The ketogenic diet (KD) is the standard of care to achieve myocardial glucose suppression (MGS) for assessing inflammation using ¹⁸F-FDG PET. However, failure to suppress physiologic glucose uptake remains a significant diagnostic barrier. Although extending the duration of KD may be effective, exogenously delivered ketones may provide a convenient, reliable, and same-day alternative. The aims of our study were to determine whether exogenous ketone administration is noninferior to the KD to achieve MGS and whether serum β-hydroxybutyrate (BHB) levels can predict MGS. Methods: KEETO-CROSS (Ketogenic Endogenous versus Exogenous Therapies for myoCaRdial glucOse SuppresSion) is a crossover, noninferiority trial of the KD (endogenous ketosis) versus ketone ester ([KE] exogenous ketosis) drink. Twenty healthy participants were enrolled into 3 arms: weight-based KE drink, 24-h KD, and 72-h KD (n = 18 completed all arms). The primary outcome was achievement of complete MGS on PET (noninferiority margin 5%). The area under receiver-operating-characteristics (AUROC) of endogenous BHB levels (analyzed in a laboratory and by point-of-care device) for predicting MGS was analyzed in 37 scans completed on the KD. Results: The mean age was 30 ± 7 y, 50% were women, and 45% were nonwhite. The median achieved BHB levels (mmol/L) were 3.82 (25th–75th percentile, 2.55–4.97) (KE drink), 0.77 (25th–75th percentile, 0.58–1.02) (25th–75th percentile, 24-h KD), and 1.30 (25th–75th percentile, 0.80–2.24) (72-h KD). The primary outcome was achieved in 44% (KE drink), 78% (24-h KD), and 83% (72-h KD) of participants (noninferiority P = 0.97 and 0.98 for KE vs. 24-h and 72-h KD). Endogenous BHB levels robustly predicted MGS (AUROC, 0.88; 95% CI 0.71, 1.00). A BHB of 0.58 or more correctly classified 92% of scans. A point-of-care device provided comparable predictive value. Conclusion: In healthy volunteers, KE was inferior to KD for achieving MGS. Serum BHB is a highly predictive biomarker for MGS and can be clinically implemented upstream of ¹⁸F-FDG PET, with rapid facilitation by point-of-care testing, to reduce false-positive scans.

^{生酮饮食 (KD) 是实现心肌葡萄糖抑制 (MGS) 以使用18} F-FDG PET评估炎症的护理标准。然而，未能抑制生理葡萄糖摄取仍然是一个重要的诊断障碍。虽然延长 KD 的持续时间可能有效，但外源性酮体可能提供一种方便、可靠且当天的替代方案。我们研究的目的是确定外源性酮给药是否不劣于 KD 以实现 MGS，以及血清 β-羟基丁酸 (BHB) 水平是否可以预测 MGS。方法：KEETO-CROSS（针对肌钙蛋白抑制的生酮内源性与外源性疗法）是 KD（内源性酮症）与酮酯（[KE] 外源性酮症）饮料的交叉、非劣效性试验。20 名健康参与者被分为 3 个组：基于体重的 KE 饮料、24 小时 KD 和 72 小时 KD（n = 18 完成所有组）。主要结果是在 PET 上实现完全 MGS（非劣效性界值 5%）。在 KD 上完成的 37 次扫描中分析了用于预测 MGS 的用于预测 MGS 的内源性 BHB 水平（在实验室和床旁设备中分析）的接受者操作特征 (AUROC) 下的面积。结果：平均年龄为 30 ± 7 岁，50% 为女性，45% 为非白人。达到的 BHB 水平中位数 (mmol/L) 为 3.82（第 25-75 个百分位数，2.55-4.97）（KE 饮料），0.77（第 25-75 个百分位数，0.58-1.02）（第 25-75 个百分位数，24 小时 KD），和 1.30（第 25-75 个百分位数，0.80-2.24）（72 小时 KD）。44%（KE 饮料）、78%（24 小时 KD）和 83%（72 小时 KD）的参与者实现了主要结果（非劣效性 P = 0.97 和 0.98，KE 对比 24 小时和72- hKD）。内源性 BHB 水平有力地预测了 MGS（AUROC，0.88；95% CI 0.71，1.00）。0.58 或更高的 BHB 正确分类了 92% 的扫描。床旁设备提供了可比较的预测值。结论：在健康志愿者中，KE 在实现 MGS 方面不如 KD。血清 BHB 是 MGS 的高度预测性生物标志物，可以在¹⁸ F-FDG PET 上游临床实施，通过即时检测快速促进，以减少假阳性扫描。