Correspondence

Surgical Ventricular Reconstruction

N Engl J Med 2009; 361:529-532July 30, 2009

Article

To the Editor:

Jones et al. (April 23 issue)1 discount the possibility that the selection of patients was a factor in the negative outcome of the Surgical Treatment for Ischemic Heart Failure (STICH) trial (ClinicalTrials.gov number, NCT00023595). Their argument, however, would be much strengthened by providing information on the clinical profile and number of patients who were eligible for the trial but were not enrolled. Such information is sorely needed to determine the generalizability of the findings of a trial in which the yearly recruitment averaged only three patients per site.

Jalal K. Ghali, M.D.
Detroit Medical Center, Detroit, MI 48201
jghali@dmc.org

1 References

1. 1

   Jones RH, Velazquez EJ, Michler RE, et al. Coronary bypass surgery with or without surgical ventricular reconstruction. N Engl J Med 2009;360:1705-1717
   Full Text | Web of Science | Medline

To the Editor:

Jones et al. report that the addition of surgical ventricular reconstruction to coronary-artery bypass grafting (CABG) did not improve survival. Patients who were enrolled in this trial had dominant anterior left ventricular dysfunction. But no information was given on the percentage of patients who had large, dyskinetic left ventricular aneurysms, and no subgroup analysis was carried out. Patients with such aneurysms have poor intraventricular hemodynamics with increased preload and wall stress, resulting in a totally different natural history. Most recent studies have reported that 5-year survival is only 47 to 70% in patients with a medically managed left ventricular dyskinetic aneurysm.1 Therefore, the conclusions of this trial may not be consistent in patients with akinesia, as compared with dyskinesia.

Patients with large aneurysms are rare in developed countries, mostly because of the use of advanced revascularization techniques. However, in developing nations, many patients still have this condition. In our center, 7% of patients undergoing CABG had dyskinetic aneurysms, and one fifth of the aneurysms were large. The operative rate of death in patients with large aneurysms was 4.1%; 1-year and 5-year survival rates were 95% and 91%, respectively.

Shengshou Hu, M.D.
Zhe Zheng, M.D.
Hongguang Fan, M.D.
Fuwai Hospital, Beijing 100037, China
shengshouhu@yahoo.com

1 References

1. 1

   Antunes MJ, Antunes PE. Left-ventricular aneurysms: from disease to repair. Expert Rev Cardiovasc Ther 2005;3:285-294
   CrossRef | Medline

To the Editor:

The report on the STICH trial does not define the role of surgical ventricular reconstruction in the management of heart failure because of the study's poor design and execution. The outcomes of patients who underwent surgical ventricular reconstruction in this trial cannot be compared with those of more than 5000 patients in registries who had regional necrosis of 35% or more from previous infarction, a left ventricular end-systolic volume index of at least 60 ml per square meter of body-surface area, and an ejection fraction of 35% or less.1-3 In the STICH trial, patients were randomly assigned to undergo surgical ventricular reconstruction only if they had dominant anterior dysfunction of the left ventricle and an ejection fraction of 35% or less, with no viability data confirming left ventricular necrosis or extent of damage (13% of the patients had no history of infarction). Only 50% had either akinesia or dyskinesia.

The original study submission called for the measurement of left ventricular end-systolic volume in all patients with the use of cardiac magnetic resonance imaging.4 However, this measurement was performed with the use of echocardiography and in only 38% of the patients.5 Jones et al. report that patients who were assigned to undergo CABG with surgical ventricular reconstruction had a 19% reduction in the end-systolic volume index, as compared with a reduction of at least 40%, as reported in multiple trials of surgical ventricular reconstruction. Therefore, such procedures were not performed according to grant-accepted guidelines and were performed on improperly selected patients.

A valid trial of surgical ventricular reconstruction requires the selection of patients with at least 35% anterior necrosis on single-photon-emission computed tomography, an end-systolic volume index of at least 60 ml per square meter, and a postoperative reduction in the end-systolic volume index of at least 30%. Patients with insufficient volume reduction must be excluded from the analysis because of an inadequate procedure.

Constantine L. Athanasuleas, M.D.
University of Alabama, Birmingham, AL 35234

Gerald D. Buckberg, M.D.
University of California, Los Angeles, Los Angeles, CA 90095
gbuckberg@mednet.ucla.edu

John V. Conte, M.D.
Johns Hopkins University, Baltimore, MD 21287

Andrew S. Wechsler, M.D.
Drexel University, Philadelphia, PA 19102

John E. Strobeck, M.D., Ph.D.
Valley Hospital, Ridgewood, NJ 07506

Friedhelm Beyersdorf, M.D.
Albert-Ludwigs-Universität Freiburg, D79106 Freiburg, Germany

Drs. Athanasuleas and Buckberg report coholding a patent on a product for ventricular reconstruction and receiving royalties from and holding stock options in Somanetics. Dr. Wechsler reports receiving consulting fees from and holding stock options in Bioventrix.

No other potential conflict of interest relevant to this letter was reported.

5 References

1. 1

   Athanasuleas CL, Buckberg GD, Stanley AW, et al. Surgical ventricular restoration in the treatment of congestive heart failure due to post-infarction ventricular dilation. J Am Coll Cardiol 2004;44:1439-1445
   CrossRef | Web of Science | Medline

2. 2

   Dor V, Sabatier M, Montiglio F, Civaia F, DiDonato M. Endoventricular patch reconstruction of ischemic failing ventricle: a single center with 20 years experience: advantages of magnetic resonance imaging assessment. Heart Fail Rev 2004;9:269-286
   CrossRef | Web of Science | Medline

3. 3

   Conte JV. Surgical ventricular restoration: technique and outcomes. Congest Heart Fail 2004;10:248-251
   CrossRef | Medline

4. 4

   Bellenger NG, Burgess MI, Ray SG, et al. Comparison of left ventricular ejection fraction and volumes in heart failure by echocardiography, radionuclide ventriculography and cardiovascular magnetic resonance: are they interchangeable? Eur Heart J 2000;21:1387-1396
   CrossRef | Web of Science | Medline

5. 5

   White HD, Norris RM, Brown MA, Brandt PW, Whitlock RM, Wild CJ. Left ventricular end-systolic volume as the major determinant of survival after recovery from myocardial infarction. Circulation 1987;76:44-51
   CrossRef | Web of Science | Medline

To the Editor:

Ventricular reconstruction surgery is based on the concept that remodeling is an adverse event that should be prevented. The left ventricular stroke volume is often normal in patients with chronic heart failure and is a function of the metabolic needs of the body. In contrast, the ejection fraction is contingent on myocardial contractility and left ventricular wall thickness.1 If the stroke volume is held constant, the end-diastolic volume must change with the ejection fraction (Figure 1AFigure 1Relationship between Ejection Fraction, End-Diastolic Volume, and Stroke Volume.), as is illustrated in patients with heart failure (Figure 1B).2 Changes in end-diastolic volume may reflect the need to normalize the stroke volume as an adaptive physiological mechanism. After myocardial damage, mechanisms such as fluid retention and increased filling pressures result in ventricular remodeling and a normalization of the stroke volume. This paradigm could explain the disappointing results of the STICH trial, as well as the Batista operation3 and extracardiac support mesh implantation.4 A reduction in the end-diastolic volume by surgical means would be predicted to cause an acute fall in stroke volume, with potentially harmful consequences. A greater understanding of the pathophysiology of heart failure is imperative before embarking on further such trials.

David H. MacIver, M.D., M.B., B.S.
Taunton and Somerset Hospital, Taunton TA1 5DA, United Kingdom

4 References

1. 1

   Maciver DH, Townsend M. A novel mechanism of heart failure with normal ejection fraction. Heart 2008;94:446-449
   CrossRef | Web of Science | Medline

2. 2

   Gaasch WH, Delorey DE, St John Sutton MG, Zile MR. Patterns of structural and functional remodeling of the left ventricle in chronic heart failure. Am J Cardiol 2008;102:459-462
   CrossRef | Web of Science | Medline

3. 3

   Starling RC, McCarthy PM, Buda T, et al. Results of partial left ventriculectomy for dilated cardiomyopathy: hemodynamic, clinical and echocardiographic observations. J Am Coll Cardiol 2000;36:2098-2103
   CrossRef | Web of Science | Medline

4. 4

   Starling RC, Jessup M, Oh JK, et al. Sustained benefits of the CorCap Cardiac Support Device on left ventricular remodeling: three year follow-up results from the Acorn clinical trial. Ann Thorac Surg 2007;84:1236-1242
   CrossRef | Web of Science | Medline

Author/Editor Response

Ghali's question about the influence of clinical-site enrollment performance on the generalizability of our trial results can be addressed from analysis of extant data that have yet to be published. It is possible to quantify the baseline risk spectrum of all patients who underwent randomization according to characteristics of the study center and country.

Hu et al. question whether our results apply to patients with large left ventricular aneurysms. Core laboratory data that were carefully interpreted without knowledge of randomized study-group assignment are currently being analyzed to determine whether specific descriptors of global and regional left ventricular function and left atrial filling identify patients who do better or worse after surgical ventricular reconstruction.

Athanasuleas et al. misunderstand and incorrectly report the simplification of criteria for Hypothesis 2 enrollment.1 Clinical sites reported that 83% of patients in Hypothesis 2 had dysfunction involving more than 35% of the anterior wall, and 84% of patients had an end-systolic volume index of more than 60 ml per square meter on randomization. In addition, the correspondents overstate the body of interpretable data from nonrandomized studies that have measured postoperative volumes. These studies used multiple techniques at widely disparate time points after the procedure and cannot serve as a reliable end point for comparison.

MacIver emphasizes the importance of an increase in the end-diastolic volume to respond to augmented stroke-volume needs as an explanation for the lack of benefit from surgical reduction in left ventricular size. The heart augments end-diastolic volume to retain stroke volume at high heart rates in high-performance athletes,2 in patients recovering from acute myocardial infarction,3 and in patients who undergo a brief interval of cardiopulmonary bypass during CABG.4 The heart appears to preferentially use preload reserve to augment cardiac output more than contractility reserve when there is limited oxygen available to the myocardium. Perhaps surgical reduction of left ventricular chamber size only changes the position, but not the area, of the left ventricular pressure–volume loop as cardiac-output needs fluctuate during activities of daily living in patients with ischemic cardiomyopathy.

Robert H. Jones, M.D.
Duke University Medical Center, Durham, NC 27710
jones060@mc.duke.edu

4 References

1. 1

   Velazquez EJ, Lee KL, O'Connor CM, et al. The rationale and design of the Surgical Treatment for Ischemic Heart Failure (STICH) trial. J Thorac Cardiovasc Surg 2007;134:1540-1547
   CrossRef | Web of Science | Medline

2. 2

   Rerych SK, Scholz PM, Sabiston DC Jr, Jones RH. Effects of exercise training on left ventricular function in normal subjects: a longitudinal study by radionuclide angiography. Am J Cardiol 1980;45:244-252
   CrossRef | Web of Science | Medline

3. 3

   Upton MT, Palmeri ST, Jones RH, Coleman RE, Cobb FR. Assessment of left ventricular function by resting and exercise radionuclide angiocardiography following acute myocardial infarction. Am Heart J 1982;104:1232-1243
   CrossRef | Web of Science | Medline

4. 4

   Sell TL, Purut CM, Silva R, Jones RH. Recovery of myocardial function during coronary artery bypass grafting: intraoperative assessment by pressure-volume loops. J Thorac Cardiovasc Surg 1991;101:681-687
   Web of Science | Medline

Citing Articles (9)

Citing Articles

1. 1

   Chien-Sung Tsai, Po-Shun Hsu, Chih-Yuan Lin. (2012) Non-transplant surgical management of end-stage heart failure. Formosan Journal of Surgery
   CrossRef

2. 2

   Timothy J. George, George J. Arnaoutakis, Ashish S. Shah. (2011) Surgical Treatment of Advanced Heart Failure: Alternatives to Heart Transplantation and Mechanical Circulatory Assist Devices. Progress in Cardiovascular Diseases 54:2, 115-131
   CrossRef

3. 3

   T. Isomura, J. Hoshino, Y. Fukada, A. Kitamura, S. Katahira, T. Kondo, T. Iwasaki, G. Buckberg, . (2011) Volume reduction rate by surgical ventricular restoration determines late outcome in ischaemic cardiomyopathy. European Journal of Heart Failure 13:4, 423-431
   CrossRef

4. 4

   Nathan Wm. Skelley, Jeremiah G. Allen, George J. Arnaoutakis, Eric S. Weiss, Nishant D. Patel, John V. Conte. (2011) The Impact of Volume Reduction on Early and Long-Term Outcomes in Surgical Ventricular Restoration for Severe Heart Failure. The Annals of Thoracic Surgery 91:1, 104-112
   CrossRef

5. 5

   Robert H. Jones, Harvey White, Eric J. Velazquez, Linda K. Shaw, Ricardo Pietrobon, Julio A. Panza, Robert O. Bonow, George Sopko, Christopher M. O'Connor, Jean-Lucien Rouleau. (2010) STICH (Surgical Treatment for Ischemic Heart Failure) Trial Enrollment. Journal of the American College of Cardiology 56:6, 490-498
   CrossRef

6. 6

   Marian Zembala, Robert E. Michler, Andrzej Rynkiewicz, Thao Huynh, Lilin She, Barbara Lubiszewska, James A. Hill, Ruzena Jandova, Francois Dagenais, Eric D. Peterson, Robert H. Jones. (2010) Clinical Characteristics of Patients Undergoing Surgical Ventricular Reconstruction by Choice and by Randomization. Journal of the American College of Cardiology 56:6, 499-507
   CrossRef

7. 7

   A. Laurie W. Shroyer, Joseph F. Collins, Frederick L. Grover. (2010) Evaluating Clinical Applicability. Journal of the American College of Cardiology 56:6, 508-509
   CrossRef

8. 8

   D. L. Mann, R. Bogaev, G. D. Buckberg. (2010) Cardiac remodelling and myocardial recovery: lost in translation?. European Journal of Heart Failure 12:8, 789-796
   CrossRef

9. 9

   David H MacIver. (2010) Current controversies in heart failure with a preserved ejection fraction. Future Cardiology 6:1, 97-111
   CrossRef