RHC is still recommended for detecting COPD-PH on echocardiography

Echocardiography has high specificity in the diagnosis of pulmonary hypertension (PH) in patients with advanced chronic obstructive pulmonary disease (COPD). However, it has low specificity for detecting PH in these patients, according to a recently published study The American Journal of the Medical Sciences.

Detection of PH in patients with COPD is very important. Patients with COPD with concomitant PH have increased risks of hospitalization, mortality, and other complications, and their PH status may influence lung transplant candidacy.

Right heart catheterization (RHC) is the standard approach for diagnosing PH, but the use of echocardiography can provide many benefits to patients. In comparison, echocardiography is less expensive and invasive, and performs well in screening a patient’s pulmonary arterial pressure (PAP); However, the effectiveness of this approach in detecting PA in patients with COPD has not been sufficiently studied. Furthermore, the RHC currently relies on multiple transplant criteria, including transplant list management, identification and treatment of left-sided heart disease, and single or double lung transplant decisions. To address this gap, researchers conducted a study to evaluate the utility of echocardiography as a less invasive diagnostic tool for PA in patients with COPD.

Patients with COPD being evaluated for lung transplantation who also underwent RHC for the diagnosis of PH were evaluated between January 2011 and May 2019. Echocardiography was performed a median of 3 days after the time of RHC, with the majority performed beforehand (76%). Individuals were classified as having low, intermediate, or high probability of PH according to their tricuspid regurgitation rate (TVR) and the presence of echocardiographic evidence of PH. Echocardiographic criteria for PH included at least 2 of the following: detection of a right/left ventricular basal diameter ratio greater than 1, flattening of the interventricular septum, right ventricular outflow Doppler acceleration up to 105 m/s, mid-systolic fraction, or early diastolic pulmonic. regurgitation speed above 2.2 m/s^-1:.

A total of 111 patients with severe COPD (defined according to the 6th World Symposium on Pulmonary Hypertension) who received RHC were evaluated. Of these 111 patients, 82 were diagnosed with COPD-PH (74%). Overall, patients had a mean PAP (mPAP) of 30.3 mm Hg, systolic PAP (sPAP) of 45.8 mm Hg, diastolic PAP (dPAP) of 21.8 mm Hg, pulmonary vascular resistance (PVR) of 4.0 mm Hg, diastolic (sPAP) of pulmonary DPG) 8.5 mm Hg, right arterial pressure (RAP) 9.7 mm Hg, and pulmonary capillary wedge pressure (PCWP) 13.5 mm Hg. Patients with COPD-PH were noted to have significantly higher levels of PAP than those without.

According to echocardiographic criteria, 20 patients (18%) had a high probability of PA, 20 (18%) had an intermediate probability, and 71 (64%) had a low probability. In these cases, the sensitivity, specificity, positive predictive, and negative predictive values ​​of echocardiography for diagnosing COPD-PH were 43%, 83%, 88%, and 34%, respectively. Additionally, these values ​​were 67%, 75%, 50%, and 86% for the diagnosis of COPD-severe PH.

In light of their findings, the authors state that the high specificity and positive predictive values ​​of echocardiography demonstrate its value in the diagnosis of COPD-PH; However, it showed limited sensitivity for excluding COPD-PH, and its performance was affected by the presence of significant hyperinflation or acute emphysema in these patients. The authors conclude by stating that their results are inconsistent with the recommendations to identify COPD-PH with non-invasive methods of advanced COPD; therefore, pretransplant RHC should still be considered.

Reference

Younis M, Al-Antari N, Dalbah R, et al. Echocardiography and pulmonary hypertension in patients with chronic obstructive pulmonary disease undergoing evaluation for lung transplantation. Am J Med Sci. Published online November 13, 2023. doi:10.1016/j.amjms.2023.11.006