Association of Smoking Cessation and Survival Among Young Adults With Myocardial Infarction in the Partners YOUNG-MI Registry

Abstract

This cohort study identifies the prevalence of tobacco use and examines the association of both smoking and smoking cessation with survival in a cohort of adults who experienced a myocardial infarction at a young age.

Key Points

Question

Is smoking cessation associated with lower mortality among young adults after an initial myocardial infarction (MI)?

Findings

In this cohort study of 2072 individuals who experienced an initial MI at 50 years or younger, approximately half were smokers at the time of their MI, and 62% continued to smoke at 1 year after MI. Smoking cessation within 1 year after MI was associated with a statistically significant reduction in long-term all-cause and cardiovascular mortality.

Meaning

Smoking cessation after MI was associated with a clinically significant reduction in all-cause and cardiovascular mortality in a cohort of patients who experienced an MI at a young age.

Abstract

Importance

Despite significant progress in primary prevention, the rate of myocardial infarction (MI) continues to increase in young adults.

Objectives

To identify the prevalence of tobacco use and to examine the association of both smoking and smoking cessation with survival in a cohort of adults who experienced an initial MI at a young age.

Design, Setting, and Participants

The Partners YOUNG-MI registry is a retrospective cohort study from 2 large academic centers in Boston, Massachusetts, that includes patients who experienced an initial MI at 50 years or younger. Smoking status at the time of presentation and at 1 year after MI was determined from electronic medical records. Participants were 2072 individuals who experienced an MI at 50 years or younger between January 2000 and April 2016. The dates of analysis were October to December 2019.

Main Outcomes and Measures

Deaths were ascertained from the Social Security Administration Death Master File, the Massachusetts Department of Vital Statistics, and the National Death Index. Cause of death was adjudicated independently by 2 cardiologists. Propensity score–adjusted Cox proportional hazards modeling was used to evaluate the association between smoking cessation and both all-cause and cardiovascular mortality.

Results

Among the 2072 individuals (median age, 45 years [interquartile range, 42-48 years]; 1669 [80.6%] men), 1088 (52.5%) were smokers at the time of their index hospitalization. Of these, 910 patients were further classified into either the cessation group (343 [37.7%]) or the persistent smoking group (567 [62.3%]) at 1 year after MI. Over a median follow-up of 11.2 years (interquartile range, 7.3-14.2 years), individuals who quit smoking had a statistically significantly lower rate of all-cause mortality (hazard ratio [HR], 0.35; 95% CI, 0.19-0.63; P < .001) and cardiovascular mortality (HR, 0.29; 95% CI, 0.11-0.79; P = .02). These values remained statistically significant after propensity score adjustment (HR, 0.30 [95% CI, 0.16-0.56; P < .001] for all-cause mortality and 0.19 [95% CI, 0.06-0.56; P = .003] for cardiovascular mortality).

Conclusions and Relevance

In this cohort study, approximately half of individuals who experienced an MI at 50 years or younger were active smokers. Among them, smoking cessation within 1 year after MI was associated with more than 50% lower all-cause and cardiovascular mortality.