Effect of morbid obesity on in-hospital mortality and coronary revascularization outcomes after acute myocardial infarction in the United States.

The aim of this study was to investigate the impact of morbid obesity (body mass index ≥40 kg/m(2)) on in-hospital mortality and coronary revascularization outcomes in patients presenting with acute myocardial infarctions (AMI). The Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project was used, and 413,673 patients hospitalized with AMIs in 2009 were reviewed. Morbidly obese patients constituted 3.7% of all patients with AMIs. Analysis of the unadjusted data revealed that morbidly obese patients compared with those not morbidly obese were more likely to undergo any invasive cardiac procedures when presenting with either ST-segment elevation myocardial infarction (97.4% vs 93.8%, p <0.0001) or non-ST-segment elevation myocardial infarction (85.5% vs 80.6%, p <0.0001). The unadjusted mortality rate for morbidly obese patients with AMIs was 3.5%, compared with 5.5% of those not obese (p <0.0001). After adjustment, lower odds of mortality in those morbidly obese compared to those not morbidly remained. In conclusion, patients with morbid obesity had lower odds of in-hospital mortality, compared to those not morbidly obese, consistent with the phenomenon of the "obesity paradox."