Association between blood urea nitrogen to creatinine ratio and neurologically favourable outcomes in out-of-hospital cardiac arrest in adults: A multicentre cohort study

Published:December 23, 2022DOI:


      • Blood Urea Nitrogen to Creatinine Ratio (BCR) may contribute to risk stratification.
      • High and low BCR were associated with poor neurological outcomes.
      • The association between BCR and outcome was stronger in patients with cardiac aetiology.



      We aimed to investigate the association between blood urea nitrogen to creatinine ratio (BCR) and survival with favourable neurological outcomes in patients with out-of-hospital cardiac arrest (OHCA).


      This prospective, multicentre, observational study conducted in Osaka, Japan enrolled consecutive OHCA patients transported to 16 participating institutions from 2012 through 2019. We included adult patients with non-traumatic OHCA who achieved a return of spontaneous circulation and whose blood urea nitrogen and creatinine levels on hospital arrival were available. Based on BCR values, they were divided into: ‘low BCR’ (BCR <10), ‘normal BCR’ (10 ≤ BCR < 20), ‘high BCR’ (20 ≤ BCR < 30), and ‘very high BCR’ (BCR ≥ 30). We evaluated the association between BCR values and neurologically favourable outcomes, defined as cerebral performance category score of 1 or 2 at one month after OHCA.


      Among 4415 eligible patients, the ‘normal BCR’ group had the highest favourable neurological outcome [19.4 % (461/2372)], followed by ‘high BCR’ [12.5 % (141/1127)], ‘low BCR’ [11.2 % (50/445)], and ‘very high BCR’ groups [6.6 % (31/471)]. In the multivariable analysis, adjusted odds ratios for ‘low BCR’, ‘high BCR’, and ‘very high BCR’ compared with ‘normal BCR’ for favourable neurological outcomes were 0.58 [95 % confidence interval (CI 0.37–0.91)], 0.70 (95 % CI 0.49–0.99), and 0.40 (95 % CI 0.21–0.76), respectively. Cubic spline analysis indicated that the association between BCR and favourable neurological outcomes was non-linear (p for non-linearity = 0.003). In subgroup analysis, there was an interaction between the aetiology of arrest and BCR in neurological outcome (p for interaction <0.001); favourable neurological outcome of cardiogenic OHCA patients was lower when the BCR was higher or lower, but not in non-cardiogenic OHCA patients.


      Both higher and lower BCR were associated with poor neurological outcomes compared to normal BCR, especially in cardiogenic OHCA patients.

      Graphical abstract


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        • Nolan J.P.
        • Sandroni C.
        • Böttiger B.W.
        • Cariou A.
        • Cronberg T.
        • Friberg H.
        • et al.
        European Resuscitation Council and European Society of Intensive Care Medicine guidelines 2021: post-resuscitation care.
        Intensive Care Med. 2021; 47: 369-421
        • Panchal A.R.
        • Bartos J.A.
        • Cabañas J.G.
        • Donnino M.W.
        • Drennan I.R.
        • Hirsch K.G.
        • et al.
        Part 3: adult basic and advanced life support: 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care.
        Circulation. 2020; 142
        • Tujjar O.
        • Mineo G.
        • Dell'Anna A.
        • Poyatos-Robles B.
        • Donadello K.
        • Scolletta S.
        • et al.
        Acute kidney injury after cardiac arrest.
        Crit Care. 2015; 19: 169
        • Kazory A.
        Emergence of blood urea nitrogen as a biomarker of neurohormonal activation in heart failure.
        Am J Cardiol. 2010; 106: 694-700
        • Brisco M.A.
        • Testani J.M.
        Novel renal biomarkers to assess cardiorenal syndrome.
        Curr Heart Fail Rep. 2014; 11: 485-499
        • Testani J.M.
        • Coca S.G.
        • Shannon R.P.
        • Kimmel S.E.
        • Cappola T.P.
        Influence of renal dysfunction phenotype on mortality in the setting of cardiac dysfunction: analysis of three randomized controlled trials.
        Eur J Heart Fail. 2011; 13: 1224-1230
        • Matsue Y.
        • van der Meer P.
        • Damman K.
        • Metra M.
        • O'Connor C.M.
        • Ponikowski P.
        • et al.
        Blood urea nitrogen-to-creatinine ratio in the general population and in patients with acute heart failure.
        Heart. 2017; 103: 407-413
        • Yamada T.
        • Kitamura T.
        • Hayakawa K.
        • Yoshiya K.
        • Irisawa T.
        • Abe Y.
        • et al.
        Rationale, design, and profile of Comprehensive Registry of In-hospital Intensive Care for OHCA Survival (CRITICAL) study in Osaka,Japan.
        J Intensive Care. 2016; 4: 10
        • Osaka Prefectural Government
        2015 report on medical institutions in Osaka Prefecture (in Japanese).
        • Kajino K.
        • Iwami T.
        • Daya M.
        • Nishiuchi T.
        • Hayashi Y.
        • Kitamura T.
        • et al.
        Impact of transport to critical care medical centers on outcomes after out-of-hospital cardiac arrest.
        Resuscitation. 2010; 81: 549-554
        • Japan Resuscitation Council
        2020 Japanese guidelines for emergency care and cardiopulmonary resuscitation.
        in: 2020 Japanese guidelines for emergency care and cardiopulmonary resuscitation. Igaku-Shoin, Tokyo2021 (in Japanese)
        • Iwami T.
        • Kawamura T.
        • Hiraide A.
        • Berg R.A.
        • Hayashi Y.
        • Nishiuchi T.
        • et al.
        Effectiveness of bystander-initiated cardiac-only resuscitation for patients with out-of-hospital cardiac arrest.
        Circulation. 2007; 116: 2900-2907
        • Iwami T.
        • Nichol G.
        • Hiraide A.
        • Hayashi Y.
        • Nishiuchi T.
        • Kajino K.
        • et al.
        Continuous improvements in “chain of survival” increased survival after out-of-hospital cardiac arrests: a large-scale population-based study.
        Circulation. 2009; 119: 728-734
        • Kitamura T.
        • Iwami T.
        • Kawamura T.
        • Nagao K.
        • Tanaka H.
        • Hiraide A.
        Nationwide public-access defibrillation in Japan.
        N Engl J Med. 2010; 362: 994-1004
        • Kitamura T.
        • Kiyohara K.
        • Sakai T.
        • Matsuyama T.
        • Hatakeyama T.
        • Shimamoto T.
        • et al.
        Public-access defibrillation and out-of-hospital cardiac arrest in Japan.
        N Engl J Med. 2016; 375: 1649-1659
        • Cummins R.O.
        • Chamberlain D.A.
        • Abramson N.S.
        • Allen M.
        • Baskett P.J.
        • Becker L.
        • et al.
        Recommended guidelines for uniform reporting of data from out-of-hospital cardiac arrest: the Utstein Style. A statement for health professionals from a task force of the American Heart Association, the European Resuscitation Council, the Heart and Stroke Foundation of Canada, and the Australian Resuscitation Council.
        Circulation. 1991; 84: 960-975
        • Becker L.B.
        • Aufderheide T.P.
        • Geocadin R.G.
        • Callaway C.W.
        • Lazar R.M.
        • Donnino M.W.
        • et al.
        Primary outcomes for resuscitation science studies: a consensus statement from the American Heart Association.
        Circulation. 2011; 124: 2158-2177
        • Matsuo S.
        • Imai E.
        • Horio M.
        • Yasuda Y.
        • Tomita K.
        • Nitta K.
        • et al.
        Revised equations for estimated GFR from serum creatinine in Japan.
        Am J Kidney Dis. 2009; 53: 982-992
        • Desquilbet L.
        • Mariotti F.
        Dose-response analyses using restricted cubic spline functions in public health research.
        Stat Med. 2010; 29: 1037-1057
        • Schrock J.W.
        • Glasenapp M.
        • Drogell K.
        Elevated blood urea nitrogen/creatinine ratio is associated with poor outcome in patients with ischemic stroke.
        Clin Neurol Neurosurg. 2012; 114: 881-884
        • Uchino S.
        • Bellomo R.
        • Goldsmith D.
        The meaning of the blood urea nitrogen/creatinine ratio in acute kidney injury.
        Clin Kidney J. 2012; 5: 187-191
        • Rachoin J.S.
        • Daher R.
        • Moussallem C.
        • Milcarek B.
        • Hunter K.
        • Schorr C.
        • et al.
        The fallacy of the BUN: creatinine ratio in critically ill patients.
        Nephrol Dial Transplant. 2012; 27: 2248-2254
        • Han D.
        • Zhang L.
        • Zheng S.
        • Xu F.
        • Li C.
        • Yang R.
        • et al.
        Prognostic value of blood urea nitrogen/creatinine ratio for septic shock: an analysis of the MIMIC-III clinical database.
        Biomed Res Int. 2021; 2021: 1-16
        • Ok F.
        • Erdogan O.
        • Durmus E.
        • Carkci S.
        • Canik A.
        Predictive values of blood urea nitrogen/creatinine ratio and other routine blood parameters on disease severity and survival of COVID-19 patients.
        J Med Virol. 2021; 93: 786-793
        • Takaya Y.
        • Yoshihara F.
        • Yokoyama H.
        • Kanzaki H.
        • Kitakaze M.
        • Goto Y.
        • et al.
        Risk stratification of acute kidney injury using the blood urea nitrogen/creatinine ratio in patients with acute decompensated heart failure.
        Circ J. 2015; 79: 1520-1525
        • 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: 877-885
        • Sujino Y.
        • Nakano S.
        • Tanno J.
        • Shiraishi Y.
        • Goda A.
        • Mizuno A.
        • et al.
        Clinical implications of the blood urea nitrogen/creatinine ratio in heart failure and their association with haemoconcentration.
        ESC Heart Fail. 2019; 6: 1274-1282
        • Schrier R.W.
        Blood urea nitrogen and serum creatinine.
        Circ Heart Fail. 2008; 1: 2-5
        • Lindenfeld J.
        • Schrier R.W.
        Blood urea nitrogen.
        J Am Coll Cardiol. 2011; 58: 383-385
        • Haines R.W.
        • Zolfaghari P.
        • Wan Y.
        • Pearse R.M.
        • Puthucheary Z.
        • Prowle J.R.
        Elevated urea-to-creatinine ratio provides a biochemical signature of muscle catabolism and persistent critical illness after major trauma.
        Intensive Care Med. 2019; 45: 1718-1731
        • Packer M.
        What causes sudden death in patients with chronic heart failure and a reduced ejection fraction?.
        Eur Heart J. 2020; 41: 1757-1763
        • Santangeli P.
        • Rame J.E.
        • Birati E.Y.
        • Marchlinski F.E.
        Management of ventricular arrhythmias in patients with advanced heart failure.
        J Am Coll Cardiol. 2017; 69: 1842-1860