Fasting vs no fasting prior to catheterisation laboratory procedures: the SCOFF trial

Abstract

Current guidelines recommend 6 hours of solid food and 2 hours of clear liquid fasting for patients undergoing cardiac procedures with conscious sedation. There are no data to support this practice, and previous single centre studies support the safety of removing fasting requirements. The objective of this study was to determine the non-inferiority of a no fasting strategy to fasting prior to cardiac catheterisation procedures which require conscious sedation. This is a multicentre, investigator-initiated, non-inferiority randomised trial conduced in Australia with a prospective open label blinded endpoint design. Patients referred for coronary angiography, percutaneous coronary intervention or cardiac implantable electronic device (CIED) related procedures were enrolled. Patients were randomised 1:1 to fasting as normal (6 hours solid food and 2 hours clear liquid) or no fasting requirements (encouraged to have regular meals but not mandated to do so). Recruitment occurred from 2022 to 2023. The primary outcome was a composite of aspiration pneumonia, hypotension, hyperglycaemia and hypoglycaemia assessed with a Bayesian approach. Secondary outcomes included patient satisfaction score, new ventilation requirement (non-invasive and invasive), new intensive care unit admission, 30-day readmission, 30-day mortality, 30-day pneumonia. 716 patients were randomised with 358 in each group. Those in the fasting arm had significantly longer solid food fasting (13.2 versus 3.0 hours, Bayes factor >100 indicating extreme evidence of difference) and clear liquid fasting times (7.0 versus 2.4 hours, Bayes factor >100). The primary composite outcome occurred in 19.1% of patients in the fasting arm and 12.0% of patients in the no fasting arm. The estimate of the mean posterior difference in proportions in the primary composite outcome was -5.2% (95% CI -9.6 to -0.9, ) favouring no fasting. This result confirms non-inferiority (posterior probability >99.5%) and superiority (posterior probability 99.1%) of no fasting for the primary composite outcome. The no fasting arm had improved patient satisfaction scores with a posterior mean difference of 4.02 points (95% CI 3.36 to 4.67, Bayes factor >100). Secondary outcome events were similar. In patients undergoing cardiac catheterisation and CIED related procedures, no fasting was non-inferior and superior to fasting for the primary composite outcome of aspiration pneumonia, hypotension, hyperglycaemia and hypoglycaemia. Patient satisfaction scores were significantly better with no fasting. This supports removing fasting requirements for patients undergoing cardiac catheterisation laboratory procedures that require conscious sedation.