Letter in response to: circulating von Willebrand factor and high molecular weight multimers as markers of endothelial injury predict COVID-19 in-hospital mortality

Excerpt

We would like to congratulate Philippe et al. [1] on the excellent work they have done to highlight the importance of von Willebrand Factor (VWF) and in particular the larger multimers, that are more biologically active, in the pathophysiology of COVID-19. The major strengths of this study are the large volume of patients enrolled (n = 208), and the ability to predict mortality. The marked difference between the VWF:Ag levels between critical patients (507%) versus non-critical (288%) was highly significant (p < 0.0001). On further analysis, the ROC for VWF:Ag was the most predictive for mortality with an AUC of 0.92 (95% CI 0.88–0.96) with cut-off levels of VWF:Ag (423%) able to predict mortality in univariate, multivariate modelling, Kaplan–Meier estimator, and Cox proportional hazard. This study is also the first to demonstrate a clear relationship between the high molecular weight VWF multimers (HMWM) and critically ill patients which stands to reason given that ultra-large VWF polymers are more biologically active and play an extremely important role in clot formation under high stress. On univariate analysis, the odds ratio of association with mortality for HMWM ratio was 116 (95% CI 10.2–1943, p < 0.001). …