EXPLANATION


Reconstruction of the right ventricular outflow tract with implantation of an extracardiac pulmonary-valved conduit may be necessary in patients with both acquired and congenital heart disease. Alternatively, the pulmonary valve may be replaced with a bioprosthetic or mechanical valve. Conduits used for this purpose include cryopreserved pulmonic or aortic homografts, Contegra conduits, and transcatheter pulmonary valves (Melody and Edwards SAPIEN). Homograft conduits have been used for the last 50-60 years, while Contegra conduit use began in the last 20-25 years. Contegra conduits are made of bovine jugular vein with a trileaflet venous valve. The Melody and Edwards SAPIEN valves are two types of percutaneously implanted pulmonary valves. The Melody valve is composed of bovine jugular vein with a trileaflet venous valve sutured into an expandable platinum stent. The Edwards SAPIEN valve is comprised of bovine pericardium that is shaped into a trileaflet valve and mounted onto an expandable cobalt-chromium frame. One large nationwide registry-based study that included all patients with at least one pulmonary valve replacement prior to 2018 by Stammnitz et al demonstrated that pulmonary valve replacement (PVR) with a bovine jugular vein valve (Contegra conduit or Melody valve) has the highest risk of infective endocarditis (IE) irrespective of mode of deployment, either surgical or percutaneous. In this study, the overall incidence of IE was 4.8% after a median follow up of 10 years per patient. Patients with a Contegra conduit had an incidence of IE of 5.4% while those with a homograft had an incidence of 1.3%. There was a 0% incidence of IE in patients with a mechanical valve or Edwards SAPIEN valve. The risk for IE was higher for surgically implanted Contegra grafts (HR, 5.62; 95% CI, 2.42–13.07; P<0.001) and transcatheter Melody Valves (HR, 7.81; 95% CI, 3.20–19.05; P<0.001) compared to homografts. The median time interval from PVR to infective endocarditis was 3 and 5 years for Contegra conduit and Melody valves respectively. The increased risk of IE with Contegra conduits and transcatheter Melody valves as compared to homograft conduits has been demonstrated in smaller studies as well.


REFERENCES


Stammnitz C, Huscher D, Bauer UMM, et al. Nationwide registry‐based analysis of infective endocarditis risk after pulmonary valve replacement. JAHA. 2022;11(5): e022231.


Haas NA, Bach S, Vcasna R, et al. The risk of bacterial endocarditis after percutaneous and surgical biological pulmonary valve implantation. Int J cardiol. 2018; 268:55-60.


Gröning M, Tahri NB, Søndergaard L, Helvind M, Ersbøll MK, Andersen HØ. Infective endocarditis in right ventricular outflow tract conduits: a register-based comparison of homografts, Contegra grafts and Melody transcatheter valves. Eur J Cardiothorac Surg .2019; 56(1):87-93.