Coenzyme Q10 and atrial fibrillation


Atrial fibrillation (AF) is a condition in which the smaller chamber of the heart does not beat regularly, but merely quivers with no rhythmic contraction. This leads to reduced heart function, but because the atrial beat contributes only about 20 percent of the blood to the left ventricle (the rest passes passively through the mitral valve) it is usually not a debilitating condition. However, because the chamber is not contracting, the blood is more likely to coagulate while collecting in the intricate channels of the atrial wall. For this reason, patients who are in persistent AF are usually put on anticoagulants, such as warfarin (Coumadin), or some of the newer agents used for the same purpose, to prevent a dislodged clot from causing a stroke or other tissue damage.

Patients with heart failure often develop AF, and they may be at a higher risk of more severe cardiac arrhythmias, depending on the severity of their heart failure. In a new study, 102 heart failure patients were given either a combination of the usual heart failure drugs with a placebo, or the same drugs plus a daily supplement of 30 mg of coenzyme Q10. The subjects included 72 men and 30 women aged 45 to 82 years. They were evaluated at the start of the study by electrocardiogram, Holter monitor for 24 hours, and blood levels of inflammatory substances that are markers for heart risks. They were then evaluated again after 6 months and 12 months.

At both follow-up evaluations, those subjects in the coenzyme Q10 treatment group had a significantly lower incidence of AF. At 12 months, the incidence of AF was 6.3 percent in the group treated with coenzyme Q10, compared with 22.2 percent in the control group. The heart muscle function (ejection fraction) was significantly better in the treatment group (24 percent increase) at both follow-up evaluations compared to the control group (19 percent increase). In addition, the inflammatory markers were markedly lower in the coenzyme Q10 treatment group than in the controls. For example, the decline in C-reactive protein (CRP) levels in the medication-only group was 20 percent, but in the coQ10 group the decline was 40 percent. (Zhao Q, et al., Effect of coenzyme q10 on the incidence of atrial fibrillation in patients with heart failure. J Investig Med. 2015 Jun;63(5):735-9.)

Practical guidelines:

Coenzyme Q10 is essential for energy production in muscle cells, and the heart requires more than any other muscle. Levels are often too low in heart patients, and treatment with statin drugs can lower it further. The dose of coenzyme Q10 in this study was very low compared to typical treatment levels (30 mg as opposed to 100 to 400 mg, or even higher in heart patients with more severe disease).

It is easy to design a study to fail, and I am surprised that this study showed such statistically significant benefits with such a small dose and with a relatively small group of subjects. In the citations found with this study, only one article gives the specific dose of coenzyme Q10, and in that one the dose averaged 100 mg per day, so I am surprised that they chose to treat with only 30 mg. My recommendation is a dose of 100 to 200 mg per day (I take 400 mg) and ubiquinol (the reduced form) is likely to be better than the more common ubiquinone (the oxidized form), although this is converted in the body to ubiquinol.

Nick’s Comment:  Another treatment is using a mixture of Lecithin and vitamin B5 which helps increase the neurotransmitter that regulates heart rate.Read the article about this treatment here