Right heart catheterization (RHC) remains the gold standard for hemodynamic assessment of the right heart and pulmonary artery. However, this is an invasive tool, and noninvasive alternatives such as transthoracic echocardiography (TTE) are preferable. Nonetheless, the correlation between measurements by TTE and RHC are debated. In this study, we prospectively examined the correlation between systolic and mean pulmonary artery pressures (sPAP and mPAP) measured by RHC and TTE in patients with hemodynamically significant rheumatic mitral stenosis (MS).
Three hundred patients with hemodynamically significant MS undergoing TTE who were scheduled to undergo RHC within 24 hours were analyzed. PAP measurements were taken for all patients by RHC (sPAP(RHC), mPAP(RHC)). Maximum velocity of tricuspid regurgitation (TR) jet obtained by continuous-wave Doppler with adding right atrial (RA) pressure was used for measuring sPAP by TTE (sPAP(TRVmax)). Mean PAP was measured using either pulmonary artery acceleration time (mPAP(PAAT)) method or by adding RA pressure to velocity-time integral of TR jet (mPAP(TRVTI)).
A good correlation between sPAP(RHC) and sPAP(TRVmax) (r = 0.89, P < 0.001), between mPAP(RHC) and mPAP(PAAT) (r = 0.9, P < 0.001), and between mPAP(RHC) and mPAP(TRVTI) (r = 0.92, P < 0.001) was found. Sensitivity and specificity of sPAP(TRV) max in detecting pulmonary hypertension (PH) were 92.8% and 86.6% and of mPAP(PAAT) were 94.1% and 73.3%, respectively.
The noninvasive assessment of sPAP and mPAP by TTE correlates well with invasive measurements and has an acceptable specificity and sensitivity in detecting PH in patients with hemodynamically significant MS.