Left ventricular outflow tract shape after aortic valve replacement with St. Jude Trifecta prosthesis

Background Aortic prosthesis area ( EOA ) is computed by continuity equation from left ventricular ( LV ) stroke volume ( SV ) derived from LV outflow tract diameter ( LVOT D ) or, when unmeasurable, from LV volumes ( SV V ). There is evidence to suggest LVOT ellipticity and recommend 3D LVOT area ( LVOT CSA ) adoption in aortic stenosis. We sought to evaluate if the same concept applies to supra‐annular aortic prosthesis comparing SV and EOA derived from LVOT D ( EOA D ) and from LVOT CSA ( EOA CSA ). EOA computed from SV V ( EAO V ) accuracy was evaluated in this setting. Patient‐prosthesis mismatch ( PPM ) was compared among different EOA computations. Methods A consecutive series of 202 patients (aged 81 ± 4 years, 43% males) underwent St.Jude Trifecta aortic valve replacement ( AVR ) and were followed up with echocardiography at one‐year (335 ± 31 days). All measurements followed the EACVI or ASE guidelines, 3D X‐plane modality was used to compute SV v and measure LVOT CSA ; SV was calculated from LVOT D ( SV D ) and LVOT CSA ( SV CSA ). PPM was indexed EOA <0.65 cm²/m². Results LVOT showed a significant ellipticity index (1.17 ± .27), independent of prosthesis size. EOA D (1.70 ± 0.55 cm²) was less than EOA CSA (1.95 ± 0.62 cm²) ( P  < .0001). SV V was significantly lower than SV D and SV CSA . Bland–Altman analysis showed a significant correlation between SV V and SV D or SV CSA although with large bias and imprecision. The correlations improved reducing bias and imprecision when LVOT time–velocity integral was <20 cm. PPM incidence was higher in EOA V (15.6%) compared to EOA D ( P  = .04) or EOA CSA ( P  < .001). Conclusions In supra‐annular AVR , LVOT retains its elliptical shape and LVOT CSA yielded larger prosthesis EOA with lower PPM incidence. PPM may be overestimated by EOA V .