RESUMEN
Objective To study the relationship between red blood cell distribution width (RDW) and the malignant arrhythmia event of patients with chronic heart failure (CHF) during hospitalization. Methods A retrospective study was conducted. The clinical data of patients with CHF admitted to Department of Emergency and Cardiology of Peking University Third Hospital from January 2014 to February 2016 were reviewed. The patients with New York Heart Association (NYHA) Class Ⅱ, Ⅲ, Ⅳ at hospital admission and courses lasted at least six months were enrolled. The patients were divided into two groups according to malignant arrhythmia events (ventricular tachycardia, ventricular flutter or ventricular fibrillation) during hospitalization, i.e. malignant arrhythmia group and non-malignant arrhythmia group. The value of RDW and left ventricular ejection fraction (LVEF) were compared between two groups, and correlation of RDW, LVEF and malignant arrhythmia events by Spearman rank correlation analysis were studied, and the predictive value of RDW and LVEF for malignant arrhythmia events in patients with CHF was analyzed with receiver operating characteristic (ROC) curve. Results A total of 226 CHF patients were enrolled with 148 male and 78 female, the average age was (61.52±13.27) years old (range: 26-91 years old), the average hospitalization days were (14.5±3.5) days (range: 14-21 days), and malignant arrhythmia occurred in 102 patients (45.13%) during hospitalization. There were no statistically differences in gender, age, past history, etiology of heart disease, the usage of angiotensin receptor converting enzyme inhibitors (ACEI) or angiotensin Ⅱ receptor inhibitors (ARB) and beta blockers, serum potassium levels and so on between two groups. Compared with non-malignant arrhythmia group, the value of the RDW was significantly increased in malignant arrhythmia group [(13.28±1.07)% vs. (12.87±1.32)%, t = 2.531, P = 0.012], but the levels of LVEF was significantly reduced (0.425±0.116 vs. 0.458±0.104, t = 2.249, P = 0.026), the proportion of patients with NYHA Class Ⅱ was significantly lower (4.90% vs. 19.35%, χ2= 10.451, P = 0.000) and that of NYHA Class Ⅳ was just the opposite (57.84% vs. 41.13%, χ2 = 6.264, P = 0.011). The value of the RDW showed positively correlation with the malignant arrhythmia events (r = 0.758, P = 0.023), while LVEF was negatively correlated (r = -0.719, P = 0.019). The area under the ROC curve (AUC) for predicting the malignant arrhythmia events of RDW and LVEF was 0.882 [95% confidence interval (95%CI) = 0.839-0.925), 0.903 (95%CI = 0.866-0.941), respectively. The sensitivity and specificity for RDW in predicting in-hospital malignant arrhythmia event respectively were 82.0% and 79.0% with the optimal cut-off of 14.20%, and those for LVEF were 78.0% and 85.0% with the optimal cut-off of 0.375. Conclusion RDW can be used to predict the occurrence of malignant arrhythmia in patients with CHF during hospitalization.