Poor functional recovery may indicate restenosis in patients after coronary angioplasty

To investigate whether poor response to exercise training can detect restenosis in asymptomatic patients after percutaneous transluminal coronary angioplasty (PTCA).

Case-control study.

A hospital-based outpatient cardiac rehabilitation program in Taiwan.

Sixteen patients aged 49.7+/-7.8 years who had undergone PTCA and completed a 3-month exercise program. Patients were separated into a restenosis group (n=7; age, 46.4+/-9.8y) and a nonrestenosis group (n=9; age, 52.3+/-12.9y), according to their angiography follow-up results. The interval between PTCA and angiography ranged from 6 months to 2 years.

Bicycle exercise workouts were conducted 3 times a week during rehabilitation, with exercise intensity adjusted to each patient's ventilatory threshold.

A graded exercise test with gas analysis was conducted before training, at 6 weeks and at 3 months after training, to evaluate the sequential changes of cardiorespiratory function.

After 3 months of training, the nonrestenosis group showed an increase of 30.4% in peak oxygen uptake (Vo(2)peak, P<.05), 13.7% in peak oxygen pulse (P<.05), 22.2% in peak rate-pressure product (P<.05), and 13.6% in peak work rate (P<.05). Most of the improvement occurred within the first 6 weeks of training. The restenosis group did not show significant increase in these variables. At the ventilatory threshold, the nonrestenosis group also displayed a significant increase of Vdot;o(2), oxygen pulse, and work rate. However, the restenosis group showed no improvement after training.

Functional recovery appears to be a good indicator of restenosis for patients after PTCA. A poor response to exercise can be noted within 6 weeks of training in PTCA patients with restenosis.