Exercise capacity and cardiovascular responses to serial exercise testing in men and women after coronary artery bypass graft surgery

We evaluated the exercise capacity and cardiovascular responses to serial treadmill exercise tests of 198 men and 42 women at six weeks (Tl)and 16 weeks (T2) after coronary artery bypass graft surgery (C.ABGS). All patients followed a prescribed home exercise program during the study period. Men (mean age, 55 ± 7 yrs) showed a significant increase in exercise capacity, from 7.4 ± 1.8 to 8.8 ± 2 METs. Women (mean age, 55 ± 9 yrs) also showed significant improvement, from 5.7 ± 1.7 to 6.6 ± 1.7 METs. Maximum exercise capacity declined 1 MET for each decile of age (40 to 70 yrs) in men and women. However, the relative improvement from T1 to T2 was not influenced by increasing age. Exercise capacity in men was not affected by low-dose beta blockade or the presence of mild left ventricular impairment before CABGS. Noncomplex (Lown grade 1A or IB) ventricular ectopic beats occurred in 31% of patients at T1 and T2, and complex ventricular ectopic beats (Lown grade >2) were seen in 14% of patients at Tl and in 9% at T2. Asymptomatic ST depression was found in 12% of subjects at Tl and in 14% at T2. These data agree with previous studies of exercise responses after CABGS and provide additional values for mean exercise capacUti in both men and women, stratified by age, four months after uncomplicated CABGS.