Current Status of Surgical Ventricular Restoration for Ischemic Cardiomyopathy

A historical appraisal of the techniques of left ventricular volume reduction in ischemic cardiomyopathy: Who did what?

Resection or exclusion of scars following a myocardial infarction on the left anterior descending artery territory started even before the beginning of the modern era of cardiac surgery. Many techniques were developed, but there is still confusion on who did what. The original techniques underwent modifications that brought to a variety of apparently new procedures that, however, were only a "revisitation" of what described before. In some case, old techniques were reproposed and renamed, without giving credit to the surgeon that was the original designer. Herein we try to describe which are the seminal procedures and some of the most important modifications, respecting however the merit of who first communicated the procedure to the scientific world.

"Frozen Apex" Repair of a Dilated Cardiomyopathy

We try to make surgical ventricular restoration simpler and more adjustable to safely enhance ventricular function. In eight patients with DiDonato type III dilated cardiomyopathy, we applied a few short-axis purse-string sutures to the endocardial side of the left ventricular apex ("Frozen-Apex" restoration) to make a smaller, cone-shaped apex, based on the concept that the left ventricular apex is important in its existence, but not in its function. The procedure took less than 15 minutes in all the patients. There was no hospital or late death with the follow-up of 549 ± 389 days. Mid-late postoperatively, New York Heart Association functional class changed from 3.5 ± 0.8 (preoperative) to 1.6 ± 0.6 (P = 0.000 vs preoperative), left ventricular diastolic diameter from 64 ± 16 to 61 ± 15 mm, systolic diameter from 57 ± 15 to 50 ± 17mm (P = 0.070), ejection fraction from 27 ± 10 to 40 ± 16% (P = 0.014). Diastolic function as assessed by the ratio of the early to late ventricular filling velocities, the ratio of mitral annular early diastolic velocity to early mitral inflow velocity, and estimated right ventricular pressure remained at the similar level to preoperative one. The new ventricular restoration was associated with better systolic left ventricular function without deteriorating diastolic one. It may improve the outcome of the treatment of selected patients with dilated cardiomyopathy.

Time series analysis of physiologic left ventricular reconstruction in ischemic cardiomyopathy

OBJECTIVE

The history of left ventricular reconstruction has demonstrated that the full spectrum of recoverable physiologic parameters is essential for a good functional result. We report the long-term outcome of a new surgical technique that arranges myocardial fibers in a near-normal disposition, also recovering left ventricular twisting.

METHODS

Between May 2006 and October 2013, 29 consecutive patients with previous anterior myocardial infarction and heart failure symptoms underwent physiologic left ventricular reconstruction surgery and coronary revascularization. Patients were examined by means of standard echocardiography and 2-dimensional speckle tracking at 8 time steps until 7 years after surgery. Ten geometric and functional parameters were evaluated at each step and analyzed by the linear mixed model test.

RESULTS

Hospital mortality was 0%. The mean percentage of indexed end-diastolic and end-systolic volume reduction was 45.7% and 50.9%, respectively. Ejection fraction and all of the volumes were significantly different in the postoperative period with a steady correction during time. Diastolic parameters were not worsened by surgical reconstruction. Ejection fraction and deceleration time showed a significant improvement during time. Left ventricular torsion increased immediately after the surgical correction from 2.8 ± 4.4 degrees to 8.7 ± 3.9 degrees (P = .02) and was still present 4 years after surgery.

CONCLUSIONS

Surgical conduction of ventricular reconstruction should be standardized to achieve the full spectrum of recoverable physiologic parameters. The renewal of ventricular torsion should be pursued as an adjunctive element of ventricular efficiency, mainly in ventricles that work at a critical level in the Frank-Starling relationship and pressure-volume loop.

Pathobiology of Ischemic Heart Disease: Past, Present and Future

This review provides a perspective on knowledge of ischemic heart disease (IHD) obtained from the contemporary era of research which began in the 1960s and has continued to the present day. Important discoveries have been made by basic and translational scientists and clinicians. Pathologists have contributed significantly to insights obtained from experimental studies and clinicopathological studies in humans. The review also provides a perspective for future directions in research in IHD aimed at increasing basic knowledge and developing additional therapeutic options for patients with IHD.

Epicardial infarct repair with basic fibroblast growth factor-enhanced CorMatrix-ECM biomaterial attenuates postischemic cardiac remodeling

OBJECTIVES

Dysregulation of extracellular matrix (ECM) following myocardial infarction is a key contributor to myocardial fibrosis, chamber dilation, and progression to heart failure. Basic fibroblast growth factor is a potent inhibitor of fibrosis. We propose a novel surgical procedure leveraging a commercially available ECM biomaterial for the treatment of ischemic heart failure.

METHODS

Epicardial infarct repair using CorMatrix-ECM biomaterial patch (CorMatrix Cardiovascular Inc, Roswell, Ga) was compared with sham in a rat myocardial infarction model. Key indices of ischemic remodeling, including inflammation, fibrosis, and myocardial performance were evaluated 16 weeks post-treatment.

RESULTS

Histology and immunohistochemistry demonstrated comprehensive integration of CorMatrix-ECM biomaterial patch without evidence of immune reaction and an increase in basic fibroblast growth factor expression in treated animals. Functional analysis by serial echocardiography of normal (n = 13), sham (n = 15), nonenhanced CorMatrix-ECM patch (n = 18), and basic fibroblast growth factor-enhanced CorMatrix-ECM patch (n = 10) animals revealed an improvement in ejection fraction in basic fibroblast growth factor-enhanced CorMatrix-ECM patch animals compared with shams (55.3% ± 8.0% vs 35.1% ± 7.6%; P < .001). Prevention of left ventricle remodeling was also confirmed by pressure volume loop analysis, which demonstrated reduced left ventricular end diastolic volumes in basic fibroblast growth factor-enhanced CorMatrix-ECM patch animals (n = 5) compared with shams (n = 6) (208.0 ± 59.3 μL vs 363. 1 ± 108.7 μL; P < .01) and improved left ventricle contractility in nonenhanced CorMatrix-ECM patch (n = 7) and basic fibroblast growth factor-enhanced CorMatrix-ECM patch animals compared with shams (0.709 ± 0.306 and 0.609 ± 0.160 vs 0.437 ± 0.218; P < .05).

CONCLUSIONS

Epicardial infarct repair with basic growth factor-enhanced CorMatrix-ECM biomaterial patch attenuates myocardial remodeling and improves cardiac performance after subacute myocardial infarction in a rat coronary ligation model. These observations establish proof-of-concept for this novel surgical approach.