Related Experiment Video
Updated: Jul 14, 2026
Effects of Surgical Masks on Cardiopulmonary Function in Healthy Subjects
Published on: February 12, 2021
Impaired chronotropic response to exercise stress testing as a predictor of mortality
M S Lauer1, G S Francis, P M Okin
1Department of Cardiology, The George M. and Linda H. Kaufman Center for Heart Failure, Cleveland Clinic Foundation, Ohio 44195, USA. lauerm@cesmtp.ccf.org
Context:
Chronotropic incompetence, an attenuated heart rate response to exercise, is a predictor of all-cause mortality in healthy populations. This association may be independent of exercise-induced myocardial perfusion defects.
Objective:
To examine the prognostic significance of chronotropic incompetence in a low-risk cohort of patients referred for treadmill stress testing with thallium imaging.
Design:
Prospective cohort study conducted between September 1990 and December 1993.
Setting:
Tertiary care academic medical center.
Patients:
Consecutive patients (1877 men and 1076 women; mean age, 58 years) who were not taking beta-blockers and who were referred for symptom-limited treadmill thallium testing.
Main Outcome Measures:
Association of chronotropic incompetence, defined as either failure to achieve 85% of the age-predicted maximum heart rate or a low chronotropic index, a heart rate response measure that accounts for effects of age, resting heart rate, and physical fitness, with all-cause mortality during 2 years of follow-up.
Results:
Three hundred sixteen patients (11%) failed to reach 85% of the age-adjusted maximum heart rate, 762 (26%) had a low chronotropic index, and 612 (21%) had thallium perfusion defects. Ninety-one patients died during the follow-up period. After adjustment for age, sex, thallium perfusion defects, and other confounders, failure to reach 85% of the age-predicted maximum heart rate was associated with increased risk of death (adjusted relative risk [RR], 1.84; 95% confidence interval [CI], 1.13-3.00; P=.01), as was a low chronotropic index (adjusted RR, 2.19; 95% CI, 1.43-3.44; P<.001).
Conclusion:
Among patients with known or suspected coronary disease, chronotropic incompetence is independently predictive of all-cause mortality, even after considering thallium perfusion defects. Incorporation of chronotropic response into the routine interpretation of stress thallium studies may improve the prognostic power of this test.
