Session number: 399-400-401-402
Session title: Fallacies from Clinical trials
Authors: Michel Bertrand (France)
Firstly, Dr LM Ruilope (Madrid) addressed the matter of fallacies in hypertension clinical trials and underlined once more the impact of high blood pressure on CV risk. Most of the fallacies in hypertension trials stem from the fact that none have been pure hypertension trials, and almost no trials achieved equal level of blood pressure.
Next, Dr K Swedberg listed a number of fallacies in heart failure trials.
• Too much hope on surrogate markers
• Incorrect interpretation of sub group analysis
• Lack of awareness of benefits in small studies revealed by meta-analysis
• Inadequate translation of mechanisms to results
• Lack of awareness of symptoms, for example importance of breathlessness and fatigue .
In his presentation, Dr P.J. Barter pointed out several fallacies in Dyslipidemia trials:
• Based on the assumption that associations equate with causality (CRP for example)
• Based on the assumption that surrogate markers equate with clinical outcome
• Based on the belief that p value < 0.05 demonstrates efficacy whilst p> 0.05 equates with lack of proof
• Based on post hoc subgroup analysis which can only generate hypothesis.
Lastly, Dr R. Califf described several fallacies in PCI clinical trials. In terms of trial methods, registries suffer from a lack of a true anchor comparison but randomized clinical trials select simple, low risk cases performed by the best operators. Fallacies in trial interpretation arise, depending on the endpoints and the duration of the trial, and finally, there are fallacies related to the quality of the treatment after discharge.
Conclusion
In conclusion, these excellent presentations showed that there are many fallacies in clinical trials.
Webcasts of Presentations available: LM Ruilope, K Swedberg , PJ Barter, RM Califf
Notes to editor
This congress report accompanies a presentation given at the ESC Congress 2008. Written by the author himself/herself, this report does not necessarily reflect the opinion of the European Society of Cardiology.
The content of this article reflects the personal opinion of the
author/s and is not necessarily the official position of the
European Society of Cardiology.