May 28th, 2013
Interpretations Differ Over Study of Coenzyme Q10 in Heart Failure
Larry Husten, PHD
Coenzyme Q10 (CoQ10) may be beneficial in heart failure (HF), according to the results of the Q-SYMBIO study presented this past weekend at the Heart Failure 2013 meeting in Lisbon, Portugal. But the results should be viewed with a critical eye, say experts.
A possible role for CoQ10 in the treatment of HF has long been proposed. A recent meta-analysis found that CoQ10 may improve ejection fraction (EF) in HF patients, but the authors warned that “the results should be interpreted with caution” due to the small number of studies and patients included in the analysis.
Q-SYMBIO is now the largest trial to date of CoQ10 in HF in the modern era. SA Mortensen presented results from 420 patients with class III or IV HF who were randomized to CoQ10 three times daily or placebo. After two years there was a significant reduction in the incidence of major adverse cardiovascular events in the CoQ10 group: 14% (29 patients) in the CoQ10 group versus 25% (55 patients) in the placebo group (hazard ratio 2.0, CI 1.3-3.2, p=0.003). Mortensen also reported a significant reduction in overall mortality: 9% (18 patients) in the CoQ10 group versus 17% (36 patients) in the placebo group (HR 2.1, CI 1.2-3.8, p=0.01). There were also significant reductions in cardiovascular mortality (p=0.02) and HF hospitalizations (p=0.05).
In an ESC press release, Mortensen said: “CoQ10 is the first medication to improve survival in chronic heart failure since ACE inhibitors and beta blockers more than a decade ago and should be added to standard heart failure therapy.” CoQ10, he said, “is a natural and safe substance, corrects a deficiency in the body and blocks the vicious metabolic cycle in chronic heart failure called the energy starved heart.”
But the results of Q-SYMBIO are “not practice changing” Aldo Maggioni told MedPage Today. He pointed to the small number of patients and events in the trial. “You cannot change clinical practice all over Europe basing your conclusion on that.”
6 Responses to “Interpretations Differ Over Study of Coenzyme Q10 in Heart Failure”
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Just want to give a shout out to Aldo Maggioni. It’s great for the investigators to be excited about their results – but clearly we need validation of these results. There is a long history of early excitement about therapies that end up not being what they first seemed. Nevertheless, good to see a possible therapy for the future. I was surprised, by the way, at the low event rates in this group of advanced heart failure.
Since statins deplete intracellular ubiquinone which is thought to contribute to the myalgias often associated with statin therapy, many physcicians recommend CoQ10 to their patients taking statins. It should be possible to find tens of thousands of patients taking CoQ10, hundreds of whom would likely have class III or IV HF if a bigger ‘n’ is needed. There are theoretical reasons why CoQ10 should have the effects reported in Q-SYMBIO trial. Practice may have already changed, even before this study.
I think it is important to remain cautious for a couple of reasons: (1) the publication of a paper is going to be important (2) it is unclear to me whether the study was powered for survival, it seems to have been powered for MACE (but I may be wrong) (3) Mechanisms need to be ironed out, just like we have seen with anti-oxidant and reducing agents in other aspects of cardiology. For example, a well designed, although admittedly smaller study from Gottlieb published in the Annals in 2000 failed to show an improved ejection fraction or oxygen consumption in patients with CHF (Ann Intern Med. 2000 Apr 18;132(8):636-40.). So this preliminary data is good news and is encouraging, but not practice changing yet.
I agree with Aldo Maggioni’s comments. Small trials with ‘small number of events’ might overestimate trial results (alfa error). A well powered design trial of Coenzyme Q10 (CoQ10) in heart failure is mandatory. It reminds me the GIK pilot trial with a similar number of patients (N=407) that showed an important reduction in hard end points with GIK in STEMI and was the basis for the CREATE/ECLA GIK trial of about 20000 STEMI patients that showed lack of GIK efficacy. Clinical practice should be changed based on well powered, well designed RCTs.
Beyond what has already been said, there is reason to be concerned about the use of CoQ10. First, this supplement is not controlled or evaluated for safety, effectiveness, or purity by the FDA. Like other supplements that are “not drugs,” the actual contents of CoQ10 capsules are not routinely evaluated, and many studies have shown that the actual dose found in the tablets or capsules of unregulated supplements often vary from the dose stated on the packaging. Melatonin, for example, has been found to vary from bottle to bottle and brand to brand, with some analyses showing 10 times as much melatonin in the tablets as is stated on the label. In addition, supplements often contain potentially dangerous contaminants, including pesticides, microbial contaminants, heavy metals, chemical toxins, and prescription drugs. There is thus some danger of adverse effects when CoQ10 is used. The truth is that we don’t really know exactly what the patient is getting when he/she takes CoQ10. It should thus be recommended with considerable caution.
Slow down!
qualifying marvelous the results of a study which involved 400 patients suffering from severe cardiac failure during 2.5 years seems to be a little exaggerated in my opinion.
Co Q 10 was considered as a placebo when we associate it to statin to decrease muscle pains and now suddenly it becomes the 21st century’s cardiac medicine
which dosage? 30, 100, 120 mg once twice thrice a day? (suggesting a comparison with the span dosage of aspirin in CVD!)
Shall I consider the possibility to treat my patients suffering from severe cardiac insufficient with Co Q 10, coffee, Mediterranean diet? However I will not forget to stop omega 3, in the meantime I will eat chocolate and wait for the Nobel Price.
does this look scientific?