Von Willebrand factor activity predicts outcome after transcatheter edge-to-edge mitral valve repair
Background
Acquired von Willebrand syndrome (AvWS) is frequently associated with valvular heart disease due to shear-stress–induced degradation of high-molecular-weight multimers. While prior data demonstrated alterations in von Willebrand factor (vWF) parameters following transcatheter edge-to-edge mitral valve repair (M-TEER), their prognostic value regarding cardiovascular outcome remains unclear.
Methods and Results
We enrolled 254 consecutive patients undergoing M-TEER for symptomatic mitral regurgitation in a single-center observational study. vWF activity (vWF:Act) and vWF antigen (vWF:Ag) were measured before and four weeks after M-TEER. AvWS was defined as vWF:Act/vWF:Ag ratio <0.7. MR was of secondary etiology in 63.9% of the study population. MR reduction to grade II or less was achieved in 94.1% of patients. To assess clinical outcome, participants were followed up for a median of 12 months on the incidence of a combined endpoint of death or hospitalization for heart failure, which occurred in 30.3% of the study population. At baseline, AvWS was present in 13.4% of patients. Four weeks after M-TEER, vWF:Ag decreased from 222±93 to 214±89 IU/dL (p=0.019), while vWF:Act remained unchanged. In consequence, vWF:Act/vWF:Ag ratio increased from 0.83±0.14 to 0.86±0.15 (p=0.002). However, neither baseline vWF:Act/vWF:Ag ratio nor its improvement after M-TEER was associated with clinical outcome during follow-up. Instead, high baseline levels of vWF:Act emerged as a strong predictor of death or hospitalization for heart failure after the procedure, remaining independent from other clinical and echocardiographic risk factors in multivariate analysis (HR 1.65 [95% CI 1.22–2.24] per 100 IU/dL, p=0.001). Accordingly, patients with baseline vWF:Act ≥147 IU/dL had a remarkably increased risk for the occurrence of the combined endpoint during follow-up (log-rank HR 3.11, p<0.0001), driven both by mortality (HR 3.28, p=0.001) and heart failure hospitalization (HR 2.50, p=0.004). Furthermore, a trend towards increased risk of major bleeding was observed in these patients (HR 3.06, p=0.06).
Conclusions
vWF activity is a strong baseline predictor of death and hospitalization for heart failure after successful M-TEER and may be a useful prognostic biomarker for identifying patients at high risk for adverse outcomes.
