Optimal aNtiplatelet pharmacotherapy guided by bedSIDE genetic or functional TESTing in elective PCI patients: A pilot study: ONSIDE TEST pilot.

BACKGROUND Dual antiplatelet therapy (DAPT) is recommended after elective percutaneous coronary intervention (PCI) in stable coronary artery disease (SCAD) patients; however, still one-third of patients do not obtain adequate platelet inhibition that may result in increased cardiovascular risk. The aim of the ONSIDE TEST study is to evaluate the clinical impact of point-of-care genotyping- and platelet function-based personalized dual antiplatelet strategies in SCAD individuals undergoing PCI. METHODS Fifty patients were randomized to one of the three study arms: 1) genotyping, 2) platelet function testing (PFT) and 3) control. Patients were tested with point-of-care Spartan RX CYP2C19 System (group 1) and VerifyNow P2Y12 assay (group 2). In cases of inadequate response to clopidogrel, a loading dose of prasugrel was administered before PCI. The main clinical endpoint is the incidence of periprocedural myocardial injury (PMI). RESULTS Five (32%) patients in the genotyping arm and two (13%) in the in the PFT arm were identi-fied as poor clopidogrel metabolizers. The periprocedural platelet reactivity was significantly lower in the genotyping (80 ± 49.0 PRU) and PFT (36.5 ± 47 PRU) arms as compared to the control arm (176 ± 67.8 PRU), p = 0.01 and p = 0.03, respectively. PMI appeared in 17 (37%) patients of the entire study population. CONCLUSIONS Personalized DAPT results in an improved platelet inhibition. Apart from genotyping and aggregometry, it is feasible to integrate into everyday clinical practice PMI rates which are relevant when comparing different strategies.