Abstract 4143796: Inpatient Mortality Trend in Obese Versus Non-Obese Patients With Acute Coronary Syndrome: “An Obesity Paradox” – 15-Year Nationwide Sample Analysis

Background: Obesity is endemic in the United States. Previous studies have reported an obesity paradox in mortality associated with acute coronary syndrome (ACS). However, percutaneous coronary intervention (PCI) and inpatient mortality trends over a long period of time in this group of patients remain unknown. Aim: To evaluate PCI and inpatient mortality trends among ACS patients with obesity over a 15-year period. Methods: We used the National Inpatient Sample from 2005 to 2019 to identify the study population using the International Classification of Diseases, Ninth and Tenth Revisions, Clinical Modification. The primary outcomes were (1) the trend in PCI use among obese patients admitted for ACS and (2) in-hospital mortality trends in these patients compared to non-obese ACS patients treated with PCI. The secondary outcome was total hospital costs over the years. Results: We evaluated 9,259,932 patients hospitalized in the United States for ACS. Of those, 1,345,937 (14.5%) were obese. Obese patients were younger (mean age 61 years) and had a higher percentage of females (41.3%) compared to non-obese counterparts (mean age 68 years, P<.001; 38.4% female, P<.001). Overall mortality among the obese patients was lower than in non-obese patients (3.0% vs 5.6%, P<.001). A total of 663,128 (49.2%) obese patients underwent PCI compared with 45% in the non-obese group (P<.001). From 2005 to 2019, the number of PCI procedures in the obese group increased approximately threefold (Figure 1A). During this period, the mortality rates among obese patients with ACS treated with PCI increased from 2.0% in 2005 to 2.9% in 2019 (P<.001), yet remained lower than those in the non-obese group, which experienced a slight decrease in mortality from 4.3% in 2005 to 3.8% in 2019 (P<.001) (Figure 1B). Length of stay and total cost were relatively similar, around 3.8 days and $23,000, respectively, in both groups. Conclusion: Over the past 15 years, an increasing trend of PCI adoption has been observed in obese patients. In these PCI-treated obese patients, we observed lower mortality rates compared with their non-obese counterparts. This obesity paradox suggests a potential protective effect of obesity, warranting further research to understand the underlying pathophysiology to improve treatment strategies for this demographic.