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Background: Assessment of pulmonary vascular resistance (PVR) is critical for accurate diagnosis and optimal pharmacotherapy in pulmonary hypertension. We aimed to test the diagnostic performance of a novel, Doppler-based method to evaluate PVR based on Ohm’s law (PVR_echo) using pragmatic estimates of pulmonary capillary wedge pressure (PCWP).

Methods and results: Simultaneous right heart catheterization (RHC) and echocardiography was performed in a derivation cohort of 111 patients in sinus rhythm referred for PH evaluation and PVR_echo independently validated in 238 patients. PVR_echo was calculated using pulmonary artery mean pressure estimates (PAMP_echo) obtained from peak tricuspid gradient employing a fixed right atrial pressure estimate, PCWP_echo was estimated as 10 or 20 mmHg using age-related mitral E/A cut-offs and cardiac output from left ventricular outflow. In the derivation cohort, both PAMP_echo and PCWP_echo estimates demonstrated excellent agreement with catheterization measurements. PVR_echo was highly feasible, demonstrated negligible bias and excellent agreement with PVR_RHC (Bias = −0.58, SD 2.2 mmHg) and outperformed the Abbas method to identify PVR_RHC > 3WU (AUC = 0.85 vs. 0.70; p = 0.02). In the validation cohort, PVR_echo preserved good invasive agreement with negligible bias, displayed strong diagnostic performance (AUC = 0.84) and significant ability to distinguish isolated post-capillary from combined post- and pre-capillary pulmonary hypertension (PH) subgroups (AUC = 0.77).

Conclusion: PVR_echo based on Ohm’s law employing pragmatic estimates of PCWP_echo demonstrates excellent agreement with invasive reference standard measurements and strong diagnostic ability to identify elevated PVR_RHC. This novel approach may be useful during therapy selection to distinguish PH hemodynamic subgroups.