Only one in two clinical trials on high-risk medical devices for heart disease are published in a peer-reviewed journal, according to a new study published in The BMJ. These devices include implantable cardioverter-defibrillators, pacemakers, coronary stents, and artificial heart valves. Researchers searched an FDA database and found information about 177 clinical trials on 106 cardiovascular devices that received premarket approval in the USA between 2000 and 2010. Of those 177 trials, only 86 (49%) had been published.

This is important, as the new European Clinical Trials Regulation (which aims to improve clinical trials transparency) does not apply to clinical trials on medical devices, and previous research found that the FDA approves many of these devices on the basis of a single trial.  The researchers highlight the importance of publishing results of trials on medical devices:

“Clinicians might not be aware of the FDA device summaries and so might not critically examine these data. Thus for many high risk devices, clinical trial evidence might never be made readily available to the medical community or might be made available only after a long delay.”

In an editorial in The BMJ accompanying the new study, Dr Sidney Wolfe, founder and senior advisor of Public Citizen’s Health Research Group, writes:

“Beyond adverse effects on patients of selective reporting in medical journals, the absence of publicly available data from clinical trials violates an important ethical principle of the Declaration of Helsinki: ‘Researchers have a duty to make publicly available the results of their research … Negative and inconclusive as well as positive results must be published or otherwise made publicly available.’ Many people participate in research because they trust that the published results might improve the health of the general population.”