OBJECTIVES: Prosthesis-patient mismatch (P-PM) is an important determinant of morbidity and mortality following open aortic valve replacement. The aims of this study were to report its incidence and determinants following transcatheter aortic valve implantation (TAVI) with the Corevalve bioprosthesis, which haveâ€”thus farâ€”not been described.
METHODS: Patients with severe calcific aortic stenosis received TAVI with the Corevalve bioprosthesis via transfemoral route. FollowingTAVI, moderate P-PM was defined as indexed aortic valve effective orifice area (AVAi) <0.85 cm2/m2 and severe P-PM as AVAi <0.65 cm2/m2. Clinical, echocardiographic, and procedural factors relating to P-PM were studied. Optimal device position was defined on fluoroscopy as final position of the proximal aspect of the Corevalve stent frame 5â€“10 mm below the native aortic annulus. Between January 2007 and January 2009, 50 consecutive patients underwent TAVI in a single centre with the Corevalve bioprosthesis.
RESULTS: Mean age was 82.8 years (SD 5.9; 70â€“93) and 48% were male. P-PM occurred in 16 of 50 cases (32%). Optimal position was achieved in 50% of cases. P-PM was unrelated to age, annulus size, LVOT size, Corevalve size, aortic angulation, ejection fraction, and sex. It was inversely correlated to optimal position (Spearman rhoÂ r = â€“0.34,Â P = 0.015). Those with optimal positioning had a 16% incidence of P-PM relative to 48% of those with suboptimal positioning (Pearson x2 P = 0.015).
CONCLUSIONS: The incidence of P-PM following TAVI with the Corevalve bioprosthesis is compared favourably with that seen after AVR with conventional open stented bioprostheses and its occurrence is influenced by device positioning.