Clinical outcome following percutaneous coronary intervention in patients with acute coronary syndromes and optimal platelet inhibition: results from a prospective registry of 864 patients

Abstract

Purpose: High on-treatment P2Y12 reactivity (PRU) is associated with thrombotic events following PCI for ACS. Low PRU is associated with increased bleeding rates. There may be an optimal PRU range within which adverse events are minimised. Methods: Patients who presented with ACS from a prospective PCI registry were studied for the presence of an optimal PRU (VerifyNow) range relative to an on-treatment combined adverse event (CAE) of death, clinical MI, stroke and BARC 2 to 5 bleeding. Results: There were 864 patients (25.0% female, mean (SD) age 63.4 (17) years, clopidogrel 94.5%, prasugrel 5.5%), followed over a median (IQR) of 3.5 (2.9) years. The optimal range proposed by the ARMYDA-PROVE investigators (PRU 178 to 239) was the most useful for identifying patients at low risk of CAEs. Applying this range, 185 (21.4%) patients had an optimal PRU, 465 (53.8%) were hypo- and 214 (24.8%) hyper-responders. Most MIs (29 of 30) occurred within the first year; rates were higher in hypo-responders (4.5% versus 2.0%, p = 0.041). In contrast there were few bleeding events by 12 months with no difference between groups, but long-term bleeding rate was higher in hyper-responders (8.4% versus 4.6%, p=0.035). In hyper-, optimal and hypo-responders, CAE rate at 12 months was 7.9%, 2.2% and 8.0%, p=0.020; and at long-term follow-up 12.6%, 2.7% and 10.1%, p=0.002 (see figure). Optimal PRU was significantly negatively associated with CAEs at 1 year (adjusted hazard ratio (aHR) 0.18, 95% CI 0.04 to 0.74, p=0.017) and at long-term follow-up (aHR 0.21, 95% CI 0.06 to 0.66, p=0.008). Conclusions: Following PCI for ACS, optimal PRU is associated with a low rate of adverse clinical events. However, only about one fifth of patients on clopidogrel naturally fall into this category.