C55-24 Inpatient Outcomes of Individuals Admitted Due to First-Time Myocardial Infarction With Preexisting Pulmonary Embolism: A Nationwide Analysis 2016-2022

Rationale Myocardial infarction (MI) is defined as the acute reduction in coronary blood flow resulting in ischemia and myocardial cell death. Pulmonary embolism (PE) is the blockage of one or more pulmonary arteries by a thrombus. Although PE is associated with an increased risk of MI, the effect of preexisting PE on individuals hospitalized with first-time MI remains relatively unexplored. Our study aimed to evaluate the link between preexisting PE and inpatient outcomes among MI hospitalizations using a large national database in the United States. Methods A retrospective cohort analysis using the National Inpatient Sample (NIS) Database from 2016-2022 was conducted. Patients admitted with a primary diagnosis of a first time MI (ST Elevated Myocardial Infarction (STEMI) and Non-ST Elevated Myocardial Infarction (NSTEMI)), with preexisting Pulmonary Embolism were identified using ICD-10 codes. Primary outcome was in-hospital mortality. Secondary outcomes included length of stay (LOS), total charges, and use of various interventions. Univariate analysis was done and variables with p < 0.2 were considered for multivariate analysis, adjusting by age, gender, race, Charlson comorbidity index, hospital location and teaching status, size, region and insurance status. Significance was defined as p < 0.05. Results Among 1,022,535 STEMI hospitalizations, 4,404 (0.43%) had preexisting PE. These patients had significantly increased odds of mortality (OR = 3.90, p = 0.00), a 6.09-day longer length of stay (LOS) (p = 0.00), and higher charges ($122,340.30, p = 0.00). They had significantly increased odds of intubation (OR = 3.42, p = 0.00) and fibrinolysis (OR = 3.72, p = 0.00), but with decreased odds of coronary angiography (OR = 0.3858, p = 0.00). Among 2,516,739 NSTEMI hospitalizations, 17,914 (0.71%) had preexisting PE. These patients had significantly increased odds of mortality (OR = 3.05, p = 0.00), a 2.52-day longer LOS (p = 0.00), and higher charges ($31,172.92, p = 0.00). They also had increased intubation odds (OR = 2.52, p = 0.00), but with lower odds of coronary angiography (OR = 0.4282, p = 0.00), PCI (OR = 0.6112, p = 0.00), and CABG (OR = 0.8042, p = 0.001). Conclusion Patients with first-time MI and preexisting PE encountered statistically significant increases in the odds of inpatient mortality, length of stay, total hospital charges, and intubation, while experiencing decreased odds of undergoing coronary angiography. Our results imply that this patient subpopulation requires enhanced vigilance for complications, aggressive supportive care, and multidisciplinary management. The reduced odds of coronary angiography may reflect concerns about procedural risk, bleeding, or hemodynamic instability in this population, but may also represent missed opportunities for guideline-directed revascularization. The elevated likelihood for intubation and longer hospital stays further highlight the severity of illness and the need for careful risk stratification and resource allocation.