Assessment of the antiplatelet effect of different p2y12 inhibitors using two methods at 30 and 120 minutes after oral loading in the cardiac catheterization laboratory

Optimal antiplatelet therapy is crucial in the acute phase after stent implantation. Current recommendations advise administering a 300 mg oral loading dose of crushed acetylsalicylic acid (ASA) to enhance intestinal absorption before percutaneous coronary intervention (PCI). Regarding the second antiplatelet agent, a P2Y12 receptor inhibitor (P2Y12i), the latest ESC guidelines on acute coronary syndromes (2023) discourage early administration (so-called "pretreatment"), reserving it for the moment of stent implantation.

To assess short-term (24-hour) safety outcomes in patients undergoing PCI without pretreatment.

To evaluate the antiplatelet effect of different P2Y12 inhibitors at 30 and 120 minutes after oral loading and to compare analytical methods used for platelet reactivity assessment.

Patients undergoing PCI were included. Blood samples were collected at 30 and 120 minutes after the P2Y12i loading dose to assess platelet reactivity using VerifyNow (VN) and thromboelastography (TEG). The primary endpoint was platelet reactivity, expressed as clot amplitude for TEG and platelet reactivity units (PRU) for VN. Clinical events were evaluated within the first 24 hours after PCI.

A total of 47 patients were included. Forty-six (98%) presented with STEMI, NSTEMI, or stable angina, most commonly NSTEMI, while one patient underwent coronary angiography for ventricular dysfunction assessment. The distribution of P2Y12 inhibitors is shown in Figure 1 as well as the clinical presentation distribution.

Results are summarized in Table 1. Ticagrelor and prasugrel achieved greater antiplatelet activity at 30 minutes compared with clopidogrel, with no significant differences between analytical methods. ASA-induced inhibition was higher at 30 minutes than that of P2Y12 inhibitors, as expected since ASA was administered hours earlier. Only two patients were on chronic ASA therapy, and none were receiving a P2Y12 inhibitor prior to the procedure.

A 10.3% test failure rate was observed, likely related to operator inexperience and technical device issues.

No adverse events occurred within 24 hours after PCI.

Our findings support the short-term safety of avoiding pretreatment in patients scheduled for percutaneous revascularization. Ticagrelor and prasugrel achieved greater platelet inhibition than clopidogrel, particularly at 30 minutes. Both TEG and VerifyNow provided consistent and comparable results.

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