title: Incidence of embolism and paravalvar leak after St Jude Silzone valve implantation: experience from the Cardiff Embolic Risk Factor Study.
abstract: BACKGROUND
  Silver coating of the sewing ring (Silzone) was introduced as a modification of the St Jude Medical standard valve to provide antibacterial protection, but the valve has recently been withdrawn.
  
  
  OBJECTIVE
  To study patients with these prostheses to assess possible adverse effects, and to guide their follow up.
  
  
  METHODS
  Prospective observational study of risk factors for stroke after valve replacement.
  
  
  METHODS
  Cardiology and cardiac surgery departments in a tertiary centre.
  
  
  METHODS
  There were 51 patients with Silzone and 116 with St Jude Medical standard valves. Patients undergoing aortic valve replacement were well matched for stroke risk factors. Silzone patients with mitral valve replacement were younger (mean (SD) age 61 (10) v 66 (7) years), more likely to be female (95% v 65%), and had more pulmonary arterial hypertension (100% v 78%), but fewer coronary artery bypass grafts (5% v 33%) than patients with standard mitral valve replacements (all p < 0.05).
  
  
  RESULTS
  Follow up was 100% in the Silzone group (mean duration 3.0 (0.9) years) and 97.4% in the standard group (4.7 (1.4) years). Survival, morbidity, and anticoagulant control were documented over 682 follow up years (153 for Silzone and 529 for standard). There were six embolic strokes and one peripheral embolism in the Silzone group, all within three months after operation, and five embolic strokes and one peripheral embolism in the standard group. Freedom from major thromboembolism at three months was 65% in the Silzone mitral valve replacement group and 100% in the standard mitral valve replacement group (difference 35%, 95% confidence interval 8% to 62%). There was one reoperation for paravalvar leak in the standard group, but none in the Silzone group (NS). Anticoagulant control in the two groups was similar.
  
  
  CONCLUSIONS
  Patients with Silzone mitral valves had a high rate of early postoperative embolism but no excess paravalvar leak.
authors.affiliation: Department of Cardiothoracic Surgery, University Hospital of Wales, Cardiff, UK.
authors.forename: A
authors.initials: A
authors.lastname: Ionescu
authors.forename: N
authors.initials: N
authors.lastname: Payne
authors.forename: A G
authors.initials: AG
authors.lastname: Fraser
authors.forename: J
authors.initials: J
authors.lastname: Giddings
authors.forename: G L
authors.initials: GL
authors.lastname: Grunkemeier
authors.forename: E G
authors.initials: EG
authors.lastname: Butchart
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use; D001021:Aortic Valve; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000601:surgery; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D011183:Postoperative Complications / Q000209:etiology*; D011446:Prospective Studies; D012307:Risk Factors; D012834:Silver / Q000097:blood; D020521:Stroke / Q000097:blood / Q000209:etiology*; D016019:Survival Analysis; D013923:Thromboembolism / Q000097:blood / Q000209:etiology* / Q000517:prevention & control
chemical_list: D000925:Anticoagulants; D012834:Silver