Surgical ventricular restoration-meta-analysis of observational studies

Background

Technique of surgical ventricular restoration (SVR) may impact its outcomes. Therefore, we conducted a meta-analysis of studies on SVR performed by using different techniques and studied outcomes.

Methods

Scientific databases were searched for studies on SVR. End points assessed were NYHA class, left ventricular ejection fraction (LVEF), end-systolic volume index (ESVI), sphericity index, apical rotations, mortality, and re-admissions for heart failure.

Results

Circular patch use showed significant increases in LVEF by 9.53% (7.62, 11.45), decreases in ESVI by - 35.16 ml (- 44.97, - 25.34), improvements in NYHA class by - 1.29 (- 1.45, - 1.13), and decreases in sphericity index by - 0.04 (- 0.08, 0.00) . In studies using rectangular patch, the LVEF showed an increase by 5.75% (3.52, 7.98,), the NYHA class improved by - 2.45 (- 2.59, - 2.32). The decrease in ESVI was - 40.36 ml (- 62.2, - 18.52). The apical rotation increased by 3.45 ⁰ (0.62, 6.29,). Re-admission for heart failure and mortality was less.When the magnitude of ESVI decrease were compared within studies using rectangular patch, the greatest decrease in ESVI was notedwith use of a rectangular patch. (- 59 ml versus - 40 ml a very narrow patch and - 22 ml use of oval patch) The improvements in sphericity index at 2 years in use of rectangular patch study was - 0.78 ± 0.11 versus 0.00 ± 0.03 in use of oval patch study.

Conclusions

Rectangular patch use resulted in maximal decreases in ESVI and sphericity index. Mortality and re-admissions for heart failure were also significantly less at mid-term after SVR.

Left ventricular reconstruction surgery in ischemic heart disease: a systematic review of the past two decades

INTRODUCTION

The aim of this paper is to systematically review the existing literature reporting on patients recruited during the past twenty years regarding the role of left ventricular (LV) reconstruction in ischemic cardiomyopathy in terms of efficacy and mortality and provide an updated overview of the current evidence.

EVIDENCE ACQUISITION

The PubMed and Cochrane bibliographical databases were thoroughly searched for the following MeSH terms: "ventricular reconstruction" OR ventriculoplasty OR "ventricular aneurysm" OR "ventricular restoration." Original studies -recruiting patients during the past twenty years- on LV reconstruction surgery in more than five cases and reporting on the associated peri- or postoperative mortality were deemed eligible.

EVIDENCE SYNTHESIS

Twenty-seven studies were included and provided data for 3220 patients with a mean age of 61 years. Angina was present in 66.6% (510/766) of the patients, while nine out of ten (635/699) had a history of myocardial infarction. Average preoperative ejection fraction was 29.9% and end-systolic volume index was 93.6 mL/m2. With respect to complications, low cardiac output syndrome and the need for intra-aortic balloon pump were prevalent in 9.3% (79/850) and 18.8% (334/1773), respectively. Thirty-day mortality was 7.1% (230/3220) and late-mortality (mean follow-up of 36.9 months) was 19.6% (548/2791), while the rate of MACCE was 40.1% (367/915). Five-year mortality was 29% (340/1171).

CONCLUSIONS

Our findings provide a current perspective of the role of LV reconstruction in the treatment of ischemic cardiomyopathy suggesting its benefit in survival. Taking into consideration the existing debate, further studies are required so that a solid conclusion to be made.

Characterization of dysfunctional remote myocardium in left ventricular anterior aneurysms and improvements following surgical ventricular restoration using cardiac magnetic resonance imaging: preliminary results

OBJECTIVES

In patients with previous myocardial infarction, the remote uninfarcted regions, although contractile, demonstrate dysfunctional wall kinetics because of increased afterload, which improves after surgical ventricular restoration (SVR). We characterized left ventricular (LV) mean myocardial velocity (MMV) through an analysis of endocardial motion and wall thickening (WT) over the cardiac cycle using standard cardiac magnetic resonance (cMR).

METHODS

LV endocardial motion and WT from cMR data in 7 heart failure (HF) patients with postinfarction antero apical aneurysm were compared against normal controls to establish a baseline for the mean myocardial velocity during phases of the cardiac cycle. The HF patients' MMV and WT curves were compared with post-SVR data.

RESULTS

Global MMV showed significant postoperative improvements in the ejection phase of systole and the early filling phase of diastole. The aneurysmal wall was dyskinetic in both systole and diastole. The remote myocardium preoperatively had a delayed peak velocity during the ejection phase of systole and diminished velocity during early filling in diastole. After SVR, the remote myocardium had an increased MMV with an earlier peaking during the ejection phase and slightly improved early diastolic velocity. WT increased cumulatively during systole and decreased during diastole with improved end-systolic and end-diastolic wall thickness after SVR. The end-systolic wall thickness showed a significant correlation with left ventricular ejection fraction (r(2) = 0.89, P = 0.001) and stroke volume (r(2) = 0.80, P = 0.02). The MMV had a significant correlation with WT over the phases of the cardiac cycle (r(2) = 0.953, P ≤ 0.0001).

CONCLUSIONS

In patients with chronic ischaemic heart disease with LV aneurysms/large areas of scar, improvements in the remote myocardial MMV and WT underline LV systolic function improvements after SVR. The persistence of myocardial WT in early diastole is the likely mechanism for incomplete or absence of relief of LV diastolic dysfunction by SVR.

Restoration of optimal left ventricular apical geometry and rotation following surgical ventricular restoration using rectangular patch plasty technique: a pilot study using cardiac magnetic resonance

OBJECTIVES

Clinical outcomes of surgical ventricular restoration (SVR) have been confirmed by Registry data. Accurate assessment of left ventricular (LV) morphology and function can help optimize these outcomes.

METHODS

LV remodelling in 7 patients (NYHA class 3 ± 1.2) with post-myocardial infarction LV aneurysms was characterized by the regional LV volume (RLVV) computed by dividing the LV in cine steady-state free precession cardiac magnetic resonance imaging (CMR) at each slice level into six radial segments. Rotation of the LV apex and base was analysed using tagged CMR. The apical conicity ratio was used to characterize the restored apical geometry.

RESULTS

The mean end-diastolic volume (EDV) was 174.8 ± 100.3 ml and the mean ejection fraction (EF) was 18.8 ± 7.8%. Following SVR, all patients had significant clinical improvements (NYHA Class I), and significant increases in the left ventricular ejection fraction (LVEF) to 38.8 ± 4.4%. The LV volumes and regional volumes at the base and apex decreased with a trend towards significance. The mean preoperative apical conicity ratio (ACR) was 1.90 ± 0.43 and, following SVR by endoventricular linear patch plasty (EVLPP), was 1.35 ± 0.3 (P = 0.02). The percent decrease in the ACR following SVR from baseline was 28.68 ± 10.98%. The apical EF increased from 1.19 ± 13.9 to 15.8 ± 8.2% (P = 0.028). The basal rotations improved from 3.13 ± 2.1 to 4.69 ± 2.94° (P = 0.04). The apical rotations also improved significantly from 2.48 ± 1.23 to 3.93 ± 2.45° (P = 0.05) and reversed to the normal anticlockwise direction.

CONCLUSIONS

SVR by geometric repair using a rectangular intracavitary patch helps restoration of a physiological apex with normalization of apical rotation reflecting a near-physiological LV function.

Stroke volume paradox in heart failure: mathematical validation

BACKGROUND

In some patients with ischemic cardiomyopathy, despite large increases in ventricular size with decreased cardiac output, the paradox of preserved stroke volume has been observed. Following surgical ventricular restoration, despite marked improvements clinically and in ventricular volumes and ejection fraction, a decrease in stroke volume was observed.

METHODS

101 consecutive patients with postinfarction left ventricular aneurysms were studied by 2-dimensional echocardiography and contrast ventriculography at baseline, and 57 of these patients at 1.7 to 2.2 years (mean 1.95 ± 0.44 years) after surgical ventricular restoration.

RESULTS

Surgical ventricular restoration resulted in a decrease in end-diastolic volume index of 40.2 mL (95% confidence interval: 33.6-46.7) and stroke volume index of 10.0 mL (95% confidence interval: 6.6-13.5), and an increase in ejection fraction of 6.7% (95% confidence interval: 5.5-7.9). The stroke volume index had a significant linear relationship with the end-diastolic volume index at rest in patients with end-diastolic volume index < 150 mL (r = 0.64, p < 0.001). In patients with end-diastolic volume index >150 mL, this linear relationship was not seen. The change in end-diastolic volume index and stroke volume index had a significant linear relationship (r = 0.72, p < 0.001) that persisted at 1.95 years after surgery.

CONCLUSIONS

In ischemic cardiomyopathy, stroke volume increases linearly with increases in end-diastolic volume up to a certain magnitude of end-diastolic volume, beyond which it decreases. Hence, following surgical ventricular restoration, decreases in stroke volume are not a reflection of impaired cardiac function.

Restoration of optimal ellipsoid left ventricular geometry: lessons learnt from in silico surgical modelling

OBJECTIVES

Several issues that are inherent in the surgical techniques of surgical ventricular restoration (SVR) need specialized devices or techniques to overcome them, which may not always result in optimal outcomes. We used a non-invasive novel in silico modelling technique to study left ventricular (LV) morphology and function before and after SVR. The cardiac magnetic resonance imaging derived actual pre- and postoperative endocardial morphology and function was compared with the in silico analysis of the same.

METHODS

Cardiac magnetic resonance steady state free precession (SSFP) cine images were employed to segment endocardial surface contours over the cardiac cycle. Using the principle of Hausdorff distance to examine phase-to-phase regional endocardial displacement, dyskinetic/akinetic areas were identified at the instant of peak basal contraction velocity. Using a three-dimensional (3D) surface clipping tool, the maximally scarred, dyskinetic or akinetic LV antero-apical areas were virtually resected and a new apex was created. A virtual rectangular patch was created upon the clipped surface LV model by 3D Delaunay triangulation. Presurgical endocardial mechanical function quantified from cine cardiac magnetic resonance, using a technique of spherical harmonics (SPHARM) surface parameterization, was applied onto the virtually clipped and patched LV surface model. Finally, the in silico model of post-SVR LV shape was analysed for quantification of regional left ventricular volumes (RLVVs) and function. This was tested in 2 patients with post-myocardial infarction antero-apical LV aneuryms. Left ventricular mechanical dysynchrony was evaluated by RLVV analysis of pre-SVR, in silico post-SVR and actual post-SVR LV endocardial surface data.

RESULTS

Following exclusion of the scarred areas, the virtual resected LV model demonstrated significantly lesser areas of akinesia. The decreases in regional LV volumes in the in silico modelling were significant and comparable with the actual decreases following SVR. Both the regional end diastolic volume (EDV) and end systolic volume (ESV) at the apex decreased significantly corresponding to greater reductions in apical volumes by the technique of rectangular patch plasty (apical EDV 2.1607 ± 0.20577 to 0.4774 ± 0.1775 ml, P = 0.007; apical ESV 1.9708 ± 0.36451 to 0.442 ± 0.047 ml, P = 0.013).

CONCLUSIONS

This pilot study was done using novel in silico techniques for virtual surgical modelling, which helped in accurate estimation and planning of optimal LV restoration by SVR.

Early results after surgical treatment of left ventricular aneurysm

Background

Left ventricular aneurysm (LVA) is a serious complication of myocardial infarction and reduces the chances of survival. Controversy still exists regarding the optimal surgical technique for LVA repair. We analyze the efficacy of two techniques, linear vs. endoventricular circular patch plasty, for repair of LVA and the efficacy of surgical ventricular restoration (SVR) on beating heart.

Methods

This study included 62 patients who underwent SVR from 1086 consecutive patients were subjected to coronary artery bypass grafting (CABG) between 2000 and 2009. All selected patients were divided either into group liner or patch according to the choice of the repair technique depended on factors such as localization, size and dimension of the scar. The patients also were divided either into group beating heart or cardioplegia. The pre-, intra- and postoperative relevant data of all selected patients were analyzed.

Results

The mortality was not significantly different between linear and patch repair groups, also the actuarial survival rates within 24 months (p= 0.529). Postoperative echocardiographic findings showed significant improvements in left ventricular function in both groups. The beating heart technique reduced postoperative peak release by 27% for Cardiac troponin I (cTnI) compared with the cardioplegia group (0.46 ± 0.06 ng/mL versus 0.63 ± 0.09 ng/mL, p= 0.004), and increased the perioperative survival by 9% (97.2% versus 88.5%), but the actuarial survival rates were not significantly different between the groups from 2 to 24 months (p= 0.151).

Conclusions

Both techniques (linear and patch) achieved good results with respect to mortality, functional status and survival. The choice of surgical technique should be adapted in each patient. The beating heart technique may to some extent relieve myocardial injury in patients undergoing SVR.

Surgical treatment of left ventricular aneurysm

When a left ventricular aneurysm leads to pulmonary congestive symptoms, aneurysmectomy may provide relief. This retrospective study included 269 patients who underwent aneurysmectomy between 1993 and 2002, by the classic Cooley operation in 164 and by Dor ventriculoplasty in 105. There were no significant differences in early and late survival between groups, although the frequency of extended anteroseptal infarction was higher in patients undergoing the Dor procedure. Postoperative echocardiographic findings showed significant improvements in left ventricular function in both groups, in terms of end-diastolic and end-systolic dimensions and ejection fraction. Left ventricular aneurysmectomy significantly improved the clinical status and hemodynamic parameters of symptomatic patients. The choice of surgical technique depends on the extent of the scar segment, especially the presence of an anteroseptal scarred area. The Dor procedure is more suitable for restoring normal left ventricular geometry in patients with extensive septal infarction.