Development and Validation of a Novel Prediction Nomogram for Patients With Chronic Obstructive Pulmonary Disease and Concurrent Pulmonary Hypertension

Background: Right heart catheterisation (RHC) is the gold standard for the diagnosis of pulmonary hypertension (PH); however, it is invasive and very expensive. Therefore, a simple, easy-to-use, and accurate disease prediction tool to evaluate whether chronic obstructive pulmonary disease (COPD) is associated with PH is necessary. This study was aimed to construct and evaluate the performance of a nomogram in evaluating whether Chinese patients have a combined PH risk. Methods: Patients diagnosed with COPD in five hospitals in China were divided randomly (7:3) into training (1072 [70.8%]) and validation (422 [29.2%]) cohorts. Patients with COPD who underwent RHC were included as the test group (N = 47) to further validate the nomogram. The performance of the nomogram was quantified using the Harrell concordance index (C-index), a calibration curve, and the area under the curve (AUC) of the receiver operating characteristic curve. A decision curve analysis (DCA) was performed to determine the net benefit of the nomogram. The main outcomes were predictors of COPD-PH and the performance of the nomogram. Findings: Age, N-terminal pro-brain natriuretic peptide level, smoking status, and right atrial diameter were incorporated into the nomogram, which had an excellent discriminative ability and performance in the training and validation cohorts (C-index, 0.821 and 0.771; AUC, 0.821 and 0.771, respectively). The DCA showed the clinical usefulness and net benefits of the nomogram. RHC and echocardiography measurements were highly correlated (r = 0.730, p < 0.001). The test group also showed a good discrimination ability of the nomogram (C-index = 0.732 and AUC = 0.831). Interpretation: Thus, this nomogram could enable the individualised prediction of COPD-PH, identification of high-risk COPD-PH groups, and development of intervention strategies. Funding Information: This work was supported in part by the grants from the Department of Science and Technology of China Grants (2016YFC0903700, 2016YFC1304102 and 2018YFC1311900), National Natural Science Foundation of China (81630004, 81800061, 81520108001, 81460011 and 81500043), Changjiang Scholars and Innovative Research Team in University grant IRT0961, Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01S155), Guangdong Department of Science and Technology Grants (2019A050510046, 2017A020215114), The Inner Mongolia Autonomous Region science and technology innovation guidance project and the Inner Mongolia Autonomous Region science and technology project (20160298), The Natural Science Foundation of Inner Mongolia Autonomous Region (2018LH0823), The Project of Health and Family Planning Commission of Inner Mongolia Autonomous Region (201702084), Independent Project of State Key Laboratory of Respiratory Disease (SKLRD-Z-202101), The General Program of State Key Laboratory of Respiratory Disease (SKLRD-MS-201901), Clinical Research Incubation Programme of Guangzhou Medical University (B185004065), Zhongnanshan Medical Foundation Of Guangdong Province(ZNSA-2020003). Declaration of Interests: No potential conflicts of interest were disclosed. Ethics Approval Statement: The study protocol was approved by the Medical Ethics Committee of the First Affiliated Hospital of Guangzhou Medical University. It was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. The requirement for informed consent was waived.