Early and Mid-Term Outcomes of Patients Undergoing Coronary Artery Bypass Grafting in Ischemic Cardiomyopathy

Selecting the appropriate patients for coronary artery bypass grafting in ischemic cardiomyopathy-importance of myocardial viability

Patients who undergo coronary artery bypass graft (CABG) surgery in ischemic cardiomyopathy have a survival advantage over medical therapy at 10 years. The survival advantage of CABG over medical therapy is due to its ability to reduce future myocardial infarction, and by conferring electrical stability. The presence of myocardial viability does not provide a differential survival advantage for CABG over medical therapy. Presence of angina and inducible ischemia are also less predictive of outcome. Moreover, CABG is associated with significant early mortality. Hence, careful patient selection is more important for reducing the early mortality and improving the long-term outcome than relying on results of myocardial viability. Younger patients with good exercise tolerance benefit the most, while patients who are frail and patients with renal dysfunction and dysfunctional right ventricle seem to have very high operative mortality. Elderly patients, because of poor life expectancy, do not benefit from CABG, but the age cutoff is not clear. Patients also need to have revascularizable targets, but this decision is often based on experience of the surgical team and heart team discussion. These recommendations are irrespective of the myocardial viability tests. Optimal medical treatment remains the cornerstone for management of ischemic cardiomyopathy.

Ischemic cardiomyopathy: epidemiology, pathophysiology, outcomes, and therapeutic options

Ischemic cardiomyopathy (ICM) is the most prevalent cause of heart failure (HF) in developed countries, with significant morbidity and mortality, despite constant improvements in the management of coronary artery disease. Current literature on this topic remains fragmented. Therefore, this review aimed to summarize the most recent data on ICM, focusing on its definition, epidemiology, outcomes, and therapeutic options. The most widely accepted definition is represented by a left ventricular dysfunction in the presence of significant coronary artery disease. The prevalence of ICM is largely influenced by age and sex, with older individuals and males being more affected. Its pathophysiology is characterized by plaque buildup, thrombus formation, hypoperfusion, ischemic cell death, and left ventricular remodeling. Despite improvements in therapy, ICM still represents a public health burden, with a 1-year mortality rate of 16% and a 5-year mortality rate of approximately 40% in the USA and Europe. Therefore, optimization of cardiovascular function, prevention of progressive remodeling, reduction of HF symptoms, and improved survival are the main goals of treatment. Therapeutic options for ICM include lifestyle changes, optimal medical therapy, revascularization, device therapy, mechanical circulatory support, and cardiac transplantation. Personalized management strategies and tailored patient care are needed to improve the outcomes of patients with ICM.

Outcomes of Coronary Artery Bypass Graft Surgery in Africa: A Systematic Review and Meta-Analysis

Coronary artery bypass graft (CABG) surgery has been in practice for many decades, and it is one of the most commonly performed cardiac surgeries worldwide. While there are several studies reporting data on perioperative outcomes following CABG in developed countries, there is a staggering paucity of data and evidence reporting the outcomes in developing areas such as Africa. Thus, it is important to study the practice and outcome of CABG in Africa to establish its clinical efficacy and safety in this region and identify factors that might be limiting its practice. The overall aim of this study is to identify all relevant clinical data on CABG in Africa and report on the perioperative outcomes and practice of CABG in the African population. Electronic search was performed using three online databases, PubMed, African Journal Online, and Research Gate, from inception to June 2023. The preferred reporting items for systematic reviews and meta-analysis (PRISMA) guideline was utilised for this study. Relevant studies fulfilling predefined eligibility criteria were included in the study. Intraoperative details, such as the number of grafts performed, operative, bypass, and cross-clamp time, were reported. The primary endpoint assessed were early mortality and overall mortality. The secondary endpoints included length of hospital stay, intensive care unit stay, and postoperative complications, such as renal impairment, atrial fibrillation, and surgical site infection. The data were pooled together and meta-analyzed using a random effect model for proportions and mean for meta-analysis with R software (version 4.3.1 (2023-06-16); R Development Core Team, Vienna, Austria). This systematic review identified 42 studies that fulfilled the study eligibility criteria, including 21 randomised controlled trials, 20 observational studies, and one cross-sectional study. Only four out of the 54 countries in Africa had studies carried out that met the criteria for this review; they included Algeria, Egypt, Nigeria, and South Africa, with a majority from Egypt. Meta-analysis reported a pooled early mortality and pooled overall mortality of 3.51% and 3.73%, respectively, for the total cohort of patients. The result of this meta-analysis suggests that mortality outcomes following CABG in Africa are relatively higher than those in developed nations. Several issues, such as lack of financial resources and poor infrastructure, continue to hinder the optimal practice of CABG procedures in many parts of Africa. Further studies focused on finding factors associated with outcomes following CABG should be done. Though there were a few limitations to the study largely from a lack of data from several regions and countries in Africa, the result from this meta-analysis can serve as a benchmark for future studies until more relevant data are reported.

Hot spot imaging in cardiovascular diseases: an information statement from SNMMI, ASNC, and EANM

This information statement from the Society of Nuclear Medicine and Molecular Imaging, American Society of Nuclear Cardiology, and European Association of Nuclear Medicine describes the performance, interpretation, and reporting of hot spot imaging in nuclear cardiology. The field of nuclear cardiology has historically focused on cold spot imaging for the interpretation of myocardial ischemia and infarction. Hot spot imaging has been an important part of nuclear medicine, particularly for oncology or infection indications, and the use of hot spot imaging in nuclear cardiology continues to expand. This document focuses on image acquisition and processing, methods of quantification, indications, protocols, and reporting of hot spot imaging. Indications discussed include myocardial viability, myocardial inflammation, device or valve infection, large vessel vasculitis, valve calcification and vulnerable plaques, and cardiac amyloidosis. This document contextualizes the foundations of image quantification and highlights reporting in each indication for the cardiac nuclear imager.

Smaller left ventricular end-systolic diameter and lower ejection fraction at baseline associated with greater ejection fraction improvement after revascularization among patients with left ventricular dysfunction

Objectives

To investigate the predictive roles of pre-operative left ventricular (LV) size and ejection fraction (EF) in EF improvement and outcome following revascularization in patients with coronary artery disease (CAD) and LV dysfunction.

Background

Revascularization may improve EF and long-term outcomes of patients with LV dysfunction. However, the determinants of EF improvement have not yet been investigated comprehensively.

Materials and methods

Patients with EF measurements before and 3 months after revascularization were enrolled in a cohort study (No. ChiCTR2100044378). All patients had baseline EF ≤ 40%. EF improvement was defined as absolute increase in EF > 5%. According to LV end-systolic diameter (LVESD) (severely enlarged or not) and EF (≤35% or of 36–40%) at baseline, patients were categorized into four groups.

Results

A total of 939 patients were identified. A total of 549 (58.5%) had EF improved. Both LVESD [odds ratio (OR) per 1 mm decrease, 1.05; 95% CI, 1.04–1.07; P < 0.001] and EF (OR per 1% decrease, 1.06; 95% CI, 1.03–1.10; P < 0.001) at baseline were predictive of EF improvement after revascularization. Patients with LVESD not severely enlarged and EF ≤ 35% had higher odds of being in the EF improved group in comparison with other three groups both in unadjusted and adjusted analysis (all P < 0.001). The median follow-up time was 3.5 years. Patients with LVESD not severely enlarged and EF ≤ 35% had significantly lower risk of all-cause death in comparison with patients with LVESD severely enlarged and EF ≤ 35% [hazard ratio (HR), 2.73; 95% CI, 1.28–5.82; P = 0.009], and tended to have lower risk in comparison with patients with LVESD severely enlarged and EF of 36–40% (HR, 2.00; 95% CI, 0.93–4.27; P = 0.074).

Conclusion

Among CAD patients with reduced EF (≤ 40%) who underwent revascularization, smaller pre-operative LVESD and lower EF had greatest potential to have EF improvement and better outcome. Our findings imply the indication for revascularization in patients with LV dysfunction who presented with lower EF but smaller LV size.

Ejection Fraction Recovery after Coronary Artery Bypass Grafting for Ischemic Cardiomyopathy

BACKGROUND

 Controversy exists about left ventricular systolic function recovery after coronary artery bypass grafting in patients with ischemic cardiomyopathy. The aim of this study is to evaluate the temporal evolvement of left ventricular systolic function after coronary artery bypass surgery in patients with ischemic cardiomyopathy.

PATIENTS AND METHODS

 A total of 50 patients with coronary artery disease and left ventricular ejection fraction (LVEF) ≤35% underwent isolated coronary artery bypass grafting in a single center in the period 2017 to 2019. We performed a retrospective analysis of the echocardiographic and clinical follow-up data at 3 months and 1 year postoperatively.

RESULTS

 Median LVEF preoperatively was 25% (20-33%), mean patient age was 66 ± 8.2 years, 33 (66%) patients were operated off-pump, and 22 (44%) procedures were non-elective. There was no in-hospital myocardial infarction, stroke, and repeat revascularization. Three (6%) patients underwent re-exploration for bleeding or tamponade. In-hospital mortality was 8% and 1-year mortality was 12%. At 1 year postoperatively, there was no repeat revascularization, no myocardial infarction, 1 (2.6%) patient had a transient ischemic attack, and 10 (20%) patients required an implantable defibrillator. There was a statistically significant median ejection fraction increase at 3 months (15% [5-22%], p < 0.0001) and 1 year (23% [13-25%], p < 0.0001) postoperatively, with an absolute increase ≥10% in 32 (74.4%) and 30 (78.9%) patients at 3 months and 1 year, respectively.

CONCLUSION

 Patients with ischemic cardiomyopathy undergoing coronary artery bypass surgery show continuous recovery of left ventricular systolic function in the first postoperative year.

Midterm outcome of off-pump CABG for severe LV dysfunction-Does LV size and function predict their midterm outcome?

BACKGROUND

The superiority of surgical revascularization in ischemic cardiomyopathy is established beyond doubt, and off-pump CABG (OP-CABG) is a safe way of revascularization in this high-risk subset. Data on the effect of postoperative ventricular function and size on their midterm outcome is scarce.

MATERIALS AND METHODS

A retrospective study was done on 211 consecutive patients with severe LV dysfunction who underwent OP-CABG from January 2017 to December 2018. Data were collected from the institutional database. Their operative and midterm outcomes were statistically analyzed.

RESULTS

The mean age of the cohort was 58.4 ± 8.3 years. An average number of grafts was 3.1 ± 0.8 (cumulative intended number of grafts-3). Operative mortality was 10.9%. Preoperative NYHA class (p < .0001; OR, 19.72) and postoperative IABP insertion (p < .008; OR, 88.75) were independent predictors of operative mortality. The mean follow-up period was 3.14 ± 0.07 years, was 97.4% complete with cardiac mortality of 5.8%. Postoperative LVEF (p = .002; OR, 0.868) and LV dimensions (systole & diastole) (p = .013, OR = 1.182 and p = .036, OR = 1.184, respectively) were independent predictors of midterm mortality. Midterm major adverse cardiovascular event-free survival of operative survivors was 89%. There was no correlation between postoperative LV dimension and NYHA status(p > .05). Myocardial viability was not associated with early (p = .17) or midterm mortality (p = .676).

CONCLUSION

OP-CABG can achieve complete revascularization in patients with severe LV dysfunction with good midterm outcomes, albeit with high early operative mortality. Postoperative change in LV dimension and EF are predictors of midterm mortality.

Early and Mid-Term Outcomes of Patients Undergoing Coronary Artery Bypass Grafting in Ischemic Cardiomyopathy

Background Many observational studies and trials have shown that coronary artery bypass grafting improves the survival in patients with ischemic cardiomyopathy. However, these results are based on data generated from developed countries. Poor socioeconomic statuses, lack of uniformity in healthcare delivery, differences in risk profile, and affordability to access optimal health care are some factors that make the conclusions from these studies irrelevant to patients from India. Methods and Results One-hundred and sixty-two patients with severe left ventricular dysfunction (ejection fraction ≤35%) who underwent coronary artery bypass grafting from 2009 to 2017 were enrolled for this study. Mean age of the study population was 58.67±9.70 years. Operative mortality was 11.62%. Thirty day/in-house composite outcome of stroke and perioperative myocardial infarction were 5.8%. The percentage of survival for 1 year was 86.6%, and 5-year survival was 79.9%. Five-year event-free survival was 49.3%. The mean ejection fraction improved from 30.7±4.08% (range 18-35) to 39.9±8.3% (range 24-60). Lack of improvement of left ventricular function was a strong predictor of late mortality (hazard ratio, 21.41; CI 4.33-105.95). Even though there was a trend towards better early outcome in off-pump CABG , the 5-year survival rates were similar in off-pump and on-pump group (73.4% and 78.9%, respectively; P value 0.356). Conclusions We showed that coronary artery bypass grafting in ischemic cardiomyopathy was associated with high early composite outcomes. However, the 5-year survival rates were good. Lack of improvement of left ventricular function was a strong predictor of late mortality.