Evaluation of the Anti-Thrombotic Efficacy of Anticoagulant and Anti-Platelet Drug Combinations in Patients with Atrial Fibrillation who undergo Percutaneous Coronary Intervention - The 66th Annual Conference of the Israel Heart Society & The Israel Society of Cardiothoracic Surgery

Chen Gurevitz ^1,2 Alon Eisen ^2,3 Eli Lev ^4,5 Osnat Itzhaki Ben Zadok ^2,3 Adaya Nissennholtz ^2,6 Leor Perl ^2,3 Abed Samara ^2,3 Avishay Elis ^1,2 Ran Kornowski ^2,3 Pia Raanani ^2,7 Eti Ziv ⁷ Galia Spectre ^2,7

¹Internal Medicine C, Rabin Medical Center, Beilinson Campus
²Sackler Faculty of Medicine, Tel-Aviv University
³Cardiology, Rabin Medical Center, Beilinson Campus
⁴Cardiology Department, Assuta Ashdod Medical Center
⁵Faculty of Health Sciences, Ben-Gurion University
⁶Geriatric Department, Rabin Medical Center, Beilinson Campus
⁷Institute of Hematology, Rabin Medical Center, Beilinson campus

Background: The optimal treatment for patients with atrial fibrillation (AF) who undergo percutaneous coronary intervention (PCI) is controversial. Recent studies have demonstrated that dual therapy (anticoagulant and clopidogrel) is associated with less bleeding events than triple therapy (anticoagulant, aspirin and clopidogrel). Nonetheless, little data exist on the antithrombotic effects of these regimens. Thrombin generation (TG) is an indicator for blood thrombogenicity. We aimed to examine TG after PCI, under triple therapy and dual therapy.

Methods: A non-interventional prospective trial in patients with AF who underwent PCI. Patients received 4 weeks of triple therapy with aspirin, clopidogrel and a Direct Oral Anticoagulant (DOAC), followed by dual therapy with clopidogrel and a DOAC. Blood was drawn on day 1 after PCI (time 0), 4 weeks after the PCI under triple therapy (time 1), and 2-4 weeks after aspirin withdrawal (time 2). TG; peak thrombin (nM) and endogenous thrombin potential (ETP; which represents the area under the curve, nM) were measured in platelet rich plasma (PRP) and platelet poor plasma (PPP).

Outcomes: Sixteen patients (81% men, mean age 77, 94% ACS) were examined. TG in PRP was higher at time 0 (peak thrombin 348±40 nM, ETP 2419±166 nM) compared to time 1 (peak thrombin 217±33 nM, ETP 1873±166 nM), P≤0.001 for both. No significant difference was noted between triple therapy (time 1) and dual therapy (time 2, peaked thrombin 281±31 nM, ETP 2157±193 nM), P= 0.72, 0.42 respectively. Consistent results were obtained when testing in PPP.

Conclusions: TG is high immediately after PCI and decreases 4 weeks after PCI. TG remains constant after aspirin withdrawal, suggesting that dual therapy may suffice. Hence, this study adds supportive laboratory data to the growing clinical evidence supporting minimizing the duration of triple therapy.