Coronary bypass surgery with or without surgical ventricular reconstruction

Core lab analysis of baseline echocardiographic studies in the STICH trial and recommendation for use of echocardiography in future clinical trials

BACKGROUND

The Surgical Treatment for Ischemic Heart Failure (STICH) randomized trial was designed to identify an optimal management strategy for patients with ischemic cardiomyopathy. Baseline echocardiographic examinations were required for all patients. The primary aim of this report is to describe the baseline STICH Echocardiography Core Laboratory data. The secondary aim is to provide recommendations regarding how echocardiography should be used in clinical practice and research on the basis of the experience gained from echocardiography in STICH.

METHODS

Between September 2002 and January 2006, 2,136 patients with ejection fractions (EFs) ≤ 35% and coronary artery disease amenable to coronary artery bypass grafting were enrolled. Echocardiography was acquired by 122 clinical enrolling sites, and measurements were performed by the Echocardiography Core Laboratory after a certification process for all clinical sites.

RESULTS

Echocardiography was available for analysis in 2,006 patients (93.9%); 1,734 (86.4%) were men, and the mean age was 60.9 ± 9.5 years. The mean left ventricular end-systolic volume index, measureable in 72.8%, was 84.0 ± 30.9 mL/m(2), and the mean EF was 28.9 ± 8.3%, with 18.5% of patients having EFs > 35%. Single-plane measurements of left ventricular and left atrial volumes were similar to their volumes by biplane measurement (r = 0.97 and r = 0.92, respectively). Mitral regurgitation severity by visual assessment was associated with a wide range of effective regurgitant orifice area, while effective regurgitant orifice area ≥ 0.2 cm(2) indicated at least moderate mitral regurgitation by visual assessment. Deceleration time of mitral inflow velocity had a weak correlation with EF (r = 0.25) but was inversely related to estimated pulmonary artery systolic pressure (r = -0.49).

CONCLUSIONS

In STICH patients with ischemic cardiomyopathy, Echocardiography Core Laboratory analysis of baseline echocardiographic findings demonstrated a wide spectrum of left ventricular shape, function, and hemodynamics, as well as the feasibility and limitations of obtaining essential echocardiographic measurements. It is critical that the use of echocardiographic parameters in clinical practice and research balance the strengths and weaknesses of the technique.

The renewed concept of the Batista operation for ischemic cardiomyopathy: maximum ventricular reduction

OBJECTIVES

The reconstruction of the left ventricle (LV) is effective in the treatment of ischemic cardiomyopathy with large akinetic or dyskinetic areas. However, late survival outcomes are related to the remnant left ventricular cavity size, thus eliminating intracavitary patch placement provides additional LV reduction. The aim of this study was to analyze the results with left ventricular reconstruction surgery using the concept of maximum ventricular reduction, with systematic patch abolition.

METHODS

Seventy-six consecutive patients with ischemic heart disease (age 30-78 years, mean 57.6 ± 10.1), evolving in functional class III and IV underwent surgical ventricular reconstruction with no use of intracavitary patches or Teflon strips for closing the left ventriculotomy.

RESULTS

The left ventricular end-systolic diameter decreased from 52.3 ± 5.4 in the preoperative period to 45.2 ± 6.9 mm in the postoperative period. LV ejection fraction increased from 34.2% ± 10.4% to 45.5% ± 9.4%. Associated CABG was performed in 75/76 patients with a mean of 2.4 grafts per patient. The 30-day mortality was 3/76 (3.9%). At an average follow up of 39 months, the majority of the patients (91.4%) remain in functional class I and II.

CONCLUSION

The concept of maximizing LV reduction with systematic patchless reconstruction is feasible, safe and effective, the early and late outcomes comparing favorably to previous series reported in the medical literature. Additionally, the concept meets the contemporary pathophysiologic basis of heart failure.

[Current topics in cardiology. Heart failure and heart transplantation]

The mission of the Heart Failure and Heart Transplantation Section of the Spanish Society of Cardiology is to study, promote interest in, and disseminate information about all aspects of myocardial dysfunction and heart transplantation. Heart failure is a highly prevalent disorder that consumes a substantial proportion of healthcare resources. Consequently, there is a very high level of interest in the condition and a wide range of preclinical and clinical research is being carried out, including research into new ways of looking at the disease that will increase our understanding. The aim of this article was to describe current developments concerning this disease and its treatment. Firstly, the latest publications on heart failure are summarized. Then, the most recent studies on advanced heart failure and ventricular assist devices are reviewed. Finally, the latest findings on heart transplantation are reported.

Reverse remodeling in heart failure--mechanisms and therapeutic opportunities

Heart failure (HF) involves changes in cardiac structure, myocardial composition, myocyte deformation, and multiple biochemical and molecular alterations that impact heart function and reserve capacity. Collectively, these changes have been referred to as 'cardiac remodeling'. Understanding the components of this process with the goal of stopping or reversing its progression has become a major objective. This concept is often termed 'reverse remodeling', and is successfully achieved by inhibitors of the renin-angiotensin-aldosterone system, β-blockers, and device therapies such as cardiac resynchronization or ventricular assist devices. Not every method of reverse remodeling has long-lasting clinical efficacy. However, thus far, every successful clinical treatment with long-term benefits on the morbidity and mortality of patients with HF reverses remodeling. Reverse remodeling is defined by lower chamber volumes (particularly end-systolic volume) and is often accompanied by improved β-adrenergic and heart-rate responsiveness. At the cellular level, reverse remodeling impacts on myocyte size, function, excitation-contraction coupling, bioenergetics, and a host of molecular pathways that regulate contraction, cell survival, mitochondrial function, oxidative stress, and other features. Here, we review the current evidence for reverse remodeling by existing therapies, and discuss novel approaches that are rapidly moving from preclinical to clinical trials.

Cardiac regeneration therapy: connections to cardiac physiology

Without heart transplantation, a large number of patients with failing hearts worldwide face poor outcomes. By means of cardiomyocyte regeneration, cardiac regeneration therapy is emerging with great promise as a means for restoring loss of cardiac function. However, the limited success of clinical trials using bone marrow-derived cells and myoblasts with heterogeneous constituents, transplanted at a wide range of cell doses, has led to disagreement on the efficacy of cell therapy. It is therefore essential to reevaluate the evidence for the efficacy of cell-based cardiac regeneration therapy, focusing on targets, materials, and methodologies. Meanwhile, the revolutionary innovation of cardiac regeneration therapy is sorely needed to help the millions of people who suffer heart failure from acquired loss of cardiomyocytes. Cardiac regeneration has been used only in limited species or as a developing process in the rodent heart; now, the possibility of cardiomyocyte turnover in the human heart is being revisited. In the pursuit of this concept, the use of cardiac stem/progenitor stem cells in the cardiac niche must be focused to usher in a second era of cardiac regeneration therapy for the severely injured heart. In addition, tissue engineering and cellular reprogramming will advance the next era of treatment that will enable current cell-based therapy to progress to "real" cardiac regeneration therapy. Although many barriers remain, the prevention of refractory heart failure through cardiac regeneration is now becoming a realistic possibility.

Short-term ventricular restraint attenuates post-infarction remodeling in rats

BACKGROUND/OBJECTIVES

Left ventricular restraint attenuates post-infarction remodeling, but may be associated with unfavorable long-term histological response. We hypothesized that beneficial effects can be obtained with short-term restraint during the early post-infarction period; for this purpose, we evaluated a biodegradable scaffold in the in vivo rat model and compared it with epicardial hydrogel application.

METHODS

A total of 230 Wistar rats (358 ± 7 g) were studied. Implantation was performed with and without prior myocardial infarction, induced by permanent coronary artery ligation. Diastolic filling was evaluated by left ventricular pressure recordings after scaffold implantation. Degradation rates and inflammatory/foreign body response were studied at 3, 7 and 15 days post-ligation. Remodeling indices were evaluated by echocardiography 15 days post-ligation.

RESULTS

No differences were found in diastolic pressure. Biodegradability was ~50% by 7 days and 100% by 15 days for both materials. Likewise, inflammatory/foreign body response peaked at 3 days post-implant, with subsequent remission, but fibroblastic reaction was more pronounced after scaffold than after hydrogel implantation. Post-ligation, ejection fraction was higher in the scaffold (40.0 ± 1.5%) or hydrogel groups (37.0 ± 1.3%), compared to controls (30.6 ± 1.9%). Wall tension index was lower with either biomaterial, but left ventricular end-diastolic diameter was shorter (p=0.044) and sphericity was attenuated (p=0.029) after scaffold, compared to hydrogel implantation.

CONCLUSIONS

Both biomaterials showed a favorable histological response and attenuated remodeling, but epicardial restraint produced better results compared to hydrogel alone. The latter approach merits further investigation due to the ease of implantation.

Surgical ventricular restoration improves the left ventricle basal wall function using quantitative gated SPECT

OBJECTIVE

It is not clear whether surgical ventricular restoration (SVR) or procedures approaching mitral complex for controlling functional mitral regurgitation (MR) affect the regional left ventricular wall function. The purpose of the present study was to evaluate the regional LV function after SVR using overlapping left ventriculoplasty (OLVP) using quantitative gated myocardial perfusion SPECT (QGS).

PATIENTS AND METHOD

Forty-one heart failure patients, including those with ischemic cardiomyopathy (ICM) (n = 25) and non-ICM (NICM) (n = 16), underwent SVR and/or papillary muscle approximation (PMA). The rest myocardial perfusion SPECT were performed before and early after operation (mean 25.8 ± 10.6 days). These patients were divided into 4 groups based on the surgical procedures (SVR and/or PMA) and etiology of patients (ICM or NICM) as follows: SVR (with or without PMA) of ICM, SVR of NICM, PMA of ICM and PMA of NICM groups. The regional wall thickening was compared before and after the operation between the four groups.

RESULTS

NYHA functional classes were improved after the operation in all four groups. MR grade was also improved in three groups other than SVR of the ICM group. The left ventricular basal wall thickening was improved postoperatively in following three groups (SVR of ICM: 12.7 ± 3.8% to 16.5 ± 4.6% p <0.05, PMA of ICM: 11.1 ± 4.3% to 14.9 ± 4.8% p <0.05, SVR of NICM: 5.8 ± 6.6% to 12.3 ± 6.4% p <0.05), whereas PMA of the NICM group did not show an improvement. Wall thickening in the middle and distal levels was not improved in all groups.

CONCLUSION

OLVP improved NYHA functional classes, and also improved the regional wall function at the basal level of the left ventricle. In contrast, lone PMA did not improve or impair the regional wall function at any of the levels.

Coronary artery disease: how should the STICH trial results affect clinical practice?

The STICH trial showed that CABG surgery does not necessarily improve cardiovascular outcomes in patients with coronary artery disease and left ventricular dysfunction who are receiving optimal medical therapy. However, surgical revascularization should still be considered if the coronary artery disease is severe and viable myocardium can be identified.

Joint ESC/EACTS guidelines on myocardial revascularization

The Guidelines for Myocardial Revascularization of the European Society of Cardiology (ESC) and European Association for Cardio-Thoracic Surgery (EACTS) are the very first reported consensus document, by a writing committee balanced between non-interventional and interventional cardiologists as well as cardiac surgeons, on this specific issue. Given the strong impact that ischaemic heart disease has on the survival and quality of life of the individual as well as the economic implications for society, the importance of the ESC/EACTS guidelines is obvious.

Surgical approach to end-stage heart failure

PURPOSE OF REVIEW

End-stage heart failure is a challenging disease with growing incidence. With decreasing heart transplant rates worldwide organ preserving therapies become, again, of interest. The purpose of the present review is to examine the potential challenges of surgical therapies in patients with end-stage heart failure.

RECENT FINDINGS

The gold-standard for end-stage heart failure is and will be cardiac transplantation. However, due to organ shortage this therapy is limited to a few patients. Therefore implantation of ventricular assist devices (VADs) or long-term minimal-invasive partial support devices will increase. Improvements in device design with smaller devices, easier implantation techniques, and modified anticoagulation outcome and long-term success will likely improve. In addition, good quality of life as destination therapy is almost available. Organ conservation surgery (coronary artery bypass grafting and surgical ventricular restoration or surgical repair of mitral valve regurgitation) in end-stage heart failure patients could not prove the expected results. Transcatheter or minimal-invasive approaches of these therapies might become routine in the near future.

SUMMARY

Due to the overwhelming outcome rates, cardiac transplantation is the most established surgical therapy for end-stage heart failure. VAD therapy is increasing and minimized VADs might further open the market for destination therapy/permanent support.

Radionuclide Imaging of Viable Myocardium: Is it Underutilized?

Coronary artery disease is the major cause of heart failure in North America. Viability assessment is important as it aims to identify patients who stand to benefit from coronary revascularization. Radionuclide modalities currently used in the assessment of viability include (201)Tl SPECT, (99m)Tc-based SPECT imaging, and (18)F-fluorodexoyglucose ((18)F-FDG)-PET imaging. Different advances have been made in the last year to improve the sensitivity and specificity of these modalities. In addition, the optimum amount of viable (yet dysfunctional) myocardium is important to identify in patients, as a risk-benefit ratio must be considered. Patients with predominantly viable/hibernating myocardium can benefit from revascularization from a mortality and morbidity standpoint. However, in patients with minimal viability (predominantly scarred myocardium), revascularization risk may certainly be too high to justify revascularization without expected benefit. Understanding different radionuclide modalities and new developments in the assessment of viability in ischemic heart failure patients is the focus of this discussion.

Narrative review: the management of acute decompensated heart failure

Acute decompensated heart failure (ADHF) is the most common reason for hospitalization in Western nations. The prognosis of patients admitted to hospital with ADHF is poor, with up to 64% being readmitted within the first 90 days after discharge and with a 1-year mortality approximating 20%. Epidemiological studies suggest that the majority of patients hospitalized with ADHF receive treatment that is inadequate and which is not based on scientific evidence. Furthermore, emerging data suggest that the "conventional" therapeutic interventions for ADHF including morphine, high-dose diuretics, and inotropic agents may be harmful. The goal of this review is to provide evidence-based recommendations for the diagnosis and management of ADHF.

Coronary-artery bypass surgery in patients with left ventricular dysfunction

BACKGROUND

The role of coronary-artery bypass grafting (CABG) in the treatment of patients with coronary artery disease and heart failure has not been clearly established.

METHODS

Between July 2002 and May 2007, a total of 1212 patients with an ejection fraction of 35% or less and coronary artery disease amenable to CABG were randomly assigned to medical therapy alone (602 patients) or medical therapy plus CABG (610 patients). The primary outcome was the rate of death from any cause. Major secondary outcomes included the rates of death from cardiovascular causes and of death from any cause or hospitalization for cardiovascular causes.

RESULTS

The primary outcome occurred in 244 patients (41%) in the medical-therapy group and 218 (36%) in the CABG group (hazard ratio with CABG, 0.86; 95% confidence interval [CI], 0.72 to 1.04; P=0.12). A total of 201 patients (33%) in the medical-therapy group and 168 (28%) in the CABG group died from an adjudicated cardiovascular cause (hazard ratio with CABG, 0.81; 95% CI, 0.66 to 1.00; P=0.05). Death from any cause or hospitalization for cardiovascular causes occurred in 411 patients (68%) in the medical-therapy group and 351 (58%) in the CABG group (hazard ratio with CABG, 0.74; 95% CI, 0.64 to 0.85; P<0.001). By the end of the follow-up period (median, 56 months), 100 patients in the medical-therapy group (17%) underwent CABG, and 555 patients in the CABG group (91%) underwent CABG.

CONCLUSIONS

In this randomized trial, there was no significant difference between medical therapy alone and medical therapy plus CABG with respect to the primary end point of death from any cause. Patients assigned to CABG, as compared with those assigned to medical therapy alone, had lower rates of death from cardiovascular causes and of death from any cause or hospitalization for cardiovascular causes. (Funded by the National Heart, Lung, and Blood Institute and Abbott Laboratories; STICH ClinicalTrials.gov number, NCT00023595.).

The causes, consequences, and treatment of left or right heart failure

Chronic heart failure (HF) is a cardiovascular disease of cardinal importance because of several factors: a) an increasing occurrence due to the aging of the population, primary and secondary prevention of cardiovascular events, and modern advances in therapy, b) a bad prognosis: around 65% of patients are dead within 5 years of diagnosis, c) a high economic cost: HF accounts for 1% to 2% of total health care expenditure. This review focuses on the main causes, consequences in terms of morbidity, mortality and costs and treatment of HF.

Inefficacy interim monitoring procedures in randomized clinical trials: the need to report

If definitive evidence concerning treatment effectiveness becomes available from an ongoing randomized clinical trial, then the trial could be stopped early, with the public release of results benefiting current and future patients. However, stopping an ongoing trial based on accruing outcome data requires methodological rigor to preserve validity of the trial conclusions. This has led to the use of formal interim monitoring procedures, which include inefficacy monitoring that will stop a trial early when the experimental treatment appears not to be working. For participants, inefficacy monitoring is especially important as it ensures that they are not being treated worse than if they had not enrolled on the trial. We discuss the importance of reporting with trial results the formal interim inefficacy monitoring guidelines that were utilized, and, if none were used, the reasons for their absence. A survey of two leading medical journals suggests that this is not current practice.

Low-risk profile for malignant ventricular arrhythmias and sudden cardiac death after surgical ventricular reconstruction

BACKGROUND

Although it has been recently demonstrated that there was no significant difference in total survival and clinical outcomes between patients who underwent coronary artery bypass grafting (CABG) with or without surgical ventricular reconstruction (SVR), the question of whether or not SVR decreases the arrhythmic risk profile in this population has not been clarified yet.

OBJECTIVE

To determine the real incidence of sudden cardiac death (SCD) and sustained ventricular tachycardia/ventricular fibrillation (sustained VT/VF) in patients following CABG added to SVR and to define their clinical and echocardiographic parameters predicting in-hospital and long-term arrhythmic events (SCD + sustained VT/VF).

METHODS

Pre- and postoperative clinical and echocardiographic values as well as postoperative electrocardiogram Holter data of 65 patients (21 female, 63 ± 11 years) who underwent SVR + CABG were retrospectively evaluated.

RESULTS

 Mean follow-up was 1,105 ± 940 days. At 3 years, the SCD-free rate was 98% and the rate free from arrhythmic events was 88%. Multivariate logistic analysis identified a preoperative left ventricular end-systolic volume index (LVESVI) > 102 mL/m(2) (odds ratio [OR] 1.4, confidence interval [CI] 1.073-1.864, P = 0.02; sensitivity 100%, specificity 94%) and a postoperative pulmonary artery systolic pressure (PASP) > 27 mmHg (OR 2.3, CI 1.887-4.487, P = 0.01; sensitivity 100%, specificity 71%) as independent predictors of arrhythmic events.

CONCLUSIONS

Our and previous studies report a low incidence of arrhythmic events in patients following SVR added to CABG, considering the high-risk profile of the study population. A preoperative LVESVI > 102 mL/m(2) and a postoperative PASP > 27 mmHg had a good sensitivity and specificity in predicting arrhythmic events.

Impact of surgical ventricular restoration on ventricular shape, wall stress, and function in heart failure patients

Surgical ventricular restoration (SVR) was designed to treat patients with aneurysms or large akinetic walls and dilated ventricles. Yet, crucial aspects essential to the efficacy of this procedure like optimal shape and size of the left ventricle (LV) are still debatable. The objective of this study is to quantify the efficacy of SVR based on LV regional shape in terms of curvedness, wall stress, and ventricular systolic function. A total of 40 patients underwent magnetic resonance imaging (MRI) before and after SVR. Both short-axis and long-axis MRI were used to reconstruct end-diastolic and end-systolic three-dimensional LV geometry. The regional shape in terms of surface curvedness, wall thickness, and wall stress indexes were determined for the entire LV. The infarct, border, and remote zones were defined in terms of end-diastolic wall thickness. The LV global systolic function in terms of global ejection fraction, the ratio between stroke work (SW) and end-diastolic volume (SW/EDV), the maximal rate of change of pressure-normalized stress (dσ*/dt(max)), and the regional function in terms of surface area change were examined. The LV end-diastolic and end-systolic volumes were significantly reduced, and global systolic function was improved in ejection fraction, SW/EDV, and dσ*/dt(max). In addition, the end-diastolic and end-systolic stresses in all zones were reduced. Although there was a slight increase in regional curvedness and surface area change in each zone, the change was not significant. Also, while SVR reduced LV wall stress with increased global LV systolic function, regional LV shape and function did not significantly improve.

Three-dimensional echocardiography for the preoperative assessment of patients with left ventricular aneurysm

BACKGROUND

Surgical ventricular reconstruction has been proposed as a treatment option in heart failure patients with left ventricular (LV) aneurysm. The feasibility of this procedure has some limitations, and extensive preoperative evaluation is necessary to give the correct indication. For this purpose, magnetic resonance imaging (MRI) is currently considered the gold standard, providing accurate quantification of LV shape, size, and global and regional function together with the assessment of myocardial scar and mitral regurgitation severity. The aim of this study was to evaluate the accuracy of real-time three-dimensional echocardiography (RT3DE) as a potential alternative to MRI for this evaluation.

METHODS

A total of 52 patients with ischemic cardiomyopathy and LV aneurysm underwent a comprehensive analysis with two-dimensional echocardiography, RT3DE, and MRI.

RESULTS

Excellent correlation (r=0.97, p<0.001) and agreement were found between RT3DE and MRI for quantification of LV volumes, ejection fraction, and sphericity index; in a segment-to-segment comparison, RT3DE was shown to be accurate also for the analysis of wall motion abnormalities (k=0.62) and LV regional thickness (k=0.56) as a marker of myocardial scar. In contrast, two-dimensional echocardiography significantly underestimated these variables. Furthermore, mitral regurgitant volume assessed by RT3DE showed excellent correlation (r=0.93) with regurgitant volume measured by MRI, without significant bias (=-0.7 mL/beat).

CONCLUSIONS

In the management of heart failure patients with LV aneurysm, RT3DE provides an accurate and comprehensive assessment, including quantification of LV size, shape, global systolic function, regional wall motion, and myocardial scar together with precise evaluation of the severity of mitral regurgitation.

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.