Abstract 2066: Does Mitral Regurgitation Regress After Aortic Valve Replacement For Aortic Stenosis ? A Prospective Multicenter Study

Abstract

Background: Mitral regurgitation (MR) is common in patients undergoing aortic valve replacement (AVR) for aortic stenosis (AS). Whether its severity may decrease after AVR remains controversial. Previous studies were mainly retrospective and the degree of MR was assessed at best semi-quantitatively. This study sought to prospectively and quantitatively assess how AVR may affect MR severity. Methods: Patients with AS scheduled for isolated AVR and presenting holosystolic MR which was not considered for replacement or repair were included. Previous mitral valve surgery; severe aortic regurgitation and poor acoustic windows were excluded. Thirty-five patients (mean age 77±7 years) were studied before (median 1, range 1– 41 days) and after AVR (median 7, range 4 –19 days). All patients underwent a comprehensive echocardiographic examination; MR was assessed by Doppler echocardiography using color flow mapping of the regurgitant jet and the PISA method. No patient had prolapsed or flail mitral leaflet as mechanism of MR. Results: Preoperative maximal and mean transaortic pressure gradients and aortic valve area were 74±26 mmHg, 44±16 mmHg, and 0.57±0.18 cm 2 , respectively. Left ventricular (LV) ejection fraction increased from 49±16 % to 55±15 % after AVR (p<0.001). LV end-diastolic volume decreased from 91±32 ml to 77±30 ml (p<0.001).The ratio of MR jet to left atrial area decreased from 30±16% to 20±14% (p<0.001). MR effective regurgitant orifice (ERO) and regurgitant volume decreased from 10±5 mm 2 to 8±6 mm 2 (p=0.015) and from 19±10 ml to 11±9 ml (p<0.0001). The decrease in ERO and in regurgitant volume was similar in patients with preserved or depressed LV ejection fraction (≤45 %) (2±3 vs 3±6 mm 2 and 7±9 vs 8±7 ml; p=NS, respectively). Conclusions: AVR is associated with an early postoperative reduction of the quantified degree of MR. This mainly results from a decrease in regurgitant volume and only modestly from a reduction in ERO, emphasizing the contributing role of the decrease in driving pressure accross the mitral regurgitant orifice.