Platelet-fibrin clot strength measured by thromboelastography could predict hypercoagulability and antiplatelet effects in patients after percutaneous coronary intervention.

BACKGROUND: It has been estimated that nearly one-fifth post-percutaneous coronary intervention (PCI) patients treated with clopidogrel continued to have recurrent thrombotic events, which implied the limitation of "one-size-fits all" strategy for antiplatelet therapy.

METHODS: From July 2017 to April 2019, patients with acute coronary syndrome [ACS, including unstable angina (UA), non-ST segment elevation myocardial infraction (NSTEMI), and ST segment elevation myocardial infraction (STEMI)] or old myocardial infarction (OMI), or patients without coronary heart disease (non-CAD) were retrospectively enrolled in this study. For CAD patients undergoing PCI, standard dual antiplatelet therapy (100 mg aspirin and 75 mg clopidogrel) was prescribed. After administration of dual antiplatelet agents for at least 5 days, whole blood samples were collected and platelet function was tested using thrombelastography (TEG). Thrombin-induced platelet-fibrin clot strength (MAthrombin) and ADPinduced platelet-fibrin clot strength (MAADP) were measured to assess the hypercoagulability and antiplatelet effects.

RESULTS: A total of 571 patients, including 479 ACS patients, 21 OMI patients and 71 non-CAD patients were enrolled. Highest level of MAthrombin was detected in STEMI patients, while lowest MAthrombin level was observed in non-CAD patients (P1 <0.05 for OMI vs. non-CAD; P2 <0.001 for ACS vs. non-CAD; P3<0.05 among ACS). Higher MAADP was also observed in STEMI and NSTEMI patients compared with UA patients (P<0.001). When MAADP was divided into trisections (MAADP <31; 31-47; >47 mm), a considerable portion of 41.8% ACS patients were in the first trisection (MAADP <31 mm), containing 50.4% of UA patients, 35.7% of NSTEMI patients and 26.5% of STEMI patients, with significant difference being observed between UA patients and other ACS patients (P<0.05 for NSTEMI vs. UA; P<0.001 for STEMI vs. UA). Meanwhile, 27.6% of NSTEMI and 31.0% of STEMI patients were in the third trisection (MAADP >47 mm), which was significantly higher than that of UA patients (12.7%) (P<0.001 for NSTEMI or STEMI vs. UA).

CONCLUSIONS: Considering various degrees of hypercoagulability and antiplatelet effects of clopidogrel among OMI and ACS patients post-PCI. More attention should be paid to personalized antiplatelet therapy according to individual's effects of P2Y12 receptor inhibitors.