title: The prognostic value of arterial blood gas analysis in high-risk acute heart failure patients: an analysis of the Korean Heart Failure (KorHF) registry.
abstract: OBJECTIVE
  In acute heart failure (AHF) patients, pulmonary oedema and low tissue perfusion may lead to changes in the acid-base balance, which may be associated with worse outcomes.
  
  
  RESULTS
  In this prospective nationwide cohort study from 24 academic hospitals, arterial blood gas (ABG) was measured in 1982 AHF patients at hospital admission. Acidosis was defined as pH <7.36, and alkalosis as pH >7.44. Mortality was stratified according to ABG results. Overall, 19% had acidosis, 37% had normal pH, and 44% had alkalosis. The most common type of acidosis was the mixed type (42%) followed by metabolic acidosis (40%), and the most common type of alkalosis was respiratory alkalosis (58%). At 12 months' follow-up 304 patients (15%) died. Patients with acidosis had higher mortality (acidosis 19.5%, neutral pH 13.7%, alkalosis 14.9%; P = 0.007). In the Cox proportional-hazards regression model, acidosis was a significant predictor of mortality (hazard ratio 1.93; 95% confidence intervals 1.27-2.93) along with N-terminal pro-brain type natriuretic peptide (NT-proBNP), among others. In contrast, alkalosis was not associated with increased mortality. pH had an incremental prognostic value over NT-proBNP (net reclassification improvement 30%; P < 0.001), and ABG analysis identified extra patients at increased risk for mortality among patients with an NT-proBNP level less than the median (12-month mortality 17.5% vs. 9.9%; P = 0.009).
  
  
  CONCLUSIONS
  In high-risk AHF patients, the most common acid-base imbalance is respiratory alkalosis. Acidosis is observed in every fifth patient and is a significant predictor of mortality. pH provides an additional prognostic value and may be used to optimize risk stratification in high-risk AHF patients.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Jin Joo
authors.initials: JJ
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Dong-Ju
authors.initials: DJ
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Chang-Hwan
authors.initials: CH
authors.lastname: Yoon
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Il-Young
authors.initials: IY
authors.lastname: Oh
authors.affiliation: the Medical Research Collaborating Centre, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Ju Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: the Medical Research Collaborating Centre, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Soyeon
authors.initials: S
authors.lastname: Ahn
authors.affiliation: Division of Cardiology, Yonsei University Wonju Severance Christian Hospital, Wonju, Korea.
authors.forename: Byung-Su
authors.initials: BS
authors.lastname: Yoo
authors.affiliation: Division of Cardiology, Yonsei University Severance Hospital, Seoul, Korea.
authors.forename: Seok-Min
authors.initials: SM
authors.lastname: Kang
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Centre, Seoul, Korea.
authors.forename: Jae-Joong
authors.initials: JJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, The Catholic University of Korea, Seoul St Mary's Hospital, Seoul, Korea.
authors.forename: Sang-Hong
authors.initials: SH
authors.lastname: Baek
authors.affiliation: Department of Internal Medicine, Chungbuk National University College of Medicine, Cheongju, Korea.
authors.forename: Myeong-Chan
authors.initials: MC
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Sungkyunkwan University College of Medicine, Samsung Medical Centre, Seoul, Korea.
authors.forename: Eun-Seok
authors.initials: ES
authors.lastname: Jeon
authors.affiliation: Department of Internal Medicine, Kyungpook National University College of Medicine, Daegu, Korea.
authors.forename: Shung Chull
authors.initials: SC
authors.lastname: Chae
authors.affiliation: Department of Internal Medicine, Konkuk University Medical Centre, Seoul, Korea.
authors.forename: Kyu-Hyung
authors.initials: KH
authors.lastname: Ryu
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Byung-Hee
authors.initials: BH
authors.lastname: Oh
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood*; D001784:Blood Gas Analysis; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000175:diagnosis / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012042:Registries; D056910:Republic of Korea
chemical_list: D015415:Biomarkers
keywords: Acute heart failure; Arterial blood gas; Prognostic value