Study: No Need to Fast Before Catheterization

Holding patients NPO before cardiac catheterization procedures was not safer but did come with costs, a randomized trial showed.

No restrictions on oral intake didn't increase the risk of the primary composite endpoint of aspiration pneumonia, periprocedural hypotension or hypo- or hyperglycemia, nausea or vomiting, and contrast-induced nephropathy (11.3% vs 9.8%, P=0.65) in the CHOW NOW trial.

This met noninferiority criteria, Abhishek Mishra, MD, of the Heart and Vascular Institute at Vidant Health in Greenville, North Carolina, reported at the virtual annual conference of the Society for Cardiovascular Angiography and Interventions (SCAI).

In-hospital mortality was similar as well (0.3% with vs 0.7% without fasting, P=0.616).

However, total cost of the hospitalization trended lower without fasting ($6,960 vs $8,446), which Mishra attributed to the nonsignificantly shorter length of stay compared with fasting prior to the catheterization.

Patient satisfaction among inpatient cases was also higher without fasting. Mishra noted this could have been because there is no set time for when those patients go to catheterization, so holding them NPO after midnight could result in longer fasting durations if there are delays for other urgent cases to be cared for first.

The costs and patient satisfaction advantages of nonfasting catheterization were significant in the 294 patients who had their procedure as an inpatient.

"If the outcomes are no worse, the nonfasting ... patients are going to be happier and more comfortable, less anxious," commented Hadley Wilson, MD, of the Sanger Heart and Vascular Institute in Charlotte, North Carolina, and an American College of Cardiology spokesperson. He agreed on "the financial impact of not having to delay heart catheterization or to keep people overnight because they ate a late breakfast" being relevant for hospitals. "There's a lot of really strong practical reasons why this may be important."

Timothy Henry, MD, of the Christ Hospital in Cincinnati, though, cautioned at an SCAI press conference that the modest-sized trial might have trouble changing minds.

"Most of this is not dictated by us as interventional cardiologists; it's dictated by hospital policies or anesthesia people," he said. "All of us in 2020 when we do caths, we almost never see patients with nausea or vomiting."

Press conference moderator Kirk Garratt, MD, medical director for the Center for Heart and Vascular Health within the Christiana Care Health System in Newark, Delaware, said he would have changed his center's policy to nonfasting years ago.

However, he noted, "we're not working in a vacuum." He suggested that looking at outcomes in diabetes patients may be "one path to getting change in policy and convincing even the anesthesia people, who are very understandably focused on their liability."

The prospective trial included 599 in- or outpatient cases of non-emergent coronary angiogram, left and right heart catheterization, or percutaneous coronary intervention at a single center in Pennsylvania. The patients were randomized in a single-blind fashion (interventional cardiologists were unaware of the fasting status of patients) to no restriction on oral intake or a standard approach of no oral intake after midnight for solid meals irrespective of the timing of the procedure and then not even clear liquids within 2 hours of the procedure. Cardiogenic shock, pregnancy, emergent catheterization, and children were reasons for exclusion.

Fasting interval for meals was 7.3 hours in the non-fasting group compared with 16.4 hours in the fasting group; it was 4.6 versus 7.4 hours for oral liquids (both P<0.0001).

Aspiration pneumonia occurred in two patients in the nonfasting group (0.7%) compared with none in the fasting group (P=0.239). One was an 85-year-old man with an embolic stroke with features of aspiration with symptom onset 12 hours after the catheterization. That patient later died in-hospital. The other was an 83-year-old woman who was hyporesponsive after her cardiac catheterization for non-ST segment elevation myocardial infarction. She was found to have aspiration pneumonia the next day. She was discharged after a 12 day hospitalization.

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