Valor preditivo da frequência cardíaca em repouso do teste ergométrico na mortalidade

Abstract

Background: Resting heart rate (which ranges from 60 to 80 bpm) is one of the simplest cardiovascular parameters, and has been considered as a predictor of cardiovascular and all-cause mortality. Objective: To determine the predictive value of resting heart rate (RHR) before exercise stress testing (ET) for cardiovascular (CV) and all-cause mortality. Methods: This was a case-control study using data from the database of the Exercise Testing Laboratory of a cardiac hospital and the death records of the Health Department of a city located in the South of Brazil from January 1995 to June 2007. A total of 7,055 patients were studied; 1,645 (23.3%) in the case group (deceased) and 5,410 (76.7%) in the control group (alive). The cut-off value of RHR for mortality was derived from the ROC curve, and a multivariate analysis was performed for the selected variables. The study's outcome measures were cardiovascular and all-cause mortality. Results: Six hundred and seventy-four patients died of cardiovascular diseases (9.5%); the cut-off value was RHR ≥ 78 bpm). After adjusting for selected variables, the odds ratio (OR) of RHR ≥ 78 bpm was 3.5 (95% CI 2.9 to 4.2) for CV mortality and 3.6 (95% CI 3.2 to 4.0) for all-cause mortality. Conclusion: Resting heart rate ≥ 78 is an independent predictor of cardiovascular and all-cause mortality.