Risk factors in young patients with myocardial infarction: what is different from the general population?

Introduction Patients that suffer from myocardial infarction (MI) at a younger age are of special medical and socioeconomic interest. Data on risk factors for MI in this patient group are however scarce.
  Methods In this case–control study, clinical characteristics of consecutive patients admitted to hospital with MI at age of ≤45 years were compared to a randomly selected cohort from the general population in the same geographic region in Germany. After 3:1 matching on age and gender and multivariable analyses, independent risk factors for the occurrence of MI at a younger age were analyzed.
  Results 522 patients with MI ≤45 years were compared to 1191 matched controls from the general population. The proportion of active smokers was more than 3-fold higher in younger MI-patients compared to the general population (82.4% vs. 24.1%, p<0.01), while the proportion of persons consuming alcohol at least 2 times a week was higher in the general population (19.9% vs. 36.6%, p<0.01). Younger patients with MI were more often obese (median body mass index 28.4 vs. 25.5 kg/m2, p<0.01), had a higher proportion of hypertension (25.1% vs. 0.5%, p<0.01) or diabetes mellitus (11.7% vs. 1.7%, p<0.01) and had more often a family history of the father (22.4% vs. 7.1%, p<0.01) or the mother (7.5% vs. 1.3%, p<0.01) for premature coronary artery disease.
  In multivariable analysis, hypertension or diabetes, active smoking, family history and body mass index ≥30 kg/m2 were strong predictors for the occurrence of MI at a younger age, while alcohol consumption was a protective factor (Figure).
  Conclusions This case-control study demonstrates a very strong association of active smoking, metabolic syndrome and family history with the occurrence of MI at a younger age. The contrary is found regarding alcohol consumption.
  These data suggest that the risk of young-onset MI goes beyond family history and underline the importance of primary prevention efforts to reduce smoking and metabolic syndrome in children, adolescents and young adults in order to reduce the burden of cardiovascular diseases.