Abstract Background Pulmonary Hypertension (PH) is a diverse condition associated with elevated mortality. We sought to determine the association of Transthoracic Echocardiography (TTE) parameters with in-hospital mortality in patients with PH admitted to Cardiac Intensive Care Unit (CICU). Methods We included 1 Clinic CICU admissions from 2007 to 2018, with available TTE parameters within the first day of CICU admission who had PH defined as an estimated right ventricular systolic pressure (RVSP) ≥36 mmHg. The primary outcome was in-hospital mortality, evaluated using logistic regression. Results We included 3085 unique CICU patients with PH, predominantly WHO group 2 and 3. Median age was 73.7 (63.8, 82.4) years, and 1343 (43.5%) were females. Heart failure (65.6%) and respiratory failure (34.0%) were the most common admission diagnoses. The median RVSP was 47 (41, 56) mmHg, and 1314 (42.6%) had RVSP ≥50 mmHg. A total of 337 (10.9%) patients died during hospitalization. In-hospital deaths had higher RVSP (51 versus 47 mmHg, p <0.001), reflecting higher right atrial (RA) pressure (14 versus 10 mmHg, p <0.001) (Figure). In-hospital mortality increased with worse TTE parameters reflecting Right Ventricle-Pulmonary Artery (RV-PA) coupling, such as Tricuspid Annular Plane Systolic Excursion/ Right Ventricular Systolic Pressure (RVSP), Tricuspid Annular Systolic Velocity (TASV)/RVSP and TASV/ Tricuspid Regurgitation velocity ratios. Conclusion In CICU patients with PH, we have identified the specific Doppler TTE parameters with strong associations with outcomes. Specifically, RA pressure and parameters of RV-PA coupling had the highest discrimination for in-hospital mortality. Comprehensive Doppler TTE is valuable for identification of high-risk PH patients to facilitate further investigation plans, management, and prognostication. Figure: In-hospital mortality in association with right ventricular (RV) function and right atrial pressure (RAP).In-hospital mortality in association wit