title: Acute Kidney Injury and mortality prognosis in Acute Coronary Syndrome patients: A meta-analysis.
abstract: OBJECTIVE
  The aim of this study is to provide a robust estimate of mortality risk in acute coronary syndrome (ACS)-associated acute kidney injury (AKI) to inform clinical practice and policy.
  
  
  METHODS
  A meta-analysis of cohort studies evaluating outcomes of ACS and which reported AKI and AKI-associated mortality. Studies were excluded if they incorporated patients not admitted through the emergency department (i.e. for elective procedures), were limited to cardiogenic shock or cardiac arrest, or relied on registry data for outcomes without further adjudication. The predictor was ACS-associated AKI and outcomes early (30 day or in-hospital) mortality and late-mortality (post-hospital discharge).
  
  
  RESULTS
  Thirty-six studies with 37 unique cohorts comprising 100 476 patients were included. The pooled rate of ACS-associated AKI was 15.8%. In 32 cohorts reporting early mortality, the crude early mortality rate was 15.0% amongst those with AKI compared with 2.0% amongst those without AKI. The pooled estimate of the relative risk of AKI-associated early mortality was 4.1 (95% confidence interval: 3.3 to 5.0) with high heterogeneity between studies (I2= 84% (61% to 88%)). When heterogeneity was accounted for mathematically using credibility ceilings, the risk of mortality was lower, but still clinically significant (3.1 (2.6 to 3.6)). In 19 cohorts reporting late mortality (1 to 10 years), the relative risk of AKI-associated mortality was 2.6 (2.0 to 3.3) with moderate heterogeneity (I2= 65 % [35% to 88%]). Following application of credibility ceiling relative risk estimate dropped to 2.2 (1.9 to 2.6).
  
  
  CONCLUSIONS
  Acute coronary syndrome-associated AKI is associated with more than a three-fold increase in early mortality and more than two-fold in long-term mortality.
authors.affiliation: Department of Medicine, University of Otago Christchurch, Christchurch, New Zealand.|Emergency Department, Christchurch hospital, Christchurch, New Zealand.
authors.forename: John W
authors.identifier: http://orcid.org/0000-0001-9475-0344
authors.initials: JW
authors.lastname: Pickering
authors.affiliation: Emergency Department, Christchurch hospital, Christchurch, New Zealand.
authors.forename: Isabella R H
authors.initials: IRH
authors.lastname: Blunt
authors.affiliation: Emergency Department, Christchurch hospital, Christchurch, New Zealand.
authors.forename: Martin P
authors.identifier: http://orcid.org/0000-0001-9399-5227
authors.initials: MP
authors.lastname: Than
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis / Q000401:mortality*; D058186:Acute Kidney Injury / Q000175:diagnosis / Q000401:mortality*; D017052:Hospital Mortality; D006801:Humans; D016017:Odds Ratio; D015995:Prevalence; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
keywords: acute coronary syndrome; acute kidney injury; contrast induced nephropathy; myocardial infarction; renal failure; unstable angina