Platelet activation predicts recurrent ischemic events after percutaneous coronary angioplasty: A 6 months prospective study

An increasing amount of evidence indicates that platelet reactivity, despite a standard anti-thrombotic therapy, is a potential risk factor for recurrent myocardial ischemia in patients with coronary artery disease. We now hypothesize that this condition, measured by collagen–epinephrine (CEPI) or collagen–ADP (CADP) closure times (CT) by Platelet Function Analyzer (PFA-100), may predict the recurrence of coronary events after percutaneous coronary intervention (PCI). CEPI and CADP-CT were measured 30 ± 8 h after PCI in 175 consecutive patients admitted with a diagnosis of stable angina ( n = 94) or acute coronary syndromes ( n = 81) and prospectively followed up for a mean period of 6 months. We stratified the patients in accordance to both the CEPI-CT ( 190 s), reflecting the intensity of cycloxygenase inhibition by aspirin and the distribution into quartiles for CADP-CT. CEPI-CT < 190 s as well as CADP-CT < 82 s were associated with a higher rate of clinical recurrence (hazard ratio 8.5, p < 0.001 and 22.9, p < 0.001, respectively). Multivariate analysis after adjustment for other risk factors confirmed that the lowest CADP-CT quartile significantly correlates with the risk of recurrent coronary events (hazard ratio 36.5, p < 0.01), as well as CEPI-CT < 190 s (hazard ratio 6.7, p = 0.01). An enhanced platelet function after PCI when measured under high shear rates by PFA-100 is an independent predictor of a worst clinical outcome, even during a short term follow-up and may help in patients risk stratification.