Clopidogrel utilization in patients with coronary artery disease and diabetes mellitus: should we determine CYP2C19*2 genotype?

PURPOSE: Clopidogrel non-responsiveness is multifactorial; several genetic and non-genetic factors may contribute to impaired platelet inhibition. The goal of this study is to determine the effect of the cytochrome P450 CYP2C19*2 polymorphism on the platelet response to clopidogrel in patients with and without diabetes mellitus (DM). METHODS: We conducted an observational study in patients with coronary artery disease and consequent exposure to clopidogrel therapy (75 mg/day for at least 7 consecutive days). We have analyzed two groups of patients: group I (DM patients) and group II (non-diabetes mellitus patients). Platelet reactivity was assessed by the VerifyNow P2Y12 assay and high on clopidogrel platelet reactivity (HPR) was defined as P2Y12 reaction units (PRU) ≥ 208. Genotyping for CYP2C19*2 polymorphism was performed by PCR-RFLP. RESULTS: We have included 150 subjects (76 DM and 74 non-diabetes mellitus patients). The carriage of CYP2C19*2 allele, in DM patients, was significantly associated to HPR (odds ratio (OR) 4.437, 95% confidence interval (CI) 1.134 to 17.359; p = 0.032). Furthermore, 8.4% of the variability in percent inhibition by clopidogrel could be attributed to CYP2C19*2 carrier status. However, in non-diabetes mellitus patients, there was no significant difference in platelet response to clopidogrel according to the presence or absence of CYP2C19*2 allele carriage (OR 1.260, 95% CI 0.288 to 5.522; p = 0.759). CONCLUSIONS: Our study suggests that the carriage of CYP2C19*2 polymorphism, in DM patients, might be a potential predictor of persisting HPR in these high-risk individuals. TRIAL REGISTRATION: Clinical Trials.gov NCT03373552 (Registered 13 December 2017).

Performance evaluation of the fully automated random-access multiparameter Sysmex CN-6000 hemostasis analyzer at a core laboratory with a high sample throughput.

INTRODUCTION: We aimed to evaluate the performance of the fully automated multiparameter CN-6000 hemostasis analyzer. METHODS: Performance evaluation of the CN-6000 analyzer was conducted for 10 tests including prothrombin time (PT), activated partial prothrombin time (aPTT), fibrinogen level, anti-Xa activity, and antithrombin activity using a unique portfolio of liquid ready-to-use reagents. Precision, sample and reagent carryovers, throughput, and sample turnaround time (STAT) function were prospectively assessed. Results from 343 samples (normal subjects, critically ill patients, patients receiving anticoagulants, subjects with high or low fibrinogen levels, and patients with decreased levels of factor II, V, VII, and X) were compared to those obtained on the STA-R Max 2® analyzer using dedicated reagents. RESULTS: Total precision (coefficient of variation) was below 7% for all parameters in both normal and pathological ranges. For all analyzed parameters, results obtained on the CN-6000 were strongly correlated with those obtained on the STA-R Max 2®analyzer. Agreement between both instruments was excellent for all assays. The CN-6000 demonstrated a 30% higher throughput compared to the STA-R Max 2® (258 vs 185 tests per hour for a panel of tests including PT, aPTT, fibrinogen, factor V, anti-Xa, and D-Dimer). STAT turnaround time for critical care samples testing was <7 minutes. CONCLUSIONS: The CN-6000 analyzer performs equivalently or better than the STA-R Max 2® with a significantly improved throughput. This new hemostasis multiparameter analyzer appears to be particularly well suited for coagulation laboratories which require high sample throughput and manage high numbers of nonstandard and critical care samples.