DLco and echocardiographic parameters in identifying mild pulmonary hypertension in the EUSTAR cohort of systemic sclerosis patients

The 2022 European Society of Cardiology (ESC)/European Respiratory Society (ERS) guidelines define pulmonary hypertension (PH) as a resting mean pulmonary artery pressure (mPAP) > 20 mmHg at right heart catheterization (RHC). Previously, patients with a mPAP between 21 and 24 mmHg were classified in a "grey zone" of unclear clinical significance. What is the diagnostic performance of the main parameters used for PH screening in detecting systemic sclerosis (SSc) patients with mPAP 21-24 mmHg at RHC? SSc patients from the European Scleroderma Trials and Research (EUSTAR) database with available tricuspid annular plane systolic excursion (TAPSE), systolic PAP (sPAP) and mPAP data were included. Patients with mPAP 21-24 mmHg and patients with mPAP ≤ 20 mmHg were considered for the analysis. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated. TAPSE/sPAP was lower in the group of SSc patients with mPAP 21-24 mmHg than in non-PH group [0.58 (0.46-0.72) mm/mmHg vs 0.69 (0.57-0.81) mm/mmHg, p < 0.01]. No difference was found in other parameters between the two groups. Diffusing capacity of the lungs for carbon monoxide (DL ) < 80% of the predicted value had the highest sensitivity (88.9%) and NPV (80%), but the lowest specificity (18.2%) and PPV (30.8%) in detecting SSc patients with mPAP 21-24 mmHg. TAPSE/sPAP < 0.55 mm/mmHg had the highest specificity (78.9%), PPV (50%) and accuracy (68.1%); its NPV was of 75.4%, while its sensibility 45.1%. DL < 80% of the predicted value is the parameter with the highest sensitivity and NPV in detecting SSc patients with mPAP 21-24 mmHg. TAPSE/sPAP < 0.55 mm/mmHg has the highest specificity, PPV and accuracy and, therefore, can be a useful additional parameter to decrease the number of unnecessary RHC.