Predicting outcome after valve replacement

Objective: To identify the key predictors of performance on a 6-minute walk and health-related quality of life (QOL) one year after cardiac valve replacement and to use the predictors to guide clinical practice and optimise outcome. Design: Prospective cohort study. Setting: Tertiary cardiothoracic centre in the UK. Patients: 225 patients having first time valve replacement with a mean age 67.1 (SD 12.1) years. Main outcome measures: Mortality, morbidity, NYHA, performance on a 6-minute walk and health-related QOL one year after surgery. Results: One year after valve replacement 90% of patients were alive and free from a major event related to their surgery. NYHA category fell by 0.6. Performance on a 6-minute walk improved by 42% and QOL improved on all subscales and both composite scores of the SF-36 QOL questionnaire. Although physical QOL scores improved they did not normalise, unlike the mental QOL scores which were near normal on both occasions. Independent baseline predictors of 6-minute walk performance at one year were baseline walk performance, age and belief in surgery as a treatment. Independent baseline predictors of one year physical QOL were baseline physical QOL and walk performance. Independent baseline predictors of one year mental QOL were depression, baseline mental QOL and age, with age having a positive effect. Conclusions: One year after valve replacement patients can expect a significant improvement in their exercise tolerance and QOL but their physical QOL is unlikely to be normal. Outcome may be improved by treating depression and modifying negative illness beliefs preoperatively.