Reasons for early discontinuing or switching of antiplatelet therapy in elderly patients after acute coronary syndrome.

OBJECTIVE: This study aims to determine frequency and reasons for prematurely discontinuing or switching antiplatelet therapy in elderly patients admitted with non-ST-elevation acute coronary syndrome (NSTE-ACS). METHOD: Patients of 75 years or older admitted with suspected NSTE-ACS were included between 2013 and 2016. Information was extracted from the patients' medical files. RESULTS: A total of 544 patients were included, 17.3% discontinued aspirin within one year, predominantly (57%) within 30 days. The most common reason was the start of a (non-vitamin-K) oral anticoagulant [(N)OAC], either combined with a P2Y12-inhibitor (43%) or as monotherapy (16%). The P2Y12-inhibitor was discontinued in 31.2% of patients within one year, of which 46% within 30 days. The most common reason was undergoing coronary artery bypass grafting (CABG; 22%). Switching of clopidogrel seldom occurred; however, ticagrelor was switched in 50/179 patients mainly due to dyspnoea (42%). Independent predictors for prematurely discontinuing antiplatelet therapy were undergoing CABG [odds ratio (OR) 3.257 (95% confidence interval [CI] 1.836-5.779)], need for (N)OAC [OR 2.167 (95% CI 1.423-3.300)] and type II ACS as final diagnosis [OR 3.793 (95% CI 1.721-8.361)]. Undergoing percutaneous coronary intervention [OR 0.393 (95% CI 0.243-0.634)] and use of clopidogrel [OR 0.441(95% CI 0.293-0.662)] were independent predictors of continuing antiplatelet therapy. CONCLUSION: In elderly patients of at least 75 years with NSTE-ACS, antiplatelet therapy is frequently discontinued prematurely, most often within 30 days. Main reasons for discontinuing are need for (N)OAC, undergoing CABG or type II ACS as final diagnosis and suffering from dyspnoea while on ticagrelor.

A Genotype-Guided Strategy for Oral P2Y12 Inhibitors in Primary PCI.

BACKGROUND: It is unknown whether patients undergoing primary percutaneous coronary intervention (PCI) benefit from genotype-guided selection of oral P2Y12 inhibitors. METHODS: We conducted a randomized, open-label, assessor-blinded trial in which patients undergoing primary PCI with stent implantation were assigned in a 1:1 ratio to receive either a P2Y12 inhibitor on the basis of early CYP2C19 genetic testing (genotype-guided group) or standard treatment with either ticagrelor or prasugrel (standard-treatment group) for 12 months. In the genotype-guided group, carriers of CYP2C19*2 or CYP2C19*3 loss-of-function alleles received ticagrelor or prasugrel, and noncarriers received clopidogrel. The two primary outcomes were net adverse clinical events - defined as death from any cause, myocardial infarction, definite stent thrombosis, stroke, or major bleeding defined according to Platelet Inhibition and Patient Outcomes (PLATO) criteria - at 12 months (primary combined outcome; tested for noninferiority, with a noninferiority margin of 2 percentage points for the absolute difference) and PLATO major or minor bleeding at 12 months (primary bleeding outcome). RESULTS: For the primary analysis, 2488 patients were included: 1242 in the genotype-guided group and 1246 in the standard-treatment group. The primary combined outcome occurred in 63 patients (5.1%) in the genotype-guided group and in 73 patients (5.9%) in the standard-treatment group (absolute difference, -0.7 percentage points; 95% confidence interval [CI], -2.0 to 0.7; P<0.001 for noninferiority). The primary bleeding outcome occurred in 122 patients (9.8%) in the genotype-guided group and in 156 patients (12.5%) in the standard-treatment group (hazard ratio, 0.78; 95% CI, 0.61 to 0.98; P = 0.04). CONCLUSIONS: In patients undergoing primary PCI, a CYP2C19 genotype-guided strategy for selection of oral P2Y12 inhibitor therapy was noninferior to standard treatment with ticagrelor or prasugrel at 12 months with respect to thrombotic events and resulted in a lower incidence of bleeding. (Funded by the Netherlands Organization for Health Research and Development; POPular Genetics ClinicalTrials.gov number, NCT01761786; Netherlands Trial Register number, NL2872.).