Background and aim of the study: The interface between the annulus and sewing cuff is the infectious center of prosthetic valve endocarditis (PVE). To decrease the incidence of PVE, the sewing cuff of the St. Jude Medical (SJM) mechanical heart valve was permanently coated with elemental silver (Silzone coating). In vitro data have supported the antimicrobial efficacy of this coating.

Methods: To study any adverse effects of the silver coating in humans, serum silver levels were determined (by graphite furnace atomic absorption spectrometry) before (baseline) and at five intervals after operation: day 1, day 3, discharge, one month, and two months. Between January and August 1997, 38 patients (71% males) underwent surgical implant of a SJM Masters Series valve with Silzone coating for the aortic valve (n = 29), mitral valve (n = 6), or both valves (n = 3). Five patients (13%) underwent concomitant procedures. Two patients (5%) presented with native active valve endocarditis.

Results: There was no hospital mortality or valve-related hospital morbidity. Blood silver concentrations peaked shortly after surgery and then decreased during the postoperative period. Average levels were consistently below 4 parts per billion (ppb). Levels below 10 ppb are considered normal. Follow up was 95% complete. There were no recurrent or new cases of endocarditis.

Conclusion: These clinical data indicate that the SJM Masters Series valve with Silzone coating performs well. No adverse effects of the silver coating could be detected, and there were no valve-related complications.