Bedside testing of CYP2C19 gene for treatment of patients with PCI with antiplatelet therapy

CYP2C19 Genetic Testing for Oral P2Y12 Inhibitor Therapy: A Scientific Statement From the American Heart Association

There is significant variability in the efficacy and safety of oral P2Y12 inhibitors, which are used to prevent ischemic outcomes in common diseases such as coronary and peripheral arterial disease and stroke. Clopidogrel, a prodrug, is the most used oral P2Y12 inhibitor and is activated primarily after being metabolized by a highly polymorphic hepatic cytochrome CYP2C219 enzyme. Loss-of-function genetic variants in CYP2C219 are common, can result in decreased active metabolite levels and increased on-treatment platelet aggregation, and are associated with increased ischemic events on clopidogrel therapy. Such patients can be identified by CYP2C19 genetic testing and can be treated with alternative therapy. Conversely, universal use of potent oral P2Y12 inhibitors such as ticagrelor or prasugrel, which are not dependent on CYP2C19 for activation, has been recommended but can result in increased bleeding. Recent clinical trials and meta-analyses have demonstrated that a precision medicine approach in which loss-of-function carriers are prescribed ticagrelor or prasugrel and noncarriers are prescribed clopidogrel results in reducing ischemic events without increasing bleeding risk. The evidence to date supports CYP2C19 genetic testing before oral P2Y12 inhibitors are prescribed in patients with acute coronary syndromes or percutaneous coronary intervention. Clinical implementation of such genetic testing will depend on among multiple factors: rapid availability of results or adoption of the concept of performing preemptive genetic testing, provision of easy-to-understand results with therapeutic recommendations, and seamless integration in the electronic health record.

Racial differences in P2Y12 inhibitor responsiveness in patients undergoing neuro-endovascular procedures: A cohort from the Middle East

BACKGROUND

Data on P2Y12 inhibitors responsiveness from the middle east is scarce. We sought to investigate patient responsiveness to P2Y12 inhibitors within a cohort of major races that characterize the UAE population. The secondary objective was to assess risk factors for hyper and hypo-responsiveness in this population.

METHODS

We conducted a cross-sectional study on adults who received either clopidogrel or ticagrelor treatments and had platelet responsiveness testing before undergoing neuro-endovascular interventions at our quaternary care hospital between March 2015 and April 2019.

RESULTS

During the study period, 249 subjects met the inclusion criteria. Overall, 17.3 % were hyper-responsive and 25.7 % were hypo-responsive to P2Y12 inhibitors. When comparing between the P2Y12 inhibitors, rates of hyper-responsiveness were significantly higher to ticagrelor when compared to clopidogrel (11 versus 6 %, p = 0.02 respectively). Contrarily, hypo-responsiveness rates were significantly higher in clopidogrel treated patients compared to their ticagrelor treated counterparts (23 versus 2 %, p < .001 respectively). Patients of Middle-Eastern origin showed a significantly higher rate of hypo-responsiveness to both clopidogrel and ticagrelor when compared to other races (41.1 % and 26.7 %, P < 0.001 respectively). Asians showed the highest rates of hyper-responsiveness for both agents. Multivariate logistic regression analysis showed that proton pump inhibitors and statin combination, (OR: 6.39, 95 %CI [1.60, 25.392]), and Middle East vs. Indian subcontinent patients (OR: 4.67, 95 %CI [1.79-12.14]) were independent predictors of hypo-responsiveness to both P2Y12 inhibitors.

CONCLUSION

This study demonstrated a high rate of hypo-responsiveness to P2Y12 inhibitors in a UAE cohort of patients undergoing neuro-endovascular procedures. In addition, therapeutic responsiveness to P2Y12 inhibitors varied markedly based on the racial background. Future larger studies are needed to evaluate genetic variations that may contribute to this rate of hypo-responsiveness in our population.

From genes to drugs: CYP2C19 and pharmacogenetics in clinical practice

The CYP2C19 gene is frequently included in different pharmacogenomic panels tested in clinical practice, due to its involvement in the metabolism of a myriad of frequently prescribed medications. Accordingly, CYP2C19 genotyping can promote precise therapeutic decisions and avoid the occurrence of significant drug-drug-gene interactions in the clinical setting. A comprehensive examination of the role of the CYP2C19 gene in real-world medical settings is presented in this review. This review summarizes the most recent information on how genetic variants in CYP2C19 affect drug metabolism and therapeutic outcomes. It goes into the wide range of CYP2C19 phenotypes, with different degrees of metabolizing activity, and their implications for customized medication response through a review of the literature. The review also analyzes the clinical significance of CYP2C19 in several medical specialties, including cardiology, psychiatry, and gastro-enterology clinics, and illuminates how it affects pharmacological efficacy, safety, and adverse effects. Finally, CYP2C19-supported clinical decision-making is outlined, highlighting the possibility of improving therapeutic outcomes and achieving more affordable treatment options, a step towards optimizing healthcare provision through precision medicine.

Safety of Bivalirudin Combined with Ticagrelor in the Emergency PCI in Patients with Acute ST-Segment Elevation Myocardial Infarction

OBJECTIVE

The present study aimed to investigate the application safety of bivalirudin combined with ticagrelor in the emergency percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS

From October 1, 2018, to December 30, 2019, 210 patients with STEMI admitted to the Department of Cardiology who underwent emergency PCI were randomly divided into the bivalirudin group (group A, N = 105) and the unfractionated heparin group (group B, N = 105). Before the emergency PCI operation after admission, the loading dose of aspirin (300 mg) was given orally, and then 100 mg/d. At the same time, the loading dose of ticagrelor (180 mg) was administered orally, and then 90 mg/bid. The adverse events and the hemorrhage events 30 days after the operation were observed and recorded.

RESULTS

There were five hemorrhage cases in the bivalirudin group, with one case of secondary hemorrhage and four cases of mild hemorrhage. There were 14 hemorrhages in the unfractionated heparin group with one case of secondary hemorrhage and thirteen cases of mild hemorrhage. In terms of mild hemorrhage, the hemorrhage rate in the bivalirudin group was significantly lower than that in the unfractionated heparin group (3.8% vs. 12.4%, P = 0.040). One patient died in the unfractionated heparin group, while no deaths occurred in the bivalirudin group during the thirty days of follow-up. No myocardial infarction, revascularization, or stroke occurred in the two groups within 30 days after the operation.

CONCLUSION

Compared with unfractionated heparin combined with ticagrelor in patients with STEMI undergoing emergency PCI treatment, bivalirudin combined with ticagrelor could significantly reduce the occurrence of mild hemorrhage events, and it would not increase the incidence of MACE during the 30 days of follow-up.

Bedside testing of CYP2C19 vs. conventional clopidogrel treatment to guide antiplatelet therapy in ST-segment elevation myocardial infarction patients

BACKGROUND

ST-segment elevation myocardial infarction (STEMI) patients are treated with dual antiplatelet therapy comprising aspirin and a P2Y₁₂ inhibitor. Clopidogrel is widely used in these patients in several areas worldwide, such as Middle East, but is associated to sub-optimal platelet inhibition in up to 1/3 of treated patients. We investigated a CYP2C19 genotype-guided strategy to select the optimal P2Y₁₂ inhibitor.

METHODS

This prospective randomized clinical trial included STEMI patients. The standard-treatment group received clopidogrel, while the genotype-guided group were genotyped for CYP2C19 loss-of-function alleles and carriers were prescribed ticagrelor and noncarriers were prescribed clopidogrel. Primary outcome was a combined ischemic and bleeding outcome, comprising myocardial infarction, non-fatal stroke, cardiovascular death, or Platelet Inhibition and Patient Outcomes major bleeding one year after STEMI.

RESULTS

STEMI patients (755) were randomized into a genotype-guided- (383) and standard-treatment group (372). In the genotype-guided group, 31 patients carrying a loss-of-function allele were treated with ticagrelor, while all other patients in both groups were treated with clopidogrel. Patients in the genotype-guided group had a significantly lower risk of primary outcome (odds ratio (OR) 0.34, 95% confidence interval (CI) 0.20-0.59,), recurrent myocardial infarction (OR 0.25, 95%CI 0.11-0.53), cardiovascular death (OR 0.16, 95%CI0.06-0.42) and major bleeding (OR 0.49, 95%CI 0.32-0.74). There was no significant difference in the rate of stent thrombosis (OR 0.85, 95%CI 0.43-1.71).

CONCLUSION

A genotype-guided escalation of P2Y12 inhibitor strategy is feasible in STEMI patients treated with clopidogrel and undergoing PCI and is associated with a reduction of primary outcomes compared to conventional antiplatelet therapy.