دانلود رایگان مقاله انجمن متغیرهای بالینی و آزمایشگاهی با پهنای توزیع سلول

Background Red blood cell distribution width (RDW) strongly predicts clinical outcomes among patients with coronary disease and heart failure. The factors underpinning this association are unknown. Methods In 6,447 individuals enrolled in the Measurement to Understand the Reclassification of Disease of Cabarrus/Kannapolis (MURDOCK) Study who had undergone coronary angiography between 2001 and 2007, we used Cox proportional hazards modeling to examine the adjusted association between RDW and death, and death or myocardial infarction (MI). Multiple linear regression using the R2 model selection method was then used to identify clinical factors associated with variation in RDW. Results Median follow-up was 4.2 (interquartile range 2.3-5.9) years, and the median RDW was 13.5% (interquartile range 12.9%-14.3%, clinical laboratory reference range 11.5%-14.5%). Red blood cell distribution width was independently associated with death (adjusted hazard ratio 1.13 per 1% increase in RDW, 95% CI 1.09-1.17), and death or MI (adjusted hazard ratio 1.12, 95% CI 1.08-1.16). Twenty-seven clinical characteristics and laboratory measures were assessed in the multivariable linear regression model; a final model containing 18 variables explained only 21% of the variation in RDW. Conclusions Although strongly associated with death and death or MI, only one-fifth of the variation in RDW was explained by routinely assessed clinical characteristics and laboratory measures. Understanding the latent factors that explain variation in RDW may provide insight into its strong association with risk and identify novel targets to mitigate that risk.

Discussion

In our cohort of 6,447 patients undergoing coronary angiography due to concern for ischemic heart disease, we confirmed a strong, independent association of RDW with death and death or MI over a median of 4.2 years of follow-up. To better understand this association, we explored what clinical factors accounted for variation in RDW, but found that only 21% of the variation could be explained by parameters readily available in routine clinical practice. A better understanding of the latent factors that account for the remaining unexplained variation in RDW could lead to novel insight about risk for adverse outcomes associated with RDW. Association between RDW and outcomes It has previously been shown that patients with greater RDW present with higher risk factor burden for coronary heart disease than patients with lower RDW.7,9,16,17 Several studies have suggested that RDW is a marker of disease progression, as it is higher among sicker patients. Our observations are consistent with these studies; we have shown not only greater prevalence of cardiac risk factors but also greater comorbidity burden as assessed by the Charlson index among patients as quartile of RDW increased.