Coronary Artery Bypass Grafting With or Without Surgical Ventricular Restoration: A Comparison

Long-term results of surgical ventricular reconstruction and comparison with the Surgical Treatment for Ischemic Heart Failure trial

OBJECTIVE

The role of surgical ventricular reconstruction (SVR) in patients with ischemic cardiomyopathy is controversial. Observational series and the Surgical Treatment of IsChemic Heart failure (STICH) trial reported contradictory results. SVR is highly dependent on operator experience. The aim of this study is to compare the long-term results of SVR between a high-volume SVR institution and the STICH trial using individual patient data.

METHODS

Patients undergoing SVR at San Donato Hospital (Milan) were compared with patients undergoing SVR in STICH (as-treated principle) by inverse probability treatment-weighted Cox regression. The primary outcome was all-cause mortality.

RESULTS

The San Donato cohort included 725 patients, whereas the STICH cohort included 501. Compared with the STICH-SVR cohort, San Donato patients were older (66.0, lower quartile, upper quartile [Q1, Q3: 58.0, 72.0] vs 61.9 [Q1, Q3: 55.1, 68.8], P < .001) and with lower left ventricular end-systolic volume index at baseline (LVESVI: 77.0 [Q1, Q3: 59.0, 97.0] vs 80.8 [Q1, Q3: 58.5, 106.8], P = .02). Propensity score weighting yielded 2 similar cohorts. At 4-year follow-up, mortality was significantly lower in the San Donato cohort compared with the STICH-SVR cohort (adjusted hazard ratio, 0.71; 95% confidence interval, 0.53-0.95; P = .001). Greater postoperative LVESVI was independently associated with mortality (hazard ratio, 1.02; 95% confidence interval, 1.01-1.03). At 4 to 6 months of follow-up, the mean reduction of LVESVI in the San Donato cohort was 39.6%, versus 10.7% in the STICH-SVR cohort (P < .001).

CONCLUSIONS

Patients with postinfarction LV remodeling undergoing SVR at a high-volume SVR institution had better long-term results than those reported in the STICH trial, suggesting that a new trial testing the SVR hypothesis may be warranted.

Surgical Restoration of Antero-Apical Left Ventricular Aneurysms: Cardiac Computed Tomography for Therapy Planning

Background

Surgical ventricular restoration (SVR) leads to functional improvement by volume reduction and restoration of left ventricular (LV) geometry. Our purpose was to refine the planning for SVR using cardiac computed tomography (CCT).

Methods

The possibility to anticipate the postoperative residual LV volume was assessed using CCT in 205 patients undergoing SVR combined with coronary artery bypass grafting (77%), mitral valve repair/replacement (19%) and LV thrombectomy (19%). The potential of CCT to guide the procedure was evaluated. Additionally, the predictive value of CCT characteristics on survival was addressed.

Results

30-day, 1- and 5-year survival was 92.6, 82.7, and 72.1%, respectively, with a marked reduction of NYHA class III-IV quota after surgery (95.1% vs. 20.5% in the follow-up). Both pre- and postoperative LV end-systolic volume index (LVESVI) were predictive of all defined endpoints according to the following tertiles: preoperative: <74 ml/m², 74–114 ml/m² and >114 ml/m²; postoperative: <58 ml/m², 58–82 ml/m² and >82 ml/m². On average, a 50 ml/m² increase of preoperative LVESVI was associated with a 35% higher hazard of death (p = 0.043). Aneurysms limited to seven antero-apical segments (1–7) were associated with a lower death risk (n = 60, HR 0.52, CI 0.28–0.96, p = 0.038). LVESVI predicted by CCT was found to correlate significantly with effectively achieved LVESVI (r = 0.87 and r = 0.88, respectively, p < 0.0001).

Conclusions

CCT-guided SVR can be performed with good mid-term survival and significant improvement in HF severity. CCT-based assessment of achievable postoperative LV volume helps estimate the probability of therapeutic success in individual patients.

Coronary artery bypass grafting in low ejection fraction: state of the art

PURPOSE OF REVIEW

As the number of patients with reduced ejection fraction secondary to ischemic cardiomyopathy (ICM) increases, coronary artery bypass grafting is being used with increasing frequency. In this review, we summarize the different operative considerations in this vulnerable patient population.

RECENT FINDINGS

Preoperative optimization with mechanical circulatory support devices, especially in the setting of hemodynamic instability, can reduce perioperative morbidity and mortality. The advantage of advanced techniques, such as off-pump CABG and multiple arterial grafting remains unclear. Concomitant procedures, such as ablation for atrial fibrillation remain important considerations that should be tailored to the individual patients risk profile.

SUMMARY

Despite improvements in perioperative care of patients undergoing CABG, patients with a reduced ejection fraction remain at elevated risk of major morbidity and mortality. Preoperative optimization and careful selection of intraoperative techniques can lead to improved outcomes.

Clinical and hemodynamic outcomes of the Dor procedure in adults with ischemic cardiomyopathy

Ischemic cardiomyopathy continues to be a major contributor to congestive heart failure, which places a significant burden on our healthcare system. Improving medications and different coronary revascularization strategies are the mainstays in the management of ischemic cardiomyopathy. Although medications and mechanical circulatory support are playing an ever-increasing role, cardiac transplantation remains the gold standard for treating advanced heart failure. Given the small number of available and suitable donor hearts, transplantation is limited for the majority of patients. Surgical ventricular restoration has repeatedly been suggested as a viable alternative in managing heart failure in select patients, as it is believed that surgically returning the ventricle to its original dimensions is possible and associated with favorable outcomes. The purpose of this manuscript is to comprehensively review the current literature on various surgical strategies for ventricular restoration. We also contextualize the published data with respect to ventricular function, volume, structure, arrhythmias, mitral regurgitation, and clinical outcomes.

Interventionelle LV-Modulation in der Herzinsuffizienztherapie

Trotz großer Fortschritte in der Akutversorgung des Myokardinfarkts entwickelt ein relevanter Teil der Patienten eine chronische Herzinsuffizienz. Der durch den Infarkt verursachte myokardiale Schaden kann pathologische Umbauprozesse im Herzen wie linksventrikuläre Dilatation, Veränderung der ventrikulären Geometrie und die Ausbildung von Narbengewebe initiieren, die in einer progredienten Herzinsuffizienzsymptomatik und -letalität resultieren können. Verschiedene chirurgische und interventionelle Therapieverfahren zur Modulation der pathologischen Umbauprozesse im Herzmuskel wurden entwickelt. Sie erwiesen sich als sicher und effektiv in der Reduktion linksventrikulärer Volumina, einer Steigerung der linksventrikulären Ejektionsfraktion sowie im Hinblick auf klinische Parameter. Randomisierte prospektive Studien, die einen Überlebensvorteil durch interventionelle oder chirurgische linksventrikuläre Modulation nachweisen, liegen zurzeit nicht vor.

Results of surgical ventricular reconstruction in a specialized center and in comparison to the STICH trial: Rationale and study protocol for a patient-level pooled analysis

INTRODUCTION

Post-infarction left ventricular remodeling is associated with increased mortality in patients with ischemic heart disease. Surgical ventricular reconstruction (SVR) in addition to coronary artery bypass grafting (CABG) has been proposed to reduce left ventricular volume and improve clinical outcomes. The Surgical Treatment for Ischemic Heart Failure (STICH) trial found that the addition of SVR to CABG did not reduce the rates of death or rehospitalization in the 5 years after surgery compared to CABG alone. Like all randomized trials, STICH has limitations and it has been hypothesized that it may have underestimated the treatment effect of SVR. The aim of this study is to evaluate the results of SVR in one of the largest contemporary single-center series and to compare the results with those of the STICH trial using individual patient's data.

METHODS AND ANALYSIS

Individual data of patients who underwent SVR with or without CABG will be obtained from San Donato University Hospital in Milan. Using multivariable Cox regression analysis, significant prognostic indicators in this cohort will be identified. We will then compare the San Donato cohort to individual patient's data from the SVR arm of Hypothesis 2 of the STICH trial and from both arms of the STICH Extended Study (STICHES). To reduce confounders, propensity score adjustment will be used for this comparison. The primary endpoint will be all-cause mortality. Data will be merged and analyzed independently at Weill Cornell Medicine in New York.

Percutaneous Ventricular Restoration with a Partitioning Device for Ischemic Heart Failure Treatment

PURPOSE OF THE REVIEW

Percutaneous ventricular restoration with a ventricular partitioning device (VPD) is a novel minimally invasive procedure designed to restore the left ventricular (LV) shape by isolating the infarcted and aneurysmal LV apex from remainder of the cavity in heart failure patients with severely reduced LV ejection fraction. In this review, we perform an in-depth analysis of the design and purpose of the VPD and review the available clinical data, with special attention to hemodynamics, outcomes, and complications.

RECENT FINDINGS

PARACHUTE trials have shown >90% procedural success rate of VPD implant. Heart failure patients had improvement in hemodynamics (reduction in LV volumes and increase in LV ejection fraction) and functional status (6-min walking distance and quality of life scores) after the VPD implant. Optimal implant position is necessary to obtain a good clinical outcome. Percutaneous VPD implantation has thus far been a safe intervention capable of improving surrogate markers of heart failure but there is still a need to develop more durable devices with a long-lasting hemodynamics effect.

Surgical options for the management of ischemic cardiomyopathy

OPINION STATEMENT

Novel surgical alternatives and the refinement of conventional surgical therapies for the treatment of ischemic cardiomyopathy are in constant evolution. Current approaches involve the determined application of the appropriateness criteria for CABG surgery, the extension of mitral valve repair to complex patients with ischemic cardiomyopathy, finding appropriate patients who might benefit from surgical ventricular reconstruction, and surgical attempts to regenerate lost or damaged myocardium with transplanted stem cells. The refinement of surgical techniques and the medical optimization of candidates for surgery remain a cornerstone of management for patients with complex heart disease like ischemic cardiomyopathy. The horizon is bright for patients suffering from this condition and concentrated research efforts by groups such as the NHLBI-sponsored Cardiothoracic Surgery Network will have a major impact on the future of patients with heart disease.

Coronary artery bypass grafting in patients with left ventricular dysfunction: predictors of long-term survival and impact of surgical strategies

BACKGROUND

In the surgical management of ischemic cardiomyopathy, factors associated with long-term prognosis after coronary artery bypass grafting (CABG) in patients with severe left ventricular (LV) dysfunction are poorly understood. This study aimed to determine predictors of clinical outcomes in patients with severe LV dysfunction undergoing CABG.

METHODS

Out of 6084 patients who underwent CABG between 1997 and 2011, 476 patients (aged 62.6 ± 9.3 years, 100 females) were identified as having severe LV dysfunction (ejection fraction ≤ 35%), preoperatively. All-cause mortality and adverse cardiac events (myocardial infarction, repeat revascularization, stroke and hospitalization due to cardiovascular causes) were evaluated during a median follow-up period of 55.2 months (inter-quartile range: 26.4-94.8 months).

RESULTS

During the follow-up, 187 patients (39.3%) died and 126 cardiac events occurred in 104 patients (21.8%). Five-year survival and event-free survival rates were 72.1 ± 2.2% and 61.3 ± 2.4%, respectively. On Cox-regression analysis, old age (P < 0.001), recent MI (P < 0.001), history of coronary stenting (P = 0.023), decreased glomerular filtration rate (P < 0.001), and presence of mitral regurgitation (≥moderate) (P = 0.012) or LV wall thinning (P = 0.007) emerged as significant and independent predictors of death. After adjustment for important covariates affecting outcomes, none of the pump strategy (off-pump vs. on-pump), concomitant mitral surgery or surgical ventricular reconstruction (SVR) affected survival or event-free survival (P = 0.082 to >0.99).

CONCLUSIONS

Long-term survival following CABG in patients with severe LV dysfunction was affected by age, renal function, recent MI, prior coronary stenting, and presence of mitral regurgitation or LV wall thinning. Neither concomitant mitral surgery nor SVR, however, had significant influence on clinical outcomes.

Analysis of patient-specific surgical ventricular restoration: importance of an ellipsoidal left ventricular geometry for diastolic and systolic function

Surgical ventricular restoration (SVR) is a procedure designed to treat heart failure by surgically excluding infarcted tissues from the dilated failing left ventricle. To elucidate and predict the effects of geometrical changes from SVR on cardiac function, we created patient-specific mathematical (finite-element) left ventricular models before and after surgery using untagged magnetic resonance images. Our results predict that the postsurgical improvement in systolic function was compromised by a decrease in diastolic distensibility in patients. These two conflicting effects typically manifested as a more depressed Starling relationship (stroke volume vs. end-diastolic pressure) after surgery. By simulating a restoration of the left ventricle back to its measured baseline sphericity, we show that both diastolic and systolic function improved. This result confirms that the increase in left ventricular sphericity commonly observed after SVR (endoventricular circular patch plasty) has a negative impact and contributes partly to the depressed Starling relationship. On the other hand, peak myofiber stress was reduced substantially (by 50%) after SVR, and the resultant left ventricular myofiber stress distribution became more uniform. This significant reduction in myofiber stress after SVR may help reduce adverse remodeling of the left ventricle. These results are consistent with the speculation proposed in the Surgical Treatment for Ischemic Heart Failure trial (20) for the neutral outcome, that "the lack of benefit seen with surgical ventricular reconstruction is that benefits anticipated from surgical reduction of left ventricular volume (reduced wall stress and improvement in systolic function) are counter-balanced by a reduction in diastolic distensibility."

Medical management is the way to go for ventricular reconstruction post STICH?

Ventricular remodeling is a complex process mediated by pathogenic factors all of which interact at the cellular, ventricular and systemic levels to cause progressive left ventricular dilation and subsequently a heart failure syndrome. Remodeling is a well-characterized response to insult or injury and is initiated early on by neurohormonal activation. Neurohormonal antagonists have formed the foundation of therapy to alter the progression of remodeling and concomitantly improve outcomes. Surgical ventricular reconstruction was designed as a surgical means to reduce the ventricular radius and in principal decrease ventricular wall stress as defined by the Law of Laplace. Despite optimistic initial results from case series, the Surgical Treatment for Ischemic Heart Failure Trial (STICH) trial, a large randomized trial of ventricular reconstruction in addition to coronary artery bypass surgery (CABG) therapy for management of patients with heart failure with a reduced ejection fraction showed no clinical benefit. We will summarize the evidence that demonstrates the foundational role of neurohormonal blockade in improving outcomes in patients with heart failure with a reduced ejection and the evidence behind its role in "medical ventricular reconstruction".

Algisyl-LVR™ with coronary artery bypass grafting reduces left ventricular wall stress and improves function in the failing human heart

BACKGROUND

Left ventricular (LV) wall stress reduction is a cornerstone in treating heart failure. Large animal models and computer simulations indicate that adding non-contractile material to the damaged LV wall can potentially reduce myofiber stress. We sought to quantify the effects of a novel implantable hydrogel (Algisyl-LVR™) treatment in combination with coronary artery bypass grafting (i.e. Algisyl-LVR™+CABG) on both LV function and wall stress in heart failure patients.

METHODS AND RESULTS

Magnetic resonance images obtained before treatment (n=3), and at 3 months (n=3) and 6 months (n=2) afterwards were used to reconstruct the LV geometry. Cardiac function was quantified using end-diastolic volume (EDV), end-systolic volume (ESV), regional wall thickness, sphericity index and regional myofiber stress computed using validated mathematical modeling. The LV became more ellipsoidal after treatment, and both EDV and ESV decreased substantially 3 months after treatment in all patients; EDV decreased from 264 ± 91 ml to 146 ± 86 ml and ESV decreased from 184 ± 85 ml to 86 ± 76 ml. Ejection fraction increased from 32 ± 8% to 47 ± 18% during that period. Volumetric-averaged wall thickness increased in all patients, from 1.06 ± 0.21 cm (baseline) to 1.3 ± 0.26 cm (3 months). These changes were accompanied by about a 35% decrease in myofiber stress at end-of-diastole and at end-of-systole. Post-treatment myofiber stress became more uniform in the LV.

CONCLUSIONS

These results support the novel concept that Algisyl-LVR™+CABG treatment leads to decreased myofiber stress, restored LV geometry and improved function.

Insights from the STICH trial: change in left ventricular size after coronary artery bypass grafting with and without surgical ventricular reconstruction

OBJECTIVE

The present analysis of the Surgical Treatment for Ischemic Heart Failure randomized trial data examined the left ventricular volumes at baseline and 4 months after surgery to determine whether any magnitude of postoperative reduction in end-systolic volume affected survival after coronary artery bypass grafting alone compared with bypass grafting plus surgical ventricular reconstruction.

METHODS

Of the 1000 patients randomized, 555 underwent an operation and had a paired imaging assessment with the same modality at baseline and 4 months postoperatively. Of the remaining 455 patients, 424 either died before the 4-month study or did not have paired imaging tests and were excluded, and 21 were not considered because they had died before surgery or did not receive surgery.

RESULTS

Surgical ventricular reconstruction resulted in improved survival compared with coronary artery bypass grafting alone when the postoperative end-systolic volume index was 70 mL/m(2) or less. However, the opposite was true for patients achieving a postoperative volume index greater than 70 mL/m(2). A reduction in the end-systolic volume index of 30% or more compared with baseline was an infrequent event in both treatment groups and did not produce a statistically significant survival benefit with ventricular reconstruction.

CONCLUSIONS

In patients undergoing coronary artery bypass grafting plus surgical ventricular reconstruction, a survival benefit was realized compared with bypass alone, with the achievement of a postoperative end-systolic volume index of 70 mL/m(2) or less. Extensive ventricular remodeling at baseline might limit the ability of ventricular reconstruction to achieve a sufficient reduction in volume and clinical benefit.

Myoblast sheet can prevent the impairment of cardiac diastolic function and late remodeling after left ventricular restoration in ischemic cardiomyopathy

BACKGROUND

Impairment of diastolic function and late remodeling are concerns after left ventricular restoration (LVR) for ischemic cardiomyopathy. This study aims to evaluate the effects of combined surgery of myoblast sheets (MS) implantation and LVR.

METHODS

Rat myocardial infarction model was established 2 weeks after left anterior descending artery ligation. They were divided into three groups: sham operation (n=15; group sham), LVR by plicating the infracted area (n=15; group LVR), and MS implantation with LVR (n=15; group LVR+MS).

RESULTS

Serial echocardiographic study revealed significant LV redilatation and decrease of ejection fraction 4 weeks after LVR in group LVR. MS implantation combined with LVR prevented those later deteriorations of LV function in group LVR+MS. Four weeks after the operation, a hemodynamic assessment using a pressure-volume loop showed significantly preserved diastolic function in group LVR+MS; end-diastolic pressure (LVR vs. LVR+MS: 9.0±6.6 mm Hg vs. 2.0±1.0 mm Hg, P<0.05), end-diastolic pressure-volume relationship (LVR vs. LVR+MS 42±23 vs. 13±6, P<0.05). Histological examination revealed cellular hypertrophy and LV fibrosis were significantly less and vascular density was significantly higher in group LVR+MS than in the other two groups. Reverse transcription polymerase chain reaction demonstrated significantly suppressed expression of transforming growth factor-beta, Smad2, and reversion-inducing cysteine-rich protein with Kazal motifs in group LVR+MS.

CONCLUSIONS

MS implantation decreased cardiac fibrosis by suppressing the profibrotic gene expression and attenuated the impairment of diastolic function and the late remodeling after LVR. It is suggesting that MS implantation may improve long-term outcome of LVR for ischemic heart disease.

The impact of volume reduction on early and long-term outcomes in surgical ventricular restoration for severe heart failure

BACKGROUND

Recent published results suggest no additive benefit to surgical ventricular restoration (SVR) when combined with coronary artery bypass grafting. However, there may still be a subgroup of patients with severe heart failure who can benefit from this procedure. We reviewed our institutional experience with SVR to determine early and late outcomes based on volume reduction.

METHODS

We retrospectively reviewed our SVR patients (January 2002 to April 2008) with follow-up to March 2009. Baseline comorbidities, operative data, and postoperative outcomes were assessed by chart review, phone calls, and mailings. Survival was modeled using the Kaplan-Meier method. Cardiac magnetic resonance imaging, myocardial perfusion scans, and echocardiography assessed cardiac function, candidacy for SVR, and volume reduction.

RESULTS

We reviewed 87 consecutive SVR patients (69 men). Mean age at operation was 61.1 years. Preoperatively, all patients had congestive heart failure, with 80 (92%) at New York Heart Association III/IV. All patients underwent preoperative viability studies. Three-vessel occlusion exceeding 50% was present in 69 (79%). After SVR, ejection fraction improved from 0.236 to 0.332 (p<0.001). Preoperative and postoperative magnetic resonance imaging in 26 patients (30.0%) showed a 30.8% reduction in left ventricular end systolic volume index. At follow-up, 51 of 66 (77%) improved to New York Heart Association I/II. One intraoperative death occurred. Preoperative left ventricular end systolic volume index of 80 to 120 was associated with improved survival (73% at 3 years).

CONCLUSIONS

SVR is a surgical option for appropriately selected patients with severe congestive heart failure. In these high-risk patients, SVR successfully increased ejection fraction and decreased symptoms. A left ventricular end systolic volume index of 80 to 120 may be the ideal range for SVR procedures.

Surgical treatment for heart failure: left ventricular restoration for cardiomyopathy

Congestive heart failure has become a major problem and the only surgical treatment for end-stage heart failure caused by dilated cardiomyopathy (DCM) had been heart transplantation. However, because of the shortage of donors, several procedures for non-transplant surgery have been developed. Published literature on left ventricular (LV) restoration was searched to review the new surgical procedures for treating patients with ischemic or non-ischemic DCM. LV restoration was initiated in the 1980s for repairing LV aneurysm. In the 1990s several surgical procedures were introduced for treating DCM, and the new evolving surgical treatment plays an important role in the management of DCM in the 21st century.

Coronary bypass surgery with or without surgical ventricular reconstruction

BACKGROUND

Surgical ventricular reconstruction is a specific procedure designed to reduce left ventricular volume in patients with heart failure caused by coronary artery disease. We conducted a trial to address the question of whether surgical ventricular reconstruction added to coronary-artery bypass grafting (CABG) would decrease the rate of death or hospitalization for cardiac causes, as compared with CABG alone.

METHODS

Between September 2002 and January 2006, a total of 1000 patients with an ejection fraction of 35% or less, coronary artery disease that was amenable to CABG, and dominant anterior left ventricular dysfunction that was amenable to surgical ventricular reconstruction were randomly assigned to undergo either CABG alone (499 patients) or CABG with surgical ventricular reconstruction (501 patients). The primary outcome was a composite of death from any cause and hospitalization for cardiac causes. The median follow-up was 48 months.

RESULTS

Surgical ventricular reconstruction reduced the end-systolic volume index by 19%, as compared with a reduction of 6% with CABG alone. Cardiac symptoms and exercise tolerance improved from baseline to a similar degree in the two study groups. However, no significant difference was observed in the primary outcome, which occurred in 292 patients (59%) who were assigned to undergo CABG alone and in 289 patients (58%) who were assigned to undergo CABG with surgical ventricular reconstruction (hazard ratio for the combined approach, 0.99; 95% confidence interval, 0.84 to 1.17; P=0.90).

CONCLUSIONS

Adding surgical ventricular reconstruction to CABG reduced the left ventricular volume, as compared with CABG alone. However, this anatomical change was not associated with a greater improvement in symptoms or exercise tolerance or with a reduction in the rate of death or hospitalization for cardiac causes. (ClinicalTrials.gov number, NCT00023595.)