Current Landscape and Future Directions of Coronary Revascularization in Patients With Heart Failure

Relationship of Race With Functional and Clinical Outcomes With the REHAB-HF Multidomain Physical Rehabilitation Intervention for Older Patients With Acute Heart Failure

Background The REHAB-HF (Rehabilitation Therapy in Older Acute Heart Failure Patients) randomized trial demonstrated that a 3-month transitional, tailored, progressive, multidomain physical rehabilitation intervention improves physical function, frailty, depression, and health-related quality of life among older adults with acute decompensated heart failure. Whether there is differential intervention efficacy by race is unknown. Methods and Results In this prespecified analysis, differential intervention effects by race were explored at 3 months for physical function (Short Physical Performance Battery [primary outcome], 6-Minute Walk Distance), cognition, depression, frailty, health-related quality of life (Kansas City Cardiomyopathy Questionnaire, EuroQoL 5-Dimension-5-Level Questionnaire) and at 6 months for hospitalizations and death. Significance level for interactions was P≤0.1. Participants (N=337, 97% of trial population) self-identified in near equal proportions as either Black (48%) or White (52%). The Short Physical Performance Battery intervention effect size was large, with values of 1.3 (95% CI, 0.4-2.1; P=0.003]) and 1.6 (95% CI, 0.8-2.4; P<0.001) in Black and White participants, respectively, and without significant interaction by race (P=0.56). Beneficial effects were also demonstrated in 6-Minute Walk Distance, gait speed, and health-related quality of life scores without significant interactions by race. There was an association between intervention and reduced all-cause rehospitalizations in White participants (rate ratio, 0.73 [95% CI, 0.55-0.98]; P=0.034) that appears attenuated in Black participants (rate ratio, 1.06 [95% CI, 0.81-1.41]; P=0.66; interaction P=0.067). Conclusions The intervention produced similarly large improvements in physical function and health-related quality of life in both older Black and White patients with acute decompensated heart failure. A future study powered to determine how the intervention impacts clinical events is required. REGISTRATION URL: https://www.clinicaltrials.gov. Identifier: NCT02196038.

Current Landscape and Future Directions of Coronary Revascularization in Ischemic Systolic Heart Failure: A Review

Ischemic heart disease is the largest cause of death worldwide and the most common cause of heart failure (HF). The incidence and prevalence of HF are increasing owing to an aging population and improvements in the acute cardiac care of previously fatal conditions such as myocardial infarction. Strategies to improve outcomes in patients with ischemic systolic HF are urgently needed. There is systematic underutilization of testing for coronary artery disease in patients with HF, and revascularization is performed in an even smaller minority despite evidence for reduced mortality with coronary artery bypass grafting (CABG) over medical therapy in the Surgical Treatment for Ischemic Heart Failure Extension Study. Percutaneous coronary intervention (PCI) is a less-invasive approach to coronary revascularization; however, the recent Revascularization for Ischemic Ventricular Dysfunction (REVIVED)-British Cardiovascular Intervention Society (BCIS2) trial failed to demonstrate a benefit of PCI compared with that of medical therapy in patients with ischemic systolic HF. The comparative effectiveness of PCI and CABG for patients with ischemic systolic HF remains unknown, particularly in the era of contemporary medical therapy. In this review, we discuss the benefit of CABG in ischemic systolic HF, its underutilization, and the unmet clinical need. We also review the recent REVIVED-BCIS2 trial comparing PCI to medical therapy, as well as upcoming randomized controlled trials of PCI for ischemic systolic HF and persistent evidence gaps that will exist despite anticipated data from ongoing trials. There remains a need for an adequately powered randomized controlled trials to establish the comparative clinical effectiveness of PCI vs CABG in ischemic systolic HF in the era of contemporary revascularization approaches and medical therapy, as well as trials of coronary revascularization in patients with HF with preserved ejection fraction or less severe forms of left ventricular systolic dysfunction.

Heterogeneous treatment effects of coronary artery bypass grafting in ischemic cardiomyopathy: A machine learning causal forest analysis

OBJECTIVES

We aim to evaluate the heterogeneous treatment effects of coronary artery bypass grafting in patients with ischemic cardiomyopathy and to identify a group of patients to have greater benefits from coronary artery bypass grafting compared with medical therapy alone.

METHODS

Machine learning causal forest modeling was performed to identify the heterogeneous treatment effects of coronary artery bypass grafting in patients with ischemic cardiomyopathy from the Surgical Treatment for Ischemic Heart Failure trial. The risks of death from any cause and death from cardiovascular causes between coronary artery bypass grafting and medical therapy alone were assessed in the identified subgroups.

RESULTS

Among 1212 patients enrolled in the Surgical Treatment for Ischemic Heart Failure trial, left ventricular end-systolic volume index, serum creatinine, and age were identified by the machine learning algorithm to distinguish patients with heterogeneous treatment effects. Among patients with left ventricular end-systolic volume index greater than 84 mL/m2 and age 60.27 years or less, coronary artery bypass grafting was associated with a significantly lower risk of death from any cause (adjusted hazard ratio, 0.61; 95% CI, 0.45-0.84) and death from cardiovascular causes (adjusted hazard ratio, 0.63; 95% CI, 0.45-0.89). By contrast, the survival benefits of coronary artery bypass grafting no longer exist in patients with left ventricular end-systolic volume index 84 mL/m2 or less and serum creatinine 1.04 mg/dL or less, or patients with left ventricular end-systolic volume index greater than 84 mL/m2 and age more than 60.27 years.

CONCLUSIONS

The current post hoc analysis of the Surgical Treatment for Ischemic Heart Failure trial identified heterogeneous treatment effects of coronary artery bypass grafting in patients with ischemic cardiomyopathy. Younger patients with severe left ventricular enlargement were more likely to derive greater survival benefits from coronary artery bypass grafting.

A Unified Model of Age-Related Cardiovascular Disease

Despite progress in biomedical technologies, cardiovascular disease remains the main cause of mortality. This is at least in part because current clinical interventions do not adequately take into account aging as a driver and are hence aimed at suboptimal targets. To achieve progress, consideration needs to be given to the role of cell aging in disease pathogenesis. We propose a model unifying the fundamental processes underlying most age-associated cardiovascular pathologies. According to this model, cell aging, leading to cell senescence, is responsible for tissue changes leading to age-related cardiovascular disease. This process, occurring due to telomerase inactivation and telomere attrition, affects all components of the cardiovascular system, including cardiomyocytes, vascular endothelial cells, smooth muscle cells, cardiac fibroblasts, and immune cells. The unified model offers insights into the relationship between upstream risk factors and downstream clinical outcomes and explains why interventions aimed at either of these components have limited success. Potential therapeutic approaches are considered based on this model. Because telomerase activity can prevent and reverse cell senescence, telomerase gene therapy is discussed as a promising intervention. Telomerase gene therapy and similar systems interventions based on the unified model are expected to be transformational in cardiovascular medicine.