The real impact of randomized clinical trials in heart valve surgery

The aim of this article is to evaluate the findings of clinical trials in cardiac valve surgery and to determine the real impact in standard of care. Also, publications on randomized clinical trials were reviewed as to integrity and validity. Nineteen randomized clinical trials were identified in 11 areas of operative and clinical management.

The Veterans Affairs and Edinburgh Heart Valve Trials confirmed the guidelines for indications for bioprostheses and mechanical prostheses. Even current prostheses have advanced technologies but the same valve-related complications determine indications. Randomized clinical trials of mechanical prostheses failed to determine prosthesis superiority. Bioprostheses of specific manufacturers contribute sub-optimal hemodynamics in small sizes. Two trials showed lack of superiority between aortic stented and stentless bioprostheses. Autografts, not allografts, are indicated for children because of structural valve deterioration of allografts. Atrial ablation surgery with concomitant mitral valve reconstruction/replacement is safe and efficacious with at least two energy sources. Minimally invasive aortic valve replacement does not provide superior results to conventional surgery. Patient-managed anticoagulation provides the most favourable thromboembolic and hemorrhagic rates with mechanical prostheses. Prosthesis sewing cuff impregnation with a bactericidal agent to reduce the incidence of prosthetic valve endocarditis was stopped because of increased incidence of major paravalvular leak requiring reoperation.

Randomized clinical trials, although limited in number, have provided advancement of the standard of care. Randomized clinical trials are indicated in the management of mild to moderate ischemic mitral regurgitation and evaluation of new transcatheter technologies to conventional surgery.