Red Cell Distribution Width Predicts 90 Day Mortality in Continuous-Flow Left Ventricular Assist Device Patients

Red blood cell distribution width predicts mortality of adult patients receiving veno-arterial extracorporeal membrane oxygenation

BACKGROUND

Red blood cell distribution width (RDW) is a numerical measure of the variation in the size of circulating red blood cells. Recently, there is increasing interest in the role of RDW as a biomarker for inflammatory states and as a prognostication tool for a wide range of clinical manifestations. The predictive power of RDW on mortality among patients receiving mechanical circulatory support remains largely unknown.

METHODS

A retrospective analysis of 281 VA-ECMO patients at a tertiary referral academic hospital from 2009 to 2019 was performed. RDW was dichotomized with RDW-Low <14.5% and RDW-High ≥14.5%. The primary outcome was all-cause mortality at 30 days and 1 year. Cox proportional hazards models were used to examine the association between RDW and the clinical outcomes after adjusting for additional confounders.

RESULTS

281 patients were included in the analysis. There were 121 patients (43%) in the RDW-Low group and 160 patients (57%) in the RDW-High group. Survival to ECMO decannulation [RDW-H: 58% versus RDW-L: 67%, p = 0.07] were similar between the two groups. Patients in RDW-H group had higher 30-days mortality (RDW-H: 67.5% vs RDW-L: 39.7%, p < 0.001) and 1 year mortality (RDW-H: 79.4% vs RDW-L: 52.9%, p < 0.001) compared to patients in the RDW-L group. After adjusting for confounders, Cox proportional hazards model demonstrated that patients with high RDW had increased odds of mortality at 30 days (hazard ratio 1.9, 95% CI 1.2-3.0, p < 0.01) and 1 year (hazard ratio 1.9, 95% CI 1.3-2.8, p < 0.01) compared to patients with low RDW.

CONCLUSIONS

Among patients receiving mechanical circulatory support with VA-ECMO, a higher RDW was independently associated with increased 30-days and 1-year mortality. RDW may serve as a simple biomarker that can be quickly obtained to help provide risk stratification and predict survival for patients receiving VA-ECMO.

In-hospital changes in the red blood cell distribution width and mortality in critically ill patients with heart failure

AIMS

A high red blood cell distribution width (RDW) at admission or discharge is associated with a worse prognosis in hospitalized patients with heart failure (HF), and the prognostic value of the in-hospital change in RDW (∆RDW) remains debatable.

METHODS AND RESULTS

We included 5514 patients with critical illness and HF from the MIMIC-IV database. The ΔRDW was calculated by the RDW at discharge minus that at admission. Clinical outcomes included all-cause mortality at 90 day, 180 day, and 1 year after discharge. The median age of the patients was 73.91 years, and 46.37% were women. Kaplan-Meier curve and Cox regression analyses were used to examine the association between the ΔRDW and all-cause mortality at different time points. A multivariable Cox proportional hazard model showed that the ΔRDW (per 1% increase) was independently associated with all-cause mortality at 90 day, 180 day, and 1 year after adjusting for confounding factors (hazard ratio [HR] = 1.17, 95% confidence interval [CI] = 1.13-1.21, P < 0.001; HR = 1.17, 95% CI = 1.14-1.20, P < 0.001; and HR = 1.18, 95% CI = 1.15-1.20, P < 0.001, respectively). Restricted cubic splines showed a non-linear relationship between the ΔRDW and the risk of clinical outcomes. High ΔRDW was associated with a high risk of mortality at different time points. A subgroup analysis showed that this positive association remained consistent in pre-specified subgroups.

CONCLUSIONS

Our study suggests that an increased RDW during hospitalization is independently associated with short- or long-term all-cause mortality in critical-ill patients with HF.

Red Blood Cell Distribution Width in Heart Failure: Pathophysiology, Prognostic Role, Controversies and Dilemmas

Red blood cell distribution width (RDW), an integral parameter of the complete blood count (CBC), has been traditionally used for the classification of several types of anemia. However, over the last decade RDW has been associated with outcome in patients with several cardiovascular diseases including heart failure. The role of RDW in acute, chronic and advanced heart failure is the focus of the present work. Several pathophysiological mechanisms of RDW’s increase in heart failure have been proposed (i.e., inflammation, oxidative stress, adrenergic stimulation, undernutrition, ineffective erythropoiesis, reduced iron mobilization, etc.); however, the exact mechanism remains unknown. Although high RDW values at admission and discharge have been associated with adverse prognosis in hospitalized heart failure patients, the prognostic role of in-hospital RDW changes (ΔRDW) remains debatable. RDW has been incorporated in recent heart failure prognostic models. Utilizing RDW as a treatment target in heart failure may be a promising area of research.

Reactivation of Cytomegalovirus Following Left Ventricular Assist Device Implantation: A Case-Control Study

While cytomegalovirus (CMV) reactivation occurs in immunocompetent patients who are critically ill and has been associated with worse outcomes, very few cases of CMV reactivation have been reported following left ventricular assist device (LVAD) implantation. We aimed to evaluate the incidence and risk factors for CMV reactivation following LVAD implantation. Retrospective chart review of patients who had undergone LVAD implantation between July 2004 and December 2018 was performed. Cases with CMV reactivation post-LVAD were randomly matched (1:2) by sex, LVAD type, and implant year with controls utilizing SAS macros. Fisher's exact and paired sample t-tests were performed to evaluate for differences between categorical and continuous variables, respectively. Days to reactivation post-LVAD implantation were calculated in cases, and the corresponding times post-LVAD implantation were determined in control patients for variable comparisons. Survival analysis was performed using the Kaplan-Meier method. Of the 349 patients reviewed, 208 (59.6%) patients were seropositive for CMV before LVAD implantation. Of these 208 patients, eight (3.8%) had CMV reactivation following LVAD implantation. The median time to CMV reactivation following LVAD implantation was 21.5 days (range, 6-177). Six (75%) patients had CMV viremia, and the other two had colitis and pneumonia without viremia. In comparison to controls, patients with CMV had higher creatinine levels (p = 0.039) and higher RDW (p = 0.05) and were more likely to have received steroids within the previous week (p = 0.028) and to have concurrent bacterial infection (p = 0.001). CMV reactivation following LVAD implantation is more frequent than expected. Early testing, diagnosis, and treatment in at-risk patients (i.e., renal failure, steroid use, elevated RDW) might improve clinical outcomes.