We reviewed 54,044 adult cases of cardiogenic shock (CS) accompanying acute coronary syndrome from the 2005 to 2014 Nationwide Inpatient Sample. We evaluated outcomes among patients who were nonobese, obese (body mass index 30.0 to 39.9 kg/m(2)) and extremely-obese (body mass index >= 40 kg/m(2)). A multivariate analysis was performed to assess their impact on in-hospital mortality. There were 3,602 (6.6%) and 1,610 (2.9%) admissions among patients who were obese and extremely-obese. Those obese and extremely-obese were younger compared with the nonobese (62.7 vs 61.2 vs 68.8 years, respectively; p <0.01) but had significantly greater comorbidity burden. CS patients who were not-obese were most likely to have an associated ST elevation myocardial infarction, compared with the obese and extremely-obese (67.7% vs 65.9% vs 60.7%; p <0.01). Compared to the nonobese, patients who were obese had higher rates of percutaneous coronary intervention (55.8% vs 51.5%; p <0.01) and coronary artery bypass grafting (24.0% vs 16.0%; p <0.01) whereas those extremely-obese had higher coronary artery bypass grafting rates (23.9% vs 16.0%; p <0.01) but similar percutaneous coronary intervention rates (51.1% vs 51.5 %; p = 0.74). Short-term mechanical support use was lowest among the nonobese followed by the extremely-obese and obese. Adjusted analysis revealed that obesity predicted less (adjusted odd ratio 0.82, 95% confidence interval 0.76 to 0.90) and extreme-obesity predicted higher in-hospital mortality (adjusted odds ratio 1.17, 95% confidence interval 1.05 to 1.32) compared with the nonobese. In conclusion, obesity and extreme-obesity are associated with greater comorbidity burden among ACS related CS admissions. Obesity predicted less in-hospital mortality, whereas extreme obesity was associated with elevated in-hospital mortality. (C) 2019 Elsevier Inc. All rights reserved.