Application of Regent mechanical valve in patients with small aortic annulus: 3-year follow-up

BACKGROUND: Aortic valve replacement (AVR) with a small aortic annulus is always challenging for the cardiac surgeon. In this study, we sought to evaluate the midterm performance of implantation with a 17-mm or 19-mm St. Jude Medical Regent (SJM Regent) mechanical valve in retrospective consecutive cohort of patients with small aortic annulus (diameter ≤ 19 mm). METHODS: From January 2008 to April 2011, 40 patients (31 female, mean age = 47.2 ± 5.8 years) with small aortic annulus (≤19 mm in diameter) underwent aortic valve replacement with a 17-mm or 19-mm St. Jude Medical Regent (SJM Regent) mechanical valve. Preoperative mean body surface area, New York Heart Association class, and mean aortic annulus were 1.61 ± 0.26 m(2), 3.2 ± 0.4, and 18 ± 1.4 mm respectively. Patients were divided into two groups, according to the implantation of 17 mm SJM Regent mechanical valve (group 1, n = 18) or 19 mm SJM Regent valve (group 2, n = 22). All patients underwent echocardiography examination preoperatively and at one year post-operation. RESULTS: There were no early deaths in either group. Follow-up time averaged 36 ± 17.6 months. The mean postoperative New York Heart Association class was 1.3 ± 0.6 (p < 0.001). By echocardiography, in group 1, the left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), and the indexed effective orifice area (EOAI) increased from 43.7% ± 11.6%, 27.3% ± 7.6%, and 0.70 ± 0.06 cm(2)/m(2) to 69.8 ± 9.3%, 41.4 ± 8.3%, and 0.92 ± 0.10 cm(2)/m(2) respectively (P < 0.05), while the left ventricular mass index (LVMI), and the aortic transvalvular pressure gradient decreased from 116.4 ± 25.4 g/m(2), 46.1 ± 8.5 mmHg to 86.7 ± 18.2 g/m(2) , 13.7 ± 5.2 mmHg respectively. In group 2, the LVEF, LVFS and EOAI increased from 45.9% ± 9.7%, 30.7% ± 8.0%, and 0.81 ± 0.09 cm(2)/m(2) to 77.4% ± 9.7%, 44.5% ± 9.6%, and 1.27 ± 0.11 cm(2)/m(2) respectively, while the LVMI, and the aortic transvalvular pressure gradient decreased from 118.3 ± 27.6 g/m(2), 44.0 ± 6.7 mmHg to 80.1 ± 19.7 g/m(2), 10.8 ± 4.1 mmHg as well. The prevalence of PPM was documented in 2 patients in Group 1. CONCLUSIONS: Patients with small aortic annulus and body surface area, experienced satisfactory clinical improvement after aortic valve replacement with modern SJM Regent bileaflet prostheses.