Abstract 14121: A New Physical Rehabilitation Program Based on Adaptation to Myocardial Ischemia is Cardioprotective for Patients With Ischemic Heart Disease: A Manifestation of Ischemic Preconditioning?
Ischemic preconditioning (IP) triggers mechanisms that are cardioprotective during subsequent, non-fatal myocardial ischemia. Thus, exercise strenuous enough to produce transient myocardial ischemia may evoke IP and confer protection to myocardium of patients with ischemic heart disease (IHD). Patients with stable IHD (age 38-65 y; ejection fraction >40%), incomplete revascularization after transcutaneous coronary angioplasty, and positive results of a diagnostic exercise stress test were studied. The IP group (53.9± 6.2 y; n=11) performed 10 treadmill exercise sessions at 70-80% of diagnostic intensity with a 48 h interval between sessions. Each training session continued until ST depression and/or angina occurred (15-25 min initially, 30-50 min after 10 sessions). The control (C) group (56.1± 4.8 y, n=10) performed 10 standard 30-min rehabilitation exercise training sessions at 50-60% of diagnostic intensity for 30 min each, with a 48 h interval between sessions. Monitored safety indices, ECG, blood pressure, heart rate, and myocardial injury markers were within normal reference ranges in both groups, except for ST depression and/or angina in the IP group. Ischemia-modified albumin increased after the first rehabilitation session in the IP group, but by session 10 it was significantly lower than in the C group. In post- rehabilitation exercise stress tests, maximum ST depression was decreased by 46.3±6.8% in the IP group vs 9.8±1.6% in the C group (p <0.001). Also, diagnostic exercise duration increased by 17.5±3.6% vs 4.1±1.2% (p <0.05); MET by 9.3±2.6% vs 2.4±1.1% (p <0.05); double product by 6.5±2.9% vs 2.1±1.0% (p=0.021). Thus, consistent with IP, strenuous physical rehabilitation increased resistance to myocardial oxygen supply/demand imbalance and also improved exercise tolerance in IHD patients.
- © 2013 by American Heart Association, Inc.