Blood urea nitrogen to serum albumin ratio as a new indicator of disease severity and prognosis in idiopathic pulmonary artery hypertension

Sicheng Zhang; Luyang Gao; Zhihui Zhao; Qing Zhao; Tao Yang; Qixian Zeng; Yi Zhang; Xin Li; Zhihua Huang; Anqi Duan; Qin Luo; Zhihong Liu

doi:10.1016/j.rmed.2024.107643

Blood urea nitrogen to serum albumin ratio as a new indicator of disease severity and prognosis in idiopathic pulmonary artery hypertension

Respir Med. 2024 Apr 23:227:107643. doi: 10.1016/j.rmed.2024.107643. Online ahead of print.

Authors

Sicheng Zhang¹, Luyang Gao¹, Zhihui Zhao¹, Qing Zhao¹, Tao Yang¹, Qixian Zeng¹, Yi Zhang¹, Xin Li¹, Zhihua Huang¹, Anqi Duan¹, Qin Luo², Zhihong Liu³

Affiliations

¹ Center for Respiratory and Pulmonary Vascular Diseases, Fuwai Hospital, National Center for Cardiovascular Diseases, National Clinical Research Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
² Center for Respiratory and Pulmonary Vascular Diseases, Fuwai Hospital, National Center for Cardiovascular Diseases, National Clinical Research Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China. Electronic address: luoqin2009@163.com.
³ Center for Respiratory and Pulmonary Vascular Diseases, Fuwai Hospital, National Center for Cardiovascular Diseases, National Clinical Research Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China. Electronic address: zhihongliufuwai@163.com.

PMID: 38657739
DOI: 10.1016/j.rmed.2024.107643

Abstract

Background: Emerging evidence has shown that the blood urea nitrogen to serum albumin ratio (BAR) is associated with the severity and prognosis of heart failure. However, its role in idiopathic pulmonary arterial hypertension (IPAH) remains unclear. This study investigated the associations between BAR and functional status, echocardiographic findings, hemodynamics, and long-term outcomes among patients with IPAH.

Methods: This study included consecutive patients who underwent right heart catheterization (RHC) and were diagnosed with IPAH between January 2013 and January 2018 at Fuwai Hospital. The primary outcome was the worsening of clinical symptoms. Spearman correlation coefficients were used to evaluate the association between the BAR and established markers of IPAH severity. Receiver operating characteristic (ROC) curve analysis was used to determine BAR's optimal cut-off and predictive performance. Kaplan-Meier analysis and Cox proportional hazard models assessed the relationship between BAR and clinical worsening.

Results: A total of 340 patients with IPAH were included in this study. BAR correlated with well-validated variables that reflected the severity of IPAH, such as World Health Organization functional class, 6-min walk distance, N-terminal pro-brain natriuretic peptide (NT-proBNP) level, mixed venous oxygen saturation, and cardiac index. Kaplan-Meier curves indicated that patients with BAR＞3.80 had a significantly higher clinical worsening rate (log-rank test, P < 0.001) than those with BAR≤3.80. Multivariate Cox analysis showed that BAR could independently predict clinical worsening [hazard ratio(HR):2.642, 95 % confidence interval (CI):1.659-4.208, P < 0.001]. In addition, BAR provided additional predictive value for the European Society of Cardiology (ESC)/European Respiratory Society (ERS) risk assessment score.

Conclusions: BAR reflects disease severity and is independently associated with the prognosis of patients with IPAH.

Keywords: Blood urea nitrogen; Idiopathic pulmonary arterial hypertension; Ratio; Risk factor; Serum albumin.