Chronotropic Responses to Exercise and Recovery in Myocardial Infarction Patients Taking β-Blockers Following Aerobic High-Intensity Interval Training: AN INTERFARCT STUDY

Association of chronotropic incompetence with reduced cardiorespiratory fitness in older adults with HIV

OBJECTIVE

Understanding the physiological drivers of reduced cardiorespiratory fitness in people with HIV (PWH) will inform strategies to optimize healthspan. Chronotropic incompetence is common in heart failure and associated with low cardiorespiratory fitness yet is understudied in PWH. The objective was to determine the prevalence of chronotropic incompetence and its relationship with cardiorespiratory fitness.

DESIGN

Participants were PWH at least 50 years of age with no prior history of heart failure or coronary heart disease who were enrolled in a randomized exercise trial. Baseline cardiopulmonary exercise testing (CPET) was used to measure cardiorespiratory fitness as peak oxygen consumption (VO2peak) and calculate the chronotropic index from heart rate values. Chronotropic incompetence was defined as an index less than 80%.

RESULTS

The 74 participants were on average 61 years old, 80% Black or African American, and 93% men. Chronotropic incompetence was present in 31.1%. VO2peak was significantly lower among participants with chronotropic incompetence compared with participants without chronotropic incompetence [mean (SD) ml/min/kg: 20.9 (5.1) vs. 25.0 (4.5), P = 0.001]. Linear regression showed that chronotropic incompetence and age were independent predictors of VO2peak, but smoking and comorbidity were not. The chronotropic index correlated with VO2peak (r = 0.48, P < 0.001).

CONCLUSION

Among older PWH without heart failure or coronary heart disease, chronotropic incompetence was present in approximately one-third of individuals and was associated with clinically relevant impaired cardiorespiratory fitness. Investigation of chronotropic incompetence in large cohorts which includes PWH and heart failure may contribute to strategies that promote healthy aging with HIV infection and offer a preclinical window for intervention.

Impact of Aerobic High-Intensity Interval Training Intervention and Mediterranean Diet Recommendations on Health-Related Quality of Life and Lifestyle Modification in Post-Myocardial Infarction Patients: Results From the INTERFARCT Surveys

This study aims to determine the impact of 2 (low vs high volume) high-intensity interval training (HIIT) programs with Mediterranean diet (MedDiet) recommendations on health-related quality of life (HRQoL) and lifestyle modification, and to examine the relationships between the changes in anxiety and depression with HRQoL and lifestyle variables after myocardial infarction (MI). Participants (n = 80) were randomized to attention control or one of the two supervised HIIT groups (2 d/weeks). Surveys before and after intervention (16 weeks): HRQoL (SF-36), anxiety and depression (HADS), MedDiet adherence (MEDAS), and physical activity (PA) and sedentary behavior (SB) levels. After intervention, there were improvements (P < .05) in HRQoL, HADS scores, and MedDiet adherence, with higher PA level in both HIIT groups with no between-HIIT group differences. The HADS score decline correlated (P < .05) with both the increase in physical component of SF-36 (r = .42), the overall metabolic expenditure (r = .26), and adherence to the MedDiet (r = .24), and the reduction in the SB (r = .35). HIIT exercise intervention with MedDiet recommendations improved HRQoL, along with reduced anxiety and depression symptoms, and a healthier lifestyle after MI. Better mental health was related to higher values of PA and MedDiet adherence.

The Role and Potential Mechanisms of Rehabilitation Exercise Improving Cardiac Remodeling

Rehabilitation exercise is a crucial non-pharmacological intervention for the secondary prevention and treatment of cardiovascular diseases, effectively ameliorating cardiac remodeling in patients. Exercise training can mitigate cardiomyocyte apoptosis, reduce extracellular matrix deposition and fibrosis, promote angiogenesis, and regulate inflammatory response to improve cardiac remodeling. This article presents a comprehensive review of recent research progress, summarizing the pivotal role and underlying mechanism of rehabilitation exercise in improving cardiac remodeling and providing valuable insights for devising effective rehabilitation treatment programs. Graphical Abstract.