Medical Care

Anti-Clotting Drugs May Be Unnecessary for Most Surgery Patients

As many as three out of four surgery patients could be receiving anti-clotting medications that they do not need, according to a study led by investigators at the University of Utah School of Medicine and published on January 23rd 2017 in Annals of Surgery.

A release from the university notes that the research challenges standard of care guidelines specifying that all general surgery patients receive anticoagulants. The treatment is meant to prevent formation of blood clots in the veins. In the worst cases, clots could break free and block blood flow to vital organs such as the lungs, causing sudden death. However the new findings suggest that the preventative measure may be unnecessary for most patients, and could even be harmful to a small proportion.

The release quotes the study’s lead author Christopher Pannucci, M.D., an assistant professor of surgery, as saying, “A ‘one-size-fits-all approach’ doesn’t always make sense. A healthy 35-year-old is very different from someone who is 85 and has a history of clots. Our research indicates that there could be a substantial number of people who are being over-treated.”

The investigators reviewed 14,776 records from 13 research studies to determine which surgical patients were most likely, and least likely, to benefit from anticoagulants. Within the studies were a broad range of surgical patients, ranging from individuals with few to multiple clotting risk factors such as obesity, advanced age, and personal or family history of blood clots. They were segregated into one of five categories indicating overall clot risk. Assessment was based on a tool called the Caprini score that gauges the impact of each patient’s collection of risk factors.

Risk stratification revealed a large patient-to-patient variation in clot risk. Patients who were not given anticoagulants, and who were gauged to be at highest risk, were 14-fold more likely to develop clots than those in the low risk category (10.7 percent vs. 0.7 percent). These findings were independent of the type of surgery required by patients.

“It was eye-opening to see that there is this huge variability in risk among the overall group of patients that walk into your office,” says Pannucci. “Unless you consider a patient’s risk based on their individual factors, you would never know.”

The good news is that high risk patients, when given anticoagulants, had significantly decreased risk for developing clots. While the results make sense, they had never before been shown, says Pannucci.

More surprising was that the same benefit did not carry over to the rest of the patients, who comprised 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.