Should we unfasten our patients? A meta-analysis of randomized trials on fasting prior to cardiac catheterization procedures

K. G. Vargas (Ibbenbüren)¹, D. Karthikesan ( Alor Setar)², K. Huber (Wien)³, T. Bekfani (Magdeburg)⁴, C. Parco (Ibbenbüren)¹, Y. Lin (Ibbenbüren)¹, G. Wolff (Ibbenbüren)^1
1Klinikum Ibbenbüren Kardiologie Ibbenbüren, Deutschland; ²Hospital Sultanah Bahiyah Alor Setar, Deutschland; ³Austrian Heart Foundation Wien, Deutschland; ⁴Universitätsklinikum Magdeburg A.ö.R. Klinik für Kardiologie, Angiologie und Pneumologie Magdeburg, Deutschland

Background: Current recommendations prior to catheterization include fasting for at least six hours to prevent adverse events. Demonstrating comparable safety between fasting and non-fasting strategies could meaningfully improve patient comfort, reduce procedure delays and inform future updates to practice guidelines. We aimed to determine the safety of not fasting prior to catheterization procedures. 
Methods: Major databases (Medline and Embase) were searched for randomized trials comparing a fasting versus a non-fasting strategy and reporting on adverse events. We used the Peto odds ratio (OR) fixed-effect method which as described by the Cochrane Handbook, performs particularly well when the expected event rates are low or rare and yields more stable estimates of effect and heterogeneity, without the need for continuity corrections for zero cell counts.
Results: Six trials (n = 2367 participants) were included. There was no significant difference on the risk of nausea or vomiting (OR 0.88; 95% CI 0.43 – 1.80; I2 0%), hypoglycemia (OR 0.73; 95% CI 0.41 – 1.29; I2 44%) and contrast-induced acute kidney injury (OR 2.18; 95% CI 0.93 – 5.11; I2 0%). There was a low number of hypotension events in both groups. Aspiration and procedure-related death were infrequent; without event adjudication. No intubation events were reported. On average, patients fasted 14.6 hours for solids and 12.7 hours for liquids.
Conclusion: Our results support the recommendations from the DGK and may help upgrade its level of evidence. Allowing patients to eat and drink before non-emergency cardiac catheterization does not seem to convey a higher risk of adverse events in comparison to the fasting strategy.

Figure 1. Forest plots on trial outcomes comparing a fasting vs. a non-fasting approach