Twelve years' clinical experience with the CarboMedics prosthetic heart valve

Background and aim of the study: The CarboMedics bileaflet prosthetic heart valve was first implanted as part of a prospective clinical study at the a uthors' institution in November 1987. The patient cohort included was part of a multicenter trial set up by the manufacturer for an FDA application. T he present report details findings over a 12-year period, with a continuous follow up on this patient cohort. Methods: Between November 1987 and August 1990, 132 patients (68 males, 64 females; median age 56 years; range 12-74 years) received a CarboMedics hea rt valve prosthesis. All patients were included in the study, whether surge ry was elective or emergency, first time or reoperation. There were 69 aort ic, 49 mitral and 12 double (aortic + mitral) valve replacements. Two patie nts had isolated tricuspid valve replacement. Concomitant surgery was perfo rmed in 15 patients. Anticoagulation with warfarin was started on postopera tive day 1. After discharge, patients were examined regularly as outpatient s for up to five years. Subsequent follow up was obtained prospectively by questionnaires to the patients' general practitioner, or by telephone calls . Actuarial estimates of survival and freedom from morbid events were calcu lated using the Kaplan-Meier method; 95% confidence limits for the distribu tion function were calculated according to the Greenwood formula. Results: Complete follow up information was available for 94% of the patien ts; total follow up was 1,014.3 patient-years (pt-yr). Actuarial survival a t 12 years was 62 +/- 0.5% overall (61 +/- 6.5% for aortic; 66 +/- 7.5% for mitral; 65 +/- 14.0% for double valve replacements). Actuarial rates of fr eedom from complications were: valve thrombosis 100%, embolism 92 +/- 2.8%, and anticoagulant-related bleeding 77 +/- 5.6%. The linearized rates per 1 00 pt-yr were: embolism 0.89 (aortic 0.74, mitral 1.30); anticoagulant-rela ted bleeding 2.56; paravalvular leakage overall 0.20 (aortic 0.37); prosthe tic valve endocarditis overall 0.20 (aortic 0.37). There was no hemolysis, prosthetic valve dysfunction or structural deterioration. Conclusion: Over a 12-year time frame, the CarboMedics prosthetic heart val ve has proven to be a highly reliable device with no structural failures, a nd a low incidence of valve-related complications.