Red cell distribution width and coronary artery bypass surgery

The Prognostic Significance of Red Cell Distribution Width in Cardiac Surgery: A Systematic Review and Meta-Analysis

RED CELL DISTRIBUTION WIDTH (RDW) is a routinely available biomarker of likely erythropoietic dysfunction, which may be associated with adverse outcomes after cardiac surgery. This systematic review and meta-analysis aimed to clarify the prognostic value of RDW in patients undergoing cardiac surgery. The authors searched MEDLINE, Embase, and the Cochrane Library from inception to May 10, 2022 for studies investigating the association between elevated RDW (as defined by the authors of included studies) and adverse outcomes after cardiac surgery. Herein, the authors extracted maximally adjusted hazard ratios (HRs) and odds ratios (ORs) with associated CIs, and pooled them using random-effects inverse- variance modeling. The authors explored interstudy heterogeneity using metaregression. The authors included 26 studies involving 48,092 patients who had undergone cardiac surgery. Elevated preoperative RDW was associated with long-term mortality (pooled HR 1.63, 95% CI 1.05-2.52), short-term mortality (pooled OR 2.16, 95% CI 1.21-3.87), acute kidney injury (AKI; pooled OR 1.30, 95% CI 1.19-1.41) and postoperative atrial fibrillation (POAF; pooled OR 1.44, 95% CI 1.05-1.96). Some studies suggested a significant association between preoperative RDW elevation and neurologic complications; however, their number was insufficient for meta-analysis. The postoperative RDW levels were less consistently reported and could not be meta-analyzed. In conclusion, the authors found that elevated preoperative RDW was associated with increased short- and long-term mortality, POAF, and AKI after cardiac surgery. Further research is needed to investigate its role in the risk stratification of patients undergoing cardiac surgery.

Red blood cell distribution width predicts gastrointestinal bleeding after coronary artery bypass grafting

Background

Red blood cell distribution width (RDW) is highly associated with adverse clinical outcomes in many diseases. The present study aimed to evaluate the relationship between RDW and gastrointestinal bleeding (GIB) after isolated coronary artery bypass grafting (CABG).

Methods

This was a retrospective observational study that included 4473 patients who received CABG, and all the data were extracted from the Medical Information Mart for Intensive Care III database. Data collected included patient demographics, associated comorbid illnesses, laboratory parameters, and medications. The receiver operating characteristic (ROC) curve was used to determine the best cutoff value of RDW for the diagnosis of GIB. Multivariable logistic regression analysis was used to analyze the relationship between RDW and GIB.

Results

The incidence of GIB in patients receiving CABG was 1.1%. Quartile analyses showed a significant increase in GIB incidence at the fourth RDW quartile (> 14.3%; P < 0.001). The ROC curve analysis revealed that an RDW level > 14.1% measured on admission had 59.6% sensitivity and 69.4% specificity in predicting GIB after CABG. After adjustment for confounders, high RDW was still associated with an increased risk of GIB in patients with CABG (odds ratio = 2.83, 95% confidence interval 1.46–5.51, P = 0.002).

Conclusions

Our study indicates that the elevated RDW level is associated with an increased risk of GIB after CABG, and it can be an independent predictor of GIB. The introduction of RDW to study GIB enriches the diagnosis method of GIB and ensures the rapid and accurate diagnosis of GIB.

Preoperative red cell distribution width to lymphocyte ratio as biomarkers for prolonged intensive care unit stay among older patients undergoing cardiac surgery: a retrospective longitudinal study

Introduction: Our aim was to use the red cell distribution width-lymphocyte ratio (RLR) as a novel biomarker to predict prolonged intensive care unit (ICU) length of stay (LOS) among older patients undergoing cardiovascular surgery. Methods: This longitudinal study included older patients admitted to a tertiary cardiovascular surgery hospital between January 2017 and January 2022. Results: A total of 574 patients were studied, including 83 patients (14.5%) who had prolonged ICU LOS and 471 (85.5%) control subjects. After adjustment for the European System for Cardiac Operative Risk Evaluation 2, the RLR score showed a 10% increased risk of prolonged ICU LOS (odds ratio: 1.10; CI: 1.05-1.16; p = 0.01). Conclusion: Preoperative RLR can be used to predict the risk of long-term intensive care stay in older cardiac surgery patients.

Factors affecting mortality after coronary bypass surgery: a scoping review

Objectives

Previous research reports numerous factors of post-operative mortality in patients undergoing isolated coronary artery bypass graft surgery. However, this evidence has not been mapped to the conceptual framework of care improvement. Without such mapping, interventions designed to improve care quality remain unfounded.

Methods

We identified reported factors of in-hospital mortality post isolated coronary artery bypass graft surgery in adults over the age of 19, published in English between January 1, 2000 and December 31, 2019, indexed in PubMed, CINAHL, and EMBASE. We grouped factors and their underlying mechanism for association with in-hospital mortality according to the augmented Donabedian framework for quality of care.

Results

We selected 52 factors reported in 83 articles and mapped them by case-mix, structure, process, and intermediary outcomes. The most reported factors were related to case-mix (characteristics of patients, their disease, and their preoperative health status) (37 articles, 27 factors). Factors related to care processes (27 articles, 12 factors) and structures (11 articles, 6 factors) were reported less frequently; most proposed mechanisms for their mortality effects.

Conclusions

Few papers reported on factors of in-hospital mortality related to structures and processes of care, where intervention for care quality improvement is possible. Therefore, there is limited evidence to support quality improvement efforts that will reduce variation in mortality after coronary artery bypass graft surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01784-z.

Developing and verifying a multivariate model to predict the survival probability after coronary artery bypass grafting in patients with coronary atherosclerosis based on the MIMIC-III database

BACKGROUND

Coronary atherosclerosis is one of the main cardiovascular diseases affecting the global population. Coronary artery bypass grafting (CABG) is commonly used to improve the survival probability of patients with coronary atherosclerosis. However, the prognosis of patients after CABG remains unclear.

OBJECTIVES

We aimed to construct a novel nomogram comprising readily available indicators to predict the 1-, 2-, and 3-year survival rates after CABG in patients with coronary atherosclerosis.

METHODS

We utilized the Medical Information Mart for Intensive Care III (MIMIC-III) database for the study. The calibration plot, concordance index (C-index), net reclassification index (NRI), integrated discrimination improvement (IDI), and area under the receiver operating characteristic curve (AUROC) were used to evaluate the performance of the model, and to compare the nomogram with the Sequential Organ Failure Assessment (SOFA) score and Simplified Acute Physiology Score II (SAPS II) in order to illustrate the clinical effectiveness of the model.

RESULTS

The multivariate Cox regression model showed that age, marital status, body mass index, creatinine, platelet count, red cell distribution width, heart rate, intensive-care unit stay time, and Elixhauser Comorbidity Index were risk factors. The C-indexes of the nomogram exceeded 0.75, and its NRI and IDI were both higher than 0. The AUROCs were larger for the nomogram than for the SAPS II and SOFA score.

CONCLUSION

Our new nomogram is a personalized tool that helps clinicians choose treatment options and predict the long-term prognosis of patients.

Role of pre-operative red cell distribution width estimation in the prediction of in-hospital mortality after off-pump coronary artery bypass grafting

Background

Red cell distribution width (RDW) level is routinely provided in a simple and inexpensive complete blood count report. However, RDW is sometimes overlooked. Recently a higher RDW level is found associated with postoperative mortality after off-pump coronary artery bypass. Many risk-prediction tools are available, like the European System for Cardiac Operative Risk Evaluation, Society of Thoracic Surgeons score, etc. but all need improvement for better prediction. So, a new risk-factor should be discovered which is simple enough for clinical use and cost-effective, and improves the risk assessment tools that help to predict and avoid preventable mortality following cardiac surgery.

Methods

The prospective study was conducted, taking a total of 150 patients of coronary artery disease who underwent elective isolated off-pump coronary artery bypass. The study population was grouped according to their preoperative RDW level as Group A (RDW ≤ 14%), Group B (RDW 14–16%), and Group C (RDW ≥ 16%). The receiver operating characteristic (ROC) curve was constructed and multivariate regression analysis was done to see the predictive value of RDW for in-hospital mortality.

Results

The mortality rate was 2.7%, N = 150. ROC curve revealed Area Under the Curve 0.841 and p = 0.020 that indicates the RDW as the reliable predictor for in-hospital mortality. Multivariate regression analysis showed the RDW to be the only variable independently predicting in-hospital mortality after off-pump coronary artery bypass among possible haematological predictors. (OR 1.838, 95% CI 1.061–3.186, p = 0.030).

Conclusion

Preoperative raised RDW level is a novel predictor of in-hospital mortality after off-pump coronary artery bypass. Further studies should be done to determine the associated mechanism.

Usefulness of red cell distribution width to predict mortality in patients undergoing endovascular repair of abdominal aortic aneurysms

BACKGROUND

Red cell distribution width (RDW) reflecting impaired erythropoyesis, has been associated with poor prognosis and mortality in several conditions. The aim of this study was to determine the relationship between RDW and the 5-year survival after the endovascular repair of abdominal aortic aneurysms (EVAR) and its ability to improve the discriminative power of a survival predictive score.

METHODS

Retrospective analysis of 284 patients undergoing EVAR at a single centre. The pattern of relationship between RDW and survival was assessed with penalized smoothing splines. Categorized RDW values were added to a predictive score based in standard preoperative variables, whose improvement in discriminative power was calculated on the basis of changes in the C-statistics and the continuous Net Reclassification Index (c-NRI).

RESULTS

The survival rate at 5 years was 66.2% and was independently associated with hemoglobin (HR=0.85,p<0.004), statin intake (HR=0.54,p<0.004), heart failure (HR=2.53,p<0.018), atrial fibrillation (HR=2.53,p<0.000) and the non-revascularized coronary artery disease (HR=2.15, p<0.005). The relationship between RDW values and 5-year survival was linear. RDW-CV and RDW-SD were categorized to cut-off values of ≥15% (n=83,29.2%) and ≥50 fL (n=82, 28.9%) that were independently associated with poorer 5-year survival rates (HR=2.03,CI95%=1.29-3.19,p=0.002 and HR=1.89, CI95%=1.21-2.95,p=0.005, respectively). The addition of the RDW CV or the RDW-SD to the baseline predictive score significantly improved the c-NRI (0.437,p<0.001 and 0.442,p<0.001, respectively).

CONCLUSIONS

High preoperative RDW levels were linear and adversely related to 5-year survival after EVAR, improved the discriminative power of a predictive score based in standard preoperative variables and may help in decision-making at the time of surgical planning.

Role of pre-operative red cell distribution width estimation in the prediction of in-hospital mortality after off-pump coronary artery bypass grafting

Background

Red cell distribution width (RDW) level is routinely provided in a simple and inexpensive complete blood count report. However, RDW is sometimes overlooked. Recently a higher RDW level is found associated with postoperative mortality after off-pump coronary artery bypass. Many risk-prediction tools are available, like the European System for Cardiac Operative Risk Evaluation, Society of Thoracic Surgeons score, etc. but all need improvement for better prediction. So, a new risk-factor should be discovered which is simple enough for clinical use and cost-effective, and improves the risk assessment tools that help to predict and avoid preventable mortality following cardiac surgery.

Methods

The prospective study was conducted, taking a total of 150 patients of coronary artery disease who underwent elective isolated off-pump coronary artery bypass. The study population was grouped according to their preoperative RDW level as Group A (RDW ≤ 14%), Group B (RDW 14–16%), and Group C (RDW ≥ 16%). The receiver operating characteristic (ROC) curve was constructed and multivariate regression analysis was done to see the predictive value of RDW for in-hospital mortality.

Results

The mortality rate was 2.7%, N = 150. ROC curve revealed Area Under the Curve 0.841 and p = 0.020 that indicates the RDW as the reliable predictor for in-hospital mortality. Multivariate regression analysis showed the RDW to be the only variable independently predicting in-hospital mortality after off-pump coronary artery bypass among possible haematological predictors. (OR 1.838, 95% CI 1.061–3.186, p = 0.030).

Conclusion

Preoperative raised RDW level is a novel predictor of in-hospital mortality after off-pump coronary artery bypass. Further studies should be done to determine the associated mechanism.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01612-w.

Monocyte-to-albumin ratio as a novel predictor of long-term adverse outcomes in patients after percutaneous coronary intervention

Background: Monocyte count and serum albumin (Alb) have been proven to be involved in the process of systemic inflammation. Therefore, we investigated the prognostic value of monocyte-to-albumin ratio (MAR) in patients who underwent percutaneous coronary intervention (PCI).

Methods: We enrolled a total of 3561 patients in the present study from January 2013 to December 2017. They were divided into two groups according to MAR cut-off value (MAR < 0.014, n=2220; MAR ≥ 0.014, n=1119) as evaluated by receiver operating characteristic (ROC) curve. The average follow-up time was 37.59 ± 22.24 months.

Results: The two groups differed significantly in the incidences of all-cause mortality (ACM; P<0.001), cardiac mortality (CM; P<0.001), major adverse cardiovascular events (MACEs; P=0.038), and major adverse cardiovascular and cerebrovascular events (MACCEs; P=0.037). Multivariate Cox regression analyses revealed MAR as an independent prognostic factor for ACM and CM. The incidence of ACM increased by 56.5% (hazard ratio [HR] = 1.565; 95% confidence interval [CI], 1.086–2.256; P=0.016) and that of CM increased by 76.3% (HR = 1.763; 95% CI, 1.106–2.810; P=0.017) in patients in the higher-MAR group. Kaplan–Meier survival analysis suggested that patients with higher MAR tended to have an increased accumulated risk of ACM (Log-rank P<0.001) and CM (Log-rank P<0.001).

Conclusion: The findings of the present study suggested that MAR was a novel independent predictor of long-term mortality in patients who underwent PCI.

Red blood cell distribution width as a novel prognostic marker after myocardial revascularization or cardiac valve surgery

The red blood cell distribution width (RDW) measures the variability in the size of circulating erythrocytes. Previous studies suggested a powerful correlation between RDW obtained from a standard complete blood count and cardiovascular diseases in both primary and secondary cardiovascular prevention. The current study aimed to evaluate the prognostic role of RDW in patients undergoing cardiac rehabilitation after myocardial revascularization and/or cardiac valve surgery. The study included 1.031 patients with available RDW levels, prospectively followed for a mean of 4.5 ± 3.5 years. The mean age was 68 ± 12 years, the mean RDW was 14.7 ± 1.8%; 492 patients (48%) underwent cardiac rehabilitation after myocardial revascularization, 371 (36%) after cardiac valve surgery, 102 (10%) after valve-plus-coronary artery by-pass graft surgery, 66 (6%) for other indications. Kaplan-Meier analysis and Cox hazard analysis were used to associate RDW with mortality. Kaplan-Meier analysis demonstrated worse survival curves free from overall (log-rank p < 0.0001) and cardiovascular (log-rank p < 0.0001) mortality in the highest RDW tertile. Cox analysis showed RDW levels correlated significantly with the probability of overall (HR 1.26; 95% CI 1.19-1.32; p < 0.001) and cardiovascular (HR 1.31; 95% CI 1.23-1.40; p < 0.001) mortality. After multiple adjustments for cardiovascular risk factors, hemoglobin, hematocrit, C-reactive protein, microalbuminuria, atrial fibrillation, glomerular filtration rate,left ventricular ejection fraction and number of exercise training sessions attended, the increased risk of overall (HR 1.10; 95% CI 1.01-1.27; p = 0.039) and cardiovascular (HR 1.13; 95% CI 1.01-1.34; p = 0.036)mortality with increasing RDW values remained significant. The RDW represents an independent predictor of overall and cardiovascular mortality in secondary cardiovascular prevention patients undergoing cardiac rehabilitation.

Red blood cell distribution width is associated with adverse cardiovascular events after septal myectomy

Background

Red blood cell distribution width (RDW) is associated with increased morbidity and mortality in several cardiovascular diseases. However, the prognostic significance of RDW in patients with hypertrophic obstructive cardiomyopathy (HOCM) who underwent septal myectomy remains unclear as no studies have been conducted on this topic. This study aimed to assess the prognostic significance of RDW in these patients.

Methods

A total of 867 adults with HOCM who underwent septal myectomy at Fuwai Hospital from 2011 to 2017 were retrospectively studied. All patients were assessed comprehensively, including their medical history, echocardiograms, and blood test results.

Results

The median age of patients was 47.9 [interquartile range (IQR), 37.0–56.0] years and 61.5% of patients were men. During a median follow-up period of 32 (IQR, 17–53) months, 26 patients died and 23 had a cardiovascular death during follow-up. Compared to patients in the lowest RDW quartile, those in the highest quartile had a significantly lower 5-year survival free from all-cause and cardiovascular death (95.9% vs. 87.6%, P<0.001; 95.9% vs. 89.9%, P<0.001). Compared with lower RDW, higher RDW was significantly associated with all-cause and cardiovascular death after adjustment for age, sex, body mass index, and relevant clinical risk factors [per RDW standard deviation (SD) hazard ratio (HR) increase =1.76, 95% confidence interval (CI): 1.54–2.05, P<0.001; per RDW SD HR =1.91, 95% CI: 1.63–2.22, P for trend <0.001].

Conclusions

Higher RDW is independently associated with all-cause and cardiovascular death in patients with HOCM after septal myectomy. Therefore, this readily available biomarker could be considered as an additive biomarker for risk stratification in these patients.

R/S ratio in lead II, and the prognostic significance of red cell distribution width in acute coronary syndrome

BACKGROUND

In spite of developing medical technologies to discover the etiopathogenesis of diseases and developments in the treatment of coronary artery disease, acute coronary syndromes (ACS) continue to be the main cause of mortality and morbidity worldwide. New cardiac biomarkers and techniques are needed to help provide rapid diagnosis in order to evaluate risk in coronary artery patients.

AIM

To evaluate the effects of R to S ratio (RSR) in the electrocardiograph of patients with ACS, from the point of the arising complication after myocardial infarction (MI), to three-vessel disease (TVD) and mortality.

METHODS

The data of 1,296 patients with ACS, who presented to the emergency department of our hospital with chest pain between January 2014 and December 2018 and were admitted to the cardiology clinic, were retrospectively included in this cross-sectional cohort study. Patients with an RSR value less than I were assigned to group I, while those with an RSR value greater than I were assigned to group II.

RESULTS

In our study, 466 (35.9%) of the 1,296 patients, 357 (38.3%) in group 1 and 109 (29.9%) in group 2, were female, with a mean age of 61.56 ± 9.42. ST-elevation MI 573 (44.2%), unstable angina (UA) 502 (38.7%) and non ST-elevation MI 220 (17%) were more prevalent in group I. Acute anterior MI 263 (20.3) in group I, and acute inferior MI 184 (14.2) in group II was higher. Ischemic heart failure was the most common complication. In group II, the red cell distribution width (RDW) was 15.42 ± 1.82, the gensini score was 48.39 ± 36.44, the left ventricular ejection fraction was 41.17 ± 10.41, the TVD was 111 (8.5), and the mortality rate was 72 (5.6), which was significantly higher than group I RDW; in MI with ST and non-ST-elevation, in TVD, mortality and complications were high and low in UA. In single and multivariate regression analyses, the variables were associated with ACS risk.

CONCLUSION

RSR levels may be an auxiliary predictive value in ACS in terms of complications developing after MI, TVD, and mortality.

Red blood distribution width and heart transplantation: any predictive role on patient outcome?

BACKGROUND

Red blood cell distribution width (RDW) has been emerging as a strong predictor of mortality among patients with cardiovascular disease. The aim of this study was to verify if RDW is able to predict survival after heart transplantation (HTx).

METHODS

Two hundred and eighteen recipients who underwent HTx between 2000 and 2013 were classified into three groups according to the pre-HTx RDW tertile values (14.6 and 16.4%), and their outcomes were compared. Mean follow-up was 6.6 ± 4.2 years.

RESULTS

RDW correlated with other markers of chronic pathological conditions, such as the Index for Mortality Prediction after Cardiac Transplantation (IMPACT) score (P = 0.002) and Charlson Comorbidity Index (P < 0.001), and with creatinine levels (P = 0.007), previous cardiac surgery (P < 0.001), diabetes mellitus (P = 0.02), haemoglobin value (P = 0.004), pulmonary capillary wedge and central venous pressures (P = 0.019 and 0.01, respectively), systolic and mean pulmonary artery pressures (P = 0.002 and 0.014, respectively). The rate of 30-day mortality from the lowest to the highest RDW tertile was 1.4, 4 and 9% (P = 0.02), respectively.Long-term mortality correlated at multivariate analysis with recipient age [hazard ratio 1.06, 95% confidence interval (95% CI) 1.02-1.09], donor age (hazard ratio 1.02, 95% CI 1.0-1.04) and RDW (hazard ratio 1.13, 95% CI 1.04-1.23). The survival probability at 4, 8 and 12 years was 90, 84 and 74% for recipients with RDW less than 14.6%, while it was 72, 60 and 42% for recipients with RDW more than 16.4% (hazard ratio 3.29, 95% CI 1.74-6.24). No differences were found between causes of death.

CONCLUSION

RDW correlated with survival in HTx recipients. This marker of blood cell size may represent a surrogate of disease and a helpful tool in the risk-assessment process.

Relation between changes in red blood cell distribution width after coronary artery bypass grafting and early postoperative morbidity

Background

Red blood cell distribution width (RDW) is highly associated with various clinical states. In the present study, we aimed to determine the natures of associations between RDW changes and early adverse events after isolated coronary artery bypass grafting (CABG).

Methods

We retrospectively analyzed medical records of enrolled 117 patients. Patients were classified into two groups depending on early adverse events (No-event vs. Event). Delta RDW values were calculated (ΔRDW: Post-Peak RDW minus Pre-RDW). Patients were divided into tertiles based on ΔRDW. The ΔRDW cut-off point for an adverse event was determined by receiver operating characteristic curve analysis. In addition, logistic regression analysis was performed to identify independent factors of early adverse events.

Results

Thirty eight patients experienced 53 early adverse events. ΔRDW and ΔC-reactive protein were significantly higher in the Events group than in the No-event group. Incidences of early adverse events increased significantly between ΔRDW tertiles (P<0.001). The ROC curve of ΔRDW showed that a ΔRDW of ≥1.45 had a sensitivity of 71.1% and a specificity of 78.2% for predicting an early adverse event after CABG (P<0.001). Multivariable analysis showed ΔRDW (P=0.042) and length of ICU stay (P<0.001) independently predicted an adverse event.

Conclusions

ΔRDW was identified to be an independent predictor of early adverse events, and a ΔRDW cut-off of 1.45 was found to predict early adverse events after CABG. Careful monitoring of RDW trends after isolated CABG provides a simple, inexpensive and objective means of predicting early adverse events.

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

Red cell distribution width (RDW) measures the variance in size of circulating red blood cells and is a strong independent predictor of morbidity and mortality in cardiovascular disease and heart failure. Predictive power of RDW on mortality after continuous-flow left ventricular assist device (CF-LVAD) implantation remains largely unknown. Four hundred nine patients who underwent CF-LVAD implantation between April 2004 and December 2015 were retrospectively analyzed. The primary outcome of interest was 90 day mortality after CF-LVAD implantation. Median RDW before CF-LVAD implantation was 15.8%. Patients with elevated RDW (>15.8%) at baseline had significantly lower hemoglobin (10.6 ± 1.8 vs. 11.9 ± 2.1 mg/dl; p < 0.001), lower mean corpuscular volume (84.9 ± 7.7. vs. 88.7 ± 5.9; p < 0.001), higher blood urea nitrogen (BUN; 36.3 ± 21.8 vs. 30.1 ± 17.1; p < 0.001), lower albumin (3.4 ± 0.6 vs. 3.7 ± 0.5; p < 0.001), and higher total bilirubin levels (1.67 ± 2.21 vs. 1.29 ± 0.96). Red cell distribution width was independently predictive of 90 day mortality (odds ratio [OR], 1.16 for 1% increase; CI, 1.04-1.31; p = 0.010). Discriminatory power of RDW alone was comparable to model of end-stage liver disease excluding international normalized ratio (MELD-Xi) and HeartMate II risk scores. Mechanical unloading with CF-LVAD was associated with a reduction in RDW levels. These findings suggest that RDW, a simple and inexpensive test available through routine complete blood count, can be successfully used for mortality risk assessment in CF-LVAD candidates.

Preoperative Red Cell Distribution Width and 30-day mortality in older patients undergoing non-cardiac surgery: a retrospective cohort observational study

Increased red cell distribution width (RDW) is associated with poorer outcomes in various patient populations. We investigated the association between preoperative RDW and anaemia on 30-day postoperative mortality among elderly patients undergoing non-cardiac surgery. Medical records of 24,579 patients aged 65 and older who underwent surgery under anaesthesia between 1 January 2012 and 31 October 2016 were retrospectively analysed. Patients who died within 30 days had higher median RDW (15.0%) than those who were alive (13.4%). Based on multivariate logistic regression, in our cohort of elderly patients undergoing non-cardiac surgery, moderate/severe preoperative anaemia (aOR 1.61, p = 0.04) and high preoperative RDW levels in the 3rd quartile (>13.4% and ≤14.3%) and 4th quartile (>14.3%) were significantly associated with increased odds of 30-day mortality - (aOR 2.12, p = 0.02) and (aOR 2.85, p = 0.001) respectively, after adjusting for the effects of transfusion, surgical severity, priority of surgery, and comorbidities. Patients with high RDW, defined as >15.7% (90th centile), and preoperative anaemia have higher odds of 30-day mortality compared to patients with anaemia and normal RDW. Thus, preoperative RDW independently increases risk of 30-day postoperative mortality, and future risk stratification strategies should include RDW as a factor.

Association between post-transplant red cell distribution width and prognosis of kidney transplant recipients

The role of elevated post-transplant red cell distribution width (RDW) as a predictive factor for graft loss remains unclear, although RDW was reported to be significantly associated with poor prognosis in various clinical fields. We performed a retrospective cohort study with 2,939 kidney transplant patients from two tertiary teaching hospitals in Korea. RDW level at transplantation and 3-months post-transplantation were collected. Those with RDW in the upper quartile range were considered to have increased RDW (>14.9%). Death-with-graft-function (DWGF), death-censored graft failure (DCGF), and composite graft loss were assessed as the study outcomes, using multivariable cox proportional hazard model. At the median follow-up duration of 6.6 (3.6–11.4) years, 336 patients experienced graft loss. There were 679 patients with elevated RDW at 3-months post-transplant. Elevated RDW was associated with composite graft loss (adjusted hazard ratio, 1.60, 95% confidence interval, 1.23–2.07, P < 0.001), even after adjusted for hemoglobin and various clinical factors. The 1% increment of post-transplant RDW was also significantly associated with the outcome, regardless of the presence of anemia. The worst prognosis was seen in patients with elevated RDW after transplantation, but not at baseline. Therefore, post-transplant RDW level may be significantly associated with patient prognosis, independent of hemoglobin values.

Prevalence of preoperative anemia, abnormal mean corpuscular volume and red cell distribution width among surgical patients in Singapore, and their influence on one year mortality

Introduction

Preoperative anemia and high red cell distribution width (RDW) are associated with higher perioperative mortality. Conditions with high RDW levels can be categorized by mean corpuscular volume (MCV). The relationship between RDW, anemia and MCV may explain causality between high RDW levels and outcomes. We aim to establish the prevalence of preoperative anemia and distribution of RDW and MCV among pre-surgical patients in Singapore. In addition, we aim to investigate the association between preoperative anemia, RDW and MCV levels with one-year mortality after surgery.

Methods

Retrospective review of 97,443 patients aged > = 18 years who underwent cardiac and non-cardiac surgeries under anesthesia between January 2012 and October 2016. Patient demographics, comorbidities, priority of surgery, surgical risk classification, perioperative transfusion, preoperative hemoglobin, RDW, MCV were collected. WHO anemia classification was used. High RDW was defined as >15.7%. Multivariate regression analyses were done to identify independent risk factors for mild or moderate/severe anemia and high RDW (>15.7). Multivariate cox regression analysis was done to determine the effect of preoperative anemia, abnormal RDW and MCV values on 1-year mortality.

Results

Our cohort comprised of 94.7% non-cardiac and 5.3% cardiac surgeries. 88.7% of patients achieved 1 year follow-up. Anemia prevalence was 27.8%—mild anemia 15.3%, moderate anemia 12.0% and severe anemia 0.5%. One-year mortality was 3.5%. Anemia increased with age in males, while in females, anemia was more prevalent between 18–49 years and > = 70 years. Most anemics were normocytic. Normocytosis and macrocytosis increased with age, while microcytosis decreased with age. Older age, male gender, higher ASA-PS score, anemia (mild- aHR 1.98; moderate/severe aHR 2.86), macrocytosis (aHR 1.47), high RDW (aHR 2.34), moderate-high risk surgery and emergency surgery were associated with higher hazard ratios of one-year mortality.

Discussion

Preoperative anemia is common. Anemia, macrocytosis and high RDW increases one year mortality.

Red blood cell distribution width predicts long term cardiovascular event after on-pump beating coronary artery bypass grafting

Background

Reports investigating the predictive value of red cell distribution width (RDW) on major cardiac and cardiovascular event (MACCE) following coronary artery bypass grafting (CABG) have major limitations, including lack of elimination of common factors affecting RDW levels, such as anemia. The purpose of this study is to identify the real effect of higher RDW level, free from the other factors, on MACCE following CABG.

Methods

Data of 500 consecutive, non-anemic patients (77.2 % male and mean age 63.05 ± 9.24) undergoing ONBHCAB between January 2007 and January 2010, were analyzed retrospectively.

Results

Overall MACCE was 7.8 % of all cases. Mean follow-up was 66.5 ± 9.96 months. In multivariate Cox regression analysis, RDW (P = 0.022) remained the only independent predictor of MACCE and the ROC analyze revealed an RDW cut-off value of 13.95 % predicting MACCE. Therefore, patients were grouped on this cut-off value. There were 238 patients in the lower RDW group (Group 1) and 262 patients in the higher RDW group (Group 2). Kaplan–Meier survival analysis of freedom from MACCE revealed significantly lower event free survival in Group 2 (P < 0.001 by the log-rank test). Group 2 showed a higher MACCE incidence in 1 year (P = 0.030), in 3 years (P < 0.001) and in 6 years (P < 0.001). The long-term follow-up was similar regarding noncardiovascular mortality.

Conclusion

An RDW level greater than 13.95 % in hospital admission is independently associated with an increased incidence of MACCE after CABG. Physicians should be more aggressive in the management of these patients.

Preoperative red cell distribution width: Not a useful prognostic indicator for 30-day mortality in patients who undergo major- or ultra-major noncardiac surgery

Background:

Red cell distribution width (RDW) has been shown to be associated with mortality in cardiac surgical patients. This study investigates the association of RDW with the 30-day mortality for those patients who undergo major- or ultra-major noncardiac surgery.

Methods:

Patients who received major- or ultra-major noncardiac surgery between July 2012 and May 2013 were included in the study and patients those with preoperative hemoglobin <10 g/day were excluded from the study. Patients were followed till day 30 from the date of surgery or death, whichever occurred earlier.

Results:

The overall 30-day mortality for major- and ultra-major surgery was 11.4%. The mean RDW of the 30-day survivors was 13.6 ± 1.6 and that of nonsurvivors was 14.2 ± 2.1 (P < 0.001). Other factors that were significantly different (P < 0.05) between survivors and nonsurvivors included age, sex, preoperative pulse rate, current or ex-alcoholic, the American Society of Anesthesiologists score, diabetes mellitus, use of antihypertensives, sepsis with 48 h before surgery, preoperative hemoglobin, white cell count, sodium, urea, creatinine, albumin, international normalized ratio (INR), pH, base excess, estimated blood loss, and emergency surgery. Logistic regression revealed that preoperative RDW > 13.35% (P = 0.025, odds ratio [OR]: 1.52), INR (P = 0.008, OR: 4.49), albumin level (P < 0.001, OR: 1.10), use of antihypertensives (P = 0.001, OR: 1.82), and preoperative pulse rate (P = 0.006, OR: 1.02) independently predicted the 30-day mortality. However, the area under receiver operating characteristic curve for the prediction of 30-day mortality using RDW was only 0.614.

Conclusions:

Although preoperative RDW independently predicted 30-day mortality in patients who underwent major- or ultra-major noncardiac surgery, it may not serve as an influential prognostic indicator in view of its low sensitivity and specificity.

The Prognostic Role of Red Blood Cell Distribution Width in Coronary Artery Disease: A Review of the Pathophysiology

Red blood cell distribution width (RDW) is a measure of red blood cell volume variations (anisocytosis) and is reported as part of a standard complete blood count. In recent years, numerous studies have noted the importance of RDW as a predictor of poor clinical outcomes in the settings of various diseases, including coronary artery disease (CAD). In this paper, we discuss the prognostic value of RDW in CAD and describe the pathophysiological connection between RDW and acute coronary syndrome. In our opinion, the negative prognostic effects of elevated RDW levels may be attributed to the adverse effects of independent risk factors such as inflammation, oxidative stress, and vitamin D₃ and iron deficiency on bone marrow function (erythropoiesis). Elevated RDW values may reflect the intensity of these phenomena and their unfavorable impacts on bone marrow erythropoiesis. Furthermore, decreased red blood cell deformability among patients with higher RDW values impairs blood flow through the microcirculation, resulting in the diminution of oxygen supply at the tissue level, particularly among patients suffering from myocardial infarction treated with urgent revascularization.

Association between red cell distribution width and the risk of heart events in patients with coronary artery disease

Red cell distribution width (RDW) has been found to be a novel prognostic biomarker in patients with coronary artery disease (CAD); however, the association between RDW and the risk of heart events in patients with CAD is yet to be fully elucidated. Thus, the aim of the present study was to determine whether an elevated RDW was associated with the Framingham risk score (FRS) in patients with CAD. Data were retrospectively collected from Affiliated Dongyang Hospital of Wenzhou Medical University (Dongyang, China). The patients had undergone a coronary angiography and their clinical data were integrated. The patients (male, 260; female, 132) were divided into two groups based on the results of the coronary angiography, namely the CAD (n=283) and control groups (n=109). The FRS was calculated for all the subjects, and complete blood count testing with biochemical measurements was performed. The mean RDW level was 13.7±1.8% in the CAD group and 13.1±1.0% in the control group, while the mean FRS was 9.0±4.9 in the CAD group and 6.4±3.9 in the control group. The RDW and FRS were significantly higher in the CAD group compared with the control group (P<0.001). No statistically significant differences were observed between the groups with regard to the hematocrit, mean corpuscular volume, platelets, glucose, urea, albumin, aspartate aminotransferase, total cholesterol, triglycerides (TG), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and N-terminal pro-brain natriuretic peptide (P>0.05). The RDW was shown to significantly correlate with the red blood cell (RBC) count (r=-0.133, P=0.029), hemoglobin level (r=-0.207, P=0.001) and TG level (r=0.226, P<0.001) within the laboratory parameters, as well as the FRS (r=0.206, P<0.001). In the stepwise multivariate linear regression, which included the RBC count, hemoglobin level, TG level and RDW, the FRS was predicted by hemoglobin (r²=0.034, P=0.001), TG (r²=0.059, P<0.001) and RDW (r²=0.030, P=0.003) parameters. Therefore, a novel association was revealed between higher levels of RDW and an elevated FRS in patients with CAD, which raises the possibility that a simple marker, RDW, may be associated with an increased risk of heart events in CAD patients.

The role of red blood cell distribution width in mortality and cardiovascular risk among patients with coronary artery diseases: a systematic review and meta-analysis

BACKGROUND

Red cell distribution width (RDW) might be a novel biomarker that reflects multiple physiological impairments related to atherosclerosis and coronary artery diseases (CAD). We conducted this systematic review and meta-analysis to evaluate the association of RDW between all-cause mortality and fatal/non-fatal cardiovascular disease (CVD) events in CAD patients.

METHODS

Relevant studies were searched and identified in the MEDLINE and EMBASE databases. English-language prospective studies that reported risk estimates for RDW and mortality/CVD events were included. Data were extracted regarding the characteristics and clinical outcomes, and a quality assessment was conducted. Results were extracted for the highest versus lowest RDW level, and meta-analyses were carried out using random effects models.

RESULTS

We identified 22 studies enrolling 80,216 participants. The study duration ranged between 1 month and 23 years. Of the 15 studies that were included in the meta-analysis, higher RDW indicated a significant increased risk for all-cause mortality in CAD patients: pooled risk ratio (RR) 2.20 (95% CI, 1.42-3.39; P<0.0004). The results for fatal, non-fatal and fatal/non-fatal events were: pooled RR 1.80 (95% CI, 1.35-2.41; P<0.0001), RR 1.86 (95% CI, 1.50-2.31; P<0.00001) and RR 2.13 (95% CI, 1.20-3.77; P=0.01). Heterogeneity was moderately present; however, sensitivity analyses for follow-up duration, CAD subtype, or RDW as dichotomous values showed similar results.

CONCLUSIONS

The meta-analysis indicates that higher RDW levels are associated with increased risk of mortality and CVD events in patients with established CAD.

Red cell distribution width as a prognostic indicator in pediatric heart disease and after surgery

Background. Red cell distribution width (RDW) is an important marker which reflects inflammatory activity in many chronic diseases. The objective of this study is to investigate the impact of RDW on morbidity and mortality before and after pediatric congenital heart surgery. Methods. 107 patients with congenital heart disease, cardiac case group, and 70 patients, control group, without heart disease were retrospectively analyzed. Pre-, and postoperative and at discharge RDW of the cardiac patients were determined. Lengths of hospital and intensive care unit (ICU) stay and exited patients were determined. Results. Mean lengths of ICU and hospital stay were 3.3 ± 2.7 and 7.3 ± 2.9 days. In control group, mean preoperative RDW was 12.6 ± 1.4, while in cardiac case group it was significantly higher (15.1 ± 3.5). In cardiac case group, postoperative RDW were significantly higher than preoperative period, while RDW at discharge were significantly lower than postoperative estimates. A significant and a positive correlation was detected between lengths of ICU and hospital stay and RDW. RDW of the exited patients were significantly higher than the survivors. Conclusions. This study demonstrates that RDW can be used as an important indicator in the prediction of morbidity and mortality during pre-, and postoperative period of the pediatric congenital heart disease surgery.

Virchow’s triad and intestinal ischemia post cardiac surgery

Background

Intestinal ischemia is associated with a very high mortality rate. We combined the principles of Virchow’s triad to produce preoperative and postoperative models for the development of intestinal ischemia.

Methods

A single institutional study was undertaken involving 18,325 consecutive patients from April 1997 to March 2012. Univariate and multivariate analysis was performed.

Results

Mortality was 87% in 91 patients who developed bowel ischemia. Multivariate logistic regression demonstrated that age, peripheral vascular disease, intraaortic balloon pump support, female sex, and preexisting renal failure were significant determinates of intestinal ischemia preoperatively. Logistic regression demonstrated that age, peripheral vascular disease, creatine kinase-MB level, reoperation for bleeding, and blood product usage were significant determinates of intestinal ischemia postoperatively.

Conclusions

Potentially remedial causes of intestinal ischemia include blood product usage, reoperation for bleeding, and creatine kinase-MB release. Age, female sex, peripheral vascular disease, intraaortic balloon pump usage, and preexisting renal failure are fixed risk factors. Despite the continuing trend of reduced blood product usage in the field of cardiac surgery, the increase in patients’ risk factors will mean that incidences of intestinal ischemia may increase in the future.