Red cell distribution width in predicting 30-day mortality in patients with pulmonary embolism

The aim of the study was to investigate red cell distribution width (RDW) in predicting 30-day mortality in patients with pulmonary embolism (PE).

A single-center, retrospective study design was used between January 1, 2014, and February 1, 2016. The primary end point was 30-day mortality after admission. The RDW predicting value was assessed by receiver operating characteristic curves and area under the curve.

A total of 309 patients with PE were included. The 30-day mortality was 14.9% (46/309). The mean RDW level was 13.9%±0.6% (range, 10.7%-21.9%) at admission. The 30-day mortality was higher in the high-RDW-level group compared with the normal-RDW-level group (12.5% vs 23.5%, χ²=5.140, P=.023), with an odds ratio of 2.164 (95% confidence interval [CI], 1.019-4.450). Logistic regression showed that presence of shock, RDW level, and simplified pulmonary embolism severity index (sPESI) were independent risk factors for 30-day mortality in patients with PE. After adjustment by these risk factors, the adjusted odds ratio was 1.439 (95% CI, 1.024-2.116). The area under the curve for RDW predicting the 30-day mortality was 0.6646 (95% CI, 0.5585-0.7518). The cutoff was 16%. The Youden index for RDW and sPESI was 0.400 and 0.453, respectively. When adding RDW into sPESI, the modified sPESI showed highest prediction accuracy, with Youden index 0.499.

Our results suggested that the RDW is a simple and useful indicator in predicting 30-day mortality in patients with PE. However, this conclusion showed be confirmed by prospective study with large sample.