Association of Thrombocytopenia, Revascularization, and In-Hospital Outcomes in Patients with Acute Myocardial Infarction

The impact of thrombocytopenia on revascularization and outcomes in patients presenting with acute myocardial infarction remains poorly understood. We sought to evaluate associations between thrombocytopenia, in-hospital management, bleeding, and cardiovascular outcomes in patients hospitalized for acute myocardial infarction in the United States.

Patients hospitalized from 2004 to 2014 with a primary diagnosis of acute myocardial infarction were identified from the National Inpatient Sample. Management of acute myocardial infarction was compared between patients with and without thrombocytopenia. Multivariable logistic regression models were used to estimate odds of in-hospital adverse events stratified by thrombocytopenia and adjusted for demographics, cardiovascular risk factors, comorbidities, and treatment.

A total of 6,717,769 patients were hospitalized with a primary diagnosis of acute myocardial infarction, and thrombocytopenia was reported in 219,351 (3.3%). Patients with thrombocytopenia were older, more likely to have other medical comorbidities, were more likely to undergo coronary artery bypass grafting (28.8% vs 8.2%, P < .001), and were less likely to receive a drug-eluting stent (15.5% vs 29.5%, P < .001). After multivariable adjustment, thrombocytopenia was independently associated with nearly twofold increased odds of in-hospital mortality (adjusted odds ratio 1.91; 95% confidence interval, 1.86-1.97). Thrombocytopenia was also independently associated with ischemic stroke, cardiogenic shock, cardiac arrest, and bleeding complications.

Patients with thrombocytopenia in the setting of acute myocardial infarction had increased odds of bleeding, cardiovascular outcomes, and mortality compared with patients without thrombocytopenia. Future investigations to mitigate the poor prognosis of patients with acute myocardial infarction and thrombocytopenia are warranted.