Relationship between red cell distribution width and right ventricular dysfunction in patients with chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a progressively debilitating disease limiting patients' survival. The prognosis of COPD worsens with the addition of right ventricular (RV) failure. Red cell distribution width (RDW) is a measure of variability in the size of circulating erythrocytes, and is a powerful predictor of outcomes in patients with both chronic and acute left heart failure. Here we attempted to test whether RDW could provide an early marker of RV failure in patients with COPD.
METHODS: Thirty-nine consecutive patients with COPD were enrolled in the study. All patients had at least 10 years' history of COPD, and all were treated appropriately. Thirty-nine age-matched and sex-matched individuals were enrolled for comparison. Red cell distribution width was obtained in all patients before transthoracic echocardiography. Right ventricular parameters were evaluated, and RV failure was identified via lateral tricuspid annulus longitudinal motion and systolic-tissue Doppler velocity, using transthoracic echocardiography.
RESULTS: Patients with COPD had significantly higher RDW values compared with control subjects (patients with COPD, mean ± SD, 16.1 ± 2.5; range, 12.3 to 23.3; control subjects, mean ± SD, 13.6 ± 1.3; range, 11.7 to 18.3; P < .001). In multivariable logistic regression, the presence of high RDW was the only parameter independently predicting RV failure in patients with COPD (odds ratio, 2.098; P = .017). Levels of RDW, obtained before echocardiography, predicted the presence of RV failure with a sensitivity of 70% and specificity of 93.1%, with a cutoff value of >17.7.
CONCLUSION: Red cell distribution width may be used to identify COPD patients with RV failure.