['Patient-prosthesis mismatch has been identified as a risk factor for mortality after aortic valve replacement and for structural valve deterioration (SVD) in patients receiving a bioprosthetic aortic valve. The aim of the present study was to compare the incidence of aortic valve bioprosthesis replacement for SVD in patients with mismatch to a population without mismatch.', 'Three hundred eighty-seven adult patients who underwent aortic valve replacement with a bioprosthesis from 1974 to 2009 were retrospectively reviewed. Mismatch was considered to be present if the anticipated indexed effective orifice area was <0.70\u2009cm(2) /m(2) . The median follow-up period was 7.2 years. Follow-up was 97% complete.', "Patient-prosthesis mismatch was present in 12% of the study population (n\u2009=\u200947). Ten-year freedom from reoperation for aortic bioprosthesis replacement was 74.3\u2009±\u20093.2%. During follow-up, 111 patients underwent reoperation for aortic bioprosthesis replacement. Causes of aortic bioprosthesis replacement were SVD of the bioprosthesis (n\u2009=\u200996), paravalvular leak (n\u2009=\u200910), and acute endocarditis (n\u2009=\u20095). According to unadjusted Kaplan-Meier analysis, patients with mismatch had a higher incidence of aortic bioprosthesis replacement for SVD when compared with patients without mismatch (log rank test: p 0.05). This result was confirmed by multivariable Cox regression analysis, which identified two independent predictors of aortic bioprosthesis replacement for SVD: patients' age (hazard ratio (HR) 0.967) and patient-prosthesis mismatch (HR 2.161)."] Does patient-prosthesis mismatch in patients undergoing bioprosthetic aortic valve implantation increase risk of reoperation for structural valve deterioration?