Mortality after myocardial infarction: impact of gender and smoking status

We have shown previously that smoking causes a first myocardial infarction (MI) to occur significantly more prematurely in women than in men. The aim of the study was to investigate mortality after MI with special emphasis on the impact of smoking and gender. The study included 2,281 consecutive patients (36.8% women) who died or were discharged from a central hospital with a diagnosis of MI from 1998 to 2005; the median follow-up of survivors was 7 years. Death after MI was adjusted for confounders. Mean age for women was 5.8 years older than for men (76.0 vs. 70.2 years) and women were less likely to have been smokers. In-hospital mortality for the first MI was 8.9% for men and 13.3% for women, and total mortality rates for all indexed MI after 7 years were 47% for men and 61% for women. Using Cox regression analysis, with all indexed MIs included, the after-discharge mortality for women was significantly lower than for men (hazard ratio 0.82; 95% confidence interval 0.70-0.96; P = 0.015). Compared with non-smokers, patients who were smokers on admission had significantly increased seven-year mortality after discharge (hazard ratio 1.30; 95% confidence interval 1.03-1.63; P = 0.002). In conclusion, current smoking at the time of the indexed MI was associated with increased mortality after 7 years follow-up. The smoking effect was independent of gender. Female gender was associated with a moderately lower risk of death during the same follow-up period.