Individual long-term variation of platelet reactivity in patients with dual antiplatelet therapy after myocardial infarction

Clinical Outcomes after Percutaneous Coronary Intervention Over Time on the Basis of CYP2C19 Polymorphisms

ABSTRACTION

The aim of this study was to investigate the association between CYP2C19 gene polymorphisms and the risk of cardiovascular events in the early stage and subsequent period after percutaneous coronary intervention (PCI) among patients who received clopidogrel. Between October 2015 and January 2017, CYP2C19 genotyped patients who were treated with clopidogrel after PCI were enrolled in this study. Included patients were categorized as non-loss-of-function metabolizers (NLOFMs), intermediate metabolizers (IMs) and poor metabolizers (PMs) based on CYP2C19 genotype. The primary outcome was a composite of any-cause mortality, nonfatal myocardial infarction, nonfatal ischemic stroke and stent thrombosis occurring during exposure to clopidogrel. The rates of clinical outcome events were compared between CYP2C19 phenotypes. Landmark analyses were processed at 90 days and 1 year post-PCI. Of 1,341 patients, 161 (12.0%) had two copy of loss-of-function (LOF) alleles, 621(46.3%) had one LOF allele, and 559 (41.7%) had no LOF allele. At the 3-month follow-up, the primary outcome events were more frequent in carriers of two LOF alleles (5.6%) than in noncarriers (1.8%) (adjusted HR 2.944, 95% CI 1.184-7.321, p = 0.020). A similar finding was observed among in patients with acute coronary syndrome indications at the index PCI (adjusted HR 3.046, 95% CI 1.237-7.501, p = 0.015). These differences did not persist within the subsequent 9 months of follow-up, among either all-comers or subjects with acute coronary syndrome. In conclusion, these data demonstrate a higher risk for ischemic events in patients with two CYP2C19 LOF alleles who are prescribed clopidogrel, seen at 3 months following PCI, that is not sustained for 12 months.

Stent Thrombosis Risk Over Time on the Basis of Clinical Presentation and Platelet Reactivity: Analysis From ADAPT-DES

OBJECTIVES

The aim of this study was to determine the risk period for increased stent thrombosis (ST) after percutaneous coronary intervention (PCI) in patients with acute coronary syndromes (ACS) and whether this increased risk is related to high platelet reactivity (HPR).

BACKGROUND

ST risk after PCI is higher among patients with ACS than those with stable ischemic heart disease. When ST risk is highest in patients with ACS and how that is affected by HPR is unknown.

METHODS

Using the ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) registry, ST rates during 2-year follow-up post-PCI with drug-eluting stents were compared among patients presenting with ACS (myocardial infarction [MI] or unstable angina) or stable ischemic heart disease (non-ACS). Landmark analyses were done at 30 days and 1 year post-PCI. Platelet reactivity on aspirin and clopidogrel post-PCI was assessed using VerifyNow assays.

RESULTS

Of 8,582 patients, 2,063 presented with MI, 2,370 with unstable angina, and 4,149 with non-ACS. Incidence rates of HPR were 48.0%, 43.3%, and 39.8%, respectively (p < 0.001). Within the first 30 days post-PCI, patients presenting with MI had increased ST risk compared with patients with non-ACS (hazard ratio [HR]: 4.52; 95% confidence interval [CI]: 2.01 to 10.14; p < 0.001). After 30 days, relative ST risks were progressively lower and no longer significant between groups (31 days to 1 year post-PCI: HR: 1.97; 95% CI: 0.80 to 4.85; >1 year post-PCI: HR: 0.89; 95% CI: 0.27 to 2.92). The elevated ST risk in patients with MI within 30 days was largely confined to those with HPR on clopidogrel (HR: 5.77; 95% CI: 2.13 to 15.63; p < 0.001).

CONCLUSIONS

Among patients undergoing PCI, rates of ST during 2-year follow-up were highest in those with MI and lowest in those with non-ACS. Increased ST risk in patients with MI was greatest in the first 30 days post-PCI and was observed predominantly among those with increased HPR on clopidogrel. These findings emphasize the importance of adequate P2Y₁₂ inhibition after MI, especially within the first 30 days after stent implantation.