Predictors of long-term prognosis based on clinical status and measurements obtained in heart failure patients after 9-week hybrid comprehensive telerehabilitation: A subanalysis of the TELEREH-HF randomized clinical trial

BACKGROUND: Assessing prognosis in heart failure (HF) is of major importance. AIMS: The study aimed to define predictors influencing long-term cardiovascular mortality or HF hospitalization ("composite outcome") based on clinical status and measurements obtained after a 9-week hybrid comprehensive telerehabilitation (HCTR) program. METHODS: This analysis is based on the TELEREH-HF (TELEREHabilitation in Heart Failure) multicenter randomized trial that enrolled 850 HF patients (left ventricular ejection fraction [LVEF] ≤40%). Patients were randomized 1:1 to 9-week HCTR plus usual care (experimental arm) or usual care only (control arm) and followed for median (interquartile range [IQR]) 24 (20-24) months for development of the composite outcome. RESULTS: Over 12-24 months of follow-up, 108 (28.1%) patients experienced the composite outcome. The predictors of our composite outcome were: nonischemic etiology of HF, diabetes, higher serum level of N-terminal prohormone of brain natriuretic peptide, creatinine, and high-sensitivity C-reactive protein; low carbon dioxide output at peak exercise; high minute ventilation and breathing frequency at maximum effort in cardiopulmonary exercise tests; increase in delta of average heart rate in 24-hour Holter ECG monitoring, lower LVEF, and patients' non-adherence to HCTR. The model discrimination C-index was 0.795 and decreased to 0.755 on validation conducted in the control sample which was not used in derivation. The 2-year risk of the composite outcome was 48% in the top tertile versus 5% in the bottom tertile of the developed risk score. CONCLUSION: Risk factors collected at the end of the 9-week telerehabilitation period performed well in stratifying patients based on their 2-year risk of the composite outcome. Patients in the top tertile had an almost ten-fold higher risk compared to patients in the bottom tertile. Treatment adherence, but not peak VO2 or quality of life, was significantly associated with the outcome.