Abstract 3236: Prosthesis-Patient Mismatch and Mitral Regurgitation After Aortic Valve Replacement: A Prospective Quantitative Study
Background: Prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR) is associated with less improvement in symptoms and functional class, and poorer prognosis. Mitral regurgitation (MR) is frequent in patients undergoing AVR, and has been shown to decrease in most patients after isolated AVR. We assessed the hypothesis that PPM affects MR severity after isolated AVR.
Methods: Patients with aortic stenosis scheduled for isolated AVR and presenting holosystolic MR with an effective regurgitant orifice (ERO) ≥10 mm2 which was not considered for replacement or repair, were prospectively included. Previous mitral valve surgery and severe aortic regurgitation were excluded. We studied 38 patients (mean age 79±6 years) before (median 1.5 days) and after (median 7 days) AVR. Aortic effective orifice area (EOA) was assessed by the continuity equation and indexed by body surface area. MR was quantified using the proximal isovelocity surface area method.
Results: Preoperative mean transaortic pressure gradient and aortic valve area were 45±18 mmHg and 0.33±0.11 cm2/m2, respectively. Postoperatively, 5 patients had severe PPM (EOA <0.65 cm2/m2, 19 had moderate PPM (EOA 0.65– 0.85 cm2/m2), and 14 had no PPM (EOA >0.85 cm2/m2). These three groups did not significantly differ in terms of preoperative MR severity, age, body surface area, blood pressure, left ventricular volumes and ejection fraction. In the whole group of patients, MR ERO and regurgitant volume decreased from 15±5 mm2 to 12±6 mm2 (p<0.001) and from 28±8 ml to 16±9 ml (p<0.0001). Severe PPM was associated with a lesser decrease in regurgitant volume and in ERO (table 1⇓).
Conclusions: Severe PPM after AVR for aortic stenosis is associated with a lesser decrease in MR, affecting both ERO and regurgitant volume. This unfavourable effect may contribute to the functional impairment and adverse outcome associated with PPM.