Effect of Baseline Thrombocytopenia on Ischemic Outcomes in Patients With Acute Coronary Syndromes Who Undergo Percutaneous Coronary Intervention

Abstract

Background: Acquired thrombocytopenia (TP) has been associated with short-and long-term adverse outcomes after percutaneous coronary intervention (PCI), but the role of baseline TP is less well defined. We sought to evaluate the effect of TP on long-term adverse outcomes in patients with acute coronary syndromes (ACS) who undergo PCI. Methods: Data from 10,603 patients who underwent PCI for non-ST-elevation ACS or ST-elevation myocardial infarction were pooled from 2 large-scale randomized trials, Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) and Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI). Patients were stratified according to baseline platelet counts. Those with platelet counts <150,000/mm(3) were considered to have normal platelet counts. Adverse event rates were compared between groups with and without multivariable adjustment. Results: Baseline TP was present in 607 (5.7%) patients. The unadjusted 1-year rates of death (6.7% vs 3.6%; P < 0.0001), occurrence of major adverse cardiac event (MACE) (20.8% vs 15.6%; P = 0.0002), and target lesion revascularization (TLR; 9.4% vs 7.2%; P = 0.01) were significantly higher in patients with baseline TP compared with patients with normal platelet counts. By multivariable analysis, the presence of TP at baseline was an independent predictor of 1-year death (hazard ratio [HR], 1.74; 95% confidence interval [CI], 1.12-2.69; P = 0.01), ischemic TLR (HR, 1.37; 95% CI, 1.04-1.81; P = 0.03), and MACE (HR, 1.39; 95% CI, 1.09-1.79; P = 0.009). Conclusions: The presence of baseline TP in the setting of ACS patients who undergo PCI was strongly predictive of death, ischemic TLR, and MACE at 1 year. Baseline TP might be a useful baseline clinical parameter to estimate future ischemic risk after PCI.