Is fasting necessary before cath lab procedures?

The SCOFF* trial presented at ESC 2024 shows that fasting is not necessary prior to cardiac catheterization procedures requiring conscious sedation.

“Fasting before a cardiac catheterization procedure has been recommended to reduce the risk of inhaling the stomach contents and developing aspiration pneumonia. However, for procedures in the catheterization laboratory, fasting may not reduce aspiration risk and there are downsides, such as patient discomfort, water depletion, poor blood sugar control, and unnecessary fasting for delayed/cancelled procedures,” noted principal investigator Dr David Ferreira from the John Hunter Hospital, Newcastle, Australia, at ESC 2024.

“In SCOFF, we were able to show no increased risk of complications with normal eating and that is good news for patients and healthcare professionals,” Ferreira continued.

In terms of the primary composite outcome of procedure-related aspiration pneumonia, hypotension, hyperglycaemia, and hypoglycaemia, the event rate was 19.1 percent in the fasting arm and 12 percent in the no-fasting arm. The posterior probability of noninferiority was >99.5 percent, while the posterior probability of superiority was 99.1 percent.

Looking at the secondary outcomes between arms, no fasting still appeared to outdo fasting, as reflected by the rates of contrast-induced nephropathy (6.3 percent vs 3.8 percent), new ventilation requirement (0 percent for both), new intensive care unit admission (0 percent for both), readmission within 30 days (7.8 for both), death within 30 days (0.3 percent for both), and pneumonia within 30 days (0.6 percent vs 0 percent).

Of the two pneumonia events that occurred within 30 days in the fasting arm, one was deemed possibly related to aspiration.

“There was decisive evidence of improvement in patient satisfaction scores with no fasting vs fasting (11 vs 15 points). The lower score indicates improved patient satisfaction,” Ferreira added.

Time to revise guidelines?

In SCOFF, individuals who had been referred for coronary angiography, coronary intervention, or cardiac implantable electronic device (CIED)-related procedures were recruited. A total of 716 participants (mean age 69 years, 65 percent men) were randomized 1:1 to fasting prior to the procedure (no solid food for 6 hours and no clear liquids for 2 hours) or no fasting (encouraged to have regular meals).

Nearly half of participants required coronary assessment due to stable angina/ischaemia workup, while about a third were referred for coronary angiography due to acute coronary syndrome (61 percent for non-ST-elevation myocardial infarction).

“[Together with previous] data … there is now a strong case [suggesting] that fasting is not needed in patients undergoing these types of procedures,” Ferreira said. [SCAI 2020, abstract 11758; JACC Cardiovasc Interv 2024;17:1200-1210; Europace 2022;24:1617-1626]

Overall, SCOFF shows that no fasting was noninferior and superior to fasting prior to coronary catheterization and CIED-related procedures for the primary composite outcome. No fasting also led to significantly better patient-reported satisfaction scores.

“Removing fasting has been consistently shown to be safe and improved satisfaction for patients undergoing cardiac procedures with conscious sedation, [as] patients often prefer not to fast … There are logistical benefits to the healthcare system if patients can eat and drink normally. With this new evidence, I think it is now time to reconsider fasting requirements in clinical guidelines,” Ferreira concluded.