Diagnostic Utility of the BUN/Creatinine Ratio in Differentiating Heart Failure, COPD, and Asthma in Emergency Department Patients with Dyspnea

Öz

Dyspnea is a common reason for emergency department (ED) visits, often caused by heart failure (HF), chronic obstructive pulmonary disease (COPD), or asthma. Differentiating among these conditions remains challenging. This study aimed to assess the diagnostic performance of the blood urea nitrogen (BUN)/creatinine ratio in distinguishing these diseases in patients presenting with acute dyspnea. We retrospectively analyzed 479 adult patients diagnosed with HF (n=109), COPD (n=226), or asthma (n=144) in a tertiary ED. Demographic data, comorbidities, and laboratory parameters including BUN, creatinine, and the BUN/creatinine ratio were collected from hospital records. Statistical comparisons were performed, and receiver operating characteristic (ROC) analysis was used to evaluate diagnostic accuracy. Median BUN was higher in HF [21.0 mg/dL (IQR: 16.0–27.0)] and COPD [21.0 (15.0–26.0)] compared with asthma [17.0 (14.0–21.7)] (p<0.001). Creatinine showed modest differences across groups (p=0.019). The BUN/creatinine ratio was greatest in HF [20.1 (16.5–26.1)], followed by COPD [19.0 (15.5–23.0)] and asthma [17.2 (14.2–21.3)] (p=0.001). ROC analysis revealed modest discriminative ability for HF (AUC=0.597, p=0.002), poor performance for asthma (AUC=0.405, p=0.001), and no significant value for COPD (AUC=0.511, p=0.666). The BUN/creatinine ratio demonstrated limited diagnostic accuracy in differentiating HF, COPD, and asthma in ED patients with acute dyspnea. Nevertheless, consistent group trends indicate that this readily available biomarker may provide supportive information during initial evaluation, and prospective studies are needed to validate these findings.

Anahtar Kelimeler

• Dyspnea
• Heart Failure
• Chronic Obstructive Pulmonary Disease
• Asthma
• Blood Urea Nitrogen
• Creatinine
• Emergency Medicine

Acil Serviste Dispne ile Başvuran Hastalarda Kalp Yetmezliği, KOAH ve Astımın Ayırıcı Tanısında BUN/Kreatinin Oranının Tanısal Değeri

Öz

Dispne, acil servise başvuruların en sık nedenlerinden biridir ve genellikle kalp yetmezliği (KY), kronik obstrüktif akciğer hastalığı (KOAH) veya astımdan kaynaklanır. Bu hastalıkların ayırıcı tanısı klinik olarak güçlük yaratmaktadır. Bu çalışmada, akut dispne ile başvuran hastalarda kan üre azotu (BUN), kreatinin ve BUN/kreatinin oranının ayırıcı tanıdaki rolü araştırıldı. Üçüncü basamak bir acil servise dispne nedeniyle başvuran ve KY (n=109), KOAH (n=226) veya astım (n=144) tanısı alan toplam 479 erişkin hasta retrospektif olarak incelendi. Demografik veriler, komorbiditeler ve laboratuvar sonuçları hastane kayıtlarından elde edildi. Gruplar arasında istatistiksel karşılaştırmalar yapıldı ve tanısal doğruluğu değerlendirmek amacıyla ROC analizi uygulandı. Medyan BUN düzeyi KY [21,0 mg/dL (IQR: 16,0–27,0)] ve KOAH [21,0 (15,0–26,0)] hastalarında, astım grubuna [17,0 (14,0–21,7)] göre daha yüksekti (p<0,001). Kreatinin düzeyleri benzer olmakla birlikte gruplar arasında hafif fark bulundu (p=0,019). BUN/kreatinin oranı KY’de [20,1 (16,5–26,1)] en yüksek, KOAH’ta [19,0 (15,5–23,0)] orta düzeyde, astımda ise [17,2 (14,2–21,3)] en düşük bulundu (p=0,001). ROC analizi, KY için sınırlı ayırıcı değer (AUC=0,597, p=0,002), astım için düşük performans (AUC=0,405, p=0,001), KOAH için ise anlamlı bir tanısal katkı göstermedi (AUC=0,511, p=0,666). Bulgularımız, BUN/kreatinin oranının KY, KOAH ve astımın ayırıcı tanısında sınırlı olmakla birlikte destekleyici bilgi sağlayabileceğini göstermektedir. Sonuçların doğrulanması için ileriye dönük çalışmalara ihtiyaç vardır.

Anahtar Kelimeler

• Dispne
• Kalp Yetmezliği
• Kronik Obstrüktif Akciğer Hastalığı
• Astım
• Kan Üre Azotu
• Kreatinin
• Acil Tıp

Kaynakça

1. 1. Gao B, Wang S, Jiang S. The occurrence mechanism, assessment, and non-pharmacological treatment of dyspnea. Med Rev. 2024;4(5):395-412.
2. 2. Laksono S, Angkasa IS. Dyspnea in emergency settings: up-to-date diagnosing and management in the emergency department. Curr Med Issues. 2024;22(1):37-44.
3. 3. Santus P, Radovanovic D, Saad M, Zilianti C, Coppola S, Chiumello DA, et al. Acute dyspnea in the emergency department: a clinical review. Intern Emerg Med. 2023;18(5):1491-507.
4. 4. Qaid EYA, Long I. Asthma unravelled: a comprehensive review of epidemiology, phenotypes, pathophysiology, and emerging therapies. Egypt J Bronchol. 2025;19(1):82.
5. 5. Yang IA, Jenkins CR, Salvi SS. Chronic obstructive pulmonary disease in never-smokers: risk factors, pathogenesis, and implications for prevention and treatment. Lancet Respir Med. 2022;10(5):497-511.
6. 6. Suau SJ, DeBlieux PM. Management of acute exacerbation of asthma and chronic obstructive pulmonary disease in the emergency department. Emerg Med Clin North Am. 2016;34(1):15-37.
7. 7. Güder G, Störk S. COPD and heart failure: differential diagnosis and comorbidity. Herz. 2019;44(6):502-8.
8. 8. Zheng X, Tan L, Cheng Y, Huang D. Predictive value of blood urea nitrogen to creatinine ratio and estimated plasma volume status in heart failure. BMC Cardiovasc Disord. 2025;25(1):282.

9. 9. Zhu X, Cheang I, Liao S, Wang K, Yao W, Yin T, et al. Blood urea nitrogen to creatinine ratio and long-term mortality in patients with acute heart failure: a prospective cohort study and meta-analysis. Cardiorenal Med. 2020;10(6):415-28.
10. 10. Matsue Y, van der Meer P, Damman K, Metra M, O’Connor CM, Ponikowski P, et al. Blood urea nitrogen-to-creatinine ratio in the general population and in patients with acute heart failure. Heart. 2017;103(6):407-13.
11. 11. Zhang J, Zhou L, Zhang Y. Diagnostic values of blood urea nitrogen, creatinine, and the ratio of blood urea nitrogen to creatinine for distinguishing heart failure from asthma and chronic obstructive pulmonary disease. Comput Math Methods Med. 2022;2022:4586458.
12. 12. Becker AB, Abrams EM. Asthma guidelines: the Global Initiative for Asthma in relation to national guidelines. Curr Opin Allergy Clin Immunol. 2017;17(2):99-103.
13. 13. Sharma M, Joshi S, Banjade P, Ghamande SA, Surani S. Global initiative for chronic obstructive lung disease (GOLD) 2023 guidelines reviewed. Open Respir Med J. 2024;18:e18743064279064.
14. 14. McDonagh TA, Metra M, Adamo M, Gardner RS, Baumbach A, Böhm M, et al. 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: Developed by the Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC) with the special contribution of the Heart Failure Association (HFA) of the ESC. Eur Heart J. 2021;42(36):3599-726.
15. 15. Debernardi E, Jaun F, Boesing M, Leuppi JD, Lüthi-Corridori G. Dyspnea management in patients presenting to the emergency department at Cantonal Hospital Baselland—a retrospective observational study and medical audit. J Clin Med. 2025;14(4):1378.
16. 16. Berliner D, Schneider N, Welte T, Bauersachs J. The differential diagnosis of dyspnea. Dtsch Arztebl Int. 2016;113(49):834-45.
17. 17. Zhu C, Wu L, Xu Y, Zhang Q, Liu W, Zhao Y, et al. Predicting mortality in heart failure: BUN/creatinine ratio in MIMIC-III. Front Cardiovasc Med. 2025;12:1510317.
18. 18. Murata A, Kasai T, Matsue Y, Matsumoto H, Yatsu S, Kato T, et al. Relationship between blood urea nitrogen-to-creatinine ratio at hospital admission and long-term mortality in patients with acute decompensated heart failure. Heart Vessels. 2018;33(8):877-85.
19. 19. Wang Y, Xu X, Shi S, Gao X, Li Y, Wu H, et al. Blood urea nitrogen to creatinine ratio and long-term survival in patients with chronic heart failure. Eur J Med Res. 2023;28(1):343.
20. 20. Tolomeo P, Butt JH, Kondo T, Campo G, Desai AS, Jhund PS, et al. Independent prognostic importance of blood urea nitrogen to creatinine ratio in heart failure. Eur J Heart Fail. 2024;26(2):245-56.
21. 21. Sakr ARM, Gomaa GFE, Wasif SME, Eladawy AHH. The prognostic role of urea-to-creatinine ratio in patients with acute heart failure syndrome: a case-control study. Egypt Heart J. 2023;75(1):78.
22. 22. Choudhary M, Yogi JP, Fiza B, Sinha M, Rathor HK, Chawdhary V. Evaluation of blood urea nitrogen, uric acid and uric acid/creatinine ratio in patients of chronic obstructive pulmonary disease (COPD). Int J Med Sci Educ. 2020;7(2):21-4.
23. 23. Gao H, Wang J, Zou X, Zhang K, Zhou J, Chen M. High blood urea nitrogen to creatinine ratio is associated with increasedrisk of sarcopenia in patients with chronic obstructive pulmonary disease. Exp Gerontol. 2022;169:111960.
24. 24.Sujino Y, Nakano S, Tanno J, Shiraishi Y, Goda A, Mizuno A,Nagatomo Y, Kohno T, Muramatsu T, Nishimura S, Kohsaka S, Yoshikawa T; West Tokyo Heart Failure Registry Investigators. Clinical implications of the blood urea nitrogen/creatinine ratio in heart failure and their association with haemoconcentration. ESC Heart Fail. 2019;6(6):1274-82