Geometry of the right heart and tricuspid regurgitation to exclude elevated pulmonary artery pressure: New insights

Abstract

The value of the right heart morphology is not well established for the evaluation of elevated pulmonary artery pressure (PAP). We aimed (1) to assess the relationship between right heart morphology and PAP and (2) to evaluate whether morphology can help to exclude elevated PAP. From 11-2010 until 01-2011, 1640 consecutive patients were included from the database of echocardiography. Tricuspid regurgitation (TR) severity, right ventricular (RV) dilatation and right atrial (RA) dilatation were evaluated for (1) tricuspid regurgitant gradient (TRG) ≤ 30 mmHg; (2) TRG = 30-40 mmHg, and (3) TRG > 40 mmHg. A weighted score model was developed to diagnose TRG > 30 mmHg. The model was validated with data from right heart catheterization in 100 patients. TR severity and RA diameter increased significantly from group 1 to group 2 and to group 3 whereas RV diameter differed only significantly from group 2 to group 3. To integrate TR severity, RA dilatation and RV dilatation, a point-based model was constructed. A total score ≥ 3 was associated with a sensitivity and specificity of 95% and 31% and with a positive and negative likelihood ratios of 1.37 and 0.17, respectively to diagnose TRG > 30 mmHg. Negative predictive value for TRG > 30 mmHg was 92%. Prediction numbers could be reproduced when right heart catheterization was used as a reference standard. Increasing TRG is characterized by a steady increase in TR severity and RA dilatation. However, the RV dilates only significantly when TRG is markedly elevated. Integrating morphological parameters could reliably exclude the presence of elevated TRG and thus can be useful in screening for elevated PAP.