The Medtronic-Hall Cardiac Valve: 7½ Years' Clinical Experience

Abstract

Clinical information on the Medtronic-Hall valve prosthesis was obtained by reviewing the records of 379 patients, 164 of whom had aortic valve replacement (AVR), 163 of whom had mitral valve replacement (MVR), and 52 of whom had double valve replacement over 90 months (1,225 patient-years) (mean follow-up, 42.01 ± 1.3 months [± standard error]). Mean age was 53.8 ± 12 years. One hundred ninety-three patients (50.9%) had some type of concomitant operation, such as tricuspid annuloplasty, coronary artery bypass grafting, or resection of ascending aortic aneurysm. Ninety-one percent were in New York Heart Association (NYHA) Functional Class III or IV pre-operatively. Early mortality and late mortality were 7.7% (29 patients) and 13.5% (51 patients), respectively. The actuarial survival at 7 1/2 years was 74.1 ± 2.7% for the total group and 69.0 ± 4.5% for those having AVR, 81.0 ± 3.2% for those having MVR, and 67.0 ± 8.9% for those having double valve replacement. All patients but 2 were maintained on a regimen of chronic anticoagulation with warfarin sodium. Twenty-six thromboembolic episodes occurred (2.1/100 patient-years): 13 after MVR (2.3/100 patient-years), 11 after AVR (2.1/100 patient-years), and 2 after double valve replacement (1.4/100 patient-years). Four thromboembolic episodes were fatal; no valve thrombosis occurred. There were no structural failures. Of the 350 late survivors, 92% were in NYHA Functional Classes I and II. Total valve-related complications have been minimal. Our 7 1/2-year experience with the Medtronic-Hall valve prosthesis reveals a low thromboembolic rate of 2.1/100 patient-years in anticoagulated patients, a well-engineered and resistant valve structure, an acceptable hemolysis, and an acceptable rate of valve-related complications.