Early in vivo hemodynamic results after aortic valve replacement with the St Jude Medical Regent mechanical heart valve in patients with pure aortic stenosis

Background: The St Jude Medical Regent(TM) is a new-generation mechanical heart valve that represents a design evolution of the St Jude Hemodynamic Plus Series (HP). The purpose of this study was to evaluate early "in vivo" hemodynamic performance of the Regent(TM) valve in patients with aortic stenosis. Methods: Between March 2000 and December 2001, 32 patients (mean age 59.9 +/- 5.9,56.3% male) with pure aortic stenosis received a Regent(TM) mechanical prosthesis in the aortic position. Hemodynamic performance was assessed by Doppler echocardiography at discharge, two months, six months, and one year by calculating peak transprosthetic velocity (V-max), mean (MG) and peak (PG) transprosthetic gradients, effective orifice area index (EOAI), left ventricular mass index (LVMI), and degree of aortic regurgitation. Results: A significant reduction in mean and peak transaortic gradients (p < 0.001) and a significant increase in EOAI (p < 0.001) over time followed valve replacement, and a bivariate analysis of variance (ANOVA) failed to demonstrate statistical differences by valve size over time(p = ns). A significant reduction in left ventricular hypertrophy occurred over time (p < 0.001) in all valve sizes (p = ns between groups): baseline LVMI was 221 +/- 57 g/cm(2); it decreased by 30 g/cm(2) (p < 0.001) at discharge. LVMI decreased from 191 +/- 54 g/cm(2) to 161 +/- 41 g/cm(2) (p < 0.001) from discharge to two months. Further reductions were not significant. At the six-month follow-up no patient in our cohort exhibited moderate or severe aortic regurgitation at Doppler echocardiography. Conclusions: Early results with the St Jude Medical Regent(TM) valve have been satisfactory. Further assessments are necessary to confirm these results.