreaseof heartmusclemass(p < 0.05).intracavitary pressure gradient (echo)(p < 0.005). and Sokolcv-Lycn (Sl) index(p < 0.01) during thefollow-upperiod(logarithmic scale)
Table 4 Comparison of echocardiographically calculated and actual heart mass ofdeceasedpatients Pat. Nr.
heart weight (&I (echol
heart weight (&I (at autopsy)
error(%)
29 64 73 (') 80 81(')
410 805 402 503 903
450 780 465 560 960
+ -
88 3.2 13.5 10.1 3.1
• died preop. and autopsied
myocardium. it was redu ced to 0.5 (± 0.1) in HOCM . The esse ntial determining factor in this skewin g of the rati o was the increase in Ca" channel density. Of th e 56 patients opera ted on. 4 died . The hospital mortality was 7.1 'Yo. Death occurred on the l " , 2 nd, 14 th and 30 th day postoperativ ely from acute left-ven tri cular insufficiency (n = 2) , from an acute necrotizing pancreatitis (n - 1). or from a severe bacterial pneumonia and renal failure (n - 1). Three of the patients who died had und er gone myectomy and mitr al valve replacement (group II). The mea n age. preoperative findin gs. and cas e histor ies did not ditTer significan tly from the average values for both groups. The late mortality was 1.8 % (n - 1). The mean follow-up was 4.2 yea rs (141 patient-years) . In the gr oup of pati ents not operated on. three patients sutTered sudden ca rdiac death. Thi s corres ponds to a mortality rat e of 8.1% ove r a mean follow-up peri od of3 .9 yea rs. Discussion
Our own data and long-term results as describ ed he re confirm that the Morrow procedure deserv es its place in the surgical treatment ofHOCM . Analogous to the experience of th e Dusseldorf team (3. 19) and the recently published results of other proponents of myectomy as th e method of choice for HOCM (2. 5. 10. 14. 16. 22). we were able to obs erve a clear clinical and functional imp rovement whic h did not dimini sh durin g the follow-up peri od.
The improvement in clinical condition was particularly marked in patients wh o. on the ind icati on of a significant mitr al insufficien cy. had received a mitral valve replacement in addition to myectomy (group II). Taking into accou nt the much poor er initial sta te of health of the patients with a significant mitra l regurgitat ion. this resul t is in our view not surprising. Similarl y, group II displayed a grea ter decrease in postoperative pressure gra dient and TPVS/LVET quoti ent. This ditTer ence was statistically significant. These findings indicate the variable contribution of the mitral valve apparatus to the seve rity of the subvalvular outflow-tract obstruction. We have no experience of our own in treating the disease via mitral valve replacemen t alone (6. 21). Since we have so far observed no cases ofVSD, irreversible conduction disturbances , or arterial embolism in association with persistent av-dysrhythmias in our pa tients, and a pro sth etic mitr al valve replacem ent carries with it a known embolism risk of 2-4 % pati ent-years, we would recommend the transaortic subvalvular myectomy as the meth od of choice. an d a n additional mitral valve replacement only in case s of hemodynamically significant regurgitation . On the othe r hand, we wer e in no case able to observ e disappearance of an accompanying mitral insufficiency following myectomy , as describ ed recen tly by th e Mainz team (18). This suggests that it is less the high systolic left ventricular press ure, and more the changes in ventricular geometry . th at are of critical significance for the development of a mitral insufficiency. Among the patien ts treated solely via myectomy (group I), there was only a single cas e involving an objectively recordab le progr ession of a pr eoperatively insignificant mitral insufficiency (in a female patient . 2.4 years post-op). The increase in calcium cha nnel den sity in HOCM represents a finding whi ch allows an explanation of the functional features peculiar to this diseas e (12). The rap id. increased calcium inflow int o the myocardial cells lead s to a shortening of isovolumetric tension time and an increase in contrac tility. The slowing of calcium reb ind ing thro ugh excessive demands on the enzymatic system - and possibly a functional disorder ofth e mechani sm of calcium rebinding - causes a decrease of compliance and an increase of the isovolumetric relaxation time. The increased cellular calcium concentration probably also leads to a stimulat ion of cellular prote in synt hes is and thus to cardiac hypertrophy. Conclusions
The Morrow procedure of transaortic su bvalvular myectomy has proven itself in our experience as a th era peutic procedure achieving contin uingly good results. On the basis of our own follow-up studies an d long-te rm results we recommend the procedure, since it produces an undiminished improvement of symptoms and an increase in physical an d hemod ynami c performances. An increased life expecta ncy could not be demonstrated in our se ries. Leftventricular functional parameters display a tendency towa rds postoperative normalization : the disea se thus app ears at least partl y reversible, in functi onal terms, via the palliative procedure of myectomy (7). As an alternative pro cedure in the surgi cal tre atm ent of HOCM . prosth etic mitral valve replacement - while produ cing comparable improvements in clinical and functional
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68
Comparison ofMyectomy A lone or in Combination with Mitral Valve Repair
Referen ces 1 2
A beiman. W H.. and B. H. Loreil: The Challenge ofCardiomyopath y. J . Am. Coil. Cardiol. 13 (1989)1219-1 239 Beahrs. M. M.. A J. Tajik. J . B. Seumrd, E. R. Giuliani. and D. C. .\fcGoon: Hypertr ophic obstructive cardiomyopathy : Ten to 21 year
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13
14
15
16
follow-up after partial septal myectomy. Am. J. Cardiol. 51 (19831 1160-11 66 W: Surgical trea tme nt of hypertrophic cardiomyopathy (Dusseldorf experience). Postgrad. Med. J. 62 (1986) 57 1-574 .. Bla nchar d. D. G.. and J. Ross: Hypertrophic card iomyopathy: prognosis with medical or surgical therapy. Clin. Cardiol. 14 (199 11 11- 19 .) Canno n, R. 0 .• C. L. Mci nt osh . W. H. Schenke. B. 1. M ar on. R. 0. Bonoto, and S . E. Eps te in: Effect of surgical red uction of left-ventricular outflow obstruction on hemodynamics. coronary flow. and myocard ial metabolism in hypertrophic cardiomyopathy. Circulation 79 (1989) 766 -775 6 Cooley . D. A , D. C. Wuka sch. and R. D. Lea chman: Mitral valve replacemen t for idiopat hicsubaortic stenosis . results in 27 patients. J. Cardiovasc. Surg. 17 (1976 ) 378-380 7 Curtius. 1. M.. 1. Stoecker, B. Loesse, R. Weslau. and D. Sc ho lz: Changes of the degree of hypertrophy in hypertrophic obstructive cardiomyopath y under medical and surgical treatm ent. Cardiology 76 (1989) 255-263 8 Deve reu x. R. B.• and N. Reich ek : Echocardiographic determ ination of left-ventricular mass in man : anatomic valida tion oft he method. Circulation 55 (1976) 613-618 OJ Fay. tv. P.• C. P. Tater cio. D. M . t tst r up. A J. Taj i k. and B. 1. Gersh : Natura l history of hypertrophic cardiomyopathy in the elderly. JACCI 6 (1990) 821 - 826 10 Korfer. R.. H. Bauscn. H, Kuh n. H. D. Sc hulte. und W. Bircks: Hyper trophische obstruktive Kardiomyopathie (HOeM ). Operative Behandl ung.lndikation and Ergebnisse. ZFA(Stuttgart) 59 (19831 634-639 II Kuhn . H.• F. Gietz en . J . Mercier. B. lbsse. E. Kohler. H. D. S chu lte . W Bircks. und F. Loagen : Untersuchungen zur Klinlk. zum Verlauf und zur Prognose versch tedene r Forme n de r hypertrophischen Kardiomy opa thie. Z. Kar diol. 72 (1983) 83- 98 3 Bl rc ks.
17
18
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heart failure : present knowledge and future directions. Cardiology 76 (1989) 338-436 Maron. B. J.. J. K. Wolfs on. E. Circa, and P. Spirito : Relation of electroca rdiogra phic abnormalities and patterns of left-ven tricular hypertrophy identified by 2-dimensiona l echocardiography in patients with hypertrophic cardiomyopathy. Am. J. Cardiol. 51 (1983 ) 189- 194 Ma ron . B. J.. S . E. Eps tein. and A G. Morrow : Symptomatic statu s and prognosis of'patients after operations for hypert rophic obstructive cardiomyopathy: efficacy of ventricular septal myotomy and myectomy. Eur. Heart J. 4 (l983) Suppl. F: 175- 185 stetacmt. P.. G. Fasoli. B. Canciani. G. Buja. C. Mammola. and S. D. Volta : Hypertrophic card iomyopathy: two-dimensional echocar diographic score versus clinical and electrocardiographic findings. Clin. Cardiol. 12 (1989) 443-452 Mohr. R.. H. V. Schaff. G. K. Danielson. F. J. Puga. J. R. Pluth. andA J. Tajik: The outcome of surgical treatm ent of the hypert rophic obstructive cardiomyopat hy. Experiences over 15 years . J . Thorac. Cardiovasc . Surg. 97 (1989) 666- 574 Morrow. A G.: Hypertrophic aortic stenosis. Operative methods ultilized to relieve left ventri cular outflow obstruction. J. Thorac. Cardiovasc. Surg. 76 (1981) 423-430 Oelert. H.. M. Drex ler. un d R. Erbel.· Intr aoperative Echokard iographie - Stand und Perspektiven. Z. Inn. Med. 45 (1990) 252-256 Sc hulte. H. D.. W Bircks. and B. Losse. Surgical trea tment of hypertrophic obstructi ve cardiomyopathy (Ha CM): early and late results. Progress in Cardiology 2/2 . Philadelphia. Lea & Feblger. 1989 195- 215 Sp irito. P.. F. Chiarella. L. Ca rrat ino, M. Z. Berisso . P. Belotti , and C. Vecchio: Clinical course and prognosis of hypertrophic cardiomyopathy in an outpatient population. New Eng. J. Med. 320 (1989) 1413 Walker. W 5.. K. G. Reid, E. W 1. Cameron. P. R. Walbaum, and A . fl. Kitchin : Comparison of ventricula r septal surgery and mitra l valve replacement for hypertrophic obstructive car diomyopathy. Ann. Thorac . Surg. 48 (1989 ) 528-535 Willi ams . W. G.• E. D. Wigle. H. Rako wski. 1. S mallhorn, J. Leblan c, and G. A Trusler: Results of surgery for hypertroph ic obstru ctive cardiomyopathy. Circulation 76 (987) Suppl. V: 104-1 08
Dr. med. D. Fritz sche
Klinlk fur Herz- und GefaBc hirurgie der Unlversltat Leipzig Ph.-Rosen thal-Str.27 0 -7010 Leipzig Germany
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parameters over the medium follow-up term - appears to us to involve a greater risk of complications than the simpler Morrow procedure, which is sufficient to produ ce good results when perform ed on its own . An explana tion of the primary defect und erlying HOeM , which is possibly to be sought in an increas ed trans-sarcolemmal calcium inflow, provides grounds for the hope that early diagnosis and efficient dru g therapy will one day rende r su rgical treat ment of this disease unne cessary.
Thome. ea rdiovasc. S urgeon 40 (1992)
Comparison of Myectomy Alone or in Combination with Mitral Valve Repair for Hypertrophic Obstructive Cardiomyopathy D. Fritzsche. R. Krakor, H. Goos, K.-F Lindenau, and L. will-Shahab » Clin ic of Card iac a nd Vascu lar Su rge ry, University of Leipzig * Institute of Heart a nd Circu latio n Rese a rch , Berli n Su ch , Germany
Betw een 1184 a nd 6/91 56 pati en ts were tr eated for hypertrophi c obstructive ca rdiomyopathy (Ha eM): th e Morr ow techniqu e alone wa s performed on 40 patients (group 1), in 16 pati ent s (group 2) an additional repl a ceme nt (0 = 13 ) or reconst ruction (0 = 3) of the mitral valve wa s indi cated. In a total of14 cas es corona ry artery bypass gr afting and aortic va lve replacement was per form ed in add ition . Postop eratively (mean follow-up 4.2 yrs, 14 1 patient-years) left-ventricular diastolic and systolic fun ction parameters , heart muscl e mass , ECG find ings, and symptomatology wer e recorded and the ratios of .a-adrenoreceptor density to density of the calcium chan ne l were measured . Result s: Pres sur e gradient decreas ed from 69 .2 ± 5.2 (grou p 1) and 75.1 ± 4.8 (group 2)\0 23.3 ± 2.7 and 11.7 ± 2.2 mm llgpostoperatively. Likewise Sokolow - Lyon ind ex decreas ed from 3.5 ± 0.2 / 3.7 ± 0.2 to 2.9 ± 0.2/2 .8 ± 0.3. The quotient tim e-to-peakvelocity/left -ventricular-ejectlon-time decreased significantl y in group 2 from 58 .6 ± 6.3 10 4 1.9 ± 5.8 (p < 0.051. The heart muscle mass, determined echo cardiographically, decreas ed from 680 g to 43 0 g (p < 0.0 5). Isovolumet ric ten sion time , isovolume tric relaxation time , and E/A ra tio at rest and after stre ss showed typica l characteristics. Ca'"-ch anne l density was clea rly rai sed in all pati ents, with no differences between th e two groups being obs ervable. We conclude from our results : - The most marked improvements in clinical and left-ventricular functional pa ram eter s we re experi enced by pat ients in group 2 (myectom y + MVR) . - Myectom y alone ac hieved good results, but did not influen ce th e severity of a concomita nt low-grade mitral insufficiency: only in one patient of th is gro up did we register a progression of the mitr al insufficiency. - This obse rva tion allows us to conclude that deterioration in left-ventric ula r ar chitecture, rather than a high intracavitary pres sure gradient, is responsible for the devel opment of mitral insufficienc y in HOCM. Prognostic crit eria for th e development of accompa nying mitral valve dysfunction could not be found . Thus, on the basis of a ca reful risk-benefit a nal ysis. there appears to us to be no au tomatic justificat ion for perform ing a combined myectom y and MVR, or MVR alon e , in cases of HOCM gene rally. Keywords
Verg leich zwi sche n a lle inige r Myek to mie un d Myektomie kombinie rt mit 1\1it ralklappen ersatz bei IIOCM Von Januar 1984 bis Juli 1991 wurde am Herzzentrum Leipzig (HZL) unter 4 970 EingrifTen am ofTenen Herze n bel 56 Pati enten die Myektomi e nachMorrow ausgeftih rt. 16 Patienten (28 %) erforderten einen zusatzlichen Mitralklapp enei ngrifT (MVR: n = 13; plastische Rekonstruktion: n = 3). Bei 14 (25 %) waren a ndere Kombinatio nse ingriffe (Aortenklappenersatz. aortoko ro nare Bypas ses) indiziert. Die Hospitalletalitat betrug 7,1 %, es trat ein Spat todesfal l a uf. In der Nach beoba chtungsz eit (bis 7 Jahre ; 141 Patlentenja hre; mea n follow-up 4,2 Jahre) wurde n Angaben tiber subjektlve Beschwerde n, EKG·Veranderungen , linksv entrikulare Funktionsparam eter sowi e die lI er zmuskelmasse erfaBt. Die Myektomi e bewi rkte eine Verschiebungdes NYHA-Sta diums von III zu I postoperativ (p < 0.05). Oer ven triku loaortale Druckg radient sank in der Gruppe . Myektomie " (Gruppe I) von 69 ,2 ± 5,2 auf 23,3 ± 2,7 mm Hg. In der Grup pe . Myektomie + Mitralklappenei ngrtff" (Gruppe II) wurde der intrakavitare Druckgradient auf 11 ,7 ± 2,2mmHg gesenkt (p < 0,05). Der Sokolov-Lyon Index betrug praoperativ 3,7 ± 0,2 un d sank postoperativ auf2 ,8 ± 0,16 . Das Verha ltnis der a -edrenoreceptor- zu Kalziumkanaldicht e von 0,5 ± 0,1 irn Vergleieh zu einer Kontrollgru ppe (n = 6) von 0,9 ± 0,08 bew eist die hohere Anza hl von Kalziumkan alrezeptoren bei HOCM·Patienten , Die aus echokard lographis chen Daten ermittelte Herzmuskelma sse reduzierte sich von 680 g auf 430 g (p < 0,05). Aus unseren Untersuchungen geht hervor, daB in der Gru ppe 2 die deutli che re Verbesserung der klinischen un d linksventrikularen Parameter zu ver zeichnen war. Mit der Myektomie alleine erzielt man zwa r ein gutes Resultat. der Schwe regrad der begleitenden Mitra linsuffizienz wird dadurch je doch nieht beeinflullt . In dies erGruppe 1 fand sieh ein Patient, bei dem es zu einer Zunahme der Mitralin suffizienz kam . Nach uns ere r Mein ung ist wen iger der h ohe intrakavitare Oru ckgradie nt als vielrnehr die Ver schlechterung der links ven tri kularen Architektur flir die Entwi cklung der Mitrali nsu ffizien z bei der HOCM verantwortlich . Es konn ten keine prognostischen Kriterien ftlr die Entwieklung der begleitenden Mitralinsuffizienz gefund en werd en . Aufgru nd eine r sorgfelngen Ris lkoa bwagung er schei nt es uns nlcht ger echt fer tigt , bei der IIOCMgen er ell eine Myektomie zusammen mit einem Mitralkla ppeneingrifT ode r n ur eine n Mitralklappeneingriff alleine vorzunehmen.
Hypertrophic ca rdiomyopathy - Myectom y - Mitral valve replacement - Morrow procedure
Thorae. cardiovasc. Surgeon 40 (992) 65 -69 © Geo rg Thieme Verlag Stuttgart- New York
Received for Publication : Septem ber 9, 1991
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Summa ry
Thorac. cardiovas c. Surgeon 40 (1992)
Introduction The hypertrophic obstructive cardiomy opathi es (HOCM) display a numbe r of special morphological and functional featu res . The etiology of these featu res , and their relation to the individual prognosis, has not yet been explained. HOCM thus rep resents a problem with both scientific and hea lthpolicy as pects (1). Common to all forms of HOCM is the formation of an intracavitary pressure grad ient, for which a num ber of factors are responsible: 1. asymmetrical hypert rophy of the se ptum, 2. hypertrophy and dislocation of the papillary muscles, 3. altera tion of the tiss ue texture in the hypertrophied portion of the se ptum, 4. convex arc hed form of the left ventricle . The mechanism s unde rlying the outflow tract obst ruc tion are comp lex , and their individual significance is
un known . In addition to the hypertrophy of the septum and of the papillary muscle , the systolic anterior movement (SAM) phenomenon and the Ventu ri effect a re also involved in the obstruction of the left-ventricular outflow tra ct. Approxima tely 85% of patie nts show symptoms; the symptoms are not, however, disease-specific. The disease can man ifest itselfat any stage in the life of an individual and displays a progressive cours e. The patients die of acute left cardiac insufficiency, experience sudde n cardiac death , or develop a myocardial insufficiency. Thera py continues to be hamp ered by considerable uncert ainties. which are above all based on the unexplained pathogenesis and the considerable functional variability of the symptoms. These factors are difficulty to record, and their relevance often cannot be judged with certainty at present. Anothe r source of difficulty is the rar eness of the disease an d, as a result, the relative lack of thera peutic expe rience on the part of the doctor in att endance. Two particu lar problems which remain completely uns olved are the estimation of individual progn oses and the ability oftherapeutic intervention to influence the individual prognosis (4, 9, 20). In our own thinking on this matte r we began with the assumption that the intracavitary gra dient has an essential effect on disease progression and patient prognos is. On this basis we would expect that reduction of a hemodynamically significant pressure gradi ent via myectomy would influenc e the course of the disease , part ly rever se the functional disturban ces, redu ce the symptoms, and improve the individual prognosis. The goal of the pr esent study was to compare the Morrow procedu re (17) alone or in combination with mitral valve repair with respect to the hemodynamic an d clinical results.
D. Fritzsche. R. Kraker. H. Goos. K..F. Lindenau. and L. Will·Sha hab Table 1 Patient details number ofpatients operatedon: 56 (m/f = 1.7) Age: 42.3 (t4 -68) y Time span between first appearance 4.3 y of symptoms anddiagnosis: 141patient y Postoperative follow-up: 4.2 y Mean follow-up:
- patients with an intracavitary pressu re gradient were to undergo cardiac surgery for other heart diseases .
We perform ed replacem ent or re pair oft he mitr al valve when patients showed an hemodynam ically significant mitral valve insufficiency preoperatively.
All patients were examin ed regularl y pre- a nd postope ratively in our outpatient department. Case notes provided the following parameters which were includ ed in our asse ssment: clinical investigation
dyspnea , angina pectoris, dizziness and syncopes, a rrhythmias, NYHAclass
ECG rhythm, conduction disturbances . signs of hypertroph y echocardiography diameter of the left vent ricle in the parast ernal short axis internal diamete r of the left vent ricle in diast ole and systole (LVEDD, LVESD) diam eter of the ventr icular septum in diastole and systole (lVSD, IVSS) diameter of the posterior wall in diastole an d systole (PWD,PW S) determi nation of left ventric ular volumes (LVEDV, LVESV) and of ejection fraction (EF) according to Sandler and Dodge from the apical 4-cham ber view calculation of cardia c output semiquan titative evaluation oft he systolic anterior move -
ment of the mitral vale (SAM phenomen). Dopplersonographic param eters mitr al valve: early and late diastole peak velocity (A, E) - filling time - time to peak velocity aorta: pea k velocity, calculation of the left-ventr icular outflowtr act pressure gradi ent (LVOT) left-ventricular ejection time (LVET) time to peak velocity (TPVS) isovolumetr ic relaxation time (lVRT) isovolumetric tens ion time (lVIT )
The Doppler echoca rdiogra phic meas urem ents were repeated after intravenous application oforciprenalin .
Mat erials and ~I ethods During the period J. J. 1984-30. 6. 1991 a total of 93 patients with the sympt oms of hypertrophic cardiomyopathy (HCM) were referred to our clinic and admitted as outpatients. 56 patients were opera ted on in this period for muscular outflow-tract obstruction (Table 1). Myectomy was indicated when : patients with an intracavitary press ure gra dient 2: 50 mm Hg at rest or under stress rem ained symptomatic despite ad equate dru g thera py;
Calculation ofheart muscle mas s (Devereux meth od [8]) Measurement oj l3-adrenoreceptor and calcium-channel densiti es 13 tissu e sampl es obtained by myectomy wer e investigated for l3-adrenoreceptor- (BAR) as well as calcium cha nnel density (dihydrop yridin e receptor; DHP). The control group (n - 6) consisted ofseptum myocardium biopsies from healthy hea rts. Invasive investigations included meas urement of left-ventricular outflow-t ract pressure
gradient at rest and under st ress [Valsa lva mano euvre , orciprenalin, Brockenb rough sign ) measurement ofleft-ventricular pressure
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66
Thome. cardiovasc. Surg eon 40 (1992)
Compa rison ofMy ectomy Alone or in Combination with Mitra l Valve Repair
Results The NYHA class was III pr eop eratively for most patients. A postoperative improvement of NYHA class to was gen erally ac hieved (p < 0.05). Th e improvement in symptoms of angina pectoris, dyspnea. dizziness . and syncopes was , as expec te d, ana logous to th e improvement in NYHA class (Tabl e 2). No significant differen ces were observ ed between th e two gro ups . When ask ed for their subjective evalua tion of th e success of the operation, 48 % of the gr oup I patien ts describ ed th eir condition as "much impro ved ", 37% as "improved" , 10 % noted no change, 5% we re free of symptoms . No patients reported a worsening of their condition. Th e subje ctive result s for the group II patients were signific antly better: 38 % claim ed to be free of symptoms , 12 % described the ir condition as "much improved" and 50% claimed an "improvement". The operation resulted in a significant decrease in the intracavitary pr essure gr ad ient (p < 0.005) . Th e remaining pr essure gr adient was sign ificantly lower in the pati ents with accompan ying mitral valve rep lacem ent (Fig. 1). A comparison of pre- and postoperative echocardiographic data for ejection frac tion rEF), stroke volume (SV) as well as LVEDV and LVESV showed a tend en cy towards normalization of the hyperc ontractility, but no statistical significance could be esta blishe d (Tab le 3). Particularly noti ceable was a shortening of the tim e to peak velocity (TPVS) and of left ventricular ejection time (LVET). The quotien t TPVS/LVET decrea sed fro m 60 .2 pr eop erati vely to 54. 2 postoper at ively ac ross both groups. Thi s shortening was stati stically significan t in group II (Fig. 2). An int eresting obs ervati on whi ch spea ks for a func tional rever sab ility of the diseas e is that we were able to calculate a sign ificant reduction of heart muscl e mass from our echocardiographical da ta . Th is is confirmed by th e red uction of th e Sokolov-Lyon ind ex (SL) (Fig. 3). Th e cor rectn ess of the calculat ed heart mass in comparison to th e actual heart weigh t was checked by weighing the hearts of pati ents who died . The average pe rcentage error in the calculation of th e heart muscle weight from echocardiographi c dat a in our study was 7.7% (-1 3.5 % to +3.2%). Of les s assi stance in the assessm ent of operative success was th e eva lua tion of electrocardiogra phic findings (with the exce ption of SLindex) and those ech ocardiographic find ings not disc uss ed in thi s paper (13 ,1 5). Whereas the ratio of ,6-adre norece ptor- to calcium channe l den sity (DHP-re ceptor) wa s 0.9 (± 0.08) in normal
Table 2
Alteration insymptomatology
angina pectoris dyspnea
preoperative
SG
postoperative
SG
72%(n = 40) 79%(n ~ 44)
2.2
3.1
35%(n ~ 19) 26%(n ~ 14)
2
1.2
dizziness/
70%(n ~ 39)
syncopes
26%(n ~ 14)
SG: average degree of severity Table 3
Average values for echocardiographic data(both groups)
EF SV LVEDV LVESV
preoperative
postoperative
76.5 (± 85.9 (± 112.7 (± 26.0 (±
72.5 (± 85.6 (± 117.8 (± 33.4 (±
1.84) 9.2)
13.1) 5.01
1.95) 6.8) 8.8) 3.5)
Ef: ejection fraction; SV: stroke volume; LVEDV: left-ventricular end-diastolic volume; LVESV: left-ventricular end-systolic volume
preoperative
postoperative
- - - - -- ---
group 1 group II
69.2 (± 5.2) 75.1 (± 4.8)
---
- --- .-
I_
23 .3 (± 2. 7) 11.7 (± 2.2)
group I
_
grou p II
~
Fig. 1 Alteration inintracavitary pressure gradient
TPVSILVET 60. --
55
-
-
-
-,-----
-- - -
-
-
-
-
,.._+ grou p I group II
-- -
-
-
-
-,
~--- --p , 0.05 - -
46
40
-
- -- + - - ---,-,----- - - -1 poatoperathlfl...-_
pre.aperative 59 .3 58.6
1 - group I
53.6 41 .9
-+-
group II
I
Fig. 2 Significant decrease of ratiottme-tc-peak-velocity/left-verrtrlculerejection-time (TPVS/LVETj ingroup II
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levograp hy in the standa rd positions, calculation of end systolic and enddiastolic volume s (EDV, ESV) (San dler and Dodge) corona rog ra phy The pati ents were divided into two group s: group I: tran saor tic subvalvular myectomy n ~ 40 gro up II: myectomy and mitral valve replacem ent n ~ 13 or reconstructive mitral valve surgery n = 3 Furthermore, a tota l of 10 pati ents across both groups required an aortic valve replacement and/or myocardial rev asc ula rization (on average 2.1 aortocoronary bypa sses). Tbe r esu lts were chec ked statistically usin g the X' test for alte rn ative features. Th e significance threshold was set at p < 0.05.
67
D. Fritzs che. R. Kraker. H. Goos. K.-F. Ltnd enau. and L. Will-Shahab
Thorae_cardiovase. Surgeon 40 (I 992) (Ig)
-..
200
--. -
20
2
.. _.-
--
- ~-
peetepererlve
preoperative
SL-Index (mV) PG (mm Hg)
2.9 (± 0.16) 19.5 (± 2.7) 430 (± 39 .2)
3.7 (±0.19) 72.1 (± 4.3) 680 (± 43.5)
muscle mass (g)
---
•
~ PO (mm Hg}
•
Slo.ind'll (mY)
o
mu. c:t, ma.. (g)
Fig.3 Significant decreaseof heartmusclemass(p < 0.05).intracavitary pressure gradient (echo)(p < 0.005). and Sokolcv-Lycn (Sl) index(p < 0.01) during thefollow-upperiod(logarithmic scale)
Table 4 Comparison of echocardiographically calculated and actual heart mass ofdeceasedpatients Pat. Nr.
heart weight (&I (echol
heart weight (&I (at autopsy)
error(%)
29 64 73 (') 80 81(')
410 805 402 503 903
450 780 465 560 960
+ -
88 3.2 13.5 10.1 3.1
• died preop. and autopsied
myocardium. it was redu ced to 0.5 (± 0.1) in HOCM . The esse ntial determining factor in this skewin g of the rati o was the increase in Ca" channel density. Of th e 56 patients opera ted on. 4 died . The hospital mortality was 7.1 'Yo. Death occurred on the l " , 2 nd, 14 th and 30 th day postoperativ ely from acute left-ven tri cular insufficiency (n = 2) , from an acute necrotizing pancreatitis (n - 1). or from a severe bacterial pneumonia and renal failure (n - 1). Three of the patients who died had und er gone myectomy and mitr al valve replacement (group II). The mea n age. preoperative findin gs. and cas e histor ies did not ditTer significan tly from the average values for both groups. The late mortality was 1.8 % (n - 1). The mean follow-up was 4.2 yea rs (141 patient-years) . In the gr oup of pati ents not operated on. three patients sutTered sudden ca rdiac death. Thi s corres ponds to a mortality rat e of 8.1% ove r a mean follow-up peri od of3 .9 yea rs. Discussion
Our own data and long-term results as describ ed he re confirm that the Morrow procedure deserv es its place in the surgical treatment ofHOCM . Analogous to the experience of th e Dusseldorf team (3. 19) and the recently published results of other proponents of myectomy as th e method of choice for HOCM (2. 5. 10. 14. 16. 22). we were able to obs erve a clear clinical and functional imp rovement whic h did not dimini sh durin g the follow-up peri od.
The improvement in clinical condition was particularly marked in patients wh o. on the ind icati on of a significant mitr al insufficien cy. had received a mitral valve replacement in addition to myectomy (group II). Taking into accou nt the much poor er initial sta te of health of the patients with a significant mitra l regurgitat ion. this resul t is in our view not surprising. Similarl y, group II displayed a grea ter decrease in postoperative pressure gra dient and TPVS/LVET quoti ent. This ditTer ence was statistically significant. These findings indicate the variable contribution of the mitral valve apparatus to the seve rity of the subvalvular outflow-tract obstruction. We have no experience of our own in treating the disease via mitral valve replacemen t alone (6. 21). Since we have so far observed no cases ofVSD, irreversible conduction disturbances , or arterial embolism in association with persistent av-dysrhythmias in our pa tients, and a pro sth etic mitr al valve replacem ent carries with it a known embolism risk of 2-4 % pati ent-years, we would recommend the transaortic subvalvular myectomy as the meth od of choice. an d a n additional mitral valve replacement only in case s of hemodynamically significant regurgitation . On the othe r hand, we wer e in no case able to observ e disappearance of an accompanying mitral insufficiency following myectomy , as describ ed recen tly by th e Mainz team (18). This suggests that it is less the high systolic left ventricular press ure, and more the changes in ventricular geometry . th at are of critical significance for the development of a mitral insufficiency. Among the patien ts treated solely via myectomy (group I), there was only a single cas e involving an objectively recordab le progr ession of a pr eoperatively insignificant mitral insufficiency (in a female patient . 2.4 years post-op). The increase in calcium cha nnel den sity in HOCM represents a finding whi ch allows an explanation of the functional features peculiar to this diseas e (12). The rap id. increased calcium inflow int o the myocardial cells lead s to a shortening of isovolumetric tension time and an increase in contrac tility. The slowing of calcium reb ind ing thro ugh excessive demands on the enzymatic system - and possibly a functional disorder ofth e mechani sm of calcium rebinding - causes a decrease of compliance and an increase of the isovolumetric relaxation time. The increased cellular calcium concentration probably also leads to a stimulat ion of cellular prote in synt hes is and thus to cardiac hypertrophy. Conclusions
The Morrow procedure of transaortic su bvalvular myectomy has proven itself in our experience as a th era peutic procedure achieving contin uingly good results. On the basis of our own follow-up studies an d long-te rm results we recommend the procedure, since it produces an undiminished improvement of symptoms and an increase in physical an d hemod ynami c performances. An increased life expecta ncy could not be demonstrated in our se ries. Leftventricular functional parameters display a tendency towa rds postoperative normalization : the disea se thus app ears at least partl y reversible, in functi onal terms, via the palliative procedure of myectomy (7). As an alternative pro cedure in the surgi cal tre atm ent of HOCM . prosth etic mitral valve replacement - while produ cing comparable improvements in clinical and functional
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68
Comparison ofMyectomy A lone or in Combination with Mitral Valve Repair
Referen ces 1 2
A beiman. W H.. and B. H. Loreil: The Challenge ofCardiomyopath y. J . Am. Coil. Cardiol. 13 (1989)1219-1 239 Beahrs. M. M.. A J. Tajik. J . B. Seumrd, E. R. Giuliani. and D. C. .\fcGoon: Hypertr ophic obstructive cardiomyopathy : Ten to 21 year
12
13
14
15
16
follow-up after partial septal myectomy. Am. J. Cardiol. 51 (19831 1160-11 66 W: Surgical trea tme nt of hypertrophic cardiomyopathy (Dusseldorf experience). Postgrad. Med. J. 62 (1986) 57 1-574 .. Bla nchar d. D. G.. and J. Ross: Hypertrophic card iomyopathy: prognosis with medical or surgical therapy. Clin. Cardiol. 14 (199 11 11- 19 .) Canno n, R. 0 .• C. L. Mci nt osh . W. H. Schenke. B. 1. M ar on. R. 0. Bonoto, and S . E. Eps te in: Effect of surgical red uction of left-ventricular outflow obstruction on hemodynamics. coronary flow. and myocard ial metabolism in hypertrophic cardiomyopathy. Circulation 79 (1989) 766 -775 6 Cooley . D. A , D. C. Wuka sch. and R. D. Lea chman: Mitral valve replacemen t for idiopat hicsubaortic stenosis . results in 27 patients. J. Cardiovasc. Surg. 17 (1976 ) 378-380 7 Curtius. 1. M.. 1. Stoecker, B. Loesse, R. Weslau. and D. Sc ho lz: Changes of the degree of hypertrophy in hypertrophic obstructive cardiomyopath y under medical and surgical treatm ent. Cardiology 76 (1989) 255-263 8 Deve reu x. R. B.• and N. Reich ek : Echocardiographic determ ination of left-ventricular mass in man : anatomic valida tion oft he method. Circulation 55 (1976) 613-618 OJ Fay. tv. P.• C. P. Tater cio. D. M . t tst r up. A J. Taj i k. and B. 1. Gersh : Natura l history of hypertrophic cardiomyopathy in the elderly. JACCI 6 (1990) 821 - 826 10 Korfer. R.. H. Bauscn. H, Kuh n. H. D. Sc hulte. und W. Bircks: Hyper trophische obstruktive Kardiomyopathie (HOeM ). Operative Behandl ung.lndikation and Ergebnisse. ZFA(Stuttgart) 59 (19831 634-639 II Kuhn . H.• F. Gietz en . J . Mercier. B. lbsse. E. Kohler. H. D. S chu lte . W Bircks. und F. Loagen : Untersuchungen zur Klinlk. zum Verlauf und zur Prognose versch tedene r Forme n de r hypertrophischen Kardiomy opa thie. Z. Kar diol. 72 (1983) 83- 98 3 Bl rc ks.
17
18
19
20
21
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heart failure : present knowledge and future directions. Cardiology 76 (1989) 338-436 Maron. B. J.. J. K. Wolfs on. E. Circa, and P. Spirito : Relation of electroca rdiogra phic abnormalities and patterns of left-ven tricular hypertrophy identified by 2-dimensiona l echocardiography in patients with hypertrophic cardiomyopathy. Am. J. Cardiol. 51 (1983 ) 189- 194 Ma ron . B. J.. S . E. Eps tein. and A G. Morrow : Symptomatic statu s and prognosis of'patients after operations for hypert rophic obstructive cardiomyopathy: efficacy of ventricular septal myotomy and myectomy. Eur. Heart J. 4 (l983) Suppl. F: 175- 185 stetacmt. P.. G. Fasoli. B. Canciani. G. Buja. C. Mammola. and S. D. Volta : Hypertrophic card iomyopathy: two-dimensional echocar diographic score versus clinical and electrocardiographic findings. Clin. Cardiol. 12 (1989) 443-452 Mohr. R.. H. V. Schaff. G. K. Danielson. F. J. Puga. J. R. Pluth. andA J. Tajik: The outcome of surgical treatm ent of the hypert rophic obstructive cardiomyopat hy. Experiences over 15 years . J . Thorac. Cardiovasc . Surg. 97 (1989) 666- 574 Morrow. A G.: Hypertrophic aortic stenosis. Operative methods ultilized to relieve left ventri cular outflow obstruction. J. Thorac. Cardiovasc. Surg. 76 (1981) 423-430 Oelert. H.. M. Drex ler. un d R. Erbel.· Intr aoperative Echokard iographie - Stand und Perspektiven. Z. Inn. Med. 45 (1990) 252-256 Sc hulte. H. D.. W Bircks. and B. Losse. Surgical trea tment of hypertrophic obstructi ve cardiomyopathy (Ha CM): early and late results. Progress in Cardiology 2/2 . Philadelphia. Lea & Feblger. 1989 195- 215 Sp irito. P.. F. Chiarella. L. Ca rrat ino, M. Z. Berisso . P. Belotti , and C. Vecchio: Clinical course and prognosis of hypertrophic cardiomyopathy in an outpatient population. New Eng. J. Med. 320 (1989) 1413 Walker. W 5.. K. G. Reid, E. W 1. Cameron. P. R. Walbaum, and A . fl. Kitchin : Comparison of ventricula r septal surgery and mitra l valve replacement for hypertrophic obstructive car diomyopathy. Ann. Thorac . Surg. 48 (1989 ) 528-535 Willi ams . W. G.• E. D. Wigle. H. Rako wski. 1. S mallhorn, J. Leblan c, and G. A Trusler: Results of surgery for hypertroph ic obstru ctive cardiomyopathy. Circulation 76 (987) Suppl. V: 104-1 08
Dr. med. D. Fritz sche
Klinlk fur Herz- und GefaBc hirurgie der Unlversltat Leipzig Ph.-Rosen thal-Str.27 0 -7010 Leipzig Germany
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parameters over the medium follow-up term - appears to us to involve a greater risk of complications than the simpler Morrow procedure, which is sufficient to produ ce good results when perform ed on its own . An explana tion of the primary defect und erlying HOeM , which is possibly to be sought in an increas ed trans-sarcolemmal calcium inflow, provides grounds for the hope that early diagnosis and efficient dru g therapy will one day rende r su rgical treat ment of this disease unne cessary.
Thome. ea rdiovasc. S urgeon 40 (1992)
