Hospitalization Outcomes After Acute Myocardial Infarction in Patients With Prior Thoracic Irradiation

Thoracic radiation therapy is a cornerstone in the treatment of malignancies such as breast cancer, lung cancer, esophageal cancer, and lymphoma. While its long-term cardiac risks are well known, there is limited data on how prior thoracic irradiation is associated with outcomes in patients hospitalized with acute myocardial infarction (AMI). This study evaluates the association between prior chest irradiation and in-hospital outcomes among patients admitted with AMI. A retrospective cohort study using the National Inpatient Sample (2016-2022) was conducted. Adult AMI admissions were identified via ICD-10 codes and stratified by history of thoracic radiation. Multivariable regression and propensity matching were used to evaluate the association of prior radiation on in-hospital mortality (primary outcome), and secondary outcomes including hospitalization cost, length of stay, and use of intensive interventions. Of 4,353,204 AMI hospitalizations, 5,280 had a history of thoracic radiation. Prior radiation was associated with increased in-hospital mortality (aOR: 1.55, 95% CI 1.06 to 2.27, p = 0.023). There were no significant differences in hospitalization cost (-$6,126, p = 0.196) or length of stay (-0.20 days, p = 0.327). Patients with prior radiation were more likely to have do-not-resuscitate orders (aOR: 2.15, p <0.001) and receive palliative care consultations (aOR: 2.43, p <0.001). Prior thoracic radiation is associated with worse in-hospital survival following AMI, along with greater palliative involvement and end-of-life care decisions. These findings underscore the need for cardio-oncology-informed inpatient care in this high-risk population.