Manufacturer-provided effective orifice area index charts and the prevention of prosthesis-patient mismatch.

Prosthesis-patient mismatch (PPM) occurs when an implanted prosthesis is too small relative to the patient's body surface area (BSA). However, mismatch can often be prevented by indexing the expected effective orifice area (EOA) of a prosthesis to the patient's BSA and then selecting the largest implantable prosthesis to avoid mismatch. Previously, prosthesis manufacturers have attempted to simplify this process by providing charts that include the expected EOA for their prosthesis, already indexed into an array of BSA values. One caveat with these charts is that the expected EOA data must truly be reliable, or the charts will misguide the implanting surgeon. Manufacturer-provided charts could be improved by standardizing the EOA data, with one potential source being the hemodynamic data submitted to the United States Food and Drug Administration. This review discusses PPM, manufacturer-provided EOA charts, and the regulation of EOA data.

Decision-making in the choice of heart valve for replacement in patients aged 60-70 years: twenty-year follow up of the St. Jude Medical aortic valve prosthesis.

BACKGROUND AND AIM OF THE STUDY: The choice of a cardiac valve for patients with aortic valvular pathology remains controversial. Younger patients may be at risk for long-term complications from chronic anticoagulation yet require prosthesis longevity, while older patients may not outlive a bioprosthesis. To gather information to help decision-making, the 20-year experience of aortic valve replacement (AVR) with the St. Jude Medical (SJM) valve by the surgeons of Cardiac Surgical Associates, P.A., was reviewed. METHODS: Cardiac Surgical Associates Research Foundation maintains a database of all patients undergoing valve replacement with the SJM aortic prosthesis since the world's first implant in October 1977. Patient follow up is conducted by questionnaire and/or telephone interview. The 20-year follow up period ended in October 1997. Follow up is 96.3% complete, and extends to 13,208 patient-years. RESULTS: A total of 2,390 aortic valves (1,500 in males, 890 in females) were replaced in the period studied. Among these patients, 1,419 had isolated AVR, whilst the remainder had AVR plus coronary artery bypass (CAB) or other procedures. The mean age was 63 +/- 14 years for AVR, and 70 +/- 10 years for AVR/CAB. Over the 20-year follow up period, freedom from valve-related events for the entire group was: thromboembolism, 97%; anticoagulant-related hemorrhage, 94%; valve thrombosis, 99.7%; prosthetic valve endocarditis, 99.2%; and paravalvular leak, 99.6%. Freedom from structural failure was 100%. Mortality for these events was low (15 deaths among 250 events; 6%). Overall survival at 5, 10, 15 and 19 years was 82, 66, 51 and 45% respectively for isolated AVR, and 72, 45, 25 and 15% respectively for AVR/CAB. CONCLUSION: The SJM valve has excellent hemodynamics and a low incidence of valve-related complications. Improvements in anticoagulation monitoring with the newly introduced and funded home monitoring program, as well as the introduction of newer and more effective antiplatelet drugs, will improve the safety of patients requiring chronic anticoagulation. With durability unquestioned, these long-term data show the SJM valve to be an excellent choice for AVR in patients aged 60-70 years.