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DOI: 10.1055/s-0031-1297661
The influence of prosthesis-patient mismatch (PPM) on survival among impaired LV-function patients after aortic valve replacement (AVR)
Introduction: The evidence for the importance of PPM after AVR is conflicting. Impaired LV-function however may play a pivotal role.
Methods: 1067 consecutive patients receiving an AVR alone or AVR plus concomitant CABG from 2001–2009 were analyzed. PPM was defined as an indexed effective orifice area (iEOA) <0.85cm2/m2 body surface area (BSA). Survival was calculated by Kaplan-Meier analysis and compared by Log-Rank test. LV-function was defined impaired if ejection fraction (EF) was less than 50%.
Results: 682 (64%) patients received an isolated AVR and 385 (36%) had concomittant CABG. 812 (76%) patients received a bioprosthetic AVR and 255 (24%) a mechanical AVR. Median age for bioprosthetic AVR was 74 years, ranging from 25–94 and for mechanical AVR 60 years, ranging from 18–83 years. Overall PPM occured in 287 (27%) patients, in bioprosthetic AVR in 278 (34%) patients and in mechanical AVR in 9 (3.5%). Overall survival was 80% after 5 years without significant difference if PPM occured. However, 67 (19%) patients with reduced LV-function and PPM had significant worse survival in comparison to 283 (81%) patients without PPM. Survial at 30 day was 82.1% vs. 91.7%, log rank <0.001, at 5 years 60.4% vs. 71.2%, log rank <0.001. In a Cox proportional hazard regression analysis, PPM showed a hazard ratio of 1.7 with a 95% CI (1.02–2.8) adjusted for gender, age, emergency status, cross-clamp time, IABP and type of prosthesis.
Conclusion: PPM appears to be a significant predictor of short and longterm outcome in patients with EF<50%. Thererfore PPM should be avoided in this subset of patients by choosing aortic prosthesis with iEOA>0.85cm2/m2 BSA.