Changes in exercise capacity induced by heart transplantation: prognostic and therapeutic implications

Survival and exercise performance are key targets of heart transplantation (HT). We designed this study to help in identifying (1) patients with chronic heart failure (CHF) at risk of poor exercise capacity after HT and (2) HT recipients presenting risk factors modifiable with exercise showing a potential impact on outcome. We enrolled 49 HT recipients (age 52 ± 12 years, 84% males) who underwent a cardiopulmonary exercise test before (9 ± 6 months) and after (20 ± 14 months) HT. In the CHF phase, lower peak oxygen consumption (VO2) (odds ratio 0.69, P=0.017) independently predicted peak VO2 improvement after HT. In the post-HT phase, body mass index (BMI) [adjusted hazard ratio (HR) 1.16, P=0.034] and VE (ventilation)/VCO2 (carbon dioxide production) slope (adjusted HR 1.07, P=0.031) independently predicted mortality. In conclusion, CHF patients with only a moderate impairment of peak VO2 are at a risk of failing to achieve a significant improvement of exercise performance after HT. In the post-HT phase, a BMI≥28 and/or a VE/VCO2 slope ≥47 represent risk factors for death, which are potentially modifiable with exercise. Prospective randomized studies are needed to analyze the effects of training on functional capacity and outcome in the different subsets of HT recipients.