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.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of prospective cohort studies
PubMed 25364520 · doi:10.3978/j.issn.2072-1439.2014.09.10
What was done
A systematic review and meta-analysis of MEDLINE and EMBASE databases was conducted to evaluate the association between red blood cell distribution width (RDW) and clinical outcomes in patients with coronary artery disease (CAD). English-language prospective studies reporting risk estimates for RDW against all-cause mortality or cardiovascular disease (CVD) events were included. Meta-analyses comparing the highest versus lowest RDW categories were performed using random-effects models.
What was found
Twenty-two prospective studies enrolling 80,216 participants with follow-up durations ranging from 1 month to 23 years were identified. Across 15 studies included in the meta-analysis, higher RDW was significantly associated with all-cause mortality (pooled RR 2.20, 95% CI 1.42-3.39; P<0.0004), fatal CVD events (pooled RR 1.80, 95% CI 1.35-2.41; P<0.0001), non-fatal CVD events (pooled RR 1.86, 95% CI 1.50-2.31; P<0.00001), and combined fatal/non-fatal CVD events (pooled RR 2.13, 95% CI 1.20-3.77; P=0.01). Moderate heterogeneity was present, but sensitivity analyses for follow-up duration, CAD subtype, or RDW as dichotomous values showed similar results.
Why it matters
RDW is a routine, low-cost blood marker that may help stratify risk for mortality and recurrent cardiovascular events in patients with established CAD.
Limits
The findings are derived entirely from observational prospective cohorts, so residual confounding cannot be ruled out and causality cannot be established. Seven of the 22 included studies could not be pooled in the meta-analysis, and specific RDW cutoff thresholds varied across studies.
Cited by
- supports Red cell distribution width (RDW) is an independent predictor of adverse clinical outcomes and mortality.