title: The role of red blood cell distribution width in mortality and cardiovascular risk among patients with coronary artery diseases: a systematic review and meta-analysis.
abstract: BACKGROUND
  Red cell distribution width (RDW) might be a novel biomarker that reflects multiple physiological impairments related to atherosclerosis and coronary artery diseases (CAD). We conducted this systematic review and meta-analysis to evaluate the association of RDW between all-cause mortality and fatal/non-fatal cardiovascular disease (CVD) events in CAD patients.
  
  
  METHODS
  Relevant studies were searched and identified in the MEDLINE and EMBASE databases. English-language prospective studies that reported risk estimates for RDW and mortality/CVD events were included. Data were extracted regarding the characteristics and clinical outcomes, and a quality assessment was conducted. Results were extracted for the highest versus lowest RDW level, and meta-analyses were carried out using random effects models.
  
  
  RESULTS
  We identified 22 studies enrolling 80,216 participants. The study duration ranged between 1 month and 23 years. Of the 15 studies that were included in the meta-analysis, higher RDW indicated a significant increased risk for all-cause mortality in CAD patients: pooled risk ratio (RR) 2.20 (95% CI, 1.42-3.39; P<0.0004). The results for fatal, non-fatal and fatal/non-fatal events were: pooled RR 1.80 (95% CI, 1.35-2.41; P<0.0001), RR 1.86 (95% CI, 1.50-2.31; P<0.00001) and RR 2.13 (95% CI, 1.20-3.77; P=0.01). Heterogeneity was moderately present; however, sensitivity analyses for follow-up duration, CAD subtype, or RDW as dichotomous values showed similar results.
  
  
  CONCLUSIONS
  The meta-analysis indicates that higher RDW levels are associated with increased risk of mortality and CVD events in patients with established CAD.
authors.affiliation: 1 Department of Hematology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China ; 2 Department of Health, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Guangzhou 510080, China ; 3 Department of Pathophysiology, ZhongShan Medical College, Sun Yat-sen University, Guangzhou 510080, China ; 4 Department of Cardiology, Huangpu Division of the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Su
authors.affiliation: 1 Department of Hematology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China ; 2 Department of Health, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Guangzhou 510080, China ; 3 Department of Pathophysiology, ZhongShan Medical College, Sun Yat-sen University, Guangzhou 510080, China ; 4 Department of Cardiology, Huangpu Division of the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China.
authors.forename: Li-Zhen
authors.initials: LZ
authors.lastname: Liao
authors.affiliation: 1 Department of Hematology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China ; 2 Department of Health, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Guangzhou 510080, China ; 3 Department of Pathophysiology, ZhongShan Medical College, Sun Yat-sen University, Guangzhou 510080, China ; 4 Department of Cardiology, Huangpu Division of the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Song
authors.affiliation: 1 Department of Hematology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China ; 2 Department of Health, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Guangzhou 510080, China ; 3 Department of Pathophysiology, ZhongShan Medical College, Sun Yat-sen University, Guangzhou 510080, China ; 4 Department of Cardiology, Huangpu Division of the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China.
authors.forename: Zhi-Wei
authors.initials: ZW
authors.lastname: Xu
authors.affiliation: 1 Department of Hematology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China ; 2 Department of Health, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Guangzhou 510080, China ; 3 Department of Pathophysiology, ZhongShan Medical College, Sun Yat-sen University, Guangzhou 510080, China ; 4 Department of Cardiology, Huangpu Division of the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China.
authors.forename: Wei-Yi
authors.initials: WY
authors.lastname: Mei
keywords: Red cell distribution width (RDW); cardiovascular (CV); coronary artery diseases (CAD); meta-analysis; mortality