Prognostic significance of BMI after PCI treatment in ST-elevation myocardial infarction A cohort study from the Swedish Coronary Angiography and Angioplasty Registry

Abstract

AbstractBackgroundObesity along with clustering of cardiovascular risk factors is a promoter for coronary artery disease. On the other hand, a high BMI appears to exert a protective effect with respect to outcomes after a coronary artery event, termed the obesity paradox.MethodsThe Swedish Coronary and Angiography and Angioplasty registry (SCAAR) collects information on all patients who undergo percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) in Sweden along with demographic- and procedure-related data. We studied the predictability of four categories of BMI for 1-year all-cause mortality in people with STEMI undergoing PCI.ResultsAmong 25,384 patients, mean (SD) age 67.7 (12.1) years and 71.1% male, who underwent PCI for STEMI a total of 5,529 (21.8%) died within one year. Using normal-weight (BMI 18.5-24.9 kg/m2) as a reference, subjects with obesity (BMI ≥30 kg/m2) had a low 1-year all-cause mortality risk in unadjusted analysis, HR 0.59 (95% CI 0.53– 0.67). However, after adjustment for age, sex and other covariates the difference became non-significant, HR 0.88 (95% CI: 0.75-1.02). Patients with overweight (BMI 25.0-29.9 kg/m2) had the lowest 1-year mortality risk in analysis adjusted for age, sex and other covariates, HR 0.87 (95% CI 0.79-0.95), whereas those with underweight (BMI <18.5 kg/m2) had the highest mortality in both unadjusted HR 2.22 (95% CI 1.69–2.92) and adjusted analysis, HR 1.72 (95% CI: 1.31-2.26).ConclusionThe protective effect of obesity with respect to 1-year mortality after coronary intervention became non-significant after adjusting for age, sex and relevant co-variates. Instead, overweight people displayed the lowest risk and underweight individuals the highest risk for adjusted all-cause mortality