The Risk of Bacterial Endocarditis after Percutaneous and Surgical Biological Pulmonary Valve Implantation

Objective: Biological pulmonary valves tend to degenerate and develop stenosis and/or incompetence that limits long-term survival of the valves. In addition there is a risk for bacterial endocarditis. We analyzed and compared the outcome of surgically and interventionally implanted pulmonary valves over a 5-year period.

Methods: Between January 1, 2010, and June 30, 2015, all patients who received a biological pulmonary valve (surgical/interventional) were identified based on our hospital documentation system. The clinical follow-up was analyzed by patient history, outpatient follow-up and echo data and if catheter or surgical reintervention was necessary. Stenosis was judged relevant if echo flow revealed a gradient of more than 2.5 m/s, insufficiency > grade 1 or history of endocarditis.

Results: We identified 221 patients with a biological pulmonary valve implantation. The mean age was 15.6 years, (SD: 12.7, median: 13.3), the mean weight 47.4 kg (SD: 25.3, median: 47 kg), and the height 144.5 cm (SD: 34.5, median: 154 cm). A total of 128 patients had tetralogy of Fallot, 21 PA with VSD, 28 with Truncus arteriosus, 9 with PS, 18 with DORV, CCTGA 5, TGA 2, Ross 3, and 10 others. There were 149 surgical patients (67.5%), with 51 homografts (23%, mean diameter: 27.4 mm) and 98 Contegra® grafts (44.3%, mean diameter: 17.6) and 72 percutaneous pulmonary valve implantations (PPVI) (32.5%) with 44 Edwards valves (19.9%, mean diameter: 24.6 mm) and 29 Melody valves (12.7%, mean diameter: 21 mm) and 1 Hanckock valve (27 mm). Mean follow-up was 2.90 years (SD: 1.67) for the Contegra conduits, 2.2 years (SD: 1.46) for the homografts, 4.26 years (SD: 1.12) for the Melody® valves and 2.30 years (SD: 1.49) for the Edwards valves. Bacterial endocarditis episodes were detected 7/98 (4%) Contegras (total 7/284.18 patient years = 0.025%/year), in 0/51 (0%) of the homografts (total follow-up: 112.06 patient years), 0/44 (0%) Edwards valves (total follow-up: 98.8 years) but in 6/29 (20.7%) of the Melody® valves (total 6/123.7 = 0.048%/year).

Conclusion: Although homografts and Edwards valves seem to have a very low risk of bacterial endocarditis, this risk is increased in Contegra conduits and apparently very high in Melody® valves. Based on this observation and the availability of smaller Edwards valves only for PPVI, we have changed our practice and stopped the implantation of Melody® valves.