title: Transcatheter aortic valve implantation leads to a restoration of von Willebrand factor (VWF) abnormalities in patients with severe aortic stenosis - Incidence and relevance of clinical and subclinical VWF dysfunction in patients undergoing transfemoral TAVI.
abstract: BACKGROUND
  In this study, we sought to analyze the incidence and relevance of von Willebrand factor (VWF) abnormalities in patients undergoing transcatheter aortic valve implantation (TAVI), especially on perioperative bleeding. Furthermore, we hypothesized that, similar to aortic valve surgery, TAVI results in a restoration of VWF abnormalities.
  
  
  RESULTS
  We performed a prospective analysis of periinterventional VWF parameters in 74 patients (80±7years, female in 37.5%) undergoing transfemoral TAVI for severe symptomatic aortic valve stenosis. At baseline, VWF:Ag was 210±90IU/dl with a mean VWF activity of 166±106IU/dl; activity-to-antigen ratio was 0.85±0.45. Heyde's syndrome (severe aortic stenosis plus GI bleeding from angiodyplasia) was observed in 2/74 (2.7%). Whereas preprocedural loss of high-molecular-weight (HMW) VWF multimers was found in thirty-six patients (48.6%), none of the patients fulfilled criteria for possible acquired VW syndrome. After TAVI, an increase of both VWF:Ag and activity compared to baseline was observed (p<0.01). In patients with HMW multimer loss, post-interventional recovery of multimers occurred in all cases. In the two patients with Heyde's syndrome, a trend towards reduced VWF:Ag was seen, with loss of HMW multimers in one patient. Of interest, all patients suffering from periprocedural major bleeding (5/74; 6.8%) exhibited activity-to-antigen ratios <0.7, indicating subclinical VWF dysfunction.
  
  
  CONCLUSIONS
  Whereas clinically relevant VWF dysfunction is rare, loss of HMW VWF multimers is common in TAVI patients. Similar to surgery, TAVI leads to a restoration of this loss. Furthermore, VWF parameters may be useful parameter to evaluate risk of periprocedural bleeding.
authors.affiliation: Med. Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Sedaghat
authors.affiliation: Med. Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn, Germany.
authors.forename: Hannah
authors.initials: H
authors.lastname: Kulka
authors.affiliation: Med. Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn, Germany.
authors.forename: Jan-Malte
authors.initials: JM
authors.lastname: Sinning
authors.affiliation: Med. Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn, Germany.
authors.forename: Nora
authors.initials: N
authors.lastname: Falkenberg
authors.affiliation: Institute of Experimental Hematology and Transfusion Medicine, Universitätsklinikum Bonn, Bonn, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Driesen
authors.affiliation: Institute of Experimental Hematology and Transfusion Medicine, Universitätsklinikum Bonn, Bonn, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Preisler
authors.affiliation: Med. Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hammerstingl
authors.affiliation: Med. Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Nickenig
authors.affiliation: Institute of Experimental Hematology and Transfusion Medicine, Universitätsklinikum Bonn, Bonn, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Pötzsch
authors.affiliation: Institute of Experimental Hematology and Transfusion Medicine, Universitätsklinikum Bonn, Bonn, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Oldenburg
authors.affiliation: Institute of Experimental Hematology and Transfusion Medicine, Universitätsklinikum Bonn, Bonn, Germany.
authors.forename: Hans-Jörg
authors.initials: HJ
authors.lastname: Hertfelder
authors.affiliation: Med. Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn, Germany. Electronic address: nwerner@uni-bonn.de.
authors.forename: Nikos
authors.initials: N
authors.lastname: Werner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000150:complications* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D065467:Transcatheter Aortic Valve Replacement / Q000379:methods; D014842:von Willebrand Diseases / Q000150:complications*; D014841:von Willebrand Factor / Q000032:analysis*
chemical_list: D014841:von Willebrand Factor
keywords: Heyde's syndrome; TAVI; VARC; Vascular complications; von Willebrand factor