Then came the news that a drug test she’d taken in advance of a competition in December 2021 showed signs of trimetazidine (TMZ), a heart medication that has been banned by the World Anti-Doping Agency since 2014. The test also identified two other heart medications in her system that are not on the banned list. As reported in The New York Times, Valieva allegedly told the Court of Arbitration for Sport that her grandfather was prescribed trimetazidine for a heart condition and may have inadvertently exposed her to the drug. The arbitrators ruled that Valieva could continue to compete in the games, with the International Olympic Committee announcing that she would not be eligible for any medals until her case was resolved. Valieva went on to win the women’s short program on February 15 and come in fourth in the long program on February 17. While it’s not possible to predict how the doping investigation will play out, here’s what’s known about the drug at the heart of the controversy, and some input from a sports medicine doctor on whether this medication can give athletes an edge.

What Is Trimetazidine (TMZ)?

Trimetazidine has been widely used in some European countries since the 1970s but is not approved in the United States. Doctors prescribe the drug to treat chest pain (angina) when more standard medications such as aspirin or beta-blockers aren’t working. Physicians also prescribe TMZ to treat ringing in the ears (tinnitus), dizziness (vertigo), and some vision disturbances. Angina occurs when arteries fail to deliver enough blood to a part of the heart that needs oxygen. Though the pain often goes away with rest, angina is usually a warning sign of heart disease. Though some studies have shown that trimetazidine works well as an adjunct to or alternative to standard treatments for angina, there have been very few randomized double-blind trials of TMZ, and studies that do exist have had conflicting results. The medication can cause side effects such as restless legs and other movement issues similar to symptoms of Parkinson’s disease. Because of these side effects, in 2012, the European Medicines Agency (EMA) recommended that doctors limit the use of TMZ for angina and stop prescribing it to treat other conditions.

How Does Trimetazidine Work?

Trimetazidine helps the heart work more efficiently by making energy easier to access. Normally, the heart gets the energy it needs first by oxidizing fatty acids, then by utilizing glucose as energy — a faster and more efficient process. What trimetazidine does is decrease reliance on the “slower” fatty acids path and encourage more immediate glucose use, increasing the heart’s efficiency. This is helpful for people with angina whose hearts may be deprived of adequate oxygen. In a study published in a 2018 issue of Advances in Therapy, patients with recently diagnosed angina had fewer incidences of chest pain and were also able to increase their walking distance after being treated with the drug.

Does TMZ Give Elite Athletes an Edge?

Trimetazidine is thought to give endurance athletes a boost because it may help the heart work more efficiently. “TMZ enhances the body’s ability to utilize oxygen under stress. Theoretically, that could provide an athlete in competition — and under physical stress  — with an advantage, enabling them to utilize more oxygen than they normally would,” says Cayce Onks, DO, a primary care sports medicine physician at Penn State Health Milton S. Hershey Medical Center in Hershey, Pennsylvania. That’s precisely why it has been banned, though the connection between TMZ and improved performance is still largely theoretical. “All Olympic athletes are looking for an edge,” says Dr. Onks. “When you’re talking about a few extra seconds in the air, or a microsecond’s difference in a race, any advantage can be beneficial.” Unlike some other banned performance-enhancing drugs, like beta-blockers, “TMZ does its work without affecting heart rate or blood pressure,” explains Onks. “Beta-blockers, on the other hand, can slow heart rate and lower blood pressure,” obviously a negative for athletes. As for Valieva, Onks agrees that a clear violation of doping rules occurred. “There is no reason for a healthy 15-year-old to be on this medication,” he says. Onks does think the drug might help an athlete get to gold. “The difference between first and second place, at this level, can be so infinitesimal that it’s not measurable,” says Onks. “We’ll just never really know the role TMZ might play in terms of that edge.”