Role of transvalvular gradient in outcome from valve replacement for aortic stenosis

Background Despite limitations the transvalvular gradient (TVG) still is commonly used in aortic stenosis when patients are referred for aortic valve replacement. We wished to ascertain if it had a role in predicting outcome from valve replacement rather than as an indicator of severity, specifically investigating if the TVG affected renal dysfunction, hospital stay, and medium-term survival after valve replacement. Methods Six hundred and twenty-three consecutive patients who had aortic valve replacement were identified and 211 of these patients were isolated as first time replacement for aortic stenosis that formed the final study group, and were followed up for up to 48 months. Variables significant (p< 0.05) on univariate analysis were included in the logistic regression multivariate analysis (renal dysfunction, prolonged hospital stay) or Cox proportional hazard regression model (medium-term mortality). Results A significant association was present between TVG and age (p = 0.001). Multivariate analysis demonstrated angina greater than or equal to grade 3 Canadian Cardiovascular Society (CCS 3; p = 0.014) and having nonelective surgery (p< 0.001) to be independent predictors of renal dysfunction. Angina greater than or equal to CCS 3 (p = 0.013) was the only independent predictor of prolonged hospital stay. Independent predictors of medium-term mortality on multivariate analysis were age (p = 0.043) and having a size 19 valve prosthesis (p = 0.015). Conclusions The TVG is inadequate as an independent predictor of the degree of aortic stenosis and outcome from aortic valve replacement in aortic stenosis. In contrast, the TVG may be a useful screening tool for detecting aortic stenosis in targeted elderly populations.