Myocardial infarction in older than 75 years: An increasing population. CASTUO Study

Objectives: Elderly patients with acute myocardial infarction constitute a population that is not adequately represented in clinical trials or medical registries. Our objective was to compare the clinical characteristics, treatments administered and mortality among patients younger and older than 75 years.

Material and methods: Observational retrospective study of patients hospitalized for acute myocardial infarction in the decade 2000-2009. Multivariate models were constructed to determine hospital and late mortality (median, 4.6 years; IQR 25-75: 2.1-7.3).

Results: We included 2,177 patients (995 men [79%]), with a mean age of 70.8 years (SD, 12.6). A total of 917 (42.0%) of the patients were 75 years of age or older. When compared with the patients younger than 75 years, the older patients had a greater prevalence of diabetes (38.3% vs. 32.5%; P<.002), chronic obstructive pulmonary disease (15.6% vs. 11.2%; P<.002), stroke (14.3% vs. 7.3%; P<.001), chronic renal failure (11.0% vs. 3.9%; P<.001), atrial fibrillation (15.9% vs. 6.9%; P<.001), heart failure (28.0% vs. 23.4%; P<.008). The older patients were treated with fewer beta-blockers (55.9% vs. 71.2%; P<.001), statins (44.3% vs. 62.3%; P<.001), coronary angiographies (17.9% vs. 48.5%; P<.001) and angioplasties (10.8% vs. 29.1%; P<.001). The patients older than 75 years had lower survival (mortality, 44.5% vs. 18.9%; HR 1.89; 95% CI 1.57-2.29). The use of beta-blockers (HR, 0.74; 95% CI 0.62-0.89), statins (HR 0.73; 95% CI 0.58-0.91) and angioplasty (HR, 0.42; 95% CI 0.30-0.57) was inversely correlated with mortality.

Conclusions: Patients older than 75 years with acute myocardial infarction had lower survival and were treated with fewer beta-blockers, statins and angioplasty, indications that are associated with lower mortality.