Standard-of-care anticoagulation may harm some patients

Nearly 75% of surgical patients may be receiving unnecessary anti-clotting medications, according to results of a recent study published in the Annals of Surgery.

Current standard-of-care guidelines specify that all general surgical patients should receive anticoagulation to prevent the formation of blood clots in the veins. Researchers at the University of Utah School of Medicine, Salt Lake City, UT, suggested that the preventative measure may not be necessary for all patients, and could have the potential to cause harm.

A uniform approach to every patient is not always the best option, according to lead author Christopher Pannucci, MD, an assistant professor of surgery.

“A healthy 35-year-old is very different from someone who is 85 with a history of clots,” he said. “Our research indicates there could be a substantial number of people who are being overtreated.”

Investigators reviewed more than 14,000 records from 13 studies to determine which surgical patients were likely to benefit from anticoagulation. The studies involved a broad range of surgical patients with varied clotting risk factors and personal or family histories of blood clots. Assessment of overall clot risk was based on the Caprini score, which gauges the impact of each patient’s collection of risk factors.

Risk stratification showed a large variation in clot risk from patient to patient. Those who were not given anticoagulants and who were at the highest risk were 14-fold more likely to develop clots than those in the low risk category, independent of the type of surgery.

High-risk patients who were given anticoagulants had significantly decreased risk for developing clots. While these results are not entirely unsurprising, Dr. Pannucci said that they had never before been shown.

What was surprising was that the benefit did not carry over to the rest of the patients—75% percent of the study population. Statistical analyses showed that the anticoagulant medications did not make a significant difference in clotting rates of mid- or low-risk patients.

“It was eye-opening to see the huge variability in risk among the overall group of patients,” Dr. Pannucci said. “Unless you consider a patient’s risk based on their individual factors, you would never know.”

Eliminating overtreatment could cut unnecessary costs, and this study suggests it could also prevent medical complications in some patients. Just under 2% of all surgery patients had bleeding complications, and these adverse events significantly increased in the group given anti-clotting drugs.

“For the first time, we have data that prophylaxis for the highest risk groups is beneficial, and data that suggests that lower risk patients may need no prophylaxis,” says Peter Henke, MD, co-author of the study and a professor of surgery at University of Michigan Health System, Ann Arbor, MI.

The data were gathered based on observational data, and prospective studies will need to be performed to prove whether anticoagulants work better for some patient populations as compared to others.

“Why would we give someone a drug if it doesn’t offer benefit and could offer them harm?” asked senior author Benjamin Brooke, MD, PhD, assistant professor of surgery at the University of Utah. “Much of health care is routine and standardized, but studies like this are forcing us to evolve our thinking toward doing what’s best for each individual.”