According to the results of a study published in the Annals of Surgery, postoperative permissive anemia appears to adversely affect outcomes, including ischemic events, 90-day mortality, and long-term mortality.
Researchers conducted a retrospective study of patients who underwent major vascular or general surgery procedures within the Veterans Health Administration system between January 2000 and December 2015. The team obtained data from the Veterans Affairs Surgical Quality Improvement Program and Corporate Data Warehouse databases and examined the effects of postoperative permissive anemia and high cardiovascular risk, which was measured using the Cardiac Risk Index. The primary end point was a composite of mortality, myocardial infarction, acute renal failure, coronary revascularization, or postoperative stroke within 90 days.
A total of 142,510 procedures were analyzed. The study population was predominantly male (96.7%) with an average patient age of 65 years (range, 18-90).
The strongest independent predictor of the composite primary end point was postoperative anemia (odds ratio, 1.43; 95% CI, 1.41-1.45). Cardiac risk status was also an independent predictor of the primary end point, and the interaction between cardiac risk status and postoperative anemia was significant (odds ratio, 1.04; P <.001), suggesting that patients with high cardiac risk are more sensitive to postoperative anemia compared with patients with lower cardiac risk.
In a multivariate analysis of the secondary end point, long-term mortality, age (hazard ratio, 1.042; 95% CI: 1.041-1.043; P <.001) and postoperative anemia (HR, 1.18; 95% CI, 1.17-1.19; P <.001) were the strongest predictors.
“Until a randomized controlled trial settles this issue definitively, a restrictive transfusion strategy should be used with caution in male patients at high cardiac risk who undergo major general and vascular surgery operations,” wrote the authors.
- Kougias P, Sharath S, Mi Z, Biswas K, Mills JL. Effect of postoperative permissive anemia and cardiovascular risk status on outcomes after major general and vascular surgery operative interventions [published online October 1, 2019]. Ann Surg. doi:10.1097/SLA.0000000000003525