Aim: Previous studies regarding on-treatment platelet reactivity have focused on response variability to individual antiplatelet agents. There are limited data on [1] response variability to both of these anti-platelet drugs, [2] efficacy of combining two point-of-care tests (POCT) simultaneously and [3] how it predicts the clinical outcome after percutaneous coronary intervention (PCI).
Methods: We analyzed 716 patients, enrolled in the CILON-T prospective randomized controlled trial, with both VerifyNow P2Y12 (PRU) and Aspirin (ARU) data at discharge. Patients were classified according to the tertile of PRU, ARU and the sum of the tertiles of PRU and ARU. The primary endpoint was the composite of cardiac death, nonfatal myocardial infarction (MI) and ischemic stroke at 6 months post-PCI.
Results: Ten patients reached the primary endpoint, four of which were nonfatal MI and six ischemic stroke. When analyzed for the primary endpoint, tertiles of ARU and PRU were not able to discriminate patients with future thrombotic events from the remainder (p= 0.197 for ARU and 0.058 for PRU with the log-rank test, respectively), whereas combining the tertiles of ARU and PRU was significantly effective (p= 0.019 for ARU+PRU with the log-rank test). Multivariate analysis showed that the highest tertile of the sum of ARU and PRU tertiles was the only significant predictor of future thrombotic events after PCI (HR 6.34, 95% confidence interval 1.32-30.47, p= 0.021).
Conclusions: In this post-hoc analysis of the CILON-T trial, combining the results of ARU and PRU simultaneously had a significant role in discriminating patients at highest risk of future thrombotic events after PCI compared with either assay alone.