A novel scoring index by Doppler echocardiography for predicting severe pulmonary hypertension due to chronic lung diseases: a cross-sectional diagnostic accuracy study

BACKGROUND Severe pulmonary hypertension (PH) resulting from a chronic lung disease (CLD) (severe CLD-PH) requires more aggressive treatment due to its increased mortality compared with mild PH. Therefore, we developed a Doppler echocardiography scoring index (ESI) to predict severe CLD-PH. METHODS A derivation cohort of 107 patients with CLD who underwent echocardiography was classified into two groups, the normal/mild PH group and the severe PH group, based on the right heart catheterization. Meanwhile, we designed the ESI by multivariate logistic regression to validate the predicted outcomes. The ESI was calculated using the following formula: ESI = ESIRVEDTD + ESIPASP + ESIPAd - ESITAPSE. Additionally, the ESI was weighted by +2 points for right ventricular end-diastolic transverse dimension ≥3.8 cm or pulmonary artery diameter ≥2.7 cm, +3 points for systolic pulmonary artery pressure (PASP) ≥61 mmHg, and -3 points for tricuspid annular plane systolic excursion ≥1.65 cm. RESULTS In the derivation cohort, PASP ≥61 mmHg estimated by echocardiography exhibited 80.4% sensitivity and 84.3% specificity with area under receiver-operating characteristic curve of 0.823 (95% CI: 0.797-0.942, P<0.0001). Compared with PASP, ESI ≥1.0 exhibited 91.1% sensitivity and 80.4% specificity, resulting in a net improvement in model performance with a change in the c-statistic from 0.823 to 0.937 and an integrated discrimination improvement of 11.3% (95% CI: 4.5%-18.2%, P=0.001). The ESI was applied to the validation cohort, resulting in 84.2% sensitivity and 81.3% specificity with 82.9% accuracy. CONCLUSION The ESI showed high capacity for predicting severe CLD-PH, further implying the value of noninvasive examinations in clinic.