May 14, 2020
CHOW NOW Study Compares Eating Versus Fasting Before Cardiac Catheterizations
May 14, 2020—The Society for Cardiovascular Angiography and Interventions (SCAI) announced findings from the single-center, randomized CHOW NOW study that aimed to compare the safety and clinical outcomes of a nonfasting (NF) strategy as compared with the current standard fasting (SF) protocol. The study was presented as late-breaking science during the SCAI 2020 Scientific Sessions Virtual Conference held May 14–16, 2020.
According to SCAI, the CHOW NOW study is the first in the United States and globally with a large number of randomized patients evaluating the safety of letting patients eat before a nonemergent cardiac catheterization. The study was performed at Guthrie Robert Packer Hospital in Sayre, Pennsylvania.
Abhishek Mishra, MD, the lead investigator, is a cardiologist at Vidant Heart & Vascular Institute in Greenville, North Carolina. In the SCAI announcement, Dr. Mishra commented, “This study really challenges one of the established practices of having the patients fast prior to a nonemergent cardiac catheterization procedure. This practice has been in place for [several] decades without having any actual evidence to support it. With advancement of procedural technology and moderate conscious sedation, the perceived risk of complications has significantly reduced.”
The study was summarized in the SCAI press release. The SF group was instructed to be nothing by mouth after midnight but could have clear liquids up to 2 hours before the procedure. The NF group had no restriction on oral intake irrespective of time of cardiac catheterization. Primary outcomes included a composite of contrast-induced nephropathy (CIN), periprocedural hypotension, aspiration pneumonia, nausea/vomiting, hypoglycemia. and hyperglycemia. Secondary outcomes included assessment of patient satisfaction, in-patient mortality, and total cost of index hospitalization.
CHOW NOW randomized a total of 599 patients (outpatients, n = 305; inpatients, n = 294). Both groups had similar baseline characteristics.
As compared with the SF group (n = 306), the NF group (n = 293) had similar rates of primary outcome (9.8% vs 11.3% respectively; P = .65) and was noninferior to the fasting strategy at a threshold of 0.059. There was no significant difference in incidence of CIN (1.6% vs 2.4%), periprocedural hypotension (1.6% vs 2%), aspiration pneumonia (0% vs 0.7%), nausea/vomiting (3.6% vs 5.1%), hyperglycemia (3.3% vs 1.4%), or hypoglycemia (1% in both).
More than 99% of patients in both groups were discharged alive. There was no significant difference with regard to the patient satisfaction score and 30-day mortality of SF versus NF (4.38 ± 0.9 vs 4.49 ± 0.77 and 1.3% vs 2.4%, respectively; P = ns for both). Cost of hospitalization was also similar in both groups.
“We hope that the findings of this study help make the cardiac catheterization procedure more ‘patient centered,’” stated Dr. Mishra. “The current fasting practice does result in more discomfort and frustration for the patients who may sometimes end up waiting several hours longer than the planned 6 hours of fasting. Imagine a diabetic patient who is fasting for a procedure overnight, only to realize that there has been an emergent procedure scheduled prior to him at the last minute and he may end up having the procedure later in the day, when he may already be fasting for nearly 14+ hours. Also, [with] patient contentedness being a focus of health care in current practice, this study is an important step to maximize patient comfort in a safe manner.”
Fasting practices currently differ based on institutional policy, and Dr. Mishra hopes that the study will provide evidence that can be incorporated into future professional society guidelines.