CoQ10 and Chronic Heart Failure
When added to conventional therapies, a supplement containing the antioxidant coenzyme Q10 (CoQ10) improved outcomes in patients with moderate-to-severe chronic heart failure, a small placebo-controlled trial showed.
At 2 years, the patients who received the supplement had a significantly lower rate of major adverse cardiovascular events than those who did not take CoQ10 (14% versus 25%), which worked out to a doubling in freedom from those events (HR 2.o, 95% CI 1.3-3.2), according to Svend Aage Mortensen, MD, DMSc, of Copenhagen University Hospital.
Both all-cause and cardiovascular mortality were significantly reduced in the supplement group, and there was a nonsignificant trend toward fewer adverse events (P=0.073), he reported at the Heart Failure Congress here.
Based on the findings, committees in charge of crafting practice guidelines might think about including information about CoQ10 as an option to be used with other heart failure therapies, Mortensen said in an interview with MedPage Today.
"CoQ10 could be considered as adjunctive treatment in heart failure," he said.
But Aldo Maggioni, MD, who was on the task force that developed the 2012 European Society of Cardiology heart failure guidelines, told MedPage Today that the results were not practice changing, pointing to the low number of patients included in the trial (420) and the low number of MACE events (84).
"You cannot change clinical practice all over Europe basing your conclusion on that," he said.
Maggioni said that if no other data were to become available, updated guidelines would probably mention the results of the current study -- which he called interesting and encouraging -- without making a specific recommendation.
"If you can use a dietary supplement -- a natural product -- without any kind of adverse event it is really very useful, taking into consideration that patients with heart failure are treated with a lot of drugs," he said. "And to have something natural without side effects -- without interactions with other drugs -- is very important."
But, he said, "in my opinion, I think that to confirm this hypothesis it is necessary to have a real large-scale clinical trial."
CoQ10 is naturally produced in the body and is involved in energy production. It was first described in the 1950s and is now sold over the counter as a supplement.
Previous studies have shown that levels of CoQ10 are lower in cardiac biopsy samples from patients with more severe heart failure and that low plasma levels are associated with increased mortality in heart failure.
Smaller trials have demonstrated some benefits from CoQ10 in patients with heart failure, but none was sufficiently powered to demonstrate an effect on survival.
Mortensen's Q-SYMBIO study -- conducted at 17 centers in Australia, Austria, Denmark, Hungary, India, Malaysia, Poland, Slovakia, and Sweden -- was designed to address that issue. It included 420 patients with chronic heart failure and New York Heart Association class III or IV disease. Most had a reduced ejection fraction (average 31%). The average age of the patients was 62.3.
On the background of standard heart failure therapy, patients were randomized to receive either CoQ10 100 mg three times daily or placebo. The primary long-term endpoint was a composite of unplanned hospitalization due to worsening heart failure, cardiovascular death, urgent cardiac transplantation, or mechanical support at 2 years, but there was also a short-term assessment performed at 3 months.
After 3 months, the percentage of patients who had improvements in NYHA class was similar in the two groups (44% with CoQ10 versus 39% with placebo).
But after 2 years, the percentage who improved was greater in the CoQ10 group (58% versus 45%, P=0.047). Mortensen said that some patients improved from class IV to class I.
In addition to the primary endpoint of MACE, there were significant reductions in all-cause death (9% versus 17%, P=0.03) and cardiovascular death (8% versus 15%, P=0.02) in the CoQ10 group.
The benefits were consistent across various subgroups.
CoQ10 is available as an over-the-counter supplement, but Mortensen said that patients should not start taking it without discussing it with their doctors. He noted, however, that there is no evidence of interactions with established heart failure medications.
Maggioni agreed that the risks of adverse events or drug interactions are very small with CoQ10.
"I do not recommend [that patients] buy and take this kind of supplement, but I'm not worried if the patients are impressed by the results and want to use this kind of approach," he said. "It is surely safe."
Mortensen S, et al
The effects of coenzyme Q10 on morbidity and mortality in chronic heart failure: results from the Q-SYMBIO study
Heart Failure Congress, Lisbon, Spain.
Copenhagen University Hospital