TOPLINE:
The association of female sex with increased coronary artery bypass graft (CABG) mortality may be mediated in large part by intraoperative anemia, especially when nadir intraoperative hematocrit values are below 22%, a new study suggested.
METHODOLOGY:
- Researchers analyzed data from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (2011-2022) for 1,434,225 CABG patients (median age, 66 years; 24%, women).
- They stratified baseline demographics by both sex and intraoperative anemia and stratified hematocrit values based on the World Health Organization anemia classification: None to mild (nadir intraoperative hematocrit, > 33%), moderate (24% to
- Researchers then calculated the attributable risk (AR; risk-adjusted strength of the association of female sex with CABG outcomes) for the primary outcome: Operative mortality, defined as all-cause death occurring within 30 days postoperatively.
TAKEAWAY:
- Compared with men, women had a lower median preoperative hematocrit (36.9% vs 41.0%), lower median estimated preoperative red blood cell volume (1093.4 vs 1420), and a lower median nadir intraoperative hematocrit (22% vs 27%).
- Women also had a lower median body surface area (BSA) than men (1.81 m2 vs 1.97 m2), and more than half of women fell into the lowest 2 deciles of BSA.
- Women had higher operative mortality than men (2.8% vs 1.7%), and the AR of the female sex for operative mortality was 1.21; this was reduced by 43% after adjustment for intraoperative anemia, and the relationship persisted in a sensitivity analysis controlling for intraoperative transfusions.
- Women comprised 58.8% of the patients with life-threatening anemia (nadir intraoperative hematocrit below 19.5%) and 51.8% of patients with a nadir intraoperative hematocrit below 22%.
- Intraoperative anemia mediated 38.5% of the increased mortality risk associated with female sex, with a stronger association between operative mortality and nadir intraoperative hematocrit at hematocrit values
IN PRACTICE:
“Intraoperative anemia represents an actionable target to improve operative mortality in women after CABG and reduce the sex gap,” the authors wrote.
In a related editorial, Thomas Schwann, MD, MBA, Oakwood Beaumont University Hospital, Royal Oak, Michigan, and Daniel T. Engelman, MD, University of Massachusetts Chan School of Medicine, Springfield, Massachusetts, said that because the retrospective study could not show causality, “it is important to resist jumping to the seductively appealing conclusion that correcting anemia, especially with a blood transfusion, in female patients undergoing CABG will in any way affect the documented disparity in mortality,” which could be caused by various factors, including the duration and severity of anemia and whether the patients received a transfusion.
SOURCE:
The study, led by Lamia Harik, MD, of Weill Cornell Medicine in New York City, was published on February 26 in the Journal of the American College of Cardiology.
LIMITATIONS:
The study is observational, cannot establish causation, and is subject to confounders and biases, including selection bias regarding which women were referred to CABG. Key variables such as target vessel, conduit quality, patient frailty, and socioeconomic factors are not captured in the database and could not be used for risk adjustment.
DISCLOSURES:
Study data were provided by the Society of Thoracic Surgeons’ National Database Participant User File Research Program. Several authors were supported by the government and/or foundation grants. For full disclosures, see the paper. Schwann and Engelman reported no relevant relationships.
Source link : https://www.medscape.com/viewarticle/intraoperative-anemia-tied-higher-cabg-mortality-women-2024a10003sy?src=rss
Author :
Publish date : 2024-02-27 11:28:33
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