Correlation Between CT Pulmonary Angiography Metrics and Right Heart Catheterization Parameters in Pre-Capillary Pulmonary Hypertension

This is a prospective, cross-sectional , analytical study. All eligible patients referred to the Pulmonary Hypertension Clinic and Catheterisation Laboratory at Assiut University Hospital who undergo both CTPA and RHC as part of standard clinical care will be enrolled consecutively after providing an informed consent.

The hospital maintains a dedicated Pulmonary Hypertension Multidisciplinary Team (MDT) comprising chest physicians, cardiologists, and cardiothoracic radiologists, and performs regular right heart catheterizations.

1. Demographic and clinical

   • Age, sex , vital signs, body mass index and 6 min walking test.
   • Comorbidities: hypertension, diabetes mellitus, coronary artery disease, chronic kidney disease, liver disease, prior DVT, recent surgery, arrhythmia .

2. CTPA Morphometric Measurements:

   All CTPA measurements will be performed independently by two trained radiologists (Reader 1 and Reader 2) who are blinded to the RHC hemodynamic results Vascular Measurements : Main PA Diameter (mPAD), Ascending Aorta Diameter Same axial level as mPAD, PA : Ao Ratio (mPAD ÷ Aortic diameter) Calculated value, RV Maximum Transverse Diameter, LV Maximum Transverse Diameter Same axial slice as RV measurement, RV : LV Diameter Ratio (RV ÷ LV), RA diameters, and lung parenchymal affection

3. Right Heart Catheterization :

   All right heart catheterization procedures will be performed in the Cardiac Catheterization Laboratory at Assiut University Hospital by an accredited cardiologist or chest physician with dedicated PH catheterization experience. The procedure will be conducted in accordance with the 2022 ESC/ERS Guidelines on PH.

   Equipment

   • 7-French balloon-tipped thermodilution Swan-Ganz catheter.
   • Multi-channel pressure transducer system, zeroed at mid-axillary line at the level of the right atrium.
   • Continuous ECG, SpO₂, and non-invasive blood pressure monitoring throughout.
   • Fluoroscopy with stored images confirming catheter position at RA, RV, PA, and PAWP RHC Hemodynamic Parameters: Right atrial pressure, Right Ventricular Pressure - systolic (RVSP), Right Ventricular End-Diastolic Pressure (RVEDP), Pulmonary Arterial Pressure - systolic (sPAP), Pulmonary Arterial Pressure - diastolic (dPAP), Mean Pulmonary Arterial Pressure (mPAP), Pulmonary Arterial Wedge Pressure - mean (PAWP), Cardiac Output ,Cardiac Index, Stroke Volume , Systemic Vascular Resistance (SVR), and Mixed Venous O₂ Saturation (SvO₂)

4. ECHOCARDIOGRAPHY Comprehensive transthoracic echocardiography (TTE) will be performed within ± 2 weeks of the RHC date by a certified echocardiographer, following the American Society of Echocardiography (ASE) and European Association of Cardiovascular Imaging (EACVI) guidelines. Echocardiography will be performed independently from CTPA and RHC result review (blinded acquisition).

   Parameters: Estimated RVSP, TAPSE (M-mode, apical 4-chamber, lateral tricuspid annulus), RV Fractional Area Change, RV S' - Tissue Doppler, lateral tricuspid annulus peak systolic velocity ,RV Free Wall Longitudinal Strain (GLS, 3-segment or 6-segment), TAPSE / sPAP Ratio , RV and LV dimensions, and RA dimensions.

5. Laboratory investigations:

The following routine laboratory investigations will be performed as part of the study baseline assessment. All samples will be collected on the day of enrolment or within 48 hours.

Parameters: Hemoglobin (Hb), Hematocrit (Hct),White Blood Cell Count (WBC),Platelet Count, MCV, renal and liver function, serology, arterial blood gases and coagulation profile