Doppler estimates of pulmonary vascular resistance to phenotype pulmonary hypertension in heart failure

An accurate distinction between isolated post-capillary pulmonary hypertension (Ipc-PH) and combined post- and pre-capillary pulmonary hypertension (Cpc-PH) is integral to therapy and prognosis in heart failure (HF). This study aimed to compare the ability of four previously validated Doppler estimates of pulmonary vascular resistance (PVR(Doppler)) to distinguish Ipc-PH from Cpc-PH in a well-defined HF population. Consecutive subjects referred for HF assessment underwent standard echocardiography immediately followed by right heart catheterization (RHC). Subjects with atrial fibrillation, acute coronary syndrome, significant valvular disease or poor image quality were excluded. PVR(Doppler) estimates were correlated with invasive PVR and agreement was studied using Bland–Altman analysis. Receiver operating characteristics analyses were performed to determine the ability of PVR(Doppler) methods to identify PVR > 3WU. 55 HF subjects (58 ± 16 years, 55% Ipc-PH) were analyzed. PVR(Doppler) estimates demonstrated weak to modest associations with invasive PVR. The Doppler method proposed by Abbas et al. demonstrated relatively strong discriminatory ability to distinguish Ipc-PH from Cpc-PH (AUC = 0.79; 95% CI 0.63–0.96; p = 0.001). However, Bland–Altman analysis revealed wide limits of agreement (bias = 0; SD = 1.83WU) and greater variability at higher mean PVR. Conclusions: PVR(Doppler) estimates demonstrate reasonable ability to distinguish Ipc-PH from Cpc-PH but may not be reliable independent PH distinguishers in HF.