Cardiac catheterisation is rife with entrenched practices devoid of robust evidence, according to cardiologists who have developed new guidance for the American Heart Association.

Updating traditional practices in light of evolving evidence could improve patient care, avoid complications and reduce cost, they suggest.

The AHA team questions the “age-old” practice of patients being required to have ‘nil by mouth’ for many hours before an invasive cardiac catheterisation procedure, sometimes embodied in a ‘nothing after midnight’ rule.

This practice arose when emesis was common due to the use of ionic, high-osmolar contrast agents and was deemed prudent in case catheterisation complications necessitated a general anaesthetic, they say.