Influence of age on clinical course, management and mortality of acute myocardial infarction in the Spanish population

Background: To assess age-related differences in cardiovascular risk factors, clinical course and management of patients with acute myocardial infarction (AMI) in intensive care (ICU) or coronary care units (CCU). Methods: A retrospective cohort study was conducted of all AMI patients listed in the ARIAM register (Analysis of Delay in AMI), a multi-centre register in which 119 Spanish hospitals participated. The study period was from January 1995 to January 2001. A univariate analysis was carried out to evaluate differences between different age groups. Multivariate analysis was used to assess whether age difference was an independent predisposing factor for mortality and for differences in patient management. Results: 17,761 patients were admitted to the ICUs/CCUs with a diagnosis of AMI. The distribution by ages was: <55 years, 3954 patients (22.3%); 55–64 years, 3593 (22.2%); 65–74 years, 5924 (33.4%); 75–84 years, 3686 (20.8%); and >84 years, 604 (3.4%) (P<0.0001); 24.6% of the patients were female, and the relative proportion of females increased with age. There were clear differences in risk factors between the different age groups, with a predominance of tobacco, cholesterol and family history of heart disease in the younger patients. The incidence of complications, including haemorrhagic complications, increased significantly with age. The older age groups had a lower rate of thrombolysis and less use of revascularisation techniques. The mortality of the above groups was 2.6, 5.4, 10.7, 17.7 and 25.8%, respectively. Age difference was an independent predictive variable for mortality and the administration of thrombolysis. Conclusions: The distinct age groups differed in cardiovascular risk factors, management and mortality. Age is a significant independent predictive variable for mortality and for the administration of thrombolysis.