title: Usefulness of Von Willebrand Factor Activity Indexes to Predict Therapeutic Response in Hypertrophic Cardiomyopathy.
abstract: Degraded by shear stress, loss of high-molecular-weight multimers of von Willebrand factor (VWF) correlates strongly with pressure gradient in aortic stenosis (AS) and obstructive hypertrophic cardiomyopathy (HC). We assessed VWF tests before and after interventions in HC and contrasted the severity of abnormalities in HC to patients with AS, mitral regurgitation, and left ventricular assist devices. Ninety patients with median (interquartile range) age 66 (53 to 72) years, 51% men, with HC had assessments of 3 VWF parameters and B-type natriuretic peptide before and after 26 discreet medical/pacing interventions, 22 alcohol septal ablations, and 28 ventricular septal myectomies. VWF multimers were abnormal in 87% of patients with obstructive HC versus 48% of patients with latent obstruction (p = 0.0001). VWF measurements correlated with peak instantaneous left ventricular outflow tract gradient, Spearman ρ 0.51 to 0.61, p <0.0001. For B-type natriuretic peptide, correlation with left ventricular outflow tract gradient was weaker, ρ = 0.37, p = 0.0005, but stronger with septal thickness or mitral E/e'. In pre-/post-medical treatment of HC, VWF multimers were abnormal in 73%/68% of patients, p = 0.74; pre-/post-septal ablation 74%/26%, p = 0.0035; and pre-/post-septal myectomy 75%/0%, p <0.0001. In obstructive HC, the degree VWF multimer loss was greater than in severe AS or severe mitral regurgitation and overlapped that seen in left ventricular assist devices. In conclusion, VWF activity indexes were predictably abnormal in patients with HC with resting obstruction to a degree where bleeding could be anticipated, accurately reflected gradient changes after intervention, and demonstrated complete normalization after septal myectomy.
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic Florida, Jacksonville, Florida. Electronic address: blackshear.joseph@mayo.edu.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Blackshear
authors.affiliation: University of Florida, Gainesville, Florida.
authors.forename: Hana
authors.initials: H
authors.lastname: Kusumoto
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic Florida, Jacksonville, Florida.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Safford
authors.affiliation: Willmar Cancer Center, Willmar, Minnesota.
authors.forename: Ewa
authors.initials: E
authors.lastname: Wysokinska
authors.affiliation: Department of Health Sciences Research, Mayo Clinic Florida, Jacksonville, Florida.
authors.forename: Colleen S
authors.initials: CS
authors.lastname: Thomas
authors.affiliation: Cardiovascular Diseases Fellowship Program, Mayo Clinic Arizona, Scottsdale, Arizona.
authors.forename: Oral A
authors.initials: OA
authors.lastname: Waldo
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic Florida, Jacksonville, Florida.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Stark
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic Florida, Jacksonville, Florida.
authors.forename: Brian P
authors.initials: BP
authors.lastname: Shapiro
authors.affiliation: Department of Cardiovascular Diseases, Mayo Clinic Florida, Jacksonville, Florida.
authors.forename: Steven
authors.initials: S
authors.lastname: Ung
authors.affiliation: First Coast Cardiovascular, Jacksonville, Florida.
authors.forename: Issam
authors.initials: I
authors.lastname: Moussa
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Mayo Clinic Florida, Jacksonville, Florida.
authors.forename: Richard C
authors.initials: RC
authors.lastname: Agnew
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Mayo Clinic Florida, Jacksonville, Florida.
authors.forename: Kevin
authors.initials: K
authors.lastname: Landolfo
authors.affiliation: Division of Hematopathology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Dong
authors.initials: D
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000379:methods*; D002312:Cardiomyopathy, Hypertrophic / Q000097:blood / Q000503:physiopathology / Q000601:surgery*; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006346:Heart Septum / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D016277:Ventricular Function, Left / Q000502:physiology*; D014841:von Willebrand Factor / Q000378:metabolism*
chemical_list: D014841:von Willebrand Factor