Characteristics and Clinical Significance of RAAS in Elderly Patients with Severe COPD Combined with Chronic Pulmonary Heart Disease

TANG Xiaojuan; WU Xi; ZHANG Yijie

doi:10.12102/j.issn.1672-1349.2025.15.019

Abstract：Objective: To explore the characteristics of renin-angiotensin-aldosterone system (RAAS) levels in elderly patients with severe chronic obstructive pulmonary disease (COPD) combined with chronic cor pulmonale and their clinical significance. Methods: A retrospective study was conducted on 84 patients with severe COPD admitted to the Western Theater Command General Hospital of the Chinese People's Liberation Army from February 2020 to January 2023. The patients were divided into a combined group (34 cases) and a non-combined group (50 cases) based on whether they had chronic cor pulmonale. General data, cardiopulmonary function indicators, and RAAS-related clinical indicators were compared between the two groups. Smooth curve fitting analysis was used to analyze the relationship between RAAS levels and the occurrence of chronic cor pulmonale in COPD patients, and threshold effect analysis was performed. Multivariate logistic regression analysis was used to identify risk factors for the development of chronic cor pulmonale in COPD patients, and a predictive model was constructed and validated. Results: There were statistically significant differences in disease duration, smoking index, frequency of COPD exacerbations, and Saint George's Respiratory Questionnaire (SGRQ) scores between the two groups (P < 0.05). Multivariate logistic regression analysis showed that the predictive model incorporating RAAS indicators had good goodness of fit and higher predictive efficiency. RAAS levels were identified as a risk factor for the development of chronic cor pulmonale in severe COPD patients (P < 0.05). After smooth curve fitting analysis, it was found that plasma renin activity (PRA) and angiotensin II (Ang II) levels were linearly positively correlated with the occurrence of chronic cor pulmonale in COPD patients, while aldosterone (ALD) levels showed a negative correlation with the risk of combination. The artificial neural network model showed that the weights of RAAS levels (PRA, Ang II, ALD), carbohydrate antigen (CA125), frequency of COPD exacerbations, and SGRQ scores were relatively high. Conclusion: There is a certain correlation between RAAS levels and the occurrence of chronic cor pulmonale in elderly patients with severe COPD, which can serve as an early identification indicator and provide clinical value for improving patient prognosis.