title: Long-term echocardiographic Doppler monitoring of Hancock bioprostheses in the mitral valve position.
abstract: Echocardiographic and Doppler studies were performed in 134 patients with a Hancock bioprosthesis in the mitral valve position during a follow-up period of 1 to 216 months. Among the xenografts, 57% were clinically normal and 43% had severe dysfunction. Among the normal bioprostheses, 35% had echocardiographically thickened mitral cusps (> or = 3 mm) with normal hemodynamic function; by setting the lower 95% confidence limit of valve area at 1.7 cm2 these patients had a significantly (p < 0.01) smaller valve area than that of normal control subjects. Evaluation of all thickened normal mitral valves showed the highest incidence of thickening at 9 years after implantation. Valve replacement surgery was subsequently performed in 33 patients with dysfunctioning bioprosthetic and echocardiographic diagnosis was confirmed in 91% of explanted valves (bioprosthetic stenosis 21%, incompetence 46%, and combined stenosis and regurgitation 33%). In 2 valves that were found to be stenotic on echocardiographic examination, a calcium-related commissural tear was also observed at reoperation, and in another, a paravalvular leak was found. Dystrophic calcification, isolated (64%) or occasionally associated with fibrous tissue overgrowth (21%), was the main cause of failure. Pannus was present in prostheses with longer satisfactory function (168 +/- 31 vs 124 +/- 21 months; p < 0.001). Long-term performance was evaluated by the Kaplan-Meier method for up to 18 years of follow-up. Freedom from structural valvular disfunction after mitral replacement was 89% at 6 years, 77% at 8 years, 56% at 10 years, 31% at 12 years, 16% at 15 years, and 15% at 18 years.
authors.affiliation: Department of Cardiology, University of Padova Medical School, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Melacini
authors.forename: C
authors.initials: C
authors.lastname: Villanova
authors.forename: G
authors.initials: G
authors.lastname: Thiene
authors.forename: M
authors.initials: M
authors.lastname: Minarini
authors.forename: G
authors.initials: G
authors.lastname: Fasoli
authors.forename: U
authors.initials: U
authors.lastname: Bortolotti
authors.forename: G
authors.initials: G
authors.lastname: Ramuscello
authors.forename: R
authors.initials: R
authors.lastname: Scognamiglio
authors.forename: A
authors.initials: A
authors.lastname: Ponchia
authors.forename: S
authors.initials: S
authors.lastname: Dalla Volta
mesh_terms: D000206:Actuarial Analysis; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001705:Bioprosthesis; D015150:Echocardiography, Doppler; D005260:Female; D006350:Heart Valve Prosthesis / Q000295:instrumentation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000601:surgery; D016011:Normal Distribution; D012189:Retrospective Studies