title: Long-term survival after valve replacement with Björk-Shiley CC valves. Björk-Shiley Study Group.
abstract: Information on the life expectancy of Bjork-Shiley convexo-concave (BScc) valve recipients is necessary when considering prophylactic replacement. However, little is known about the late results after valve replacement with BScc valves. We describe long-term survival and its determinants of the Dutch BScc cohort and compare mortality figures with those of the general population and those used in guidelines for prophylactic replacement. Follow-up was obtained on all Dutch BScc valve recipients (n = 2,264) (end of study 1996). Survival over a 15-year period and its determinants were described using the Kaplan-Meier product-limit method and Cox regression, respectively. Standardized mortality ratios (SMRs) were used to compare mortality rates of BScc valve recipients who survived at least 30 days after surgery with the Dutch population rates. Survival at 15 years for aortic, mitral, and double valve recipients was 55.0% (95% confidence interval [CI] 51.9 to 58.1), 40.8% (95% CI 37.1 to 44.4), and 38.6% (95% CI 33.2 to 43.9), respectively. The determinants of survival were patient, history, and procedure related. The SMR for all BScc valve recipients was 4.2 (95% CI 3.4 to 5.2) in the first year of follow-up, after which it decreased to 2.0 (95% CI 1.8 to 2.3) and remained constant until the 14th year. SMRs depended on time since implantation, age at the time of implantation, and position of the valve replaced. Most of life expectancy estimates in prophylactic replacement guidelines of BScc valves underrate the true survival estimates. Age, valve position, and time- specific risks of death after valvular surgery should be accounted for. Different excess mortality rates should be applied for patients from different age groups: the older the patient the lower the excess.
authors.affiliation: Julius Center for Patient Oriented Research, Utrecht University, Medical School, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Kallewaard
authors.forename: A
authors.initials: A
authors.lastname: Algra
authors.forename: J
authors.initials: J
authors.lastname: Defauw
authors.forename: D
authors.initials: D
authors.lastname: Grobbee
authors.forename: Y
authors.initials: Y
authors.lastname: van der Graaf
mesh_terms: D001021:Aortic Valve; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000401:mortality*; D006801:Humans; D008017:Life Expectancy; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D009426:Netherlands / Q000453:epidemiology; D016016:Proportional Hazards Models; D015996:Survival Rate; D013997:Time Factors