Influence of body mass index on the management and outcomes of acute myocardial infarction-cardiogenic shock in the United States, 2008–2017

Background: There are limited data on influence of body mass index (BMI) on outcomes of acute myocardial infarction-cardiogenic shock (AMI-CS). Methods: Adult AMI-CS admissions from 2008 to 2017 were identified from the National Inpatient Sample and stratified by BMI into underweight (<19.9 kg/m²), normal-BMI (19.9–24.9 kg/m²) and overweight/obese (>24.9 kg/m²). Outcomes of interest included in-hospital mortality, invasive cardiac procedures use, hospitalization costs, and discharge disposition. Results: Of 339,364 AMI-CS admissions, underweight and overweight/obese constitute 2356 (0.7%) and 46,675 (13.8%), respectively. In 2017, compared to 2008, there was an increase in underweight (adjusted odds ratio [aOR] 6.40 [95% confidence interval {CI} 4.91–8.31]; p < 0.001) and overweight/obese admissions (aOR 2.93 [95% CI 2.78–3.10]; p < 0.001). Underweight admissions were on average older, female, with non-ST-segment-elevation AMI-CS, and higher comorbidity. Compared to normal and overweight/obese admissions, underweight admissions had lower rates of coronary angiography (57% vs 72% vs 78%), percutaneous coronary intervention (40% vs 54% vs 54%), and mechanical circulatory support (28% vs 46% vs 49%) (p < 0.001). In-hospital mortality was lower in underweight (32.9% vs 34.1%, aOR 0.64 [95% CI 0.57–0.71], p < 0.001) and overweight/obese (27.6% vs 38.4%, aOR 0.89 [95% CI 0.87–0.92], p < 0.001) admissions. Higher hospitalization costs were seen in overweight/obese admissions while underweight admissions were discharged more often to skilled nursing facilities. Conclusion: Underweight patients received less frequent cardiac procedures and were discharged more often to skilled nursing facilities. Underweight and overweight/obese AMI-CS admissions had lower in-hospital mortality compared to normal BMI.