Heart Rate Recovery after Submaximal Exercise Testing as a Predictor of Mortality in a Cardiovascularly Healthy Cohort

Background: Abnormal heart rate recovery after symptom-limited exercise predicts death. It is unknown whether this is also true among patients undergoing submaximal testing. Objective: To test the prognostic implications of heart rate recovery in cardiovascularly healthy adults undergoing submaximal exercise testing. Design: Population-based cohort study. Setting: 10 primary care sites. Participants: 5234 adults without evidence of cardiovascular disease who were enrolled in the Lipid Research Clinics Prevalence Study. Measurements: Heart rate recovery was defined as the change from peak heart rate to that measured 2 minutes later (heart rate recovery was defined as ≤42 beats/min). Results: During 12 years of follow-up, 312 participants died. Abnormal heart rate recovery predicted death (relative risk, 2.58 [Cl, 2.06 to 3.20]). After adjustment for standard risk factors, fitness, and resting and exercise heart rates, abnormal heart rate recovery remained predictive (adjusted relative risk, 1.55 [Cl, 1.22 to 1.98]) (P < 0.001). Conclusion: Even after submaximal exercise, abnormal heart rate recovery predicts death.