Echocardiographic estimation of pulmonary pressure in patients with severe tricuspid regurgitation

The estimation of systolic pulmonary artery pressure (sPAP) by transthoracic echocardiography (TTE) is challenging in patients with severe tricuspid regurgitation (TR). The study aimed to determine the reliability of the assessment of sPAP by TTE in this population.

This study was a single-centre analysis of consecutive patients at the University Hospital of Rennes with right heart catheterisation and TTE, performed with a maximum delay of 48 hours. Lin's concordance coefficient (LCC) and Bland-Altman analysis were used to compare the values.

After applying the exclusion criteria, 236 patients were included in the analysis (age 71±11.5 years old; male 56%). The two principal indications were TR (34.3%) and mitral regurgitation (32.2%). The correlation between the two procedures was good in the total population (LCC=0.80; 95% limits of agreement (LOA): 0.74, 0.84), but weaker in the 78 patients (33%) with severe TR (LCC=0.67; 95% LOA: 0.49, 0.80), with a propensity to an underestimation by TTE. An elevated right atrial pressure (RAP) was associated with an underestimation by TTE of about 8 mmHg. The presence of a 'V-wave cut-off' sign on continuous-wave Doppler (OR=3.74; 95% CI 1.48, 9.30; p<0.01), found exclusively in patients with severe TR, was an independent predictor of sPAP misestimation by TTE.

The reliability of the estimation of sPAP in patients with severe TR could be altered by high RAP which cannot be estimated with current thresholds.