Cerebral microbleeds have been observed in “asymptomatic” elderly patients undergoing systematic MRIs and might be related with cognitive decline. A defect in Von Willebrand factor (VWF) after Trans Aortic-valve Replacement (TAVR) enhanced bleeding risk and possibly contributes to vascular malformations.

To define the occurrence of “acute” microbleeds during TAVR and the clinical and procedural factors associated with this occurrence including a post-procedural defect in VWF.

A prospective cohort of patients with aortic stenosis referred for TAVR was included. A standardized neurological assessment, a cerebral magnetic resonance imaging (MRI) and a biological analysis including quantification of VWF multimers and PFA-CADP were performed before and after TAVR.

Eighty-four patients completed the imaging protocol. On pre-procedural MRI, 22 patients (26%, 95%CI=17–37%) had at least one microbleeds. After TAVR, new microbleeds were observed in 19 (23%, 95%CI=14–33%) patients. The occurrence of new microbleeds was independent of the presence microbleeds at baseline. A lower HMW-multimer-ratio as measured immediately at the end of the procedure was associated with the occurrence of new microbleed detected on the MRI performed 3 days after the procedure (0.90±0.14 vs. 1.06±0.27, P=0.009). The same observation was made with a higher CT-ADP (165±72 vs. 127±57, P=0.02). A prolonged procedure (RR=1.21 [1.01–1.170] for every 5min of fluoroscopy time, P=0.04) and post-procedural acquired-VWF-defect (RR=1.42 [1.08–1.89] for every lower “0.1 unit” of HMW-multimer-ratio, P=0.004) were the only factors associated with the occurrence of new post-procedural microbleed(s).

We report for the first time a high incidence (23%, 95%CI=14–33%) of new post-procedural cerebral microbleeds occurring during TAVR. Procedural management and persistence of acquired-VWF defect could play a major role in the occurrence of those new microbleeds.