Preliminary experience with Silzone-coated St. Jude medical valves in acute infective endocarditis

The rate of recurrent postoperative endocarditis after valve replacement in early-stage acute infective endocarditis is extremely high. Metallic silver coating of the sewing ring may improve the short- and long-term outcome after valve implantation. This report details our experience with the St. Jude Medical Silzone prosthesis in early surgical treatment of acute infective endocarditis.

Ten patients (mean age 66.4 years) referred for native valve or prosthetic valve endocarditis were operated on between April 1998 and June 1999. The microorganisms responsible for the acute infection were Staphylococcus (n = 1), Streptococcus (n = 1) and Pseudomonas aeruginosa (n = 1); blood cultures remained negative in two cases. The indication for surgical treatment was related to hemodynamic condition (n = 5), a major cerebral event (stroke; n = 1), annulus abscess (n = 1), and echocardiographic evidence of large cuspal vegetations (n = 3). All patients had received preoperative intravenous antibiotics (mean 7.8 days). Four mitral, five aortic valve replacements, and one double mitral-aortic valve replacement, were performed after extensive debridement of the infected and necrotic tissues. Mean duration of postoperative antibiotic treatment was 32.3 days. Postoperative follow up (mean 6 months; range: 2-14.2 months) was 100% complete, and included prospective repeated transthoracic echocardiography at one week, and one, six and 12 months postoperatively.

One patient died early in the immediate postoperative period from pneumonia and major hypoxemia. All other patients are symptom-free, without evidence of recurrent infection and perivalvular leak.

Although these early results with the St. Jude Medical Silzone prosthesis require confirmation by more extensive studies, they infer that silver coating of the sewing ring may dramatically improve management of patients with active endocarditis.