Prosthesis-patient mismatch in bovine pericardial aortic valves: Evaluation using 3 different modalities and associated medium-term outcomes

Background-The prevalence of prosthesis-patient mismatch (PPM) and its impact on survival after aortic valve replacement have not been clearly defined. Historically, the presence of PPM was identified from postoperative echocardiograms or preoperative manufacturer-provided charts, resulting in wide discrepancies. The 2009 American Society of Echocardiography (ASE) guidelines proposed an algorithmic approach to calculate PPM. This study compared PPM prevalence and its impact on survival using 3 modalities: (1) the ASE guidelines-suggested algorithm (ASE PPM); (2) the manufacturer-provided charts (M PPM); and (3) the echocardiographically measured, body surface area-indexed, effective orifice area (EOAi PPM) measurement. Methods and Results-A total of 614 patients underwent aortic valve replacement with bovine pericardial valves from 2004 to 2009 and had normal preoperative systolic function. EOAi PPM was severe if EOAi was ≤0.60 cm²/m², moderate if EOAi was 0.60 to 0.85 cm²/m², and absent (none) if EOAi was ≥0.85 cm²/m². ASE PPM was severe in 22 (3.6%), moderate in 6 (1%), and absent (none) in 586 (95.4%). ASE PPM was similar to manufacturer-provided PPM (P=1.00). ASE PPM differed significantly from EOAi PPM (P<0.001), which identified severe mismatch in 170 (29.7%), moderate in 191 (33.4%), and absent (none) in 211 patients (36.9%). Irrespective of the PPM classification method, PPM did not adversely affect midterm survival (average follow-up, 4.1±1.8 years; median, 3.9 years; range, 0.01-8 years). There were no reoperations for PPM. Conclusions-In patients with normal systolic function undergoing bovine pericardial aortic valve replacement, the prevalence of PPM using the algorithmic-ASE approach was low and correlated well with manufacturer-provided PPM. Independent of the method of PPM assessment, PPM was not associated with medium-term mortality.