Incidence and mortality of myocardial infarction among Catalonian older adults with and without underlying risk conditions: The CAPAMIS study

Background Population-based data about the epidemiology of acute myocardial infarction is limited. This study investigated incidence and mortality of acute myocardial infarction in older adults with specific underlying chronic conditions and evaluated the influence of these conditions in developing acute myocardial infarction. Design and methods This was a population-based cohort study involving 27,204 individuals >= 60 years of age in Tarragona (Catalonia, Spain). Data on all cases of hospitalised acute myocardial infarction were collected from 1 December 2008-30 November 2011. Incidence rates and 30-day mortality were estimated according to age, sex, chronic illnesses and underlying conditions. Multivariable Cox regression analysis was used to calculate hazard ratios and to estimate the association between baseline conditions and risk of developing acute myocardial infarction. Results The incidence of acute myocardial infarction was 475 per 100,000 person-years. Maximum rates appeared among individuals with history of coronary artery disease (2839 per 100,000), chronic severe nephropathy (1407 per 100,000), atrial fibrillation (1226 per 100,000), chronic heart disease (1149 per 100,000), history of stroke (1147 per 100,000) and diabetes mellitus (914 per 100,000). Thirty-day mortality was 15.3% overall, reaching 31.6% among patients over 80 years. In the multivariable analysis, history of coronary artery disease, age > 70 years, sex male, chronic heart disease, history of stroke, atrial fibrillation, diabetes mellitus and hypertension emerged as significantly associated with an increased risk of acute myocardial infarction. Conclusions The incidence and mortality of acute myocardial infarction remain considerable in our setting. Considering classical major risk factors, diabetes mellitus and hypertension were the underlying conditions most strongly associated with an increased risk in our study population.