Catheterization and Cardiovascular Interventions 87:E69–E74 (2016)
VALVULAR AND STRUCTURAL HEART DISEASES Original Studies Use of Intracardiac Echocardiography to Guide Percutaneous Transluminal Mitral Commissurotomy: A 20-Patient Case Series Mike Saji, MD, Michael Ragosta, MD, John Dent, MD, and D. Scott Lim,* MD Objectives: To report the efficacy and safety of the use adjunctive intracardiac echocardiography (ICE) during percutaneous transluminal mitral commissurotomy (PTMC) in patients without transesophageal echocardiography (TEE). Background: Patients with mitral stenosis are at a high risk of developing a left atrial (LA) thrombus. Traditionally, TEE has been used prior to PTMC to identify the presence of LA thrombi. There have been no reports of the use of ICE to assess the LA for thrombi prior to PTMC. Methods: We retrospectively reviewed 20 patients who underwent ICE prior to PTMC. All PTMC procedures were performed via the antegrade transvenous approach using an Inoue balloon. Initially, ICE was used from the right atrium to confirm the absence of a thrombus on the left side of the septum and was subsequently used to guide the transseptal puncture. Following these procedures, the ICE was advanced into the LA through a transseptal sheath to visualize the LAA. Results: Visualization of the thrombus/spontaneous echo contrast was considered to be diagnostic in all cases. Seventy percent of the patients were discharged on day after the procedure. No patients required intubation during the procedure, and there were no complications that could be attributed to the use of ICE. At six months after the PTMC, the incidence of stroke was zero. Conclusions: ICE-guided PTMC offers excellent visualization of the LA and the LAA with satisfactory clinical outcomes and low risk. As a part of the PTMC procedure, ICE safely provides a valid alternative to a separate TEE procedure. VC 2015 Wiley Periodicals, Inc. Key words: ICE; left atrial appendage; mitral stenosis; outcome; PTMC; PMBV
INTRODUCTION
Percutaneous transluminal mitral commissurotomy (PTMC) was initially described in 1984 as a novel technique for the management of mitral stenosis (MS) [1]. PTMC provides excellent results that are comparable to those of surgical mitral commissurotomy but is less invasive and is currently the standard of care for selected patients with significant, symptomatic MS [2]. Patients with MS, particularly those with concomitant atrial fibrillation, are at a high risk of left atrial (LA) thrombi [3,4]. Transesophageal echocardiography (TEE) has traditionally been recommended for the identification of LA left atrial appendage (LAA) thrombi prior to PTMC to avoid procedure-related cerebrovascular events. Intracardiac echocardiography (ICE) is commonly used to guide other percutaneous interventions such as C 2015 Wiley Periodicals, Inc. V
atrial septal defect closure [5]. There are no published reports of the use of ICE to assess the LA and the LAA for the presence of thrombi prior to PTMC in patients with MS. The aim of the present study was to Advanced Cardiac Valve Center, Department of Medicine, University of Virginia, Charlottesville, Virginia Conflicts of interest: Nothing to report. *Correspondence to: Scott Lim, Advanced Cardiac Valve Center, Department of Medicine, University of Virginia, 1215 Lee Street, Charlottesville, VA 22908. E-mail: [email protected] Received 26 June 2013; Revision accepted 14 March 2015 DOI: 10.1002/ccd.25943 Published online 6 May 2015 in Wiley Online Library (wileyonlinelibrary.com)
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Fig. 3. Intracardiac echocardiographs showing SEC in the LA appendage in patients with atrial fibrillation (arrow).
Fig. 1. The ICE catheter (8-French, AcuNav catheter) is advanced into the left atrium (arrow) to visualize the LA appendage following transseptal puncture through a 9-French Mullins sheath (*).
Fig. 2. Intracardiac echocardiograph clearly showing the absence of a thrombus and SEC in the LA appendage (arrow).
investigate the efficacy and safety of the use of adjunctive ICE during PTMC. MATERIALS AND METHODS Study Population A retrospective analysis of 20 consecutive patients with MS who underwent PTMC procedures at the
University of Virginia between January 2007 and December 2012 was conducted. The indication for treatment was determined according to the current guidelines [6]. All patients were reviewed by a multidisciplinary heart valve team consisting of cardiac surgeons, interventional cardiologists and cardiologists dedicated to echocardiographic imaging. The institutional review board approved this study. Intracardiac Echocardiography An 8-French phased-array ICE catheter, AcuNav (Siemens Medical solutions, Mountain View, CA) was used with an Acuson Sequoia C512 ultrasound system (Siemens Medical solutions, Mountain View, CA). The catheter was advanced into the right atrium from the femoral vein and rotated clockwise. The left side of the atrial septum was evaluated from the right atrium to determine whether it was free of thrombi. After this evaluation, a transseptal puncture was performed with ICE guidance, and the ICE catheter was subsequently retracted from the 8-French sheath and advanced into the LA through a 9-French Mullins introducer sheath that crossed the atrial septum to visualize the LAA (Fig. 1). In the LA, the ICE probe was retroflexed and rotated counterclockwise to allow for the clear visualization of the LAA and the confirmation of the absence of a thrombi (Figs. 2 and 3). The images obtained from both atriums were saved onto a disc. Percutaneous Transluminal Mitral Commissurotomy
All of the PTMC procedures were performed via the antegrade transvenous approach using the Inoue balloon system (Toray Medical, Tokyo, Japan) [7] with conscious sedation. To evaluate the hemodynamics,
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
PTMC with ICE TABLE I. Baseline Characteristics n ¼ 20 Age (yrs) Female Body surface area (m2) Comorbidity History of atrial fibrillation History of cerebral vascular event Pulmonary hypertension Prior commissurotomy Coronary artery disease NYHA functional classification II III, IV Preprocedural echocardiographic findings Mitral stenosis Rheumatic Mitral valve area (cm2): planimetry method Mean pressure gradient (mm Hg) MR Trace: Mild Moderate Ejection fraction (%): Modified Simpson’s LA volume (mm): M mode Right ventricular systolic pressure (mm Hg) Medication Aspirin Warfarin
60 12 (47–83) 19 (95) 1.8 0.2 9 (45) 3 (15) 10 (50) 3 (15) 0 (0) 2.7 0.5 4 (20) 16 (80)
20 (100) 1.1 0.5 11.6 4.6 18 (90) 2 (10) 55 8.2 (35–70) 47 7.6 54 27 6 (30) 8 (40)
Values are n (%) or mean SD; NYHA: New York Heart Association
right and left heart catheterizations were performed pre- and post-procedure. The cardiac output was determined by thermodilution or the Fick method. The mitral valve area (MVA) was calculated using the Gorlin formula [8]. The maximal balloon size was selected based on the patient’s height according to the following formula: maximum balloon size (mm) ¼ [patient’s height (cm)/10] þ 10 [9]. The procedure was initiated using a balloon that was 2 – 4 mm smaller depending on morphology and calcification of the mitral valve. Transthoracic echocardiography and left ventriculography (when needed) were performed to assess the mitral regurgitation (MR) severity preprocedure and postprocedure. MR severity was graded as follows: Trace (0), Mild (1þ), Moderate (2þ), Moderately Severe (3þ), and Severe (4þ). After each dilatation, the operator simultaneously obtained the LA pressure through the middle port of the Inoue catheter and the left ventricular (LV) pressure through the pigtail catheter. If the pressure gradient between the LA and LV did not decrease by >50%, and the MR did not increase by more than one degree, the PTMC was repeated with a larger-diameter balloon; the balloon diameters were incremented in 1-mm steps. Evaluation of the Images of the LAA Appendage by ICE Two blinded, independent reviewers who were experienced in the interpretation of echo imaging were
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asked to rate each ICE image on a scale of 1 – 3 in terms of diagnostic quality (1 ¼ poor or nondiagnostic; 2 ¼ fair or partially diagnostic; and 3 ¼ good or fully diagnostic) in terms of the following aspects of the image: (a) the overall image of the LA; (b) the complete image of the LAA, and (c) the presence of a thrombus or spontaneous echo contrast (SEC). Thrombi were diagnosed based on the presence of a clearly defined echogenic intracavity mass with an echo texture that differed from that of the underlying endocardium that was not due to pectinate muscle [10]. SEC was diagnosed based on the presence of dynamic smoke-like echo in the LA that exhibited a characteristic swirling motion that was distinct from white noise artifact after properly adjusting the gain settings. Definitions in the Procedure and Follow-Up
Procedural success was defined as an MVA 1.5 cm2 or an increase in MVA 50% and the absence of more than moderate MR. The procedurerelated events that were tracked included the following: in-hospital death related to the PTMC procedure; the need for acute mitral valve replacement; worsening MR that was more than moderately severe; pericardial tamponade; and thromboembolic events including cerebral vascular accidents and major bleeding. The sixmonth events included cardiovascular death, the need for surgical mitral valve replacement, New York Heart Association (NYHA) functional classification as III or IV, and the need for repeated PTMC. All information was obtained from the medical records. Statistical Analyses Continuous variables are expressed as the mean the standard deviation (SD), and categorical variables are expressed as percentages. Differences between the two groups were assessed using paired t-tests for normally distributed continuous variables and Wilcoxon tests for non-normally distributed continuous variables. P values < 0.05 were considered statistically significant, and all reported p values are 2-sided. All analyses were performed using the PRISM statistical package (Graphpad, version 6.01 for Windows) RESULTS Study Population Twenty patients underwent ICE during the PTMC procedure (Table I). Their mean age was 60 12 years, and 95% were female. Nine patients (45%) had histories of atrial fibrillation, and three had histories of previous cerebral vascular events. Eight patients (40%) were on warfarin to prevent a cerebral vascular event.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
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TABLE II.
Procedural Characteristics n ¼ 20
Procedural success Hemodynamic findings Mitral valve area (cm2): Gorlin formula Preprocedure Postprocedure Pressure gradient: mean (mm Hg) Preprocedure Postprocedure LA pressure: mean (mm Hg) Preprocedure Postprocedure Systolic pulmonary artery pressure (mm Hg) Preprocedure Postprocedure Postprocedural MR Trace to moderate Moderately severe to Severe Final balloon size (mm) Number of Inflation(s) Fluoro-time (min) Contrast volume (ml) ICE Adverse event related to procedure Thrombus in left atrium/atrial appendage SEC in left atrium/atrial appendage Length of stay two days 6 months mortality 6 months adverse event Surgical mitral valve replacement Heart failure requiring hospitalization
17 (85)
1.2 0.3 2.2 0.6
P < 0.001a
14 7.1 6.3 5.3
P < 0.001a
25 8.0 21 7.1
P < 0.001a
57 23 52 22
P ¼ 0.004a
18 (90) 2 (10) 26 1.5 3 2 (1–6) 15 5.0 75 29 0 (0) 0 (0) 8 (40) 14 (70) 0 (0) 3 (15) 2 1
Values are n (%) or mean SD. a vs. postprocedure.
Intracardiac Echocardiography
There were no complications that could be attributed to the use of ICE. The scorings of the ICE images were as follows: (a) the overall image of the LA was “fully diagnostic” in all cases (3.0 0), (b) the complete image of the LAA was “fully diagnostic” in fifteen cases (2.6 0.8), and (c) the presence of a thrombus or SEC was “fully diagnostic” in all cases (3.0 0). Among the nine patients with histories of atrial fibrillation, eight had an SEC in the LA or the LAA. No patients exhibited evidence of a thrombus in either the LA or the LAA. Procedural Outcomes of PTMC The procedural success of PTMC was 85% (Table II). There was a significant increase in MVA (1.2 0.3 to 2.2 0.6 cm2, P < 0.001), a decrease in mean pressure gradient (14 7.1 to 6.3 5.3 mm Hg, P < 0.001), a decrease in mean LA pressure (25 8.0 to 21 7.1 mm Hg, P < 0.001) and a decrease in systolic pulmonary artery pressure (57 23 to 52 22, P ¼ 0.004).
Postprocedure, two patients had MR that was rated as more than moderate. One patient had cardiac tamponade requiring pericardiocentesis via the dislocation of transseptal needle during the transseptal puncture. However, no patients had respiratory compromise requiring intubation or respiratory support. No cerebral vascular events occurred during the PTMC procedure. Fourteen patients (70%) were admitted to the hospital on day of the procedure and discharged on the following day. The six-month mortality and event rates were 0 and 15%, respectively. Two patients ultimately underwent surgical mitral valve replacement, and one patient was admitted to the hospital due to heart failure (NYHA functional class III). No patient suffered a cerebrovascular accident within six months of PTMC. DISCUSSION
This study aimed to investigate the efficacy and safety of the use of adjunctive ICE during PTMC. PTMC was found to offer excellent visualization of the LA and the LAA and to provide satisfactory clinical outcomes while maintaining a low risk profile. Efficacy and Safety of ICE
This study demonstrated that ICE provides excellent visualization of the LA and the LAA for the detection of thrombi prior to the PTMC procedure. All of the categories from (a) to (c) received excellent rating. Our data suggest that the quality of the image of the LAA obtained by ICE is at least equivalent and likely superior that of TEE. Because the majority of patients with histories of atrial fibrillation were taking adequate levels of warfarin prior to the procedures, no cases of LAA thrombi were observed in this study. However, we demonstrated the excellent visualization of the SEC afforded by ICE in eight patients. We believe that thrombi in the LAA can easily be detected with ICE. Although ICE images could also possibly be obtained from the coronary sinus or the pulmonary artery [11,12], all of the patients were referred for PTMC, and transseptal punctures were therefore planned. We endorse the insertion of an ICE probe into the LA through the transseptal puncture as a much more straightforward and less risky approach compared to coronary sinus cannulation with the large blunt tip of the ICE probe. Although there have been studies that have reported the imaging of the LAA using ICE from the LA [13,14], this study is the first to observe the LAA with ICE for the detection of thrombi prior to PTMC [15]. ICE has been shown to improve the safeties of a variety of invasive cardiovascular procedures [16,17]. In
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
PTMC with ICE
our series, there were no complications that could be attributed to the use of ICE. ICE not only reduces the risk of the procedural complications, such as those that can occur during transseptal puncture but also allows for the immediate identification of potential complications. Compared with TEE, ICE has many advantages, including the elimination of the need for the patient to be esophageally intubated and the requirement of the use of deep sedation or general anesthesia. The use of ICE during PTMC results in a less invasive percutaneous treatment that is free of the risks of anesthesia complications, such as postprocedural hypotension, delirium, and aspiration pneumonia. Furthermore, it is possible that less fluoroscopy time would be needed when ICE is used, and anesthesia and echo cardiac imaging personnel are not needed, which would lead reductions in the cost of the procedure [18]. However, whether ICE can provide systematic, diagnostic images of the LAA with the consistency afforded by TEE requires depended on the significant learning curve faced by individual operators. Furthermore, the current generation of ICE imaging only provided a single plane. The use of other transcatheter interventions, such as LAA closure, is controversial [19] because they require appropriate measurements of the appendage based on a complete image of the entire LAA cavity. It is possible that the next generation of threedimensional ICE probes will allow for better measurements of the LAA. Procedural Outcomes of PTMC using ICE
Only a few case studies have reported on the use of ICE during PTMC [20,21]. Our retrospective analyses of the immediate and six-month results following the use of ICE during PTMC are encouraging; no mortality and few complications were observed [22]. In our series, two patients underwent elective mitral valve replacement following increases in the severity of MR after PTMC. Selection of the maximal balloon size according the ICE measurement of the annular diameter or the distribution of calcification might potentially avoid the risk of the tearing of leaflets in these patients. When it becomes available, three-dimensional ICE will add additional imaging detail. Further investigations that include long-term results and larger study sizes areneeded. LIMITATIONS
This study reflects the experiences at a single center with a small number of patients; thus, the extent to which these data can be generalized to all patients who undergo PTMC could not be established. The
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visualization of the LAA for the detection of thrombi was not compared between two imaging modalities (e.g., ICE vs. TEE or CT).
CONCLUSIONS
ICE-guided PTMC offers excellent visualization of the LA and the LAA with satisfactory clinical outcomes and a low risk profile. ICE as a part of the PTMC procedure safely provides a valid alternative to TEE that precludes the need for a separate TEE procedure. ICE is the echocardiographic imaging procedure of choice for PTMC. REFERENCES 1. Inoue K, Owaki T, Nakamura T, Kitamura F, Miyamoto N. Clinical application of transvenous mitral commissurotomy by a new balloon catheter. J Thorac Cardiovasc Surg 1984;873:394– 402. 2. Nobuyoshi M, Arita T, Shirai S, Hamasaki N, Yokoi H, Iwabuchi M, Yasumoto H, Nosaka H. Percutaneous balloon mitral valvuloplasty: A review. Circulation 2009;1198:e211–219. 3. Saidi SJ, Motamedi MH. Incidence and factors influencing left atrial clot in patients with mitral stenosis and normal sinus rhythm. Heart 2004;9011:1342–1343. 4. Manjunath CN, Srinivasa KH, Panneerselvam A, Prabhavathi B, Ravindranath KS, Rangan K, Dhanalakshmi C. Incidence and predictors of left atrial thrombus in patients with rheumatic mitral stenosis and sinus rhythm: A transesophageal echocardiographic study. Echocardiography 2011;284:457–460. 5. Patel A, Cao QL, Koenig PR, Hijazi ZM. Intracardiac echocardiography to guide closure of atrial septal defects in children less than 15 kilograms. Catheter Cardiovasc Interv 2006;682: 287–291. 6. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP III, Guyton RA, O’Gara PT, Ruiz CE, Skubas NJ, Sorajja P, Sundt TM III, Thomas JD; American College of Cardiology/ American Heart Association Task Force on Practice Guidelines. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: Executive summary: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2014;63: 2438–2488. 7. Palacios I, Block PC, Brandi S, Blanco P, Casal H, et al. Percutaneous balloon valvotomy for patients with severe mitral stenosis. Circulation 1987;754:778–784. 8. Gorlin R, Gorlin SG. Hydraulic formula for calculation of the area of the stenotic mitral valve, other cardiac valves, and central circulatory shunts. I. Am Heart J 1951;411:1–29. 9. Lau KW, Hung JS. A simple balloon-sizing method in Inoue-balloon percutaneous transvenous mitral commissurotomy. Cathet Cardiovasc Diagn 1994;332:120–129; discussion 130121. 10. Goswami KC, Narang R, Bahl VK, Talwar KK, Manchanda SC. Comparative evaluation of transthoracic and transesophageal echocardiography in detection of left atrial thrombus before percutaneous transvenous mitral commissurotomy. Do all patients need transesophageal examination? Int J Cardiol 1997; 623:237–249.
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11. Melman YF, Foppa M, Huang H, Anter E. Visualization of the left atrial appendage from the coronary sinus by intracardiac echocardiography. Heart Rhythm 2014;119:1603–1604. 12. Baran J, Stec S, Pilichowska-Paszkiet E, Zaborska B, SikoraFrac M, Krynski T, Michalowska I, Lopatka R, Kulakowski P. Intracardiac echocardiography for detection of thrombus in the left atrial appendage: Comparison with transesophageal echocardiography in patients undergoing ablation for atrial fibrillation: The Action-Ice I Study. Circ Arrhythm Electrophysiol 2013;66: 1074–1081. 13. Reddy VY, Neuzil P, Ruskin JN. Intracardiac echocardiographic imaging of the left atrial appendage. Heart Rhythm 2005;211: 1272–1273. 14. Blendea D, Heist EK, Danik SB, Barrett C, Ruskin JN, Mansour M. Analysis of the left atrial appendage morphology by intracardiac echocardiography in patients with atrial fibrillation. J Interv Card Electrophysiol 2011;313:191–196. 15. Hutchinson MD, Jacobson JT, Michele JJ, Silvestry FE, Callans DJ. A comparison of intracardiac and transesophageal echocardiography to detect left atrial appendage thrombus in a swine model. J Interv Card Electrophysiol 2010;271:3–7. 16. Mangrum JM, Mounsey JP, Kok LC, DiMarco JP, Haines DE. Intracardiac echocardiography-guided, anatomically based radiofrequency ablation of focal atrial fibrillation originating
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from pulmonary veins. J Am Coll Cardiol 2002;3912: 1964–1972. Ren JF, Marchlinski FE, Callans DJ, Herrmann HC. Clinical use of AcuNav diagnostic ultrasound catheter imaging during left heart radiofrequency ablation and transcatheter closure procedures. J Am Soc Echocardiogr 2002;1510 Pt 2:1301–1308. Budts W, Troost E, Voigt JU, Gewillig M. Intra-cardiac echocardiography in atrial septal interventions: impact on hospitalization costs. Acta Cardiol 2010;652:147–152. Hijazi ZM, Suradi H. Intracardiac echocardiography-guided interventions: Do we need trials to prove equivalency/superiority to transesophageal echocardiography? JACC Cardiovasc Interv 2014;79:1045–1047. Salem MI, Makaryus AN, Kort S, Chung E, Marchant D, Ong L, Mangion J. Intracardiac echocardiography using the AcuNav ultrasound catheter during percutaneous balloon mitral valvuloplasty. J Am Soc Echocardiogr 2002;1512:1533–1537. Marmagkiolis K, Cilingiroglu M. Intracardiac echocardiographyguided percutaneous mitral balloon valvuloplasty. Rev Port Cardiol 2013;324:337–339. Arora R, Kalra GS, Singh S, Mukhopadhyay S, Kumar A, Mohan JC, Nigam M. Percutaneous transvenous mitral commissurotomy: Immediate and long-term follow-up results. Catheter Cardiovasc Interv 2002;554:450–456.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
VALVULAR AND STRUCTURAL HEART DISEASES Original Studies Use of Intracardiac Echocardiography to Guide Percutaneous Transluminal Mitral Commissurotomy: A 20-Patient Case Series Mike Saji, MD, Michael Ragosta, MD, John Dent, MD, and D. Scott Lim,* MD Objectives: To report the efficacy and safety of the use adjunctive intracardiac echocardiography (ICE) during percutaneous transluminal mitral commissurotomy (PTMC) in patients without transesophageal echocardiography (TEE). Background: Patients with mitral stenosis are at a high risk of developing a left atrial (LA) thrombus. Traditionally, TEE has been used prior to PTMC to identify the presence of LA thrombi. There have been no reports of the use of ICE to assess the LA for thrombi prior to PTMC. Methods: We retrospectively reviewed 20 patients who underwent ICE prior to PTMC. All PTMC procedures were performed via the antegrade transvenous approach using an Inoue balloon. Initially, ICE was used from the right atrium to confirm the absence of a thrombus on the left side of the septum and was subsequently used to guide the transseptal puncture. Following these procedures, the ICE was advanced into the LA through a transseptal sheath to visualize the LAA. Results: Visualization of the thrombus/spontaneous echo contrast was considered to be diagnostic in all cases. Seventy percent of the patients were discharged on day after the procedure. No patients required intubation during the procedure, and there were no complications that could be attributed to the use of ICE. At six months after the PTMC, the incidence of stroke was zero. Conclusions: ICE-guided PTMC offers excellent visualization of the LA and the LAA with satisfactory clinical outcomes and low risk. As a part of the PTMC procedure, ICE safely provides a valid alternative to a separate TEE procedure. VC 2015 Wiley Periodicals, Inc. Key words: ICE; left atrial appendage; mitral stenosis; outcome; PTMC; PMBV
INTRODUCTION
Percutaneous transluminal mitral commissurotomy (PTMC) was initially described in 1984 as a novel technique for the management of mitral stenosis (MS) [1]. PTMC provides excellent results that are comparable to those of surgical mitral commissurotomy but is less invasive and is currently the standard of care for selected patients with significant, symptomatic MS [2]. Patients with MS, particularly those with concomitant atrial fibrillation, are at a high risk of left atrial (LA) thrombi [3,4]. Transesophageal echocardiography (TEE) has traditionally been recommended for the identification of LA left atrial appendage (LAA) thrombi prior to PTMC to avoid procedure-related cerebrovascular events. Intracardiac echocardiography (ICE) is commonly used to guide other percutaneous interventions such as C 2015 Wiley Periodicals, Inc. V
atrial septal defect closure [5]. There are no published reports of the use of ICE to assess the LA and the LAA for the presence of thrombi prior to PTMC in patients with MS. The aim of the present study was to Advanced Cardiac Valve Center, Department of Medicine, University of Virginia, Charlottesville, Virginia Conflicts of interest: Nothing to report. *Correspondence to: Scott Lim, Advanced Cardiac Valve Center, Department of Medicine, University of Virginia, 1215 Lee Street, Charlottesville, VA 22908. E-mail: [email protected] Received 26 June 2013; Revision accepted 14 March 2015 DOI: 10.1002/ccd.25943 Published online 6 May 2015 in Wiley Online Library (wileyonlinelibrary.com)
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Fig. 3. Intracardiac echocardiographs showing SEC in the LA appendage in patients with atrial fibrillation (arrow).
Fig. 1. The ICE catheter (8-French, AcuNav catheter) is advanced into the left atrium (arrow) to visualize the LA appendage following transseptal puncture through a 9-French Mullins sheath (*).
Fig. 2. Intracardiac echocardiograph clearly showing the absence of a thrombus and SEC in the LA appendage (arrow).
investigate the efficacy and safety of the use of adjunctive ICE during PTMC. MATERIALS AND METHODS Study Population A retrospective analysis of 20 consecutive patients with MS who underwent PTMC procedures at the
University of Virginia between January 2007 and December 2012 was conducted. The indication for treatment was determined according to the current guidelines [6]. All patients were reviewed by a multidisciplinary heart valve team consisting of cardiac surgeons, interventional cardiologists and cardiologists dedicated to echocardiographic imaging. The institutional review board approved this study. Intracardiac Echocardiography An 8-French phased-array ICE catheter, AcuNav (Siemens Medical solutions, Mountain View, CA) was used with an Acuson Sequoia C512 ultrasound system (Siemens Medical solutions, Mountain View, CA). The catheter was advanced into the right atrium from the femoral vein and rotated clockwise. The left side of the atrial septum was evaluated from the right atrium to determine whether it was free of thrombi. After this evaluation, a transseptal puncture was performed with ICE guidance, and the ICE catheter was subsequently retracted from the 8-French sheath and advanced into the LA through a 9-French Mullins introducer sheath that crossed the atrial septum to visualize the LAA (Fig. 1). In the LA, the ICE probe was retroflexed and rotated counterclockwise to allow for the clear visualization of the LAA and the confirmation of the absence of a thrombi (Figs. 2 and 3). The images obtained from both atriums were saved onto a disc. Percutaneous Transluminal Mitral Commissurotomy
All of the PTMC procedures were performed via the antegrade transvenous approach using the Inoue balloon system (Toray Medical, Tokyo, Japan) [7] with conscious sedation. To evaluate the hemodynamics,
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
PTMC with ICE TABLE I. Baseline Characteristics n ¼ 20 Age (yrs) Female Body surface area (m2) Comorbidity History of atrial fibrillation History of cerebral vascular event Pulmonary hypertension Prior commissurotomy Coronary artery disease NYHA functional classification II III, IV Preprocedural echocardiographic findings Mitral stenosis Rheumatic Mitral valve area (cm2): planimetry method Mean pressure gradient (mm Hg) MR Trace: Mild Moderate Ejection fraction (%): Modified Simpson’s LA volume (mm): M mode Right ventricular systolic pressure (mm Hg) Medication Aspirin Warfarin
60 12 (47–83) 19 (95) 1.8 0.2 9 (45) 3 (15) 10 (50) 3 (15) 0 (0) 2.7 0.5 4 (20) 16 (80)
20 (100) 1.1 0.5 11.6 4.6 18 (90) 2 (10) 55 8.2 (35–70) 47 7.6 54 27 6 (30) 8 (40)
Values are n (%) or mean SD; NYHA: New York Heart Association
right and left heart catheterizations were performed pre- and post-procedure. The cardiac output was determined by thermodilution or the Fick method. The mitral valve area (MVA) was calculated using the Gorlin formula [8]. The maximal balloon size was selected based on the patient’s height according to the following formula: maximum balloon size (mm) ¼ [patient’s height (cm)/10] þ 10 [9]. The procedure was initiated using a balloon that was 2 – 4 mm smaller depending on morphology and calcification of the mitral valve. Transthoracic echocardiography and left ventriculography (when needed) were performed to assess the mitral regurgitation (MR) severity preprocedure and postprocedure. MR severity was graded as follows: Trace (0), Mild (1þ), Moderate (2þ), Moderately Severe (3þ), and Severe (4þ). After each dilatation, the operator simultaneously obtained the LA pressure through the middle port of the Inoue catheter and the left ventricular (LV) pressure through the pigtail catheter. If the pressure gradient between the LA and LV did not decrease by >50%, and the MR did not increase by more than one degree, the PTMC was repeated with a larger-diameter balloon; the balloon diameters were incremented in 1-mm steps. Evaluation of the Images of the LAA Appendage by ICE Two blinded, independent reviewers who were experienced in the interpretation of echo imaging were
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asked to rate each ICE image on a scale of 1 – 3 in terms of diagnostic quality (1 ¼ poor or nondiagnostic; 2 ¼ fair or partially diagnostic; and 3 ¼ good or fully diagnostic) in terms of the following aspects of the image: (a) the overall image of the LA; (b) the complete image of the LAA, and (c) the presence of a thrombus or spontaneous echo contrast (SEC). Thrombi were diagnosed based on the presence of a clearly defined echogenic intracavity mass with an echo texture that differed from that of the underlying endocardium that was not due to pectinate muscle [10]. SEC was diagnosed based on the presence of dynamic smoke-like echo in the LA that exhibited a characteristic swirling motion that was distinct from white noise artifact after properly adjusting the gain settings. Definitions in the Procedure and Follow-Up
Procedural success was defined as an MVA 1.5 cm2 or an increase in MVA 50% and the absence of more than moderate MR. The procedurerelated events that were tracked included the following: in-hospital death related to the PTMC procedure; the need for acute mitral valve replacement; worsening MR that was more than moderately severe; pericardial tamponade; and thromboembolic events including cerebral vascular accidents and major bleeding. The sixmonth events included cardiovascular death, the need for surgical mitral valve replacement, New York Heart Association (NYHA) functional classification as III or IV, and the need for repeated PTMC. All information was obtained from the medical records. Statistical Analyses Continuous variables are expressed as the mean the standard deviation (SD), and categorical variables are expressed as percentages. Differences between the two groups were assessed using paired t-tests for normally distributed continuous variables and Wilcoxon tests for non-normally distributed continuous variables. P values < 0.05 were considered statistically significant, and all reported p values are 2-sided. All analyses were performed using the PRISM statistical package (Graphpad, version 6.01 for Windows) RESULTS Study Population Twenty patients underwent ICE during the PTMC procedure (Table I). Their mean age was 60 12 years, and 95% were female. Nine patients (45%) had histories of atrial fibrillation, and three had histories of previous cerebral vascular events. Eight patients (40%) were on warfarin to prevent a cerebral vascular event.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
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TABLE II.
Procedural Characteristics n ¼ 20
Procedural success Hemodynamic findings Mitral valve area (cm2): Gorlin formula Preprocedure Postprocedure Pressure gradient: mean (mm Hg) Preprocedure Postprocedure LA pressure: mean (mm Hg) Preprocedure Postprocedure Systolic pulmonary artery pressure (mm Hg) Preprocedure Postprocedure Postprocedural MR Trace to moderate Moderately severe to Severe Final balloon size (mm) Number of Inflation(s) Fluoro-time (min) Contrast volume (ml) ICE Adverse event related to procedure Thrombus in left atrium/atrial appendage SEC in left atrium/atrial appendage Length of stay two days 6 months mortality 6 months adverse event Surgical mitral valve replacement Heart failure requiring hospitalization
17 (85)
1.2 0.3 2.2 0.6
P < 0.001a
14 7.1 6.3 5.3
P < 0.001a
25 8.0 21 7.1
P < 0.001a
57 23 52 22
P ¼ 0.004a
18 (90) 2 (10) 26 1.5 3 2 (1–6) 15 5.0 75 29 0 (0) 0 (0) 8 (40) 14 (70) 0 (0) 3 (15) 2 1
Values are n (%) or mean SD. a vs. postprocedure.
Intracardiac Echocardiography
There were no complications that could be attributed to the use of ICE. The scorings of the ICE images were as follows: (a) the overall image of the LA was “fully diagnostic” in all cases (3.0 0), (b) the complete image of the LAA was “fully diagnostic” in fifteen cases (2.6 0.8), and (c) the presence of a thrombus or SEC was “fully diagnostic” in all cases (3.0 0). Among the nine patients with histories of atrial fibrillation, eight had an SEC in the LA or the LAA. No patients exhibited evidence of a thrombus in either the LA or the LAA. Procedural Outcomes of PTMC The procedural success of PTMC was 85% (Table II). There was a significant increase in MVA (1.2 0.3 to 2.2 0.6 cm2, P < 0.001), a decrease in mean pressure gradient (14 7.1 to 6.3 5.3 mm Hg, P < 0.001), a decrease in mean LA pressure (25 8.0 to 21 7.1 mm Hg, P < 0.001) and a decrease in systolic pulmonary artery pressure (57 23 to 52 22, P ¼ 0.004).
Postprocedure, two patients had MR that was rated as more than moderate. One patient had cardiac tamponade requiring pericardiocentesis via the dislocation of transseptal needle during the transseptal puncture. However, no patients had respiratory compromise requiring intubation or respiratory support. No cerebral vascular events occurred during the PTMC procedure. Fourteen patients (70%) were admitted to the hospital on day of the procedure and discharged on the following day. The six-month mortality and event rates were 0 and 15%, respectively. Two patients ultimately underwent surgical mitral valve replacement, and one patient was admitted to the hospital due to heart failure (NYHA functional class III). No patient suffered a cerebrovascular accident within six months of PTMC. DISCUSSION
This study aimed to investigate the efficacy and safety of the use of adjunctive ICE during PTMC. PTMC was found to offer excellent visualization of the LA and the LAA and to provide satisfactory clinical outcomes while maintaining a low risk profile. Efficacy and Safety of ICE
This study demonstrated that ICE provides excellent visualization of the LA and the LAA for the detection of thrombi prior to the PTMC procedure. All of the categories from (a) to (c) received excellent rating. Our data suggest that the quality of the image of the LAA obtained by ICE is at least equivalent and likely superior that of TEE. Because the majority of patients with histories of atrial fibrillation were taking adequate levels of warfarin prior to the procedures, no cases of LAA thrombi were observed in this study. However, we demonstrated the excellent visualization of the SEC afforded by ICE in eight patients. We believe that thrombi in the LAA can easily be detected with ICE. Although ICE images could also possibly be obtained from the coronary sinus or the pulmonary artery [11,12], all of the patients were referred for PTMC, and transseptal punctures were therefore planned. We endorse the insertion of an ICE probe into the LA through the transseptal puncture as a much more straightforward and less risky approach compared to coronary sinus cannulation with the large blunt tip of the ICE probe. Although there have been studies that have reported the imaging of the LAA using ICE from the LA [13,14], this study is the first to observe the LAA with ICE for the detection of thrombi prior to PTMC [15]. ICE has been shown to improve the safeties of a variety of invasive cardiovascular procedures [16,17]. In
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
PTMC with ICE
our series, there were no complications that could be attributed to the use of ICE. ICE not only reduces the risk of the procedural complications, such as those that can occur during transseptal puncture but also allows for the immediate identification of potential complications. Compared with TEE, ICE has many advantages, including the elimination of the need for the patient to be esophageally intubated and the requirement of the use of deep sedation or general anesthesia. The use of ICE during PTMC results in a less invasive percutaneous treatment that is free of the risks of anesthesia complications, such as postprocedural hypotension, delirium, and aspiration pneumonia. Furthermore, it is possible that less fluoroscopy time would be needed when ICE is used, and anesthesia and echo cardiac imaging personnel are not needed, which would lead reductions in the cost of the procedure [18]. However, whether ICE can provide systematic, diagnostic images of the LAA with the consistency afforded by TEE requires depended on the significant learning curve faced by individual operators. Furthermore, the current generation of ICE imaging only provided a single plane. The use of other transcatheter interventions, such as LAA closure, is controversial [19] because they require appropriate measurements of the appendage based on a complete image of the entire LAA cavity. It is possible that the next generation of threedimensional ICE probes will allow for better measurements of the LAA. Procedural Outcomes of PTMC using ICE
Only a few case studies have reported on the use of ICE during PTMC [20,21]. Our retrospective analyses of the immediate and six-month results following the use of ICE during PTMC are encouraging; no mortality and few complications were observed [22]. In our series, two patients underwent elective mitral valve replacement following increases in the severity of MR after PTMC. Selection of the maximal balloon size according the ICE measurement of the annular diameter or the distribution of calcification might potentially avoid the risk of the tearing of leaflets in these patients. When it becomes available, three-dimensional ICE will add additional imaging detail. Further investigations that include long-term results and larger study sizes areneeded. LIMITATIONS
This study reflects the experiences at a single center with a small number of patients; thus, the extent to which these data can be generalized to all patients who undergo PTMC could not be established. The
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visualization of the LAA for the detection of thrombi was not compared between two imaging modalities (e.g., ICE vs. TEE or CT).
CONCLUSIONS
ICE-guided PTMC offers excellent visualization of the LA and the LAA with satisfactory clinical outcomes and a low risk profile. ICE as a part of the PTMC procedure safely provides a valid alternative to TEE that precludes the need for a separate TEE procedure. ICE is the echocardiographic imaging procedure of choice for PTMC. REFERENCES 1. Inoue K, Owaki T, Nakamura T, Kitamura F, Miyamoto N. Clinical application of transvenous mitral commissurotomy by a new balloon catheter. J Thorac Cardiovasc Surg 1984;873:394– 402. 2. Nobuyoshi M, Arita T, Shirai S, Hamasaki N, Yokoi H, Iwabuchi M, Yasumoto H, Nosaka H. Percutaneous balloon mitral valvuloplasty: A review. Circulation 2009;1198:e211–219. 3. Saidi SJ, Motamedi MH. Incidence and factors influencing left atrial clot in patients with mitral stenosis and normal sinus rhythm. Heart 2004;9011:1342–1343. 4. Manjunath CN, Srinivasa KH, Panneerselvam A, Prabhavathi B, Ravindranath KS, Rangan K, Dhanalakshmi C. Incidence and predictors of left atrial thrombus in patients with rheumatic mitral stenosis and sinus rhythm: A transesophageal echocardiographic study. Echocardiography 2011;284:457–460. 5. Patel A, Cao QL, Koenig PR, Hijazi ZM. Intracardiac echocardiography to guide closure of atrial septal defects in children less than 15 kilograms. Catheter Cardiovasc Interv 2006;682: 287–291. 6. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP III, Guyton RA, O’Gara PT, Ruiz CE, Skubas NJ, Sorajja P, Sundt TM III, Thomas JD; American College of Cardiology/ American Heart Association Task Force on Practice Guidelines. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: Executive summary: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2014;63: 2438–2488. 7. Palacios I, Block PC, Brandi S, Blanco P, Casal H, et al. Percutaneous balloon valvotomy for patients with severe mitral stenosis. Circulation 1987;754:778–784. 8. Gorlin R, Gorlin SG. Hydraulic formula for calculation of the area of the stenotic mitral valve, other cardiac valves, and central circulatory shunts. I. Am Heart J 1951;411:1–29. 9. Lau KW, Hung JS. A simple balloon-sizing method in Inoue-balloon percutaneous transvenous mitral commissurotomy. Cathet Cardiovasc Diagn 1994;332:120–129; discussion 130121. 10. Goswami KC, Narang R, Bahl VK, Talwar KK, Manchanda SC. Comparative evaluation of transthoracic and transesophageal echocardiography in detection of left atrial thrombus before percutaneous transvenous mitral commissurotomy. Do all patients need transesophageal examination? Int J Cardiol 1997; 623:237–249.
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