Relationship between Body Mass Index and Outcome of Elective Percutaneous Coronary Intervention

Studies have shown controversial effects of obesity on major adverse cardiac events (MACE) after percutaneous coronary intervention (PCI). We sought to investigate the impact of the body mass index (BMI) on the mid-term outcome following successful PCI. Between March 2006 and August 2008, 3948 patients underwent successful elective PCI in Tehran Heart Center, Tehran, Iran, and were retrospectively included in this study. Patients who underwent PCI on the same day as the occurrence of myocardial infarction were excluded. The demographic, procedural, in-hospital, and follow-up information of these patients was extracted from the PCI Data Registry of our institution. The patients were divided into three groups: normal weight (No. 1058, BMI < 25 kg/m2 age = 58 ± 10 years); overweight (No. 1867, 25 ≤ BMI < 30 kg/m2, age = 57 ± 10 years); and obese (No. 1023, BMI ≥ 30 kg/m2, age = 56 ± 10 years). MACE included death, myocardial infarction, target vessel revascularization, and target lesion revascularization. Compared with the other patients, the obese individuals were significantly younger and more frequently female, had a higher ejection fraction, and more frequently presented with hypertension, diabetes, and hyperlipidemia. There was no association between the BMI and the angiographic and procedural findings in the univariate analysis. While no difference was found in the rate of in-hospital death between the groups, the number of the obese patients undergoing emergent cardiac surgery was marginally different in the univariate analysis (p value = 0.06). At 9 months'' follow-up, MACE had occurred in 92 (2.3%) patients and cardiac mortality was 9 (0.2%). After adjustments for confounders, no significant difference was observed in terms of MACE between the BMI groups. The BMI had no significant effect on the rate of MACE at 9 months'' follow-up in our study population. Interventionists'' recommendations for patients undergoing PCI should, therefore, not be significantly influenced by the BMI status.