BACKGROUNDPatient-prosthesis mismatch (PPM) after aortic valve replacement potentially affects the outcome after the operation. This study sought to determine whether PPM has an impact on long-term mortality and reoperation rates.METHODSWe included 645 patients who underwent biologic aortic valve replacement between 2000 and 2007. Based on echocardiographic examinations at postoperative month 6, the incidence of PPM was determined according to an indexed effective orifice area <0.85 cm2/m2. Survival and reoperation status were analyzed during 15 years of follow-up.RESULTSPPM was present in 256 patients (40%), of whom 175 had moderate PPM and 81 had severe PPM. In multivariable adjusted analysis, survival was not statistically significantly impaired in patients with moderate PPM compared with patients with no PPM, whereas patients with severe PPM showed a marginally significant impairment of survival (hazard ratio [HR], 1.40; 95% CI, 0.99-1.97; P = .054). Risk factors for survival were higher age (HR, 1.12; 95% CI, 1.10-1.14; P < .001), arterial hypertension (HR, 1.78; 95% CI, 1.38-2.31; P < .001), and diabetes mellitus (HR, 1.67; 95% CI, 1.31-2.14; P < .001). In patients with no, moderate, and severe PPM, there were 10.1, 8.5, and 14.8 events of reoperation/1000 patient-years, respectively. The corresponding 10-year cumulative incidence of reoperation was 8.3%, 6.7%, and 12.1%, respectively. In multivariable adjusted analysis, PPM category was not significantly associated with the risk of reoperation (P > .2).CONCLUSIONSIn our study with directly measured effective orifice area, PPM was only marginally related to long-term survival and was not statistically significantly associated with the risk of reintervention.