PROPHYLACTIC REPLACEMENT OF BJORK-SHILEY CONVEXO-CONCAVE HEART-VALVES- AN EASY-TO-USE TOOL TO AID DECISION-MAKING IN INDIVIDUAL PATIENTS

Objective - To develop an easy-to-use tool for decision-making on prop hylactic replacement of Bjork-Shiley convexo-concave heart valves. Des ign - Decision analysis comparing elective replacement with observatio n. Setting - Referral centres for patients with artificial heart valve s. Patients - Quantitative estimates were obtained from a follow up st udy conducted in The Netherlands, including 2303 patients with a mean follow up of 6.6 years and from recently published studies. Interventi on - Elective valve replacement with a new artificial heart valve. Mai n outcome measure - Loss of life-expectancy. Results - A simple graph was constructed to present the loss of life-expectancy caused by strut fracture for combinations of basal life-expectancy (life-expectancy w ithout strut fracture) and lethal fracture risk (strut fracture risk m ultiplied by lethality of fracture). This loss can be compared directl y with the loss of life-expectancy caused by surgical mortality. This quantitative approach takes into account individual patient characteri stics, such as age, gender, cardiac comorbidity, and position of the v alve, but the final estimation of surgical mortality also requires cli nical judgment. The calculations can be made easily by hand or with a simple computer application. Conclusions - This decision support tool enables the direct estimation of the gain or loss of life-expectancy t hat is Likely with replacement of a Bjork-Shiley convexo-concave heart valve. It can be used to evaluate individual patients as well as grou ps of patients, and allows for easy incorporation of revisions of frac ture risk estimates.