Photo Credit: Rasi Bhadramani

The following is a summary of “A nomogram model based on clinical and 3D-EIT parameters for CTEPH diagnosis,” published in the April 2025 issue of Respiratory Research by Xu et al. 

Chronic thromboembolic pulmonary hypertension (CTEPH) often presents with nonspecific clinical features, making timely and accurate diagnosis challenging. Three-dimensional electrical impedance tomography (3D-EIT) offers real-time, bedside monitoring of whole-lung perfusion and may aid in differentiating CTEPH from other causes of pulmonary hypertension. This study aimed to investigate 3D-EIT characteristics in patients with suspected CTEPH and to develop a nomogram model combining clinical and 3D-EIT parameters to enhance diagnostic accuracy.

This retrospective analysis enrolled patients with suspected pulmonary hypertension, excluding those with PH secondary to left heart disease or chronic hypoxia. Based on confirmatory diagnostic tests, participants were classified into CTEPH and non-CTEPH groups. Clinical history, laboratory findings, and 3D-EIT assessments were collected. Of the 70 patients enrolled, 50 were assigned to a training cohort for nomogram development. The diagnostic model was calibrated and validated through receiver operating characteristic (ROC) curve analysis, decision curve analysis (DCA), and clinical impact curve (CIC) evaluation to assess its predictive performance and clinical utility.

Using univariate analysis, the Wald test, Akaike information criterion (AIC), and Bayesian information criterion (BIC), five independent predictors of CTEPH were identified: history of venous thromboembolism (VTE), D-dimer levels, maximum regional ventilation/perfusion ratio (V/Qmax), perfusion range (P-Range), and percentage of ventilation/perfusion matched areas (VQMatch). These variables were incorporated into the final nomogram model. In the training cohort, the nomogram demonstrated excellent discrimination with a concordance index (C-index) of 0.926 (95% CI: 0.859–0.993). Comparative analysis showed that the nomogram outperformed models based on VTE history alone, VTE history combined with D-dimer, and models using only EIT parameters, as indicated by larger areas under the ROC curves in both the training and test cohorts. Furthermore, DCA and CIC analyses confirmed that the model provided significant clinical benefit, supporting its potential use in guiding clinical decision-making.

The integration of clinical parameters and 3D-EIT measurements into a nomogram model significantly improves the diagnostic accuracy for CTEPH. This model offers a valuable, non-invasive tool to support early identification and management of CTEPH in clinical practice, potentially improving patient outcomes through earlier intervention.

Source: respiratory-research.biomedcentral.com/articles/10.1186/s12931-025-03206-9