CTEPH: A Kaiser Permanente Northern California Experience

Development and validation of a Prediction Model for Chronic Thromboembolic Pulmonary Disease

BACKGROUND

Acute pulmonary embolism (APE) is a critical disease with a high mortality rate, some of the surviving patients may develop chronic thromboembolic pulmonary disease (CTEPD), which affects the patient's prognosis. However, the research on the early diagnosis of CTEPD is limited. This study aimed to establish a prediction model for earlier identification of CTEPD.

METHODS

This prospective study included 464 consecutive patients with APE confirmed between January 2020 and September 2023, at 7 centers from China. After follow-up for at least 3 months, the patients were divided into the CTEPD and non-CTEPD groups based on symptoms and computed tomography pulmonary angiography (CTPA) or pulmonary ventilation perfusion (V/Q) scans showing residual thrombosis. The independent risk factors for CTEPD were identified via univariate and multivariate logistic regression analyses. Next, a nomogram of predictive model was established, and validation was completed via decision curve analysis (DCA) and receiver operating characteristic curve analysis.

RESULT

In total, 130 (28%) patients presented with CTEPD, 17% (22/130) of CTEPD patients developed chronic thromboembolic pulmonary hypertension (CTEPH). Based on the multivariate analysis, a time interval from symptoms onset to diagnosis (time-to-diagnosis) ≥ 15 days (95% confidence interval [CI]: 3.392-14.972, p < 0.001), recurrent pulmonary embolism (RPE) (95%CI: 1.560-17.300, p = 0.007), right ventricular dysfunction (RVD) (95%CI: 1.042-6.437, p = 0.040), central embolus (95%CI: 1.776-7.383, p < 0.001) and residual pulmonary vascular obstruction (RPVO) > 10% (95%CI: 4.884-21.449, p < 0.001) were identified as the independent predictors of CTEPD. Then, A prediction model with a C-index of 0.895 (95% CI 0.863-0.927) was established for high-risk patients. The nomogram had an excellent predictive performance for earlier identification of CTEPD, with an area under the curve of 0.908 (95%CI: 0.875-0.941) in the training cohort and 0.875 (95%CI: 0.803-0.947) in the validation cohort.

CONCLUSION

The current study established and validated a reliable nomogram for predicting CTEPD, which would assist clinicians identify the high-risk patients for CTEPD earlier.

Pulmonary Thromboendarterectomy: The Potentially Curative Treatment of Choice for Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a consequence of unresolved organized thromboembolic obstruction of the pulmonary arteries, which can cause pulmonary hypertension and right ventricular failure. Owing to its subtle signs, determining its exact incidence and prevalence is challenging. Furthermore, CTEPH may also present without any prior venous thromboembolic history, contributing to underdiagnosis and undertreatment. Diagnosis requires a high degree of suspicion and is ruled out by a normal ventilation/perfusion ratio scintigraphy. Additional imaging by computed tomography and/or conventional angiography, as well as right heart catheterization, are required to confirm CTEPH and formulate treatment plans. Pulmonary thromboendarterectomy is the treatment of choice for eligible patients and can be potentially curative. Pulmonary thromboendarterectomy has a low mortality rate of 1% to 2% at expert centers and offers excellent long-term survival. Furthermore, recent advances in the techniques allow distal endarterectomy with comparable outcomes. Alternative treatment options are available for those who may not be operable or have prohibitive risks, providing some benefit. However, CTEPH is a progressive disease with low long-term survival rates if left untreated. Given excellent short- and long-term outcomes of surgery, as well as the benefits seen with other treatment modalities in noncandidate patients, it is crucial that precapillary pulmonary hypertension and CTEPH are ruled out in any patient with dyspnea of unexplained etiology. These patients should be referred to expert centers where accurate operability assessment and appropriate treatment strategies can be offered by a multidisciplinary team.

Analysis of genes characterizing chronic thrombosis and associated pathways in chronic thromboembolic pulmonary hypertension

PURPOSE

In chronic thromboembolic pulmonary hypertension (CTEPH), fibrosis of thrombi in the lumen of blood vessels and obstruction of blood vessels are important factors in the progression of the disease. Therefore, it is important to explore the key genes that lead to chronic thrombosis in order to understand the development of CTEPH, and at the same time, it is beneficial to provide new directions for early identification, disease prevention, clinical diagnosis and treatment, and development of novel therapeutic agents.

METHODS

The GSE130391 dataset was downloaded from the Gene Expression Omnibus (GEO) public database, which includes the full gene expression profiles of patients with CTEPH and Idiopathic Pulmonary Arterial Hypertension (IPAH). Differentially Expressed Genes (DEGs) of CTEPH and IPAH were screened, and then Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) functional enrichment analyses were performed on the DEGs; Weighted Gene Co-Expression Network Analysis (WGCNA) to screen the key gene modules and take the intersection genes of DEGs and the key module genes in WGCNA; STRING database was used to construct the protein-protein interaction (PPI) network; and cytoHubba analysis was performed to identify the hub genes.

RESULTS

A total of 924 DEGs were screened, and the MEturquoise module with the strongest correlation was selected to take the intersection with DEGs A total of 757 intersecting genes were screened. The top ten hub genes were analyzed by cytoHubba: IL-1B, CXCL8, CCL22, CCL5, CCL20, TNF, IL-12B, JUN, EP300, and CCL4.

CONCLUSION

IL-1B, CXCL8, CCL22, CCL5, CCL20, TNF, IL-12B, JUN, EP300, and CCL4 have diagnostic and therapeutic value in CTEPH disease, especially playing a role in chronic thrombosis. The discovery of NF-κB, AP-1 transcription factors, and TNF signaling pathway through pivotal genes may be involved in the disease progression process.