Abstract 19184: Prosthesis-Patient Mismatch and Mitral Regurgitation Persistence Late after Aortic Valve Replacement.
Background: Mitral regurgitation (MR) is a common finding in patients undergoing isolated aortic valve replacement (AVR). In this context, a mild degree of MR in absence of organic disease generally improves after AVR surgery. Conditions inhibiting the decrease of left ventricular (LV) afterload subsequent to AVR may prevent MR downgrading. We hypothesized that MR persistence after AVR could be related to the occurrence of prosthesis-patient mismatch (PPM).
Methods and Results: Patients undergoing AVR for aortic stenosis and presenting functional MR with a regurgitant volume (RV) >30 ml/beat not considered for surgery, were studied. Clinical and echocardiographic follow-up were completed at a median time of 18 months. PPM was defined absent as an effective orifice area index >0.85cm2/m2. Variables identified as significant predictors of MR persistence (defined as RV>30ml/beat at follow-up) at univariate analysis were tested in a multivariate stepwise logistic regression. In addition, to assess the clinical relevance of these findings, a 6-minute walk test (6MWT) was performed. The study population consisted of 82 patients who received either a biological (n=51) or mechanical (n=31) AVR. Different degrees of PPM were found in 34/82 (41%) patients. There were no significant differences in baseline and operative characteristics between patients with or without PPM. At univariate analysis left atrial (LA) diameter (p<0.001), LV ejection fraction (p=0.09), LV mass index (p=0.08) and PPM (p=0.002) showed a significant association with MR persistence late after AVR. At multivariate analysis only PPM (p=0.03) and LA diameter (p<0.001) were found to independently predict MR persistence late after surgery. At 6MWT, patients without the association of PPM and MR had significantly better results (324±70 versus 226±42 meters for patients with PPM and MR persistence; 95%CI:−145.29 to −51.71; p=0.0002)
Conclusions: This study shows that following AVR, the occurrence of PPM is associated with MR persistence late after surgery and has a clinical impact on these patients as showed by the 6MWT. This unfavourable effect may contribute to the adverse outcomes associated with PPM. Further studies are needed to confirm these findings.
- © 2010 by American Heart Association, Inc.