Association of red blood cell distribution width with postoperative new-onset atrial fibrillation following cardiac valve replacement surgery: A retrospective study

Relationship between Preoperative Red Cell Distribution Width and Prolonged Postoperative Use of Catecholamines in Minimally Invasive Mitral Valve Surgery Patients: A Retrospective Cohort Study

Background/Objectives: Elevated RDW has emerged in cardiac surgery as a potential means of preoperative risk stratification with the capacity to predict short- and long-term postoperative mortality, acute kidney injury, and postoperative atrial fibrillation. The question as to whether perioperative hemodynamic instability may be predicted by such a marker remains a topic of ongoing debate. The aim of this study was to explore the relationship between preoperative RDW and prolonged postoperative catecholamine use in minimally invasive mitral valve surgery. Methods: We performed a retrospective monocentric cohort study in an academic hospital; we enrolled patients who had undergone minimally invasive mitral valve surgery (including both robot-assisted and non-robot-assisted procedures) between January 2019 and December 2022. We considered the use of inotropes and/or vasopressors for at least twelve hours after post-surgery ICU admission to qualify as the prolonged postoperative use of catecholamines (PPUC). The RDW was obtained from the routine full blood count analysis performed upon admission or a maximum of 72 h before surgery. We also performed a multivariable logistic regression analysis with PPUC as the dependent variable. Results: We finally enrolled 343 patients. Upon multivariate analysis, RDW >14.4% was independently associated with prolonged postoperative catecholamine use when compared to the reference group (OR 2.62 [1.06-4.84]; p = 0.03). Moreover, the EuroSCORE II score (OR 1.38 [1.03-1.85]; p = 0.03), the cross-clamp time (OR 1.01 [1.01-1.02]; p < 0.01), and robot-assisted mitral valve surgery (OR 0.53 [0.30-0.93]; p < 0.03) were independently associated with the prolonged postoperative use of catecholamines. Conclusions: This study identified that an elevated preoperative RDW (>14.4%), the EuroSCORE II score, and the cross-clamp time independently predict prolonged postoperative catecholamine use in minimally invasive mitral valve surgery patients. Conversely, the robot-assisted approach was associated with a smaller hemodynamic impairment.

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.