Author + information
- Paul S Watson, MB, BS, FRACPa,
- Gregory M Scalia, MB, BS, FRACPa,
- Andrew Galbraith, MB, BS, FRACPa,
- Darryl J Burstow, MB, BS, FRACPa,
- Nicholas Bett, MB, BS, FRACPa and
- Constantine N Aroney, MD, BS, FRACPa
We thank Dr. Mortensen for his interest in our study (1). We assure him that the data we reported on patient demographics are correct—that over three-quarters of our patients suffered from dilated cardiomyopathy while the remainder had coronary heart disease. When we stated that we would require 17 patients in order to demonstrate an increase in left ventricular ejection fraction from 25% to 30% with a standard deviation (SD) of 5% using 95% confidence intervals (CI) with a power of 80% (1), we did no more than calculate the probability that our failure to show such as change (a negative study) would reflect a true lack of effort.
The design of the Scandinavian study to which Dr. Mortensen refers (2) was very similar to that of our trial. Despite having nearly three times as many patients, it also failed to show any significant difference (p < 0.05) in this primary end point. The study reported by Permanetter et al. (3) also failed to show any therapeutic effect of coenzyme Q10. Meta-analysis of clinical trials of coenzyme Q10 treatment of congestive heart failure might be seen as encouraging but cannot be taken as any more than an argument for more blinded control studies (4,5).
We agree with Dr. Mortensen that if agents such as coenzyme Q10 are to be helpful, this would more likely be demonstrable early in the course of heart failure. Unfortunately, success in treating chronic failure with angiotensin-converting enzyme inhibitors (6), beta-adrenergic blockers (7), and spironolactone (8) means that it has become increasingly difficult to recruit patients for trials of unproven agents until they have been stabilized on what must now be regarded as standard therapy.
- American College of Cardiology
- Watson P.S.,
- Scalia G.M.,
- Galbraith A.,
- Burstow D.J.,
- Bett N.,
- Aroney C.N.
- Permanetter B.,
- Rossy W.,
- Klein G.,
- Weingartner F.,
- Seidl K.F.,
- Blomer H.
- Heidenreich P.A.,
- Lee T.T.,
- Massie B.M.