Background: In patients with myocardial infarction (MI), risk factors for bleeding and ischemic events tend to overlap, but the combined effects of these factors have scarcely been studied. We aimed to assess the combined impact of five established risk factors using nationwide registries.
Methods: Using SWEDEHEART and the National Patient Registry, patients hospitalized for MI and managed invasively in Sweden from 2006–2014 were included. The following five risk factors were considered for the primary ischemic outcome of cardiovascular death (CVD)/MI/stroke, and for the outcome major bleeding hospitalization: multivessel disease, diabetes mellitus, chronic kidney disease, prior MI, and age ≥65.
Results: During the study period, 100,879 patients had invasively managed MI, of whom 20,831 (20.6%) experienced CVD/MI/Stroke and 5,939 (5.9%) major bleeding, during a median follow-up of 3.6 years. The majority (53.5%) had two or more risk factors. With each added risk factor, there was a marked but gradual increase in incidence of the composite endpoint. This was also seen for bleeding, but to a lesser extent. Presence of all risk factors vs. only one was associated with a 5–9 times increased incidence of CVD/MI/Stroke, and a 2–4 times increased incidence of major bleeding (Figure).
Conclusions: The majority of patients with MI had two or more established risk factors. Increasing number of risk factors was associated with higher incidence of ischemic events, although this pattern was not as pronounced for major bleeding. The higher incidence of ischemic events in those with multiple risk factors highlights an unmet need for additional preventive measures.