Smoking Status and Risk for Recurrent Coronary Events after Myocardial Infarction

17 September 2002 | Volume 137 Issue 6 | Pages 494-500

Background: Questions remain about the importance of smoking and smoking cessation after incident myocardial infarction.

Objective: To assess the association between smoking status and risk for recurrent coronary events.

Design: Retrospective, population-based, inception cohort study.

Setting: Health maintenance organization from 1986 to 1996.

Patients: 2619 persons who survived to hospital discharge after a first myocardial infarction.

Measurements: Relative risk (RR), assessed by using Cox proportional-hazards regression analysis, for recurrent coronary events in nonsmokers (persons with no history of smoking), former smokers (persons who had stopped smoking before infarction), quitters (persons who stopped smoking after infarction), and active smokers (persons who continued smoking after infarction).

Results: At the time of incident infarction, 33.6% of patients were nonsmokers, 35.5% were former smokers, and 30.9% were active smokers. Of the 808 persons who were active smokers at the time of incident infarction, 449 quit smoking during hospitalization or after discharge. With nonsmokers as the reference group, the multivariable RR for recurrent coronary events (n = 433) was 1.17 (95% CI, 0.93 to 1.43) for former smokers and 1.51 (CI, 1.10 to 2.07) for active smokers. Among quitters, the RR decreased as duration of cessation increased: With nonsmokers as the reference group, the RR for quitters was 1.62 (CI, 1.02 to 2.61) if the duration of cessation was 0 to less than 6 months, 1.60 (CI, 0.97 to 2.60) if the duration was 6 to less than 18 months, 1.48 (CI, 0.76 to 2.51) if the duration was 18 to less than 36 months, and 1.02 (CI, 0.54 to 1.86) if the duration was 36 months or more (P = 0.01 for trend).

Conclusion: After incident myocardial infarction, smoking was associated with an elevated risk for recurrent coronary events. In persons who quit smoking after infarction, the risk declined to equal that of nonsmokers by 3 years after cessation.

Editors' Notes Background Smoking cessation decreases the risk for myocardial infarction among people without previous coronary disease, but its effect on risk reduction after a first myocardial infarction has not been well studied. Contribution The researchers retrospectively observed relative risk for recurrent coronary events in patients discharged from the hospital after an incident myocardial infarction. Compared to nonsmokers, active smokers were 1.5 times more likely to have reinfarction. Among persons who had stopped smoking, relative risk decreased gradually to the nonsmokers' level over 36 months. Implications Physicians should emphasize the proven benefits of smoking cessation to encourage patients to quit after a first myocardial infarction. –The Editors

 

Author and Article Information

Grant Support: By grants HL53375, HL40628, and HL43201 from the National Heart, Lung, and Blood Institute, Bethesda, Maryland.

Potential Financial Conflicts of Interest: None disclosed.

Requests for Single Reprints: Thomas D. Rea, MD, MPH, University of Washington, Cardiovascular Health Research Unit, Metropolitan Park, East Tower, 1730 Minor Avenue, Suite 1360, Seattle, WA 98101; e-mail, rea123{at}u.washington.edu.

Current Author Addresses: Drs. Rea, Heckbert, Smith, Lemaitre, and Psaty: University of Washington, Cardiovascular Health Research Unit, Metropolitan Park, East Tower, 1730 Minor Avenue, Suite 1360, Seattle, WA 98101.

Dr. Kaplan: Department of Epidemiology and Social Medicine, Belfer Room 1308C, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461.

Author Contributions: Conception and design: T.D. Rea, S.R. Heckbert, B.M. Psaty.

Analysis and interpretation of the data: T.D. Rea, S.R. Heckbert, R.C. Kaplan, N.L. Smith, R.N. Lemaitre.

Drafting of the article: T.D. Rea, R.C. Kaplan.

Critical revision of the article for important intellectual content: T.D. Rea, S.R. Heckbert, R.C. Kaplan, N.L. Smith, R.N. Lemaitre.

Final approval of the article: T.D. Rea, S.R. Heckbert, R.C. Kaplan, N.L. Smith, B.M. Psaty.

Provision of study materials or patients: S.R. Heckbert, B.M. Psaty.

Statistical expertise: T.D. Rea, S.R. Heckbert, R.C. Kaplan, B.M. Psaty.

Obtaining of funding: S.R. Heckbert, B.M. Psaty.

Administrative, technical, or logistic support: S.R. Heckbert, R.C. Kaplan, B.M. Psaty.

Collection and assembly of data: S.R. Heckbert, R.C. Kaplan, B.M. Psaty.