Related Experiment Video
Updated: Aug 19, 2025

Continuous Manual Exchange Transfusion for Patients with Sickle Cell Disease: An Efficient Method to Avoid Iron Overload
Published on: March 14, 2017
Morbidity and Mortality Associated With Blood Transfusions in Elective Adult Cardiac Surgery
Yas Sanaiha1, Joseph Hadaya1, Arjun Verma1
1Cardiovascular Outcomes Research Laboratories (CORELAB), University of California Los Angeles, Los Angeles, CA.
Insights
Restrictive transfusion strategies in cardiac surgery are effective. Higher preoperative hematocrit (HCT) reduced mortality, while perioperative transfusions increased 30-day mortality in patients undergoing coronary artery bypass grafting and valve surgeries.
Area of Science:
- Cardiovascular Surgery
- Transfusion Medicine
- Critical Care Medicine
Background:
- Perioperative transfusion thresholds are increasingly scrutinized, with restrictive strategies demonstrating noninferiority.
- Understanding the impact of transfusion on outcomes in complex cardiac surgeries is crucial for optimizing patient care.
Purpose of the Study:
- To evaluate the association between perioperative transfusions and 30-day mortality in adult patients undergoing coronary artery bypass grafting (CABG) and/or valve surgeries.
- To assess the relationship between preoperative hematocrit (HCT) and adverse outcomes.
Main Methods:
- Analysis of data from a statewide academic collaborative of 5 institutions, including 7,762 adult patients undergoing CABG and/or valve surgeries (2013-2019).
- Multivariate regression and machine learning (ML) models were used to evaluate predictors of transfusion and 30-day mortality.
- Examined the association between packed red blood cell (pRBC) and coagulation product (CP) transfusions and 30-day mortality, adjusting for preoperative HCT and other baseline features.
Main Results:
- Higher preoperative HCT was associated with reduced odds of mortality, renal failure, and prolonged mechanical ventilation.
- Perioperative transfusions were significantly associated with increased 30-day mortality after adjustment for preoperative HCT and baseline characteristics.
- ML models accurately predicted 30-day mortality (AUC 0.814-0.850), with perioperative transfusions identified as the most important predictive feature.
Conclusions:
- Increasing preoperative HCT is associated with a lower incidence of mortality in cardiac surgery patients.
- A direct dose-response association exists between perioperative transfusions and adverse outcomes, including mortality.
- Findings support a more restrictive approach to perioperative transfusions in CABG and valve surgery.
Objectives:
Perioperative transfusion thresholds have garnered increasing scrutiny as restrictive strategies have been shown to be noninferior. The study authors used data from a statewide academic collaborative to test the association between transfusion and 30-day mortality.
Design:
All adult patients undergoing coronary artery bypass grafting (CABG) and/or valve surgeries between 2013 and 2019 in the authors' Academic Cardiac Surgery Consortium were examined. The relationship between the number of overall packed red blood cell (pRBC) and coagulation product (CP) (fresh frozen plasma, cryoprecipitate, platelets) transfusions on 30-day mortality was evaluated. Multivariate regression was used to evaluate predictors of transfusion and study endpoints. Machine learning (ML) models also were developed to predict 30-day mortality and rank transfusion-related features by relative importance.
Setting:
At an Academic Cardiac Surgery Consortium of 5 institutions.
Participants:
Patients ≥18 years old undergoing CABG and/or valve surgeries.
Measurements And Main Results:
Of the 7,762 patients (median hematocrit [HCT] 39%, IQR 35%-43%) who were included in the final study cohort, >40% were transfused at least 1 unit of pRBC or CP. In adjusted analyses, higher preoperative HCT was associated with reduced odds of mortality (adjusted odds ratio [aOR] 0.95, 95% CI 0.92-0.98), renal failure (aOR 0.95, 95% CI 0.92-0.98), and prolonged mechanical ventilation (aOR 0.97, 95% CI 0.95-0.99). In contrast, perioperative transfusions were associated with increased 30-day mortality after adjustment for preoperative HCT and other baseline features. The ML models were able to predict 30-day mortality with an area under the curve of 0.814-to-0.850, with perioperative transfusions displaying the highest feature importance.
Conclusions:
The present analysis found increasing HCT to be associated with a lower incidence of mortality. The study authors also found a direct dose-response association between transfusions and all study endpoints examined.
Related Concept Videos
Cardiomyopathy VII: Pre and Post Operative Nursing Management
Blood Transfusion
Blood Transfusion Overview
A blood transfusion is a medical procedure used to replace blood lost due to injury, surgery, or to treat conditions such as anemia or cancer. During a transfusion, donor blood is...
Blood Transfusion and Agglutination
History
The history of blood transfusion dates back to the 17th century, when early attempts were made in animals. In 1818 James Blundell, a British doctor, performed the first successful human blood transfusion. Later in 1900, Karl...
Cardiomyopathy V: Interprofessional Care
Bone Marrow Sampling and Transplants
The transplant begins with high doses of chemotherapy and radiation treatment, which aim to destroy...
Tissue Transplantation
The Biology of Tissue Transplantation
The biology of tissue transplantation hinges on the Major Histocompatibility Complex (MHC) molecules. These molecules...

