Exercise and cardioprotection in coronary artery disease: a pilot quasi-experimental study

Sirtuin-1 is a protein that may orchestrate the cardioprotective effect of exercise by controlling cellular processes. This pilot study assessed the feasibility of performing a quasi-experimental study in this area. Patients with postacute myocardial infarction were recruited across four hospital sites in the United Kingdom. The participants were offered one weekly exercise session at Phase-III and Phase-IV cardiac rehabilitation (CR). Measurements were obtained pre-Phase-III CR (Week 1), post-Phase-III CR (Week 8), and post-Phase-IV CR (Week 22). Twenty-eight patients were recruited (79% male, 100% White, 60.2 ± 10.5 years old). The recruitment rate was not fulfilled (<70% eligible patients recruited; 0.9 participants recruited per week over 30 weeks). The success criteria for dropout rate, adherence rate, and collection of sirtuin-1 measures were satisfied. A large increase in sirtuin-1 (0.14 ± 0.03, d ≥ 0.8) was seen after Phase-III and Phase-IV CR. Collectively, a quasi-experimental study is feasible with a revised recruitment strategy.