Impact of Baseline Thrombocytopenia on Bleeding and Mortality After Percutaneous Coronary Intervention

It is still controversial whether baseline thrombocytopenia is independently associated with adverse events after percutaneous coronary intervention. We evaluated the influence of baseline thrombocytopenia against ischemic, bleeding and mortality among the 19,353 patients whose baseline platelet counts were available in the pooled database from the 3 studies in Japan. Baseline thrombocytopenia was classified as follows: mild, ≥100 and <150 × 10⁹/L; moderate, ≥50 and <100 × 10⁹/L; and severe, <50 × 10⁹/L. Primary ischemic outcome measure was defined as composite of myocardial infarction and ischemic stroke, and primary bleeding outcome measure was defined by the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded arteries trial as moderate or severe bleeding. There were 2,590 patients (13.4%) with baseline thrombocytopenia comprising 292 patients (1.5%) with moderate/severe (moderate: 277 and severe: 15) thrombocytopenia and 2,298 patients (11.9%) with mild thrombocytopenia, whereas 16,763 patients (86.6%) had no thrombocytopenia. During 3-year follow-up, the adjusted risks of moderate/severe and mild thrombocytopenia relative to none were neutral for primary ischemic outcome (hazard ratio [HR] 1.07 [95% confidence interval [CI] 0.72 to 1.60], p = 0.74, and HR 0.93 [0.79 to 1.09], p = 0.37, respectively) but were significantly higher for primary bleeding outcome (HR 2.35 [1.80 to 3.08], p <0.001, and HR 1.20 [1.03 to 1.40], p = 0.02), and for mortality (HR 2.34 [1.87 to 2.93], p <0.001, and HR 1.26 [1.11 to 1.43], p <0.001). In conclusion, patients with baseline thrombocytopenia, even a mild one, had a higher risk of bleeding events and all-cause death, but not for ischemic events after percutaneous coronary intervention.