Hemodynamics and early clinical performance of the St. Jude Medical Regent mechanical aortic valve.

Background: The St. Jude Medical Regent valve is the next-generation bileaflet aortic prosthesis, modified from the currently marketed St. Jude Medical mechanical valve to achieve a larger geometric orifice without changing the existing design of the pivot mechanism or blood-contact surface areas. The present study reports the hemodynamic and early clinical results of an ongoing multicenter trial investigating the performance of the Regent valve.

Methods: Between July 1998 and July 2001, 361 patients at 17 centers in North America and Europe underwent implantation of a Regent mechanical aortic valve prosthesis. Clinical status was prospectively recorded, and echocardiography with Doppler was performed at discharge and at 2 months, 6 months, 1 year, and 2 years after operation.

Results: Follow-up to date is 300 patient-years (average, 0.8 +/- 0.7 years per patient; range, 0.0 to 2.7 years). There were low rates of clinical adverse events. Mean gradient at 6 months was 9.7 +/- 5.3 mm Hg, 7.6 +/- 5.2 mm Hg, 6.3 +/- 3.7 mm Hg, 5.8 +/- 3.4 mm Hg, and 4.0 +/- 2.6 mm Hg, respectively, for 19-mm, 21-mm, 23-mm, 25-mm, and 27-mm valves; effective orifice area was 1.6 +/- 0.4 cm2, 2.0 +/- 0.7 cm2, 2.2 +/- 0.9 cm2, 2.5 +/- 0.9 cm2, and 3.6 +/- 1.3 cm2, respectively. Indexed effective orifice area was equal to or greater than 1.0 cm2/m2 for all valve sizes. Left ventricular mass index decreased significantly between early postoperative (165.9 +/- 57.1 g/m2) and 6-month follow-up (137.9 +/- 41.0 g/m2; delta = -28.0 +/- 49.1 g/m2; p < 0.0001).

Conclusions: The St. Jude Medical Regent aortic valve has excellent hemodynamics and early clinical results, with rapid and significant left ventricular mass regression. Long-term clinical assessment is ongoing.