The impact of left ventricular reconstruction on survival in patients with ischemic cardiomyopathy

Basic fibroblast growth factor attenuates left-ventricular remodeling following surgical ventricular restoration in a rat ischemic cardiomyopathy model

OBJECTIVE

Although surgical ventricular restoration for ischemic cardiomyopathy is expected as an alternative or bridge to heart transplantation, post-operative remodeling of left ventricle (LV) needs to be addressed. This study aimed to examine the effect of basic fibroblast growth factor (bFGF), which induces angiogenesis and tissue regeneration in ischemic myocardium, to prevent remodeling after surgical ventricular restoration (SVR) using a rat ischemic cardiomyopathy model.

METHODS

Four weeks after coronary artery ligation, rats were divided into two groups: rats treated with SVR alone (SVR; n = 21), and rats treated with SVR and local sustained release of bFGF using gelatin hydrogel sheet (SVR + bFGF; n = 22). Cardiac function was assessed by serial echocardiography and cardiac catheterization. Cardiac tissue sections were histologically examined for vascular density and fibrosis.

RESULTS

Higher systolic function and lower LV end-diastolic pressure (LVEDP) were observed in rats treated with SVR + bFGF (SVR vs SVR + bFGF; Ees: 0.22 ± 0.11 vs 0.33 ± 0.22 mmHg/μL, p = 0.0328; LVEDP: 12.7 ± 7.0 vs 8.5 ± 4.3 mmHg, p = 0.0230). LV area tended to be lower in rats treated with SVR + bFGF compared to rats treated with SVR alone (left-ventricular end-diastolic area: 0.66 ± 0.07 vs 0.62 ± 0.07 cm², p = 0.071). Vascular density tended to be higher in rats treated with SVR + bFGF than those without bFGF (23.3 ± 8.1 vs 28.8 ± 9.5/mm², p = 0.0509).

CONCLUSIONS

BFGF induced angiogenesis and attenuated remodeling after SVR which secured the efficacy of SVR in a rat ischemic cardiomyopathy model.

Role of surgical ventricular restoration post surgical treatment of heart failure (STICH) trial

Objective

To compare the outcomes of isolated coronary artery bypass grafting (CABG) versus surgical ventricular restoration (SVR) with or without CABG for patients with ischemic cardiomyopathy (ICM).

Methods

Retrospectively, 49 patients with ICM and severe LV dysfunction (LVEF < 35%) who underwent SVR with or without CABG from January 2009 to December 2016 at a single institution was compared with 49 patients who underwent isolated CABG. The two groups were matched for preoperative clinical and echocardiographic parameters including left ventricular end-diastolic diameter (LVIDd), left ventricular end-systolic diameter (LVIDs), left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), and left ventricular end-systolic volume (LVESV). Primary outcomes analyzed included early mortality, late mortality, and major adverse cardiac or cerebrovascular events (MACCE). Secondary outcomes analyzed included echocardiographic parameters of left ventricular volume and function-indexed left ventricular end-diastolic volume (LVEDVi), indexed left ventricular end-systolic volume (LVESVi), and LVEF. Cox and survival analysis was performed.

Results

Early and late mortality in SVR vs. CABG groups were 4 (8.1%) and 6 (12.2%) vs. 1 (2%) and 5 (10.2%) respectively. Mean improvement in LVEF was 3.39 ± 7.51 compared to 4.97 ± 5.45 between the two groups at 3-month follow-up. Mean improvement in LVEF was 5.1 ± 8.3 in the SVR group vs 5.9 ± 7.1 in the CABG group at the last follow-up. There was no statistically significant improvement between the two groups in terms of LVEF at 3 months or the last follow-up. There were statistically significant differences between LVEDVi and LVESVi between the two groups at 3 months and the last follow-up. The 5-year rates of survival were 85 ± 6 and 82 ± 9% for SVR and CABG groups respectively. The 5-year rates of freedom from MACCE were 75 ± 7 and 60 ± 11% for SVR and CABG groups respectively.

Conclusion

Compared with isolated CABG, SVR plus CABG results in equivalent late mortality and better left ventricular reverse remodeling (as evidenced by LV volume reduction) and better freedom from MACCE at 5-year follow-up.

A single center's experience with total arterial revascularization and spiral aneurysmorrhaphy for ischemic cardiac disease

The restoration of left ventricular (LV) geometry in combination with coronary artery bypass grafting for the treatment of ischemic cardiac disease remains controversial. We hereby present the experience of our center with total arterial myocardial revascularization (TAMR) and spiral aneurysmorrhaphy for ischemic heart disease. A retrospective analysis of 101 patients with advanced cardiovascular disease who underwent TAMR and spiral aneurysmorrhaphy was performed. Spiral aneurysmorrhaphy is a modification of the linear aneurysmorrhaphy and was applied to patients who had a LV aneurysm with a diameter of less than 5 cm. Peri-operative and in-hospital data were retrieved. The majority of the patients were male (87.13%) with a mean age of 63.1 years. Mean pre-operative ejection fraction (EF) was 35.7% ranging between 20 and 65%. An average of 3.23 grafts was required per patient. Early mortality was 6.93% (one intra-operative and six in-hospital deaths). Addition of concomitant valve surgery was associated with prolonged total operative, cardiopulmonary bypass and cross-clamp time (p < 0.001), increased need for blood (p = 0.012) and plasma (p = 0.038), longer intensive care unit (ICU) stay (p = 0.045) and higher rate of post-operative cerebrovascular accident (p = 0.011). Furthermore, patients with a pre-operative EF between 30 and 50% had a shorter ICU stay (p = 0.045) and LoS (p = 0.029) compared with patients with EF <30%. Early mortality and post-operative complication rates following this combined procedure are in consistency with the relevant available data suggesting its feasibility regardless of the EF or addition of concomitant surgeries. Data from the follow-up of these patients are required to examine the long-term efficacy of this surgical modality.

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.

Off-pump versus on-pump coronary artery bypass surgery in patients with triple-vessel disease and enlarged ventricles

BACKGROUND AND OBJECTIVES

Off-pump coronary artery bypass grafting (OPCAB) is a popular treatment for patients with ischemic heart disease, especially for high-risk patients. However, whether OPCAB can lead to better clinical outcomes than on-pump coronary artery bypass grafting (ONCAB) in patients with enlarged ventricles remains controversial. This prospective randomized study was designed to characterize comparison of early clinical outcome and mid-term follow-up following ONCAB versus OPCAB in patients with triple-vessel disease and enlarged ventricles.

DESIGN AND SETTINGS

Prospective randomized trial of patients treated at The First Affiliated Hospital, China Medical University, over a 3-year period (2007-2010).

METHODS

A total of 102 patients with triple-vessel disease and enlarged ventricles (end-diastolic dimension >=6.0 cm) were randomized to OPCAB or ONCAB between July 2007 and December 2010. The in-hospital out.comes were analyzed. The study included a mid-term follow-up, with a mean follow-up time of 49.40 (12.88 months).

RESULTS

No significant differences were recorded in the baseline clinical characteristics of ONCAB and OPCAB groups. A statistical difference was found between the two groups at the time of extubation, intensive care unit stay, hospital stay, blood requirements, incidence of intra-aortic balloon pump support, pulmonary complications, stroke, reoperation for bleeding, and inotropic requirements > 24 hours (P < .05). The number of anastomoses performed per patient, the incidence of postoperative ventricular arrhythmia, myocardial infarction, new-onset atrial fibrillation, hemodialysis, infective complications, recurrent angina, and percutaneous reintervention were similar between the 2 groups (P > .05). The left ventricular end-diastolic dimension was significantly smaller at 6 months' follow-up in the 2 groups than it was before operation ( < .05). No differences in hospital mortality and mid-term mortality between OPCAB and ONCAB groups were found. During the follow-up, no patient in either group had undergone repeat coronary artery bypass grafting.

CONCLUSION

No differences in early and mid-term mortality were found between OPCAB and ONCAB in patients with triple-vessel disease and enlarged ventricles. However, OPCAB seems to have a beneficial effect on postoperative complications.

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.

Surgical ventricular restoration to reverse left ventricular remodeling

Heart failure is one of the major health care issues in the Western world. An increasing number of patients are affected, leading to a high rate of hospitalization and high costs. Even with administration of the best available medical treatment, mortality remains high. The increase in left ventricular volume after a myocardial infarction is a component of the remodeling process. Surgical Ventricular Restoration (SVR) has been introduced as an optional therapeutic strategy to reduce left ventricular volume and restore heart geometry. So far, it has been established that SVR improves cardiac function, clinical status, and survival in patients with ischemic, dilated cardiomyopathy and heart failure. Since its first description , SVR has been refined in an effort to standardize the procedure and to optimize the results. This review will discuss the rationale behind surgical reversal of LV remodeling, the SVR technique, its impact on cardiac function and survival, and future expectations.

Surgical therapies for post-myocardial infarction patients

Occasionally, high-risk patients in the post-myocardial infarction (MI) period require surgical intervention for stabilization and/or revascularization. In a meta-analysis involving 3,088 patients with ischemic heart disease, revascularization was associated with nearly an 80% reduction in the risk of death. Coronary artery bypass graft (CABG) surgery is commonly performed in post-MI patients and is associated with more favorable outcomes than medical therapy. However, several factors have to be considered in proper patient selection for CABG, such as the left ventricular ejection fraction (LVEF), severity of heart failure (HF), and myocardial viability. The ongoing Surgical Treatment for Ischemic Heart Failure (STICH) trial will assess the benefits of CABG in patients with both a low LVEF and HF. Unstable post-MI patients who fail revascularization can be managed via mechanical circulatory support devices or pumps. These options significantly improve hemodynamic parameters. In addition, other surgical techniques, such as mitral valve repair, ventricular reconstruction surgery, and atrial fibrillation ablation, are being evaluated in patients with ischemic heart disease.

Surgery for ventricular tachycardia and left ventricular aneurysm provides arrhythmia control

OBJECTIVES

Report long-term freedom from ventricular tachycardia (VT), survival, and causes of death in patients with left ventricular aneurysm and VT, who underwent a combined procedure for VT and surgical ventricular restoration (SVR).

DESIGN

The primary outcome measures VT, survival, and cause of death, were ascertained by review of patients' records, interrogation of implanted cardioverter-defibrillators and use of national registers.

RESULTS

Mean follow-up was 5.2 years. Overall survival was 62% at 5 years and 51% at 9 years. Freedom from spontaneous VT was 89%. In 32 patients who were non-inducible at postoperative testing, there was no occurrence of VT during a mean follow-up of 6.0 years. Causes of death were cardiac in 17 patients, and non-cardiac in 6 patients. No patient died from ventricular arrhythmia.

CONCLUSIONS

Direct surgery for VT combined with SVR resulted in a very low risk of late recurrence of VT and good long-term survival. Implantation of a cardioverter-defibrillator can safely be withheld in patients who are non-inducible on postoperative programmed electrical stimulation.

Left ventricular torsional mechanics after left ventricular reconstruction surgery for ischemic cardiomyopathy

OBJECTIVES

Surgical left ventricular reconstruction improves symptoms and potentially prognosis in patients with ischemic cardiomyopathy; however, the effects of reconstruction on myocardial mechanics are not well defined. Therefore, we have computed left ventricular rotation and torsion in patients undergoing left ventricular reconstruction to determine its effects on these quantitative measures of myocardial mechanics.

METHODS

Magnetic resonance imaging with tissue grid-tagging was performed in 26 patients (19 male/7 female, 62 +/- 11 years) (mean +/- standard deviation) before (23 +/- 29 days) and after (231 +/- 106 days) left ventricular reconstruction, as well as in 7 healthy volunteers (5 male/2 female, 34 +/- 7 years). Left ventricular rotation was computed at basal and apical short-axis levels; torsion was defined as the difference between apical and basal rotation.

RESULTS

Before left ventricular reconstruction, maximal apical rotation was significantly impaired relative to that of healthy volunteers (P = .001), although maximal basal rotation was preserved (P = .84). After reconstruction, maximal torsion did not change significantly: torsion was 6 degrees +/- 3 degrees both before and after reconstruction (P = .84). However, the rate of early diastolic untwist improved significantly after reconstruction (-18 degrees/s +/- 13 degrees/s vs -23 degrees/s +/- 14 degrees/s; P = .04). Furthermore, patients with relatively worse torsion before reconstruction demonstrated more improved function after reconstruction; patients with torsion of less than 6 degrees (n = 12) showed greater improvement in ejection fraction (15% vs 6%; P = .005), torsion (1 degrees vs -1 degrees; P = .01), and diastolic untwist (-9 degrees/s vs -25 degrees/s; P < .001) than did patients with torsion of 6 degrees or more (n = 14).

CONCLUSIONS

Torsional mechanics were severely impaired by ischemic cardiomyopathy. On average, left ventricular reconstruction did not affect systolic torsion generation significantly; however, patients with relatively worse torsion did show improvement. Furthermore, the rate of untwist improved after surgery, suggesting that diastolic function was improved.

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.