Modified Application of Cardiac Rehabilitation in Older Adults (MACRO) Trial: Protocol changes in a pragmatic multi-site randomized controlled trial in response to the COVID-19 pandemic.

BACKGROUND: Older adults are at higher risk for cardiovascular disease and functional decline, often leading to deterioration and dependency. Cardiac rehabilitation (CR) provides opportunity to improve clinical and functional recovery, yet participation in CR decreases with age. Modified Application of CR in Older Adults (MACRO) is a National Institute on Aging (NIA)-funded pragmatic trial that responds to this gap by aiming to increase enrollment of older adults into CR and improving functional outcomes. This article describes the methodology and novel features of the MACRO trial. METHODS: Randomized, controlled trial of a coaching intervention (MACRO-I) vs. usual care for older adults (age ≥ 70 years) eligible for CR after an incident cardiac hospitalization. MACRO-I incorporates innovations including holistic risk assessments, flexible CR format (i.e., helping patients to select a CR design that aligns with their personal risks and preferences), motivational prompts, nutritional emphasis, facilitated deprescription, enhanced education, and home visits. Key modifications were necessitated by the COVID-19 pandemic, including switching from a performance-based primary endpoint (Short Physical Performance Battery) to a patient-reported measure (Activity Measure for Post-Acute Care Computerized Adaptive Testing). Changes prompted by COVID-19 maintain the original intent of the trial and provide key methodologic advantages. CONCLUSIONS: MACRO is exploring a novel individualized coaching intervention to better enable older patients to participate in CR. Due to COVID-19 many aspects of the MACRO protocol required modification, but the primary objective of the trial is maintained and the updated protocol will more effectively achieve the original goals of the study.

Metformin in Pulmonary Hypertension in Left Heart Disease.

Metformin is ubiquitously used in the management of Type II Diabetes Mellitus (DMII). Over the years, our growing knowledge of its therapeutic potential has broadened its use to the treatment of infertility in polycystic ovarian syndrome, gestational diabetes, and even obesity. Recently, it has been suggested as a novel therapy in cardiovascular disease (CVD). Given that CVD is the leading cause of death in patients with DMII, with ~ 75% dying from a cardiovascular event, the intersection of DMII and CVD provides a unique therapeutic target. In particular, pulmonary hypertension (PH) related to CVD (Group II PH) may be an optimal target for metformin therapy. The objective of this review article is to provide an overview of the pathophysiology of PH related to left heart disease (PH-LHD), outline the proposed pathophysiologic mechanism of insulin resistance in heart failure and PH-LHD, and evaluate the role metformin may have in heart failure and PH-LHD.

Colchicine Toxicity: The Fatal Masquerader.

Colchicine toxicity results in fatal multiorgan failure. We present a case of colchicine toxicity resulting in transient biventricular failure and cardiogenic shock that were successfully treated with packed red blood cell exchange. (Level of Difficulty: Beginner.).

Dietary nitrate's effects on exercise performance in heart failure with reduced ejection fraction (HFrEF).

Heart failure with reduced ejection fraction (HFrEF) is a deadly and disabling disease. A key derangement contributing to impaired exercise performance in HFrEF is decreased nitric oxide (NO) bioavailability. Scientists recently discovered the inorganic nitrate pathway for increasing NO. This has advantages over organic nitrates and NO synthase production of NO. Small studies using beetroot juice as a source of inorganic nitrate demonstrate its power to improve exercise performance in HFrEF. A larger-scale trial is now underway to determine if inorganic nitrate may be a new arrow for physicians' quiver of HFrEF treatments.