Acute Myocardial Infarction in Smokers

pp 65-73

Abstract

Background

It is well established that cigarette smoking is a major contributor to the risk of myocardial infarction. Paradoxically, the short-term prognosis after myocardial infarction has been reported to be better in smokers. The purpose of this study was to identify factors that could contribute to this curious finding. To examine this, we analyzed data from the GEMICA I (Grupo Estudios Multicentricos deInsuficiencia Coronaria en Argentina) study.

Methods and results

The study population consisted of 751 patients admitted to the hospital with myocardial infarction.Patients were divided into three groups: nonsmokers, ex-smokers and active smokers. The smoking group included less women, was younger, had a lower prevalence of hypertension and diabetes mellitus and a lower rate of past history of previous myocardial infarction or heart failure. The in-hospital mortality of current smokers was lower than that of ex-smokers and nonsmokers: 2.68 % versus 9.18% and 8.83%, respectively (p < 0.0026).When the baseline variables that were associated with in-hospital mortality were accounted for, the odds ratios of ex-smokers and smokers in relation to nonsmokers were respectively: 0.98 (IC 95% _0.42-2.27) and 0.45 (IC 95% = 0.20-0.99).

Conclusions

While cigarette smoking is a risk factor for myocardial infarction, smokers have a significantly better hospital outcome than ex-smokers and non-smokers. Factors which might explain this unex-ected finding include the possibility of a less severe degree of underlying coronary disease and the exclusion of patients who died prior to hospital admission.