Identifying future risk from routine tests?*

RDW Value may Increase the Diagnostic Accuracy of MPS

Objectives:

As the feasibility of obtaining health care has improved in the last decade, there is an increase in the number of performing unnecessary coronary angiogram. Red Cell Distribution Width (RDW), which shows erythrocyte dispersion volume, is associated with coronary artery disease. The present study aims to evaluate the relationship between RDW value and the severity of coronary artery disease in patients who undergo myocardial perfusion scintigraphy (MPS) as an evaluation for coronary ischemia and after which patients had a coronary angiography.

Methods:

This retrospective study included 452 patients diagnosed as stabile angina that had MPS to evaluate coronary ischemia and after which coronary angiography was performed. Complete blood count was obtained on the same day. Patients were first divided into two groups: patients with and without ischemia on MPS. Then, the group who had ischemia on the MPS where divided into another two groups: patients who had RDW values ≥13.5 and the others who had RDW value <13.5. Patients who had fixed perfusion defect, chronic kidney disease, thyroid dysfunction, hematological disease, those who use iron supplements, and those who had active infectious disease were excluded from this study.

Results:

The basic characteristics were the same between study groups. We found that severe coronary vessel disease, single vessel, two vessels and three vessels diseases were higher in patients who had ischemia on the MPS and RDW values ≥13.5 (p-value were 0.032, 0.004, 0.042 respectively). RDW values ≥13.5 was found to be an independent predictor for the presence of severe coronary artery disease (p<0.001 OR: 3.55).

Conclusion:

Patients who have MPS for ischemic evaluation and RDW values of ≥ 13.5 were more severe coronary heart diseases. As a result, the findings suggest that using of RDW value is a cheap and feasible parameter that may prevent performing unnecessary coronary angiography for patients after MPS.

Association of red cell distribution width with all-cause and cardiovascular-specific mortality in African American and white adults: a prospective cohort study

Background

While the mortality rate is declining in the United States, the life expectancy gap among different population groups suggests a need to identify biomarkers to improve early identification of individuals at risk. Red cell distribution width (RDW), a measure of anisocytosis, is an emerging biomarker of chronic disease morbidity and mortality, particularly in the elderly. However, little is known about its association with mortality risk in younger adults. The objectives of this study were to investigate the association between RDW and overall and cause-specific mortality risk, and to identify novel determinants of RDW level.

Methods

We used prospectively collected data from the Healthy Aging in Neighborhoods of Diversity across the Life Span study conducted in Baltimore, Maryland. At baseline (2004–2009), the study recruited 3720 African American and white men and women aged 30–64 years. Participants provided peripheral venous blood for RDW measurement as part of complete blood count, and genotyping. Mortality status was ascertained using the National Death Index database through December 31, 2013. Multivariable adjusted Cox proportional hazards regression models were fitted to assess mortality risk, and multiple linear regression models to identify determinants of RDW level.

Results

Participants’ mean age was 48.1 (9.2) years. Of 2726 participants included in the present analyses, 57% were African Americans, and 56% were women. After 18,424 person-years of follow-up time, there were 226 deaths, and the leading cause of death were cardiovascular diseases (31.9%). Participants in the highest quartile of RDW had a 1.73-fold increased all-cause mortality risk (highest quartile vs. lowest quartile, multivariable adjusted hazard ratio = 1.73, 95% confidence interval: 1.10–2.74, p-trend = 0.006). This effect was significantly modified by body mass index (p-interaction = 0.004). Similar risk was observed for cardiovascular disease-specific mortality. Independent of body mass index, waist-hip ratio and illicit drug use were significantly associated with RDW.

Conclusions

Elevated RDW was associated with a substantial risk of all-cause and cardiovascular disease-specific mortalities that was modified by body mass index. Central obesity and illicit drug use influence RDW level. In vulnerable populations at-risk for health disparities, RDW could provide a useful and inexpensive biomarker of mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1313-6) contains supplementary material, which is available to authorized users.

Does the addition of RDW improve current ICU scoring systems?

BACKGROUND

The aim of this study was to evaluate whether the addition of red blood cell distribution width (RDW) improves the prognostic value of current intensive care unit (ICU) scoring systems, namely APACHE III.

DESIGN AND METHODS

All patients admitted to a mixed ICU in Brisbane between June 2013 and July 2014 for whom RDW was available were included in the study. Analyses included descriptive statistics, linear regression correlation, and receiver operating characteristic (ROC) curves.

RESULTS

The study included 708 patients for whom both ICU mortality prediction and RDW were available. In univariate analysis higher RDW values were associated with increased hospital mortality. Adding RDW to APACHE III increased the area under the ROC marginally (from 0.9586 to 0.9613). RDW was not correlated with C-reactive protein, white cell count, or patient's length of stay in ICU.

CONCLUSION

RDW was an independent predictor of mortality. The addition of RDW to APACHE III improved its mortality prediction marginally. The underlying mechanism of RDW elevation warrants further investigation.