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Safety and Comfort of Nonfasting vs Fasting Before Interventional Coronary Procedures
abstract
This abstract is available on the publisher's site.
Access this abstract now Full Text Available for ClinicalKey SubscribersBACKGROUND
Fasting before coronary procedures is currently recommended to reduce complications despite the lack of scientific evidence.
OBJECTIVES
The TONIC (Comparison Between Fasting and No Fasting Before Interventional Coronary Intervention on the Occurrence of Adverse Events) noninferiority trial investigated the safety and comfort of a nonfasting strategy (ad libitum food and drinks) vs traditional fasting (>6 hours for solid food and liquids) before coronary procedures.
METHODS
In this monocentric, prospective, single-blind randomized controlled trial, 739 patients undergoing coronary procedures were included and randomized to a fasting or a nonfasting strategy. Emergency procedures were excluded. The primary endpoint was a composite of vasovagal reaction, hypoglycemia (defined by blood sugar ≤0.7 g/L), and isolated nausea and/or vomiting. Noninferiority margin was 4%. Secondary endpoints were contrast-induced nephropathy and patients' satisfaction.
RESULTS
Among the 739 procedures (697 elective and 42 semiurgent), 517 angiographies, and 222 angioplasties (including complex and high-risk procedures) were performed. The primary endpoint occurred in 30 of 365 nonfasting patients (8.2%) vs 37 of 374 fasting patients (9.9%), demonstrating noninferiority (absolute between-group difference, −1.7%; 1-sided 95% CI upper limit: 1.8%). No food-related adverse event occurred, and contrast-related acute kidney injuries were similar between groups. Overall, procedure satisfaction and perceived pain were similar in both groups, but nonfasting patients reported less hunger and thirst (P < 0.01). In case of redo coronary procedures, most patients (79%) would choose a nonfasting strategy.
CONCLUSIONS
The TONIC randomized trial demonstrates the noninferiority of a nonfasting strategy to the usual fasting strategy for coronary procedures regarding safety, while improving patients' comfort.
Additional Info
Disclosure statements are available on the authors' profiles:
A Randomized Controlled Trial of Nonfasting vs Fasting Before Interventional Coronary Procedures: The TONIC Trial
JACC Cardiovasc Interv 2024 May 27;17(10)1200-1210, M Boukantar, PM Chiaroni, R Gallet, P Zamora, T Truong, A Mangiameli, L Rostain, AS Tuffreau-Martin, PA Natella, N Oubaya, E TeigerFrom MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
Is it time to change practice?
It was 10 years ago that a retrospective study by Hamid et al1 raised this question pertaining to fasting before coronary procedures as it did not note any significant disadvantage of doing so. Certainly, patients undergoing emergency PCI for ST-segment elevation myocardial infarction are not always fasting, and complications related to the nonfasting state have not emerged as major concerns; however, to address the concerns of the skeptic, randomized clinical trials are needed, and this trial accomplished exactly that.
The TONIC trial randomized 755 patients who planned to undergo an elective or semiurgent angiography and/or PCI (507 outpatients, 248 inpatients) to fasting (n = 379) or nonfasting (n = 376) before the procedure between May 2020 and July 2021. Patients in the fasting group were told to fast for at least 6 hours for both solid food and liquids. Patients allocated to the nonfasting group were allowed to eat and drink at their convenience. This allocation translated into fivefold longer mean fasting times in the fasting than in the nonfasting group (15 h vs 3 h, respectively). The primary endpoint was a composite of vasovagal reaction, hypoglycemia, and isolated nausea and/or vomiting up to 4 hours after the procedure. This endpoint was reached in 8.2% of patients in the nonfasting group and 9.9% of patients in the fasting group, which did not exceed the prespecified margins of noninferiority. Secondary outcome measures such as aspiration pneumonia and acute kidney injury were also not statistically different between the groups. Procedural satisfaction and perceived pain were likewise similar. Nonfasting patients did report less hunger and thirst, and, in case of repeat coronary procedures, approximately 80% of patients would choose a nonfasting strategy.
As with any trial, the crossover rates have to be considered, and in this trial, 4% of the fasting group misunderstood the instructions and did not fast whereas around 20% of the nonfasting group fasted for more than 6 hours for solids and liquids (because of delays or personal preference). Is this enough to skew the results? Per-protocol and intention-to-treat analyses did not yield differences in results; however, it is pertinent to mention that the per-protocol analysis excluded only patients from the fasting group who did not fast for at least 6 hours. It did not exclude patients in the nonfasting group who fasted for at least 6 hours. A subanalysis, however, was performed within the nonfasting group based on fasting for 3 hours or more or not; this did not show different outcomes either, except for hypoglycemia. Overall, vagal reactions seemed to be significantly reduced with nonfasting, and a potential benefit was evident in patients aged 75 years or older.
Overall, this trial and the voice of the patient speak. Personal experience would add that vagal reactions are, indeed, exaggerated and noted in patients who have been fasting for prolonged periods of time, even for more than 12 or even 18 hours (as it can occur if without intake since the night before the procedure and owing to being delayed due to a busy catheterization laboratory schedule). Dehydration can furthermore generate access problems, especially for venous access (due to readily collapsing veins), and arterial catheterizations in patients prone to vasospasm needing vasodilators, which can precipitate significant blood pressure drops. Hypovolemia may also mask or underestimate hemodynamic conditions such as constriction and restriction (reduced atrial and ventricular compliances). Although these potential scenarios can be overcome by intravenous hydration of patients, it is not considered, not possible, and/or adds complexity. The same applies to patients prone to hypoglycemia.
Thus, the TONIC trial, patients, and experiences speak, but will it be enough to change clinical practice? Additional randomized clinical trials such as the SCOFF and CHOW NOW trials will continue to inform us more. A debate for 10 years and counting, but the time to change clinical practice may eventually come.
Reference