Long-Term Follow=Up of Patients Undergoing Myotomy/Myectomy for Obstructive Hypertrophic Cardiomyopathy Lawrence H. Cohn, MD, Hemant Trehan, MD, and John J. Collins, Jr., MD
The long-term resutts of patients undergoing myotomy/myectomy of the ventrkubr septum for obstructive hypertrophic cardiomyopathy are documented in 31 patients (15 women, 16 men, age range 21 to 60 years [mean SS]) with mean New York Heart Assoctatton functional class III to IV congestive heart failure, who underwent radtcal myotomy/myectomy at the Brtgham and Women’s Hospital from 1972 to 1991. Preoperative gradients by catheterization or echocardiography ranged from 26 to 240 mm Hg (average 96). There were no operatcve deaths. Two patients developed early postoperative complete heart block requiring a transvenous pacemaker. Clinical follow-up was 1 to 14 years (mean 6.5). All survtving patients were restudied by echocardtography and clinical examination. The mean postoperative functional class was II. Postoperattve gradients ranged from 0 to 30 mm Hg (mean 4.5) (p 20 Division of Cardiac Surgery, Brigham and Women’sHospital, Boston, Massachusetts.This study was presentedat the American College of mm measured by echocardiography. Preoperative miCardiology, Dallas, Texas, April 10,1992. Manuscript receivedMarch tral regurgitation was presentin 19 of 31 patients: l+ in 9,1992; revisedmanuscript receivedand acceptedMay 18,1992. 10 patients, 2+ in 7, 3+ in 1, and 4+ in 1. The resting Addressfor reprints: Lawrence H. Cohn, MD, Division of Cardiac Surgery, Brigham and Women’s Hospital, 75 Francis Street, Boston, left ventricular gradients acrossthe left ventricular subaortic obstruction ranged from 26 to 240 mm Hg (averMassachusetts02115. MYOTOMY/MYECTOMY
FOR HYPERTROPHIC CARDIOMYOPATHY
657
lar cavity with both myotomies. By a combination of sharp dissection and debridement with a pituitary rongeur, a large channel through the hypertrophic muscle is created by resection of this muscle block. All muscle bundles toward the free wall are liberated and resected. This channel is then in opposition to the anterior leaflet of the mitral and the papillary muscle which form the other part of this funnel-shapedobstructive area. In addition to this procedure, 8 patients underwent surgical procedures:6 patients had a concomitant coronary bypass,and 2 patients had aortic and mitral valvuloplasty. Patients in chronic atria1 fibrillation underwent anticoagulation postoperativelywith warfarin, and those with coronary diseaserequiring coronary artery bypass were prescribed 1 aspirin per day. All patients were followed with periodic echocardiogram and clinical examination by their cardiologists, and were called back for a functional evaluation beginning in the late spring of 1991. Follow-up echocardio-
age 96). The gradients were measuredby preoperative simultaneous left ventricular and aortic catheters, by pullback (all patients) and, most recently, with echocardiography. All patients underwent operation with the useof cardiopulmonary bypassand underwent transaortic radical myotomy/myectomy similar to the procedure described by Morro~.~ The anterior leaflet of mitral valve and papillary muscle are protected inferiorly by a malleable brain retractor, and a sponge stick helps to evert the septum into the outflow tract. The right coronary aortic leaflet is retracted with another smaller malleable brain retractor. The first septal incision is made approximately at the midportion of the distance underneath the right coronary aortic leaflet, and a second myotomy made to the left of this about 1 cm in width to prevent the production of complete heart block by injuring the bundle of His. The myotomy is then carried down through the hypertrophic septum into free left ventricu-
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THE AMERICAN JOURNAL OF CARDIOLOGY VOLUME 70
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grams were recorded in all patients to determine the extent of any residual subaortic obstruction. RESULTS There was no operative mortality. Two patients developed complete heart block (8%) after myotomy/ myectomy, requiring a permanent transvenousatrioventricular sequential pacemaker.There were no other major early postoperative complications. Clinical follow-up was 1 to 14 years (mean 6.5). Five patients had late deaths; 4 of these 5 had undergone a concomitant coronary bypassoperation and had complete reconstruction. One patients had a single, 3 had a double and 2 had a triple coronary bypassconcomitantly. Four of 6 patients who had concomitant coronary bypass grafting died in the late postoperative period. There was only 1 late death occurring in 25 patients who did not have coronary bypass grafting, an incidence of 4% (p = 0.05). Two patients with coronary diseasedied of low cardiac output from restrictive cardiomyopathy 11 and 14 years postoperatively; 2 additional patients with coronary artery disease died of stroke 7 and 12 years postoperatively, and 1 patient with coronary diseasedied of acute respiratory failure. The actuarial survival for all patients was 86 f 9% (SEM) at 10 years (Figure 1). The probability of freedom from thromboembolism in patients after surgery for HC was 92 f 7% (Figure 2). The functional classitication in the 26 surviving patients was a mean of II; 17 were in functional class I, 6 were in functional class II, and 5 were in functional class III. The patients restudied in the late postoperativeperiod by echocardiography to evaluate subaortic obstruction had gradients ranging from 0 to 30 mm Hg (mean of 4.5; p
The long-term resutts of patients undergoing myotomy/myectomy of the ventrkubr septum for obstructive hypertrophic cardiomyopathy are documented in 31 patients (15 women, 16 men, age range 21 to 60 years [mean SS]) with mean New York Heart Assoctatton functional class III to IV congestive heart failure, who underwent radtcal myotomy/myectomy at the Brtgham and Women’s Hospital from 1972 to 1991. Preoperative gradients by catheterization or echocardiography ranged from 26 to 240 mm Hg (average 96). There were no operatcve deaths. Two patients developed early postoperative complete heart block requiring a transvenous pacemaker. Clinical follow-up was 1 to 14 years (mean 6.5). All survtving patients were restudied by echocardtography and clinical examination. The mean postoperative functional class was II. Postoperattve gradients ranged from 0 to 30 mm Hg (mean 4.5) (p 20 Division of Cardiac Surgery, Brigham and Women’sHospital, Boston, Massachusetts.This study was presentedat the American College of mm measured by echocardiography. Preoperative miCardiology, Dallas, Texas, April 10,1992. Manuscript receivedMarch tral regurgitation was presentin 19 of 31 patients: l+ in 9,1992; revisedmanuscript receivedand acceptedMay 18,1992. 10 patients, 2+ in 7, 3+ in 1, and 4+ in 1. The resting Addressfor reprints: Lawrence H. Cohn, MD, Division of Cardiac Surgery, Brigham and Women’s Hospital, 75 Francis Street, Boston, left ventricular gradients acrossthe left ventricular subaortic obstruction ranged from 26 to 240 mm Hg (averMassachusetts02115. MYOTOMY/MYECTOMY
FOR HYPERTROPHIC CARDIOMYOPATHY
657
lar cavity with both myotomies. By a combination of sharp dissection and debridement with a pituitary rongeur, a large channel through the hypertrophic muscle is created by resection of this muscle block. All muscle bundles toward the free wall are liberated and resected. This channel is then in opposition to the anterior leaflet of the mitral and the papillary muscle which form the other part of this funnel-shapedobstructive area. In addition to this procedure, 8 patients underwent surgical procedures:6 patients had a concomitant coronary bypass,and 2 patients had aortic and mitral valvuloplasty. Patients in chronic atria1 fibrillation underwent anticoagulation postoperativelywith warfarin, and those with coronary diseaserequiring coronary artery bypass were prescribed 1 aspirin per day. All patients were followed with periodic echocardiogram and clinical examination by their cardiologists, and were called back for a functional evaluation beginning in the late spring of 1991. Follow-up echocardio-
age 96). The gradients were measuredby preoperative simultaneous left ventricular and aortic catheters, by pullback (all patients) and, most recently, with echocardiography. All patients underwent operation with the useof cardiopulmonary bypassand underwent transaortic radical myotomy/myectomy similar to the procedure described by Morro~.~ The anterior leaflet of mitral valve and papillary muscle are protected inferiorly by a malleable brain retractor, and a sponge stick helps to evert the septum into the outflow tract. The right coronary aortic leaflet is retracted with another smaller malleable brain retractor. The first septal incision is made approximately at the midportion of the distance underneath the right coronary aortic leaflet, and a second myotomy made to the left of this about 1 cm in width to prevent the production of complete heart block by injuring the bundle of His. The myotomy is then carried down through the hypertrophic septum into free left ventricu-
80
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30
28
23
21
18
15
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658
THE AMERICAN JOURNAL OF CARDIOLOGY VOLUME 70
SEPTEMBER 1. 1992
1
P= .ool
grams were recorded in all patients to determine the extent of any residual subaortic obstruction. RESULTS There was no operative mortality. Two patients developed complete heart block (8%) after myotomy/ myectomy, requiring a permanent transvenousatrioventricular sequential pacemaker.There were no other major early postoperative complications. Clinical follow-up was 1 to 14 years (mean 6.5). Five patients had late deaths; 4 of these 5 had undergone a concomitant coronary bypassoperation and had complete reconstruction. One patients had a single, 3 had a double and 2 had a triple coronary bypassconcomitantly. Four of 6 patients who had concomitant coronary bypass grafting died in the late postoperative period. There was only 1 late death occurring in 25 patients who did not have coronary bypass grafting, an incidence of 4% (p = 0.05). Two patients with coronary diseasedied of low cardiac output from restrictive cardiomyopathy 11 and 14 years postoperatively; 2 additional patients with coronary artery disease died of stroke 7 and 12 years postoperatively, and 1 patient with coronary diseasedied of acute respiratory failure. The actuarial survival for all patients was 86 f 9% (SEM) at 10 years (Figure 1). The probability of freedom from thromboembolism in patients after surgery for HC was 92 f 7% (Figure 2). The functional classitication in the 26 surviving patients was a mean of II; 17 were in functional class I, 6 were in functional class II, and 5 were in functional class III. The patients restudied in the late postoperativeperiod by echocardiography to evaluate subaortic obstruction had gradients ranging from 0 to 30 mm Hg (mean of 4.5; p
