Fibrin clot strength is associated with increased risk of major adverse cardiac events after TAVR.

BACKGROUND: Patients after transcatheter aortic valve replacement (TAVR) are at increased risk of both major adverse cardiac events (MACE), including ischemic and thrombotic complications, as well as significant bleeding. Given this delicate balance between prothrombotic and hemorrhagic risk, the assessment of hemostatic markers might help identify patients at increased risk. AIM: To identify hemostatic markers associated with MACE and bleeding following TAVR. METHODS: In this prospective single-center cohort study, of patients undergoing TAVR from November 2020 to June 2022, the association of hemostatic profiles and clinical outcomes was assessed. The profiling included thromboelastography (TEG), light transmission aggregometry (LTA), and conventional laboratory markers to assess thrombogenicity. The outcome was MACE (death, myocardial infarction, or stroke) and major/non-major clinically relevant bleeding at 6 months. RESULTS: Of the 107 patients included, 104 completed follow-up. At 6 months, 9% experienced MACE, and 10% had clinically relevant bleeding. Platelet-fibrin clot strength, reflected by the maximum amplitude (MA-citrated kaolin) in thrombelastography, was elevated in patients with MACE (per 1 mm increase: HR 1.26 [1.02;1.56], p = 0.03). Fibrin's role in the maximum clot strength was crucial. Elevated fibrinogen levels, increased citrated functional fibrinogen (MA-CFF), and faster fibrin formation (alpha-angle[α]) associated with a higher risk of MACE (per 20 mg/dL fibrinogen increase: HR 1.15 [1.02-1.28], p = 0.02; per 5 mm MA-CFF increase: HR 1.59 [1.12-2.26], p < 0.01; per degree α-citrated rapid TEG increase: HR 1.55 [1.10-2.19], p = 0.01), respectively. High on-treatment ADP-induced platelet reactivity assessed by LTA was associated with a lower risk of major and non-major clinically relevant bleeding at 6 months (per 10% MA-ADP increase: HR 0.66 [0.47;0.93] p=0.02 ). CONCLUSION: Selected hemostatic markers associated with the risk of MACE and bleeding within 6 months in patients post-TAVR, with fibrin clot strength identified as a principal marker.