Surgical ventricular reverse remodeling in severe ischemic dilated cardiomyopathy: the relevance of the left ventricular equator as a prognostic factor

Surgical ventricular restoration for the treatment of heart failure

Heart failure (HF) is an emerging epidemic affecting 15 million people in the USA and Europe. HF-related mortality was unchanged between 1995 and 2009, despite a decrease in the incidence of cardiovascular disease. Conventional explanations include an aging population and improved treatment of acute myocardial infarction and HF. An adverse relationship between structure and function is the central theme in patients with systolic dysfunction. The normal elliptical ventricular shape becomes spherical in ischemic, valvular, and nonischemic dilated cardiomyopathy. Therapeutic decisions should be made on the basis of ventricular volume rather than ejection fraction. When left ventricular end-systolic volume index exceeds 60 ml/m², medical therapy, CABG surgery, and mitral repair have limited benefit. This form-function relationship can be corrected by surgical ventricular restoration (SVR), which returns the ventricle to a normal volume and shape. Consistent early and late benefits in the treatment of ischemic dilated cardiomyopathy with SVR have been reported in >5,000 patients from various international centers. The prospective, randomized STICH trial did not confirm these findings and the reasons for this discrepancy are examined in detail. Future surgical options for SVR in nonischemic and valvular dilated cardiomyopathy, and its integration with left ventricular assist devices and cell therapy, are described.

Influence of baseline left ventricular function on the clinical outcome of surgical ventricular reconstruction in patients with ischaemic cardiomyopathy

AIMS

The Surgical Treatment for Ischemic Heart Failure (STICH) trial demonstrated no overall benefit when surgical ventricular reconstruction (SVR) was added to coronary artery bypass grafting (CABG) in patients with ischaemic cardiomyopathy. The present analysis was to determine whether, based on baseline left ventricular (LV) function parameters, any subgroups could be identified that benefited from SVR.

METHODS AND RESULTS

Among the 1000 patients enrolled, Core Lab measures of baseline LV function with adequate quality were obtained in 710 patients using echocardiography, in 352 using cardiovascular magnetic resonance, and in 344 using radionuclide imaging. The relationship between LV end-systolic volume index (ESVI), end-diastolic volume index, ejection fraction (EF), regional wall motion abnormalities, and outcome were first assessed only by echocardiographic measures, and then by 13 algorithms using a different hierarchy of imaging modalities and their quality. The median ESVI and EF were 78.0 (range: 22.8-283.8) mL/m2 and 28.0%, respectively. Hazard ratios comparing the randomized arms by subgroups of LVESVI and LVEF measured by echocardiography found that patients with smaller ventricles (LVESVI <60 mL/m2) and better LVEF (≥33%) may have benefitted by SVR, while those with larger ventricles (LVESVI >90 mL/m(2)) and lower LVEF (≤25%) did worse with SVR. Algorithms using all three imaging modalities found a weaker relationship between LV global function and the effects of SVR. The extent of regional wall motion abnormality did not influence the effects of SVR.

CONCLUSIONS

Subgroup analyses of the STICH trial suggest that patients with less dilated LV and better LVEF may benefit from SVR, while those with larger LV and poorer LVEF may do worse. Clinical Trial Registration #: NCT00023595.

Clinical characteristics of patients undergoing surgical ventricular reconstruction by choice and by randomization

OBJECTIVES

The aim of this study was to confirm the generalizability of the conclusions of the STICH (Surgical Treatment for Ischemic Heart Failure) trial.

BACKGROUND

Surgical ventricular reconstruction (SVR) added to coronary artery bypass grafting (CABG) did not decrease death or cardiac hospitalization in STICH patients randomized to CABG with (n = 501) or without (n = 499) SVR.

METHODS

Baseline clinical characteristics of 1,000 STICH SVR hypothesis patients and 1,036 STICH-eligible Society of Thoracic Surgeons (STS) National Cardiac Database patients undergoing CABG plus SVR were entered into a multivariate model equation to predict a mortality that placed these 2,036 patients in 1 of 32 risk at randomization (RAR) groups. The number of patients in each RAR group profiled the risk of STICH treatment arms and of STICH and STS STICH-eligible patients.

RESULTS

That 85% of the 1,000 STICH patients known to have no significant differences in baseline characteristics between the 2 treatment arms shared the same RAR group suggests that the RAR methodology has sufficient accuracy to compare RAR profiles of STICH and STS patients. RAR group was shared by 1,522 of 2,036 STICH and STS STICH-eligible patients (75%) who underwent CABG plus SVR. Differences in baseline characteristics responsible for more low-risk STICH patients and more high-risk STS patients were modest. Cox proportional hazard ratios of 1,000 STICH patients in 3 RAR groups suggested by STICH and STS RAR differences showed no differential treatment effect on survival across the low-, intermediate-, and high-risk groups.

CONCLUSIONS

The STICH conclusion of no benefit from adding SVR to CABG applies to a broad spectrum of CABG-eligible patients with ischemic cardiomyopathy. (Comparison of Surgical and Medical Treatment for Congestive Heart Failure and Coronary Artery Disease; NCT00023595).

Left ventricular surgical restoration for anteroseptal scars: volume versus shape

OBJECTIVE

We report the long-term results of left ventricular surgical restoration in which 2 different strategies were used, which had restoration of ventricular volume or ventricular shape as their target.

METHODS

From 1988 to 2008, 308 patients with anterior scars underwent elective left ventricular surgical restoration. Before 2002, a Dor procedure was performed in 107 cases to reduce left ventricular volume (group V); from 1998 to 2001, a Guilmet procedure was performed in 32 patients to rebuild a left ventricular conical shape (group S). From 2002, 169 patients (group S) underwent left ventricular surgical restoration to reshape a conical left ventricle by means of the Dor procedure (n = 29, septoapical scars) or septal reshaping (n = 140, when the septum was more involved than the anterior wall). The 2 groups were similar for all features but age, mitral regurgitation grade, mitral valve surgery rate (higher in group S), and ejection fraction (higher in group V).

RESULTS

Early mortality was 7.8% (11.2% in group V vs 6.0% in group S, P = .102). Logistic regression showed that volume reduction was significantly related to higher early mortality. Five-year cardiac survival, cardiac event-free survival, and event-free survival were higher in group S. Cox analysis showed that the choice of volume reduction provided lower survival (hazard ratio, 2.1), cardiac survival (hazard ratio, 3.0), cardiac event-free survival (hazard ratio, 2.7), and event-free survival (hazard ratio, 2.2). When 30-day events were excluded, volume reduction was still a risk factor for cardiac event-free survival (hazard ratio, 2.2).

CONCLUSIONS

When the main target of left ventricular surgical restoration is left ventricular reshaping rather than left ventricular volume reduction, early and late outcomes seem to improve.

An unsupervised clustering framework for automatic segmentation of left ventricle cavity in human heart angiograms

Cardiac function is routinely assessed from X-rays angiograms acquired at the cardiac catheterization rooms. Currently, the evaluation of cardiac function involves the global measurement of volumes and ejection fraction (EF). This evaluation requires the segmentation of the left ventricle (LV) contour. Several automatic segmentation methods have been reported, however, they are not yet fully validated and accepted in the clinical work. This paper reports on an automatic segmentation method for the ventricular cavity in mono-plane and bi-plane ventriculographic image sequences. The first step is the preprocessing, where a linear regression model is applied to exploit the functional relationship between the original input image and its smoothed version. A two stage clustering algorithm is used for segmenting the left ventricle cavity. First, an approximate initial segmentation is achieved by using a simple linkage region growing algorithm on the preprocessed version of the input image. The second stage is based on a region growing method by multiple linkage. This second stage is intended for refining the initial approximate segmentation. A validation is performed by comparing the estimated contours with respect to contours traced manually by several cardiologists. The average positioning error considering 15 mono-plane and 3 bi-plane angiographic sequences is 0.72mm at end-diastole (ED) and 0.91mm at end-systole (ES). The average contour error is 6.67% at ED and 12.44% at ES. The average area error is 8.58% at ED and 3.32% at ES. The left ventricle volume and the ejection fraction are estimated from manual contours and from the estimated contours showing an excellent correlation: 0.999 for ED volume, 0.998 for ES volume, and 0.952 for EF.

Trends in cardiac surgery: exploring the past and looking into the future

Today's successes would not be possible without the foundation of yesterday's practitioners and patients. This article assists in the exploration of cardiac surgery procedures, provides a brief historical review of the significant changes in cardiothoracic surgery, and provides an overview of current and future methods of treatment for coronary revascularization and heart failure. It is difficult for one article to encompass all aspects of cardiothoracic surgery. This article highlights many of the transforming moments that have led us to where we are today and explores the current trends of cardiac surgery and possibilities for tomorrow.

Implantation of an elastic ring at equator of the left ventricle influences cardiac mechanics in experimental acute ventricular dysfunction

OBJECTIVES

We hypothesize that the implantation of an endoventricular elastic ring at the left ventricle (LV) equatorial site will positively affect the cardiac mechanics in an experimental model of acute LV dysfunction.

BACKGROUND

Changes in the elastic properties of LV occur in the dilated and failing heart, contributing to overall cardiac mechanical dysfunction. No interventions are as yet specifically designed to improve LV elasticity in failing hearts.

METHODS

Acute LV enlargement and dysfunction was induced in 13 healthy sheep via the insertion of a large Dacron patch into the lateral wall. In 6 of these sheep, a customized elastic ring was implanted at the inner surface of the LV equator (ring group), and the remaining 7 served as control subjects (dysfunction group). Systolic and diastolic function was evaluated using echocardiography and pressure-volume (P-V) analysis.

RESULTS

In the ring group, both the maximum rate of pressure increase and the slope of end-systolic P-V relationship were significantly different from those without ring (1,718 +/- 726 vs. 1,049 +/- 269 and 1.25 +/- 0.30 vs. 0.88 +/- 0.19; both p < 0.05). Preload recruitable stroke work changed even more prominently (33 +/- 11 vs. 17 +/- 5; p = 0.005), along with stroke volume, ejection fraction, and stroke work. Although ring implantation had no effect on end-diastolic P-V relationship, it positively affected the active component of diastole: the maximum rate of pressure decrease declined significantly (p = 0.037). The time constant of relaxation tended to decrease (37 +/- 8 vs. 44 +/- 6; p = 0.088).

CONCLUSIONS

Improving the elastic component of the LV at its equatorial site substantially augments contractility and early relaxation in acute systodiastolic LV dysfunction.

The year in cardiovascular surgery

This paper highlights information from cardiovascular surgical articles published in 2006 that are likely to have a broad impact on the practice of cardiovascular specialists in years ahead. Preference was given to articles that are innovative in purpose, thoughtful in design, and definitive in conclusions.

Left ventricular reconstruction as an alternative to heart transplantation: a case report

A 57-year-old man with dilated cardiomyopathy was referred to our institution to be assessed for heart transplantation. He had symptoms of severe heart failure and left ventricular dysfunction. We proposed surgical ventricular restoration (the Dor procedure) as an alternative to heart transplantation. The patient underwent successful surgery and an uneventful postoperative course. Pre- and postoperative investigations are presented. One year after surgery, the patient is in good clinical and functional condition. This case illustrates that surgical ventricular restoration can be an alternative to heart transplantation.