Prognostic value of red cell distribution width in patients undergoing percutaneous coronary intervention: a meta-analysis

OBJECTIVE: To evaluate the prognostic value of baseline red cell distribution width (RDW) in patients with coronary artery diseases (CADs) undergoing percutaneous coronary intervention (PCI) by conducting a meta-analysis. DESIGN: Systematic review and meta-analysis. DATA SOURCE: PubMed, Embase, Wanfang, CNKI and VIP databases were searched from their inceptions to 19 June 2019. ELIGIBLE CRITERIA: Studies investigating the value of baseline RDW for predicting all-cause mortality, cardiovascular mortality and major adverse cardiac events (MACEs) in patients with CAD undergoing PCI were included. DATA EXTRACTION AND SYNTHESIS: Two authors independently extracted the data and evaluated the methodological quality using the Newcastle–Ottawa Scale. STATA V.12.0 software was applied to produce the forest plots using a random-effect model. RESULTS: Twelve studies (13 articles) involving 17 113 patients were included and analysed. Comparison between the highest and lowest RDW category indicated that the pooled risk ratio (RR) was 1.77 (95% CI 1.32 to 2.37) for all-cause mortality, 1.70 (95% CI 1.25 to 2.32) for cardiovascular mortality and 1.62 (95% CI 1.21 to 2.18) for MACEs. The predictive effect of elevated RDW for all-cause mortality was stronger in the subgroup of patients without anaemia (RR 4.59; 95% CI 3.07 to 6.86) than with anaemia. CONCLUSIONS: This meta-analysis indicated that elevated RDW was associated with higher risk of mortality and adverse cardiac events in patients with CAD undergoing PCI. The value of elevated RDW for predicting all-cause mortality appears to be stronger in patients without anaemia. RDW may be served as a promising prognostic biomarker in patients undergoing PCI.