Mitral Effective Regurgitant Orifice Area Predicts Pulmonary Artery Pressure Level in Patients with Aortic Valve Stenosis

Background: Mitral regurgitation (MR) and elevated pulmonary artery pressure are common findings in patients with aortic valve stenosis (AS). The pathophysiologic role of quantitatively defined MR as a determinant of pulmonary hypertension (PH) is incompletely characterized across the whole spectrum of AS degrees. The purpose of the study was to investigate whether the quantification of MR reveals a link to PH in patients with AS. Methods: Consecutive patients undergoing comprehensive echocardiography and presenting peak aortic velocity ≥ 2.5 m/sec were prospectively enrolled. Effective regurgitant orifice area (ERO) and regurgitant volume were obtained using the proximal isovelocity surface area method. Systolic pulmonary artery pressure was calculated by adding right atrial pressure to the tricuspid regurgitation pressure gradient. Results: A total of 642 patients were enrolled between 2008 and 2013 (mean age, 79 ± 11 years; mean ejection fraction, 62 ± 10%; mean aortic valve area, 1.09 ± 0.39 cm²); MR was present in 187 (29%). Of note, 154 of 187 patients (82%) showed ERO < 0.20 cm². ERO and regurgitant volume had the most significant associations with systolic pulmonary artery pressure (R² = 0.30 and R² = 0.35, respectively, P <.0001). This relationship persisted after multivariate adjustment and in the subgroups of patients with severe AS or reduced ejection fraction (P <.0001). For each 0.10-cm² increase, the odds ratio for PH was 3.56 (95% CI, 2.65–4.86; P <.0001). Conclusions: In patients with MR and a wide range of AS severity, ERO is independently associated with PH. Also, the role of MR quantification appears stronger than other continuous variables commonly associated with left ventricular diastolic dysfunction, such as E/e′ ratio and left atrial volume.