Greater prognostic value of peak VO2 after exercise training program completion in heart failure patients

Exercise capacity, best reflected by peak exercise oxygen consumption (peak VO(2)), is a powerful prognostic factor in patients with chronic heart failure (CHF). However, the optimal time to assess exercise capacity for prognosis remains unclear and whether an exercise training program (ETP) to improve exercise capacity alters the prognostic value of cardiopulmonary exercise (CPX) testing variables in CHF is unknown.

CHF patients who underwent an ETP in two cardiac rehabilitation centers between 2004 and 2009 were prospectively included, and CPX testing was performed before and after ETP completion. We included 285 consecutive patients who underwent an ETP (19.4 ± 8.7 training sessions in 4 to 10 weeks), including segmental gymnastics and cycling sessions. During follow-up (12 months), 14 patients died, 6 underwent cardiac transplantation and 15 were hospitalized for acute heart failure. Univariate analysis and receiver operating characteristic (ROC) curve analysis showed that CPX variables, especially peak oxygen consumption and circulatory power (product of peak VO(2) × peak systolic blood pressure) before and after ETP completion predicted prognosis. However, CPX data obtained after ETP completion had the best prognostic value (area under the ROC curve = 0.79 ± 0.03 for peak VO(2) after ETP completion vs 0.64 ± 0.04 before ETP completion, p < 0.0001). The results did not change even when considering only deaths.

In patients with stable CHF who can exercise, the prognostic value of CPX data seems greater after versus before completion of a hospital-based ETP. Therefore, CPX capacity for prognostic purposes should at best be assessed after cardiac rehabilitation.