Thrombin generation, fibrin clot permeation and lysis in patients with severe mitral regurgitation undergoing transcatheter edge-to-edge mitral valve repair: Mitral Fibrin Study.

Introduction: Intricate management of heart failure (HF), especially in the context of reduced ejection fraction, is further complicated by an elevated risk of thromboembolic events. Studies published so far offer inconclusive insight into the interplay between mitral regurgitation (MR) and the coagulation system.

Objectives: This study aimed to investigate the impact of transcatheter edge‑to‑edge repair (TEER) on specific coagulation parameters in HF patients.

Patients and methods: A cohort of 31 HF patients with severe MR treated with TEER underwent a systematic evaluation at 3 visits (V1, V2, and V3). Coagulation parameters, including fibrinogen concentration, thrombin generation, fibrin clot permeability, and clot lysis time (CLT) were assessed (n = 27 at V2; n = 25 at V3).

Results: TEER induced changes in fibrinogen levels (P = 0.01; V3 vs V2) and improved fibrin clot properties over 50‑day follow‑up (P = 0.01; V3 vs V2). No significant differences were observed between time points in the analyzed blood clot parameters. Correlation analysis showed that baseline CLT was associated with ΔN‑terminal pro-B‑type natriuretic peptide (NT‑proBNP) level (P = 0.049; r = 0.4). Multivariable analysis identified baseline CLT as an independent predictor of early post‑TEER NT‑proBNP change (R2 = 0.55; P = 0.02).

Conclusions: We found decreased level of fibrinogen and increased permeation coefficient over a median 50 (interquartile range, 32.5-75.5)-day post‑TEER follow‑up, as compared with early postprocedural assessments. Other blood coagulation parameters remained unchanged from baseline at both follow‑up time points after TEER. Finally, CLT was an independent predictor of early NT‑proBNP increase, emphasizing its role as an indicator of hemodynamic response to TEER.