title: Acute kidney injury and death associated with renin angiotensin system blockade in cardiothoracic surgery: a meta-analysis of observational studies.
abstract: BACKGROUND
  Acute kidney injury (AKI) is a common complication after cardiovascular surgery. The use of renin angiotensin system (RAS) blockers preoperatively is controversial due to conflicting results of their effect on the incidence of postoperative AKI and mortality.
  
  
  METHODS
  Meta-analysis of prospective or retrospective observational studies (1950 to January 2013) using MEDLINE, EMBASE, the Cochrane Library, conferences, and ClinicalTrials.gov, without language restriction.
  
  
  METHODS
  Patients undergoing cardiovascular surgery.
  
  
  METHODS
  Retrospective or prospective studies evaluating the effect of preoperative use of RAS blockers in the development of postoperative AKI and/or mortality in adult patients.
  
  
  METHODS
  Preoperative use of RAS blockers. RAS-blocker use was defined as long-term use of either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers until the day of surgery.
  
  
  RESULTS
  The primary outcome was the development of postoperative AKI; the secondary outcome was mortality. AKI was defined by different authors using different criteria. Death was ascertained in the hospital, at 30 days, or at 90 days in different studies.
  
  
  RESULTS
  29 studies were included (4 prospective and 25 retrospective); 23 of these involving 69,027 patients examined AKI, and 18 involving 54,418 patients studied mortality. Heterogeneity was found across studies regarding AKI (I2 = 82.5%), whereas studies were homogeneous regarding mortality (I2 = 20.5%). Preoperative RAS-blocker use was associated with increased odds for both postoperative AKI (OR, 1.17; 95% CI, 1.01-1.36; P = 0.04) and mortality (OR, 1.20; 95% CI, 1.06-1.35; P = 0.005).
  
  
  CONCLUSIONS
  Lack of randomized controlled trials, different definitions of AKI, different durations of follow-up used to analyze death outcome, and inability to exclude outcome reporting bias.
  
  
  CONCLUSIONS
  In retrospective studies, preoperative use of RAS blockers was associated with increased odds of postoperative AKI and mortality in patients undergoing cardiovascular surgery. A large, multicenter, randomized, controlled trial should be performed to confirm these findings.
authors.affiliation: Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, New York, NY.
authors.forename: Rabi
authors.initials: R
authors.lastname: Yacoub
authors.forename: Nilang
authors.initials: N
authors.lastname: Patel
authors.forename: James W
authors.initials: JW
authors.lastname: Lohr
authors.forename: Srini
authors.initials: S
authors.lastname: Rajagopalan
authors.forename: Nader
authors.initials: N
authors.lastname: Nader
authors.forename: Pradeep
authors.initials: P
authors.lastname: Arora
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced* / Q000401:mortality*; D000328:Adult; D047228:Angiotensin II Type 1 Receptor Blockers / Q000009:adverse effects* / Q000627:therapeutic use; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D006348:Cardiac Surgical Procedures; D001026:Coronary Artery Bypass; D006801:Humans; D011183:Postoperative Complications / Q000139:chemically induced / Q000401:mortality; D011300:Preoperative Care; D012084:Renin-Angiotensin System / Q000187:drug effects*; D019616:Thoracic Surgical Procedures
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors
keywords: Acute kidney injury; cardiac surgery; mortality; renin-angiotensin blockers