Author + information
- Christian Madelaire, MD∗ (, )
- Gunnar Gislason, MD, PhD,
- Christian Torp-Pedersen, MD, DMSc and
- Morten Schou, MD, PhD
- ↵∗Department of Cardiology, Cardiovascular Research Unit 1-Post 635, Copenhagen University Hospital, Herlev og Gentofte, Kildegårdsvej 28, DK-2900 Hellerup, Denmark
We thank Dr. Aimo and colleagues for taking interest in our paper (1). We agree that a very large sample would be necessary to examine the observed difference in a prospective randomized clinical trial. However, we disagree that power considerations are relevant for the interpretation of our results. This was an observational study based on data from administrative registers; thus, the sample size depended on the available sample in the Danish population, it could not be larger, and there was no point in selecting it smaller. The correct evaluation of the uncertainty associated with the results is to consider the 95% confidence interval. Analyzing the risk of a composite outcome of death, myocardial infarction, and stroke, we found a hazard ratio between the group of aspirin users and the group of nonusers of 0.98 and 95% confidence interval of 0.91 to 1.05. This implies that there is a 2.5% probability of overlooking a reduction in a hazard of 9% (or more) and a 2.5% probability of overlooking an increase in hazard of 5% (or more), with respect to aspirin.
Considerations of limitations due to study design and methods are already thoroughly discussed in the paper. From a scientific point of view, the “aspirin debate” is quite peculiar, although no randomized clinical trial has ever proven that long-term use in heart failure is safe and/or cost-effective; the party claiming aspirin is effective is given the benefit of the doubt, whereas the other side bears the burden of proof. We believe that clinical use of aspirin in heart failure should be based on positive results from a randomized clinical trial.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2018 American College of Cardiology Foundation