The prognostic value of heart rate recovery in patients with coronary artery disease: A systematic review and meta-analysis

Background: Routine outpatient care of patients with coronary artery disease (CAD) lacks a simple measure of physical fitness and risk of mortality. Heart rate recovery (HRR) is noninvasive and easily obtainable in outpatient settings. Prior studies have suggested that delayed postexercise HRR in the first minutes is associated with mortality in several types of populations. However, a comprehensive overview of the prognostic value of delayed HRR for time to mortality specifically in CAD patients is not available. The purpose of the current meta-analysis is to evaluate the prognostic value of delayed HRR in CAD patients. Methods: We conducted a systematic search in OVID MEDLINE and OVID EMBASE to identify studies reporting on HRR and risk of incident cardiovascular events or mortality in CAD patients. Hazard ratios for delayed versus nondelayed HRR were pooled using random-effects meta-analysis. Results: Four studies were included, comprising 2,428 CAD patients. The study quality of the included studies was rated moderate (n = 2) to high (n = 2). Delayed HRR was defined by ≤12 to ≤21 beat/min in the recovery period. During follow-up (range 2.0-9.8 years), 151 patients died (6.2% [range 2.5%-19.5%]). Only data on mortality could be pooled. Heterogeneity was limited (I2 = 32%; P =.23); pooled unadjusted hazard ratio for mortality, based on 3 studies, was 5.8 (95% CI 3.2-10.4). Conclusions: In CAD patients, delayed HRR is significantly associated with all-cause mortality. As exercise testing is performed routinely in CAD patients, HRR can be considered in monitoring exercise; still, further research must investigate the addition of HRR in current risk scores.