Can Pulmonary Hypertension and Increased Pulmonary Vascular Resistance Be Ruled in and Ruled Out by Echocardiography?

Abstract

Several treatment options are available for pulmonary vascular disease, and more patients are considered for right heart catheterization. The aims of this study were to evaluate the diagnostic ability of echocardiography to detect pulmonary hypertension and increased pulmonary vascular resistance (PVR). This retrospective study comprised 118 patients investigated within 48 hours of right heart catheterization. Echocardiography was used to assess pulmonary artery systolic pressure and pulmonary artery mean pressure, filling pressures, cardiac output, and PVR. To diagnose increased PVR, three echocardiographic variables related to pressure reflection in the pulmonary circulation were used. Separate cutoff values aimed at ruling in (high positive likelihood ratio [PLR]) and ruling out (low negative likelihood ratio) pulmonary hypertension (pulmonary artery mean pressure >25 mm Hg) and increased PVR (>3 Wood units) were determined from a derivation group (n= 59, receiver operating characteristic curve analysis) and evaluated in a test group (n= 59). The linear relations between hemodynamic variables assessed with simultaneous echocardiography and right heart catheterization were moderate to strong (R= 0.55 to 0.95), and there were no significant differences, but the limits of agreement were wide. With Doppler pulmonary artery systolic pressure >39mm Hg, the PLR for pulmonary artery mean pressure >25 mm Hg was 4.7, and with Doppler pulmonary artery systolic pressure ≤29 mm Hg, the negative likelihood ratio was 0.12. The PLR for pressure reflection variables with ruling-in cutoff values ranged from 4.3 to 6.4. With all three variables positive, the PLR was 9.9. The negative likelihood ratio with ruling-out cutoff values ranged from 0.22 to 0.08. Echocardiography that includes assessment of pressure reflection in the pulmonary circulation can rule in and rule out pulmonary hypertension and increased PVR.