Mechanical Heart Valves

Abstract

The report by Svennevig and colleagues in this issue of Circulation will stand as an important contribution to our knowledge of the outcomes after heart valve replacement.1 This article, along with other extensive published series of patients followed up for as many as 4 decades after mechanical heart valve replacement, now help form the basis on which present and future decisions are made for patients with valvular heart disease. Article p 1795 Decades ago, the properties of an ideal valve replacement were described by the late Dr Dwight Harken, a pioneer in cardiac surgery2; included in these properties are durability (at least as good as a native valve), no thrombogenicity (hence, warfarin anticoagulation not required), no inherent gradient, and easy to implant. How close a prosthetic heart valve approaches these ideals can only be determined after large numbers of implants, assiduous management of anticoagulation, complete patient follow-up, and the test of time… decades. Because mechanical aortic valves are generally implanted in younger patients, the interaction of the prosthesis with the patient, the propensity (or lack thereof) of tissue ingrowth that can interfere with valve function, the long-term structural integrity, and the thrombogenicity and relative resistance to variability in anticoagulation can only be determined with the patient population size and duration of thorough follow-up reported in this issue of Circulation for the Hall-Medtronic prosthesis, as well as in previous publications for other mechanical heart valves. To date, no mechanical or bioprosthetic valve prosthesis has achieved the ideal profile described by Harken. However, we now recognize that some available valve prostheses may approach these ideal properties, and this type of long-term outcome study should guide prosthesis selection as we go forward. Valve replacement surgery has a long and important history, with initial efforts aimed to deal with aortic …