The presence of idiopathic thrombocytopenic purpura correlates with lower rate of acute ST-elevation myocardial infarction.

Background: Platelets are important in the pathogenesis of myocardial infarction (MI). We hypothesize that patients with acquired thrombocytopenia such as idiopathic thrombocytopenic purpura (ITP) may have lower MI rate. Materials & method: The Nationwide Inpatient Sample was used for this study. We analyzed the correlation between ST-elevation MI (STEMI) and ITP utilizing ICD-9 codes. Results: STEMI rate was lower in patients with ITP. We found that, in 2002, STEMI occurred in 0.64% of patients with ITP versus 0.89 (p < 0.007) and for 2011 0.30 versus 0.48 (p < 0.005). After adjusting for tobacco use, diabetes, hypertension, hyperlipidemia, gender and age, STEMI rate remained lower in ITP patients. Conclusion: ITP appears to be associated with lower STEMI rate suggesting low platelet count may exert protective effect from STEMI.