Prediction of Exercise Pulmonary Hypertension in Asymptomatic Degenerative Mitral Regurgitation

Objective: Exercise systolic pulmonary arterial pressure (SPAP) predicts the occurrence of symptoms in patients with degenerative mitral regurgitation (MR). However, this measurement is not always available. The purpose of this study was to identify resting echocardiographic predictors of exercise SPAP and whether predicted exercise SPAP may predict symptom-free survival. Methods: We prospectively enrolled 89 consecutive asymptomatic patients with moderate or greater degenerative MR in whom exercise SPAP was measurable. Left ventricular (LV) systolic and diastolic function were assessed by comprehensive transthoracic echocardiography. Tissue Doppler imaging was used to measure Ea- (early diastolic) and Sa- (systolic) wave velocities and time-to-peak (TP) Sa velocity. Multiple linear regression was built to identify resting predictors of exercise SPAP. Results: Patients with exercise pulmonary hypertension (PHT) (n = 45, 51%) were significantly older and more frequently male, and had shorter TP-Sa velocity and higher E/Ea ratio and LV end-diastolic volume than those without exercise PHT. Exercise SPAP was best correlated with resting LV end-diastolic volume (r = 0.55), TP-Sa (r = 0.72), and E/Ea ratio (r = 0.52). Multiple linear regression analysis allowed us to build the following predictive equation with good precision (r(2) = 0.80): Predicted Exercise SPAP = 0.13 x Age + 0.05 x LVED Vol + 0.7 x E/Ea ratio - TP.Sa/10 + 51mm Hg By using this formula, predicted exercise SPAP was well correlated with observed exercise SPAP (r = 0.89). Predicted exercise PHT was associated with significant reduced symptom-free survival in both univariate (P = .04) and multivariate (P = .045) analyses. Conclusion: In asymptomatic patients with degenerative MR, exercise PHT can be accurately predicted using resting comprehensive echocardiography. (J Am Soc Echocardiogr 2011; 24: 1004-12.)