Long-term prognostic factors of young patients (≤ 35 years) having acute myocardial infarction: the detrimental role of continuation of smoking

Abstract

Background There are few and conflicting data regarding the prognostic role of continued smoking in very young survivors of acute myocardial infraction (AMI) after the event. Design We conducted a prospective study to evaluate the impact of smoking habits on long-term outcome in individuals who sustained AMI at the age of ≤ 35 years. Methods We recruited 147 consecutive patients who had survived their first AMI at the age of ≤ 35 years. Patients were followed up for up to 10 years. Clinical end points were: readmission for acute coronary syndrome, cardiac death or coronary revascularization because of clinical deterioration. Results The most prevalent risk factor at presentation was smoking (94.8%). Follow-up data were obtained by 135 patients (32 ± 3 yeas old, 115 men). During follow-up 75 (55.6%) patients reported continuation of smoking. Forty-four (32.6%) patients presented cardiac events (three cardiac deaths, 30 acute coronary syndromes, and 11 revascularizations). Multivariate data analysis showed that persistence of smoking (relative risk = 2.35, 95% confidence interval 1.5–5.25, P = 0.03) and ejection fraction at presentation (relative risk = 0.95, 95% confidence interval 0.91–0.98, P= 0.008) were the only significant predictors of cardiac events after adjusting for various confounding factors. In addition, continuation of smoking was the most significant predictor of cardiac events during follow-up in our sample (i.e. had the lowest log-likelihood ratio as compared with ejection fraction or other covariates). Conclusion Persistence of smoking is the most powerful predictor for the recurrence of cardiac events in patients with premature AMI.