Prevalence and risk prediction value of tricuspid regurgitation by echocardiography in precapillary pulmonary hypertension

BACKGROUND: In precapillary pulmonary hypertension (PH), the incidence of different tricuspid regurgitation (TR) degree is poorly defined. The impact of TR severity on pulmonary artery pressure (PAP) assessment and clinical risk stratification in precapillary PH remains unclear. METHODS: A total of 207 patients diagnosed precapillary PH who underwent right heart catheterization (RHC) and echocardiography within 3 days were included. The severity of TR was graded as trace, mild, moderate and severe. Pearson correlation analysis was performed to evaluate the correlation between systolic PAP by echocardiography (sPAP(ECHO)) and mean PAP by RHC (mPAP(RHC)) in different TR degree groups. The impact factors on risk stratification of precapillary PH were analyzed by logistic regression analysis. RESULTS: The proportion of None, Trace, Mild, Moderate and Severe TR group was 2.4%, 23.7%, 39.1%, 28.5% and 6.3% respectively. Right atrium (RA) area increased gradually with TR aggravation (p < 0.001). Moderate and Severe TR group had higher N-terminal pro-B-type natriuretic peptide (p < 0.001), right atrial pressure (RAP) (p = 0.018), right ventricular basal diameter (RVD)/left ventricular basal diameter (LVD) ratio (p < 0.001), larger right ventricle (RV) (p < 0.001) and lower tricuspid annular plane systolic excursion (p = 0.006) compared with Trace and Mild group. TR-sPAP(ECHO) in Moderate TR group had the greatest correlation coefficient with mPAP(RHC) (0.742, p < 0.001) followed by Mild (0.635, p < 0.001) and severe group (0.592, p = 0.033), while there was no correlation in Trace TR group (0.308, p = 0.076). Multivariate logistic regression showed three significant independent echocardiography predictors of high-risk precapillary PH: RVD/LVD ratio (OR = 5.734; 95%CI1.502–21.889, p = 0.011), RA area (OR 1.054; 95% CI 1.004–1.107, p = 0.035) and systolic annular tissue velocity of the lateral tricuspid annulus (S’) (OR 0.735, 95% CI 0.569–0.949, p = 0.018). CONCLUSIONS: Precapillary PH was not necessarily accompanied by significant TR. None or Trace TRaccounted for 26% in our population and TR-sPAP(ECHO) was not applicable to estimate PAP in these patients. RVD/LVD ratio, RA area and S’ can independently predict the high-risk patients with precapillary PH. TR may play an indirect role in risk stratification by affecting these indicators.