Abstract 10841: Prosthesis-patient Mismatch Affects Long-term Survival After Aortic Valve Replacement
Introduction: There is an ongoing discussion about the impact of prosthesis-patient mismatch (PPM) on long-term survival after aortic valve replacement. In most of the previous studies PPM was assessed by the mean effective orifice area (EOA) obtained from reference tables provided in literature (projected EOA).
Hypothesis: We assessed the hypothesis that PPM effects long-term survival after aortic valve replacement.
Methods: Before discharge the EOA was measured by transthoracic echocardiography in 1012 patients undergoing aortic valve replacement between 1996 and 2006. Mean age was 70±10 years. Follow-up was 99% complete with 6172 patient-years and mean time of 6.1 years. Cox-regression was used to estimate the impact of indexed EOA on survival. The optimal transformation of indexed EOA (linear or binary) was determined by the greatest drop in deviance (deviance of the model without indexed EOA – deviance with indexed EOA in several transformations).
Results: Predictors of survival time were age, pulmonary hypertension, atrial fibrillation, ejection fraction <60%, diabetes mellitus, chronic obstructive pulmonary disease, peripheral artery disease, emergency procedure, creatinine concentration. The adjusted hazard ratio of measured indexed EOA (linearly) was 0.6 (p-Value: 0.085, deviance drop: 3.1). Indexed EOA <0.65 cm2/m2 was identified as a significant predictor of survival time (HR: 1.3, p-Value: 0.015, deviance drop: 5.9). The projected indexed EOA was not a significant predictor of survival time neither in linear (p=0.31) nor in binary transformation (p=0.24). The scatter plot in the Figure below shows the relationship between projected and measured EOA, e.g. in patients with a projected EOA determined by reference values from literature of 1.5 cm2 the real measured EOA varied between 0.7 and 2.2 cm2.
Conclusions: Long-term survival was impaired by prosthesis-patient mismatch assessed by postoperatively echocardiographic measured EOA .
- © 2010 by American Heart Association, Inc.