There are some benefits and potentially serious risks when people with heart failure use complementary and alternative medicines (CAM), to manage symptoms, so involving the health care team is important for safety, according to a new American Heart Association scientific statement published today in the Association’s flagship, peer-reviewed journal Circulation.

An estimated 6 million people ages 20 and older in the U.S. have heart failure, a condition that occurs when the heart isn’t functioning normally. The statement, “Complementary and Alternative Medicines in the Management of Heart Failure,” assesses the effectiveness and safety of CAM therapies used for heart failure treatment. According to the statement, it’s estimated that more than 30% of people with heart failure in the U.S. use complementary and alternative medicines.

The statement defines complementary and alternative medicine therapy as medical practices, supplements and approaches that do not conform to the standards of conventional, evidence-based practice guidelines. Complementary and alternative products are available without prescriptions or medical guidance at pharmacies, health food stores and online retailers.

These products are not federally regulated, and they are available to consumers without having to demonstrate efficacy or safety to meet the same standards as prescription medications. People rarely tell their health care team about their use of supplements or other alternative therapies unless specifically asked, and they may not be aware of the possibility of interactions with prescription medicines or other effects on their health. The combination of unregulated, readily accessible therapies and the lack of patient disclosure creates significant potential for harm.”

Chair of the scientific statement writing committee Sheryl L. Chow, Pharm.D., FAHA, an associate professor of pharmacy practice and administration at Western University of Health Sciences in Pomona, Calif., and associate clinical professor of medicine at the University of California in Irvine

Examples of complementary and alternative therapies that heart failure patients might use include supplements such as Co-Q10, vitamin D, Ginkgo, grapefruit juice, devil’s claw, alcohol, aloe vera and caffeine, or practices such as yoga and tai-chi. The statement writing group reviewed research published before Nov. 2021 on CAM among people with heart failure.

The statement writing group advises health care professionals to ask their patients with heart failure at every health care visit about their use of complementary and alternative therapies and talk about potential medication interactions, benefits and potential side effects of CAM. In addition, they suggest that pharmacists are included in the multidisciplinary health care team to provide consultations about the use of complementary and alternative therapies for people with heart failure.

Alternative therapies that may benefit people with heart failure include:

• Omega-3 polyunsaturated fatty acids (PUFA, fish oil) have the strongest evidence among complementary and alternative agents for clinical benefit in people with heart failure and may be used safely, in moderation, in consultation with their health care team. Omega-3 PUFA is associated with a lower risk of developing heart failure and, for those who already have heart failure, improvements in the heart’s pumping ability. There appears to be a dose-related increase in atrial fibrillation (an irregular heart rhythm), so doses of 4 grams or more should be avoided.
• Yoga and Tai Chi, in addition to standard treatment, may help improve exercise tolerance and quality of life and decrease blood pressure.

Meanwhile, some therapies were found to have harmful effects, such as interactions with common heart failure medications and changes in heart contraction, blood pressure, electrolytes and fluid levels:

• While low blood levels of vitamin D are associated with worse heart failure outcomes, supplementation hasn’t shown benefit and may be harmful when taken with heart failure medications such as digoxin, calcium channel blockers and diuretics.
• The herbal supplement blue cohosh, from the root of a flowering plant found in hardwood forests, might cause a fast heart rate called tachycardia, high blood pressure, chest pain and may increase blood glucose. It may also decrease the effect of medications taken to treat high blood pressure and Type 2 diabetes.
• Lily of the valley, the root, stems and flower of which are used in supplements, has long been used in mild heart failure because it contains active chemicals similar to, but less potent than, the heart failure medicine digoxin. It may be harmful when taken with digoxin by causing very low potassium levels, a condition known as hypokalemia. Lily of the valley also may cause irregular heartbeat, confusion and tiredness.

Other therapies have been shown as ineffective based on current data, or have mixed findings, highlighting the importance of patients having a discussion with a health care professional about any non-prescribed treatments:

• Routine thiamine supplementation isn’t shown to be effective for heart failure treatment unless someone has this specific nutrient deficiency.
• Research on alcohol varies, with some data showing that drinking low-to-moderate amounts (1 to 2 drinks per day) is associated with preventing heart failure, while habitual drinking or intake of higher amounts is toxic to the heart muscle and known to contribute to heart failure.
• There are mixed findings about vitamin E. It may have some benefit in reducing the risk of heart failure with preserved ejection fraction, a type of heart failure in which the left ventricle is unable to properly fill with blood between heartbeats. However, it has also been associated with an increased risk of hospitalization in people with heart failure.
• Co-Q10, or coenzyme Q10, is an antioxidant found in small amounts in organ meats, oily fish and soybean oil, and commonly taken as a dietary supplement. Small studies show it may help improve heart failure class, symptoms and quality of life, however, it may interact with blood pressure lowering and anti-clotting medicines. Larger trials are needed to better understand its effects.
• Hawthorn, a flowering shrub, has been shown in some studies to increase exercise tolerance and improve heart failure symptoms such as fatigue. Yet it also has the potential to worsen heart failure, and there is conflicting research about whether it interacts with digoxin.

“Overall, more quality research and well-powered randomized controlled trials are needed to better understand the risks and benefits of complementary and alternative medicine therapies for people with heart failure,” said Chow. “This scientific statement provides critical information to health care professionals who treat people with heart failure and may be used as a resource for consumers about the potential benefit and harm associated with complementary and alternative medicine products.”