Effect of incremental exercise training interventions in a Cardiac Rehabilitation Program following myocardial infarction

Abstract Background Exercise-based cardiac rehabilitation is recommended after myocardial infarction (MI) to improve prognosis, quality of life and control of cardiovascular risk factors. However, the specific impact of different exercise training interventions remains incompletely understood. Purpose To study the health outcomes of three incremental exercise training interventions during a Cardiac Rehabilitation Program (CRP) following MI. Methods We implemented a post-MI Phase 2 CRP in 2022. After initial exercise testing, a 3-month, individualized aerobic and strength ambulatory training program was provided by Cardiologists and Physical Medicine and Rehabilitation physicians (Group 1, n=58). Additionally, a subset of patients received one session of supervised teaching of aerobic and strength training by physiotherapists (Group 2, n=19), and another subset received 8-20 sessions of in-hospital supervised training (Group 3, n=13). Exercise testing was repeated at the end of Phase 2 and peak oxygen consumption (peak VO2) was measured. We analysed quality of life (SF-36), depression (PHQ2), anxiety (GAD2), adherence to Mediterranean diet (PREDIMED) and pharmacological treatment (Morisky-Green), and weekly physical activity (IPAQ). Health outcomes were compared at the beginning and after Phase 2 CRP. Results The cohort comprised 90 patients who completed Phase 2 CRP (mean age 61.2±10.8 years, 84.4% male and 47.8% smokers). Reductions in systolic blood pressure (-10.3±13.8mmHg), LDL cholesterol (-60.7±35.4mg/dL), weight (-2.8±6.6kg, -3±7.8%) and body mass index (-1±2.2) were attained (p<0.05). Smoking abstinence was accomplished in 88.4% of smokers and most patients achieved an LDL<55mg/dL (81.1%). Improvements in quality of life (SF-36 +10.4±19.4 points, p<0.001) and anxiety and depression symptoms (PHQ2 -0.5±1.6 points and GAD2 -0.6±1.6 points, p<0.01) were noted. An increase in peak VO2 (+5.12±5.44ml/kg/min, +23.5±27.4% from baseline, p<0.001) and predicted functional capacity (+13.4±23.8%, p<0.001) was achieved. Patients increased their reported weekly physical activity by 2520.3±2935.4 METS/week (+132% from baseline, p<0.001) and most of them were adherent to Mediterranean diet (91.1%) and pharmacological treatment (95.6%). Patients achieved similar health outcomes regardless of their exercise training group, except for patients in Group 3, who experienced a more pronounced improvement in peak VO2 (+8.1±6.4ml/kg/min, +37.8±34.7% from baseline; p<0.05) and a trend towards higher increase in predicted functional capacity (+21.7±19.2%, p<0.25) and greater weight loss (-5.5±9.4kg, -5.9±9.6%; p<0.2). Conclusions Supervised in-hospital training during a Phase 2 CRP provides superior physical fitness improvements and more pronounced weight loss in MI patients. However, a Phase 2 CRP based on ambulatory training provides similar benefits regarding other health outcomes, such as control of cardiovascular risk factors and quality of life amelioration.Exercise training interventions in a CRP