In‐Hospital Outcomes of Acute Myocardial Infarction With Essential Thrombocythemia and Polycythemia Vera: Insights From the National Inpatient Sample

BACKGROUND: Acute myocardial infarction (AMI) with essential thrombocythemia (ET) or polycythemia vera is rare, and there are scarce real‐world data on its management and impact on in‐hospital outcomes. METHODS AND RESULTS: Dates of current retrospective cohort study were obtained from the US National Inpatient Sample from October 2015 to 2019 for hospitalizations with AMI. The primary outcome was in‐hospital mortality, and the secondary outcome was major adverse cardiac or cerebrovascular events, stroke, and bleeding; major adverse cardiac or cerebrovascular event was defined by a composite of all‐cause mortality, stroke, and cardiac complications. Of the 2 871 934 weighted AMI hospitalizations, 0.27% were with ET and 0.1% were with polycythemia vera. Before propensity matching, AMI hospitalization with ET was associated with increased risk of in‐hospital mortality (7.1% versus 5.7%; odds ratio [OR], 1.14 [95% CI, 1.04–1.24]), major adverse cardiac or cerebrovascular events (12.6% versus 9%; OR, 1.36 [95% CI, 1.26–1.45]), bleeding (12.7% versus 5.8%; OR, 2.28 [95% CI, 2.13–2.44]), and stroke (3.1% versus 1.8%; OR, 1.66 [95% CI, 1.46–1.89]). Polycythemia vera was associated with an increased risk of in‐hospital mortality (7.8% versus 5.7%; OR, 1.21 [95% CI, 1.04–1.39]) and major adverse cardiac or cerebrovascular events (12.0% versus 9%; OR, 1.18 [95% CI, 1.05–1.33]). After propensity matching, ET was associated with increased risk of bleeding (12.6% versus 6.1%; OR, 2.22 [95% CI, 1.70–2.90]), and AMI with polycythemia vera was not associated with worse in‐hospital outcomes. CONCLUSIONS: AMI hospitalization with ET is associated with high bleeding risk before and after propensity score matching, particularly for hospitalizations treated with percutaneous coronary intervention. The management of AMI requires a multidisciplinary and patient‐centered approach to ensure safety and improve outcomes.