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Association of cigarette smoking with chronotropic incompetence and prognosis in the Framingham Heart Study
M S Lauer1, F J Pashkow, M G Larson
1Department of Cardiology, Cleveland Clinic Foundation, Ohio 44195, USA. lauerm@cesmtp.ccf.org
Insights
Cigarette smoking is linked to chronotropic incompetence, a condition where the heart rate doesn't increase adequately during exercise. Male smokers with this condition face a significantly higher risk of death and coronary heart disease.
Area of Science:
- Cardiology
- Public Health
- Smoking Cessation
Background:
- Chronotropic incompetence (CI) is a condition affecting heart rate response during exercise.
- The association between cigarette smoking and CI requires further investigation.
- Understanding the prognostic implications of smoking-related CI is crucial for cardiovascular health.
Purpose of the Study:
- To determine if cigarette smoking is associated with chronotropic incompetence.
- To explore the prognostic implications of this association in a large cohort.
Main Methods:
- Utilized data from the Framingham Offspring Study, including 1468 men and 1642 women.
- Assessed chronotropic incompetence using two methods: failure to reach target heart rate and a low chronotropic index.
- Followed participants for 8 years to track mortality and coronary heart disease events.
Main Results:
- Smokers were significantly more likely than non-smokers to exhibit chronotropic incompetence in both men and women.
- These associations remained significant after adjusting for cardiovascular risk factors and pulmonary function.
- Among men, smoking combined with chronotropic incompetence was associated with a substantially increased risk of death and coronary heart disease.
Conclusions:
- Cigarette smoking is a significant predictor of chronotropic incompetence in a population-based cohort.
- Male smokers with chronotropic incompetence face a particularly high risk of adverse cardiovascular outcomes, including mortality and coronary heart disease.
Background:
In this study, we sought to determine whether cigarette smoking is associated with chronotropic incompetence and to explore prognostic implications of this association.
Methods And Results:
Members of the Framingham Offspring Study (1468 men and 1642 women) underwent graded exercise. Chronotropic incompetence was assessed in two ways: (1) failure to achieve an age-predicted target heart rate and (2) a low chronotropic index, a heart rate response measure that accounts for effects of age, resting heart rate, and physical fitness. Smokers were more likely to fail to reach target heart rate than were nonsmokers (men, 25% versus 15%, odds ratio [OR], 1.97; 95% confidence interval [CI], 1.51 to 2.56; women, 32% versus 18%; OR, 2.10; 95% CI, 1.63 to 2.61) and were more likely to have a low chronotropic index (men, 17% versus 12%; OR, 1.50; 95% CI, 1.12 to 2.03; women, 17% versus 8%; OR, 2.28; 95% CI, 1.68 to 3.09). These associations persisted after adjustment for age, cardiovascular risk factors, pulmonary function, and ST-segment response to graded exercise. During 8 years of follow-up, there were 48 deaths and 90 incident coronary heart disease events among the men. After adjustment for the same confounders, men who were smokers and failed to achieve target heart rate were at particularly high risk for death (adjusted relative risk [RR], 2.45; 95% CI, 1.14 to 5.24) and for coronary heart disease (adjusted RR, 4.92; 95% CI, 2.84 to 8.53). There were too few end points in women for analysis.
Conclusions:
In this population-based cohort, cigarette smoking was predictive of chronotropic incompetence. Male smokers who manifested chronotropic incompetence were at particularly high risk for death and coronary heart disease events.