Home-based versus hospital-based exercise programs in patients with coronary artery disease: effects on coronary...

In a randomized study, we recently documented that a vigorous, hospital-based exercise training (ET) program improves coronary endothelial function in coronary artery disease. The aim of this consecutive study was to assess whether a home-based exercise program with reduced average training duration can sustain previously achieved effects on coronary endothelial function.

Nineteen patients with coronary endothelial dysfunction documented by acetylcholine-induced vasoconstriction were randomly assigned to a training group (n = 10) or a control group (n = 9). After 4 weeks of inhospital training (60 min of bicycle ergometry per day), all training patients were enrolled in a 5-month home-based program of 20 minutes' ergometry training per day and 1 group training session per week. At baseline, after 4 weeks and 6 months, endothelium-mediated vasodilation was assessed by quantitative coronary angiography after intracoronary infusions of acetylcholine. Average peak velocity (APV) was measured with a Doppler wire. Coronary blood flow (CBF) was calculated by multiplying vascular cross-sectional area and APV.

CBF increased in response to 7.2 microg/min acetylcholine, from 27% +/- 11% at the beginning of the study to 110% +/- 24% after 4 weeks (P <.01 vs control group). After 6 months, the increase in CBF was lower versus inhospital training (67% +/- 18%, P <.05 vs 4 weeks). Changes in APV between 1 and 6 months correlated with daily training durations (r = 0.65, P =.03).

Home-based ET sustained part of the effects of hospital-based ET on endothelium-dependent vasodilation in coronary artery disease. However, acetylcholine-induced increases in CBF were lower after home-based ET, suggesting a relation between daily training duration and improvement of coronary vasomotion.