Cardiovascular mortality and chronotropic incompetence in systolic heart failure: The importance of a reappraisal of current cut-off criteria

Aims: An independent role for the exercise-induced heart rate (HR) response- and specifically the chronotropic incompetence (CI)-in the prognosis of heart failure (HF) is still debated. The multicentre study reported here sought to investigate the prognostic values of HR and CI variables on cardiovascular mortality in a large cohort of systolic HF patients. Methods A total of 1045 HF patients were recruited and prospectively followed in three Italian HF centres. The study endpoint and results: was cardiovascular mortality. Besides a full clinical examination, each patient underwent a maximal cardiopulmonary exercise test at study enrolment. The age-predicted peak HR (%pHR) and the peak HR reserve (%pHRR) according to different cut-off values (60-80% of the maximum predicted) were adopted to identify the presence of CI. The median follow-up was 876 days (interquartile range 386-1590 days). Cardiovascular death occurred in 145 cases (13.8%). Besides LVEF, peak oxygen uptake, ventilation vs. carbon dioxide production slope, and beta-blocker therapy, the multivariate analysis showed that both %pHR and %pHRR were able to predict prognosis when considered as continuous variables. Conversely, the presence of CI was associated with the study endpoint only when the 70% (%pHR