Related Experiment Video
Updated: Nov 26, 2025

Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function
Published on: March 15, 2022
Effects of individualized antiplatelet therapy, based on CYP2C19 genotyping, on platelet function in patients
Min Zhang1,2, Jiangrong Wang1, Yong Zhang1
1Department of Cardiology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China.
Objective:
To evaluate the effect of individualized antiplatelet therapy, based on CYP2C19 genotyping, on platelet function in patients underwent PCI and to compare this treatment with conventional antiplatelet therapy.
Methods:
All patients were treated with 100 mg aspirin once a day. Additionally, the CA group received 75 mg clopidogrel once a day. The IA group was divided into extensive metabolizers (EMs, no loss-of-function, i.e. LOF allele, 75 mg clopidogrel once a day), intermediate metabolizers (IMs, carrying one LOF alleles, 75 mg clopidogrel twice daily), and poor metabolizers group (PMs, carrying two LOF alleles, 90 mg ticagrelor twice daily). After taking these antiplatelet medications for ⩾5 days, we assessed platelet function by thromboelastography, and recorded the MAADP (maximum amplitude produced by adenosine diphosphate) value. MAADP > 47 mm was defined as residual HPR, indicating a high risk of thrombosis. MAADP ≤ 31 mm indicated a high risk of bleeding.
Results:
The proportion of patients with MAADP > 47 mm was significantly lower in the IA group (29.6%) than the CA group (38.1%). The proportion of patients with MAADP ≤ 31 mm was significantly higher in the IA group (31.0%) than the CA group (21.3%). No significant differences were found in the proportions of patients with MAADP > 47 mm or MAADP ≤31 mm when compared between the EMs and IMs group.
Conclusion:
Individualized antiplatelet therapy, based on CYP2C19 genotyping, can reduce the incidence of HPR in ACS patients after PCI compared to conventional therapy. By taking a double dose of clopidogrel, patients with a CYP2C19 LOF allele can therefore overcome the reduced efficacy of clopidogrel associated with LOF alleles without increasing the risk of bleeding, which is of guiding significance for the management of antiplatelet therapy on ACS patients after PCI especially considering the CYP2C19 LOF alleles that carry an important predictor for the ischemic events.
Clinical Trial Registration Number:
chiCTR-INC-17011550.
Related Concept Videos
Antiplatelet Drugs: Prostaglandin Synthesis, P2Y12 and Glycoprotein IIb/IIIa Inhibitors
Prostaglandin synthesis inhibitors, exemplified by the widely known aspirin, wield their power by irreversibly acetylating...
Peripheral Artery Disease III: Interprofessional Care
Coronary Artery Disease V: Interprofessional Care
Treatment for Pulmonary Arterial Hypertension: Receptor Tyrosine Kinase Inhibitors and Calcium Channel Blockers
TKIs, such as imatinib (Gleevec), are particularly effective in tackling the growth and mitogenic factors that become upregulated in PAH patients. These factors contribute to the...
Angina IV: Management
Antianginal Drugs: Calcium Channel Blockers and Ranolazine
CCBs, a diverse class that includes dihydropyridines (nifedipine) and diphenylalkylamines (verapamil and diltiazem), exert their effect by blocking calcium channels in cardiac and smooth muscle cells. This...

