Many cardiac devices are not subject to rigorous safety and effectiveness research before being approved for use, new research has found.

A study by UC San Francisco found that implanted cardiac devices such as pacemakers and stents are receiving US Food and Drug Administration approval based on data from just one trial, questioning the quality of data, according to a report in the Journal of the American Medical Assocation.

Co-author of the paper and medical resident Dr Sanket Dhruva said that drugs have been given far greater attention than medical devices by the safety agency.

“We didn’t expect that all the devices would need multiple studies or randomised studies. But we were surprised that so many devices were approved on the basis of a single study,” Dhruva said.

The study found that 65% of the pre-market approval applications for high-risk devices were supported by a single study while only 27% of the studies were randomised and only 14% were blinded.