# Red Cell Distribution Width is Associated with Bleeding Complications after Coronary Artery Bypass Grafting

## TL;DR

High red cell distribution width (RDW) is linked to increased bleeding risks after heart surgery, suggesting it could help predict complications before surgery.

## Contribution

This study shows that elevated RDW is an independent predictor of bleeding complications after CABG, offering a new preoperative risk stratification tool.

## Key findings

- Higher RDW was associated with increased odds of transfusion, re-exploration, and high chest tube output after CABG.
- RDW was also linked to greater platelet/plasma use and longer ICU stays, but not to 30-day mortality.
- RDW may serve as a simple biomarker for preoperative bleeding risk assessment in CABG patients.

## Abstract

Elevated red cell distribution width (RDW) has been associated with adverse outcomes in coronary artery disease but its role in bleeding after cardiac surgery is unclear. We evaluated whether preoperative RDW predicts bleeding after isolated coronary artery bypass grafting (CABG).

This was a nationwide retrospective study of patients undergoing isolated CABG in Iceland, 2003-2019. RDW was analysed continuously (per 1% increase) and dichotomized (>14.0% vs ≤14.0%). Primary bleeding outcomes included transfusion >4 red blood cell units, re-exploration for bleeding, and chest tube output >1000 mL/24h. Multivariable logistic regression adjusted for demographics, comorbidities, operative urgency, cardiopulmonary bypass, and perioperative factors.

The study included 1929 patients. Elevated RDW was associated with older age, anaemia, comorbidities, and urgent procedures. After adjustment, higher RDW predicted transfusion >4 RBC units (OR 1.25 per 1%, OR 1.72 for >14.0%), re-exploration (OR 1.30 per 1%, OR 2.39 for >14.0%), and chest tube output >1000 mL/24 h (OR 1.13 per 1%, OR 1.34 for >14.0%). RDW was also associated with greater platelet/plasma use, longer ICU stay, and major complications, but not to 30-day mortality (OR 1.21, 95% CI 0.55-2.52).

Elevated RDW was independently associated with multiple bleeding complications after CABG. RDW may serve as a simple, inexpensive biomarker to improve preoperative bleeding risk stratification in CABG patients.

Coronary artery bypass grafting (CABG) is the recommended treatment for selected patients with advanced coronary artery disease (CAD) and is performed globally with generally favourable outcomes.