Body mass index and acute and long-term outcomes after acute myocardial infarction (from the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction Trial)

The clinical outcome of acute cardiovascular events may be more favorable in patients with a high body mass index (BMI), although obesity increases the risk for cardiovascular diseases. The authors sought to define the association between BMI and acute and long-term outcome of patients presenting within 12 hours of ST-segment myocardial infarction (STEMI) in a large multinational cohort. A total of 3,579 patients enrolled in the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction trial were stratified according to BMI quartiles: <24.5, 24.5 to <27.1, 27.1 to 30.1, and >30.1 kg/m² (quartiles 1, 2, 3, and 4, respectively). Death, myocardial reinfarction, ischemia-driven target vessel revascularization, stroke, and noncoronary artery bypass grafting-related major bleeding events were centrally adjudicated for the acute, 30 days, and yearly follow-up. Patients with a BMI in the highest quartile were younger than patients in the lower BMI quartiles and more frequently had hypertension, hyperlipidemia, and diabetes mellitus. Complete occlusions and noncalcified lesions were more common in patients with a high BMI. In-hospital mortality decreased with increasing BMI due to lower cardiac mortality (2.9%, 2.3%, 1.2%, and 1.0% for quartiles 1, 2, 3, and 4, respectively, p <0.05). Out-of-hospital 3-year mortality was also lower in higher-weight patients due to lower noncardiac mortality (4.2%, 2.6%, 2.3%, and 1.7% for quartiles 1 to 4, respectively, p = 0.01). After adjustment for covariates, BMI was no longer predictive of acute or long-term mortality after STEMI. In conclusion, as BMI increases, patients have a more extensive adjusted cardiovascular risk profile and disease burden and premature STEMI onset but similar adjusted acute and long-term outcomes.