Timing of P2Y12 Inhibitor Administration in Patients With STEMI Undergoing Primary PCI.

BACKGROUND: The optimal timing of P2Y12 inhibitor administration in patients with ST-segment elevation myocardial infarction (STEMI) has not been completely elucidating. OBJECTIVES: This analysis from a prospective multicenter registry sought to assess the safety and effectiveness of P2Y12 inhibitor pretreatment in patients transferred for primary percutaneous coronary intervention (PCI) within a regional STEMI network. METHODS: Pretreatment was defined as P2Y12 inhibitor administration before coronary angiography. Endpoints were major adverse cardiac events (MACE), major bleeding, and net adverse clinical events, a composite of MACE or major bleeding, within 30 days of index admission. Association of P2Y12 inhibitor pretreatment with outcomes was modeled using doubly robust weighted estimators based on propensity score analysis. RESULTS: Of 1,624 patients included, 1,033 received P2Y12 inhibitors before angiography and 591 in the catheterization laboratory (cath lab). The non-pretreated cohort more often had history of coronary artery disease and were more likely to receive antiplatelet therapy before the index admission. After adjustment for confounding and dependent censoring, pretreatment with P2Y12 inhibitors predicted lower risk of MACE (adjusted HR: 0.53; 95% CI: 0.37-0.76), without increasing bleeding risk (adjusted HR: 0.62; 95% CI: 0.36-1.05), resulting in superior net clinical benefit (adjusted HR: 0.47; 95% CI: 0.26-0.86) compared with in-cath lab administration of P2Y12 inhibitors. There was a significant treatment-by-time interaction for MACE risk, whereby the observed benefits of pretreatment only became apparent when time between P2Y12 inhibitor administration and PCI was longer than 80 minutes. CONCLUSIONS: In contemporary patients with STEMI transferred for primary PCI, pretreatment with P2Y12 inhibitors was associated with a significant time-dependent reduction of 30-day MACE without increasing bleeding risk.

Nonadherence to ticagrelor versus clopidogrel and clinical outcomes in patients with ACS. Results from the CREA-ARIAM registry.

INTRODUCTION AND OBJECTIVES: Prior studies have not determined whether the effect of dual antiplatelet therapy (DAPT) cessation on the subsequent risk of major adverse cardiac events (MACE) varies by the choice of P2Y12-inhibitor after acute coronary syndrome (ACS). METHODS: We performed a prespecified subanalysis of a multicenter, prospective registry of ACS patients discharged on ticagrelor or clopidogrel between 2015 and2019. Nonadherence to DAPT was categorized as physician-guided discontinuation and disruption due to adverse effects, nonadherence, or bleeding. The association between DAPT cessation and 1-year MACE was analyzed using multivariate time-updated Cox models with inverse probability of censoring weighted estimators. RESULTS: Out of 2180 patients, 174 (8.3%) prematurely discontinued DAPT (physician-guided, n=126; disruption, n=48). Nonadherent patients were older and had more comorbidities than those on DAPT. Compared with physician-guided discontinuation, disruption occurred earlier after discharge and was more frequent with ticagrelor than with clopidogrel. In time-varying analysis, DAPT cessation was associated with an increased risk of MACE (adjusted HR, 1.32, 95%CI, 1.10-1.76), largely driven by disruption (adjusted HR, 1.47, 95%CI, 1.22-1.73). There was an exponential increase in MACE risk after DAPT cessation within 90 days after ACS, especially after disruption of ticagrelor compared with clopidogrel (Pinteraction<.001). After adjustment for DAPT duration, this interaction was not statistically significant on the additive scale (relative excess risk due to interaction 0.12, 95%CI,-0.99-1.24). CONCLUSIONS: In this all-comers registry, 1 in 12 patients prematurely discontinued DAPT within 1 year after ACS. Compared with physician-recommended discontinuation, disruption resulted in a significantly higher risk of MACE. After adjustment for DAPT duration, this association was not moderated by the choice of P2Y12-inhibitor. Clinical trial registered at ClinicalTrials.gov (Identifier: NCT02500290).

Comparative Safety and Effectiveness of Ticagrelor versus Clopidogrel in Patients With Acute Coronary Syndrome: An On-Treatment Analysis From a Multicenter Registry.

Background: The net clinical benefit of ticagrelor over clopidogrel in acute coronary syndrome (ACS) has recently been questioned by observational studies which did not account for time-dependent confounders. We aimed to assess the comparative safety and effectiveness of ticagrelor vs. clopidogrel accounting for non-adherence in a real-life setting. Methods: This is a prospective, multicenter cohort study of patients with ACS discharged on ticagrelor or clopidogrel between 2015 and 2019. Major exclusions were previous intracranial bleeding, and the use of prasugrel or oral anticoagulation. Association of P2Y12 inhibitor therapy with 1-year risk of Bleeding Academic Research Consortium Type 3 or 5 bleeding; major adverse cardiac events (MACEs), a composite endpoint of all-cause death, nonfatal myocardial infarction (MI), nonfatal stroke, or urgent target lesion revascularization; definite/probable stent thrombosis; vascular death; and net adverse clinical event (a composite endpoint of major bleeding and MACE) were analyzed according to the "on-treatment" principle, using fully adjusted Cox and Fine-Gray regression models with doubly robust inverse probability of censoring weighted estimators. Results: Among 2,070 patients (mean age 63 years, 27% women, 62.5% ST-elevation MI), 1,035 were discharged on ticagrelor and clopidogrel, respectively. Ticagrelor-treated patients were younger and had few comorbidities, but high rates of medication non-compliance, compared with clopidogrel users. After comprehensive multivariate adjustments, ticagrelor did not increase the risk of major bleeding compared with clopidogrel [subhazard ratio, 1.40; 95% confidence interval (CI), 0.96-2.05], while proved superior in reducing MACE (hazard ratio 0.62; 95% CI, 0.43-0.90), vascular death (subhazard ratio, 0.71; 95% CI, 0.52-0.97) and definite/probable stent thrombosis (subhazard ratio, 0.54; 95% CI, 0.30-0.79); thereby resulting in a favorable net clinical benefit (hazard ratio 0.78; 95% CI, 0.60-0.98) compared with clopidogrel. Results from sensitivity analyses were consistent with those from the primary analysis, whereas those from the intention-to-treat (ITT) analysis went in the opposite direction. Conclusion: Among all-comers with ACS, ticagrelor did not significantly increase the risk of major bleeding, while resulting in a net clinical benefit compared with clopidogrel. Further research is warranted to confirm these findings in high bleeding risk populations. CREA-ARIAM Andalucía: (ClinicalTrials.gov Identifier: NCT02500290); Current pre-specified analysis (ClinicalTrials.gov Identifier: NCT04630288).