Determinants of VO2peak changes after aerobic training in coronary heart disease patients.

This study aimed to highlight the ventilatory and circulatory determinants of changes in VO2peak after exercise-based cardiac rehabilitation (ECR) in patients with coronary heart disease (CHD). Eighty-two CHD patients performed, before and after a 3-month ECR, a cardiopulmonary exercise testing (CPET) on a bike with gas exchanges measurments (VO2peak, minute ventilation; VE) and cardiac output (Qc). The arteriovenous difference in O2 (C(a-v )O2) and the alveolar capillary gradient in O2 (PAi-aO2) were calculated using Fick's laws. Oxygen uptake efficiency slope (OUES) was calculated. A 5.0% cut off was applied for differentiating non- (NR: ∆VO2<0.0%), low (LR: 0.0≤ ∆VO2<5.0%), moderate- (MR: 5.0≤∆VO2<10.0%) and high responders (HR: ∆VO2≥10.0%) to ECR. Forty-four % of patients were HR (n=36), 20% MR (n=16), 23% LR (n=19) and 13% NR (n=11). For HR, the VO2peak increase (p<0.01) was associated to increases in VE (+12.8±13.0L/min, p<0.01), Qc (+1.0±0.9L/min, p<0.01), and C(a-v)O2 (+2.3±2.5mLO2/100mL, p<0.01). MR patients were characterized by +6.7±19.7L/min increase in VE (p=0.04) and +0.7±1.0L/min of Qc (p<0.01). ECR induced decreases in VE (p=0.04) and C(a-v )O2 (p<0.01) and Qc increase in LR and NR patients (p<0.01). Peripheral and ventilatory responses more than central adaptations could responsible of the VO2peak change with ECR in CHD patients.

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The authors declare that they have no conflict of interest.