Simplified ¹⁸F-FDG PET Myocardial Viability Preparation Protocol Reduces Hypoglycemia and Improves Workflow...

¹⁸F-FDG PET viability imaging is commonly used to identify hibernating myocardium in patients with ischemic epicardial disease. Patient preparation protocols typically rely on glucose loading and insulin to stimulate myocardial glucose metabolism. However, these methods often require multiple blood glucose (BG) measurements, variable insulin dosing, prolonged preparation times, risk of hypoglycemia, and disruption of clinical workflows. We developed a simplified ¹⁸F-FDG myocardial viability protocol to activate myocardial glucose uptake while minimizing hypoglycemia risk and improving workflow efficiency without sacrificing image quality. Methods: ¹⁸F-FDG myocardial viability studies performed between 2007 and 2025 were retrospectively analyzed. The 100 most recent studies using a conventional preparation protocol based on the American Society of Nuclear Cardiology guidelines were compared with 100 studies performed after implementation of a simplified protocol. The new protocol combines simultaneous glucose loading and intravenous insulin administration without requiring a specific BG target before ¹⁸F-FDG injection. Primary endpoints were hypoglycemia incidence (≤4.7 mmol/L [≤85 mg/dL]) and image quality. Secondary endpoints included time to ¹⁸F-FDG injection, total examination duration, number of BG measurements, and repeat imaging as a result of persistent blood-pool activity. Image quality was visually assessed using a 5-category grading system and quantitatively using ¹⁸F-FDG-to-rest perfusion and ¹⁸F-FDG peak-to-center activity ratios. Results: Hypoglycemia decreased from 21% with the conventional protocol to 3% with the simplified protocol (P < 0.001). The time from the first BG measurement to the ¹⁸F-FDG injection (i.e., time to ¹⁸F-FDG injection) decreased from 87 ± 36 min to 65 ± 17 min (P < 0.001). Total imaging time decreased from 175 ± 41 min to 144 ± 25 min (P < 0.001), representing a mean reduction of 31 min. The number of BG measurements decreased from 8 ± 2 to 4 ± 1 (P < 0.001). Persistent blood-pool activity beyond 90 min decreased from 11% to 6% (P = 0.2). Across the full cohort of 955 studies, the simplified protocol improved the proportion of good-or-better image quality from 81% to 87% (P = 0.03) and reduced the rate of poor or nondiagnostic studies from 5.4% to 1% (P < 0.001). Quantitative image quality metrics showed strong agreement with visual assessment (area under the concentration curve, >0.9). Conclusion: This simplified ¹⁸F-FDG PET viability preparation protocol reduced hypoglycemia, shortened preparation and imaging times, decreased glucose monitoring requirements, and maintained or improved image quality. The protocol provides a safer, more efficient approach for myocardial viability imaging.