Background: The significant role of mitral regurgitation (MR) in development of pulmonary hypertension (PH) has been proved in previous studies. Experts suggest systolic pulmonary arterial pressure (SPAP) ⩾60 mmHg during exercise as a significant threshold of negative prognostic value in patients with MR.
Purpose: The aim of this study was to evaluate the changes of SPAP and to ascertain the determinants of exercise induced pulmonary hypertension (EIPH) in patients with asymptomatic primary MR.
Methods: We performed a prospective study that included 50 patients with asymptomatic primary moderate to severe MR with preserved left ventricular ejection fraction (LV EF ⩾60%) at rest. They were divided into two groups according to the presence (PH group; n = 13) or absence (non-PH group; n = 37) of EIPH. Rest and stress (bicycle ergometry) echocardiography and speckle-tracking offline analysis were performed.
Results: An increment of SPAP from rest to peak stress was higher in PH group (p < 0.001). Multivariate regression analysis showed that MR effective regurgitation orifice area (EROA; p = 0.008) and regurgitant volume (RVol; p = 0.006) contributed significantly to SPAP at rest. Higher increment of MR EROA during stress and worse parameters of LV diastolic function at rest (E, A, E/e') correlated significantly with higher SPAP during peak stress and they had a major role in predicting EIPH according to univariate logistic regression analysis. In ROC analysis SPAP >33.1 mmHg at rest could predict EIPH with 84.6% sensitivity and 87.1% specificity (95%CI 0.849-1.000; p < 0.001).
Conclusions: Parameters of MR severity (EROA and RVol) were significant determinants of SPAP at rest, while the increment of MR EROA during stress and parameters of resting LV diastolic function were the best predictors of significant EIPH.
Keywords: primary mitral regurgitation; pulmonary hypertension; stress echocardiography.