Aims: The Stent Thrombosis In Belgium (STIB) trial aimed to determine whether assessing platelet reactivity (PR) in patients with stable coronary artery disease undergoing elective percutaneous coronary intervention (PCI) could predict the risk of ischaemic complications and adverse clinical events up to 30 days post PCI.
Methods and results: PR before intervention was determined in 891 patients undergoing PCI for stable angina pectoris. Twelve to 24 hours before PCI, all patients received a 600 mg clopidogrel dose followed by 75 mg daily, and 500 mg of aspirin followed by 80-100 mg daily. Residual PR was assessed by VerifyNow point-of-care aspirin and P2Y12 assay before PCI. "Non-responders" to antiplatelet therapy were defined as aspirin reaction unit (ARU) >550 and as P2Y12 reaction unit (PRU) >230. The endpoint of the study was the composite of periprocedural myonecrosis, stent thrombosis, non-fatal myocardial infarction (MI), stroke and death at 30 days in patients with or without high PR. The endpoint was observed in 180 patients: four deaths, one stroke, 11 Q-wave MI, three non-Q-wave MI and 161 periprocedural myonecroses. At multivariate analysis, the endpoint was predicted by total stent length (OR: 1.020), GFR <60 ml/min (OR: 1.87), history of PCI (OR: 0.58), white blood cell count (OR: 1.95) and diabetes (OR: 1.83). No significant association was found between residual PR and the primary endpoint or any of its components.
Conclusions: PR measured before PCI in stable patients undergoing elective PCI who are preloaded with 500 mg of aspirin and 600 mg of clopidogrel is not predictive of periprocedural myocardial injury or adverse ischaemic complications up to 30 days.