Predictors of exercise capacity and adaptability to training in patients with coronary artery disease

Systolic left ventricular dysfunction is a weak predictor of exercise tolerance in patients with chronic congestive heart failure. This study aimed to determine physiologic and other predictors of effort tolerance and adaptability to training in a wide variety of patients with coronary artery disease.

One hundred seventy-one patients (group 0) with documented coronary artery disease and various degrees of left ventricular dysfunction were enrolled into a medically supervised exercise training program for 6 months. One hundred six patients had an ejection fraction greater than 50% (group 1), 38 patients between 35% and 50% (group 2), and 27 patients less than 35% (group 3).

Resting parameters of systolic and diastolic left ventricular function did not predict the effort tolerance of patients with coronary artery disease at any level of left ventricular impairment. Noncardiac factors including age, gender, Broca index, and forced vital capacity explained 50% of the variation in peak oxygen uptake in group 0. Peak oxygen uptake, ventilatory threshold, and treadmill time to exhaustion increased significantly after training in all groups. The magnitude of the improvement in these variables was the same for all groups.

Noncardiac factors were better predictors of the effort tolerance of patients with coronary artery disease than parameters of left ventricular function at entry to an exercise program or after 6 months of training. A similar degree of adaptation to training was seen in all patients regardless of their degree of left ventricular systolic or diastolic dysfunction.