Currently, cutoffs of quantitative [¹⁵O]H₂O PET to detect fractional flow reserve (FFR)–defined coronary artery disease (CAD) were derived from a single cohort that included patients without prior CAD. However, prior CAD, sex, and age can influence myocardial blood flow (MBF). Therefore, the present study determined the influence of prior CAD, sex, and age on optimal cutoffs of hyperemic MBF (hMBF) and coronary flow reserve (CFR) and evaluated whether cutoff optimization enhanced diagnostic performance of quantitative [¹⁵O]H₂O PET against an FFR reference standard. Methods: Patients with chronic coronary symptoms underwent [¹⁵O]H₂O PET and invasive coronary angiography with FFR. Optimal cutoffs for patients with and without prior CAD and subpopulations based on sex and age were determined. Results: This multicenter study included 560 patients. Optimal cutoffs were similar for patients with (n = 186) and without prior CAD (hMBF, 2.3 vs. 2.3 mL·min⁻¹·g⁻¹; CFR, 2.7 vs. 2.6). Females (n = 190) had higher hMBF cutoffs than males (2.8 vs. 2.3 mL·min⁻¹·g⁻¹), whereas CFRs were comparable (2.6 vs. 2.7). However, female sex–specific hMBF cutoff implementation decreased diagnostic accuracy as compared with the cutoff of 2.3 mL·min⁻¹·g⁻¹ (72% vs. 82%, P < 0.001). Patients aged more than 70 y (n = 79) had lower hMBF (1.7 mL·min⁻¹·g⁻¹) and CFR (2.3) cutoffs than did patients aged 50 y or less, 51–60 y, and 61–70 y (hMBF, 2.3–2.4 mL·min⁻¹·g⁻¹; CFR, 2.7). Age-specific cutoffs in patients aged more than 70 y yielded comparable accuracy to the previously established cutoffs (hMBF, 72% vs. 76%, P = 0.664; CFR, 80% vs. 75%, P = 0.289). Conclusion: Patients with and without prior CAD had similar [¹⁵O]H₂O PET cutoffs for detecting FFR-defined significant CAD. Stratifying patients according to sex and age led to different optimal cutoffs; however, these values did not translate into an increased overall accuracy as compared with previously established thresholds for MBF.

目前，用于检测血流储备分数 (FFR) 定义的冠状动脉疾病 (CAD) 的定量 [ ¹⁵ O]H ₂ O PET 的截止值源自一个队列，其中包括既往无 CAD 的患者。然而，既往 CAD、性别和年龄会影响心肌血流量 (MBF)。因此，本研究确定了既往 CAD、性别和年龄对充血 MBF (hMBF) 和冠状动脉血流储备 (CFR) 最佳截止值的影响，并评估了截止值优化是否增强了定量 [ ¹⁵ O]H ₂ O PET的诊断性能对照 FFR 参考标准。方法：患有慢性冠状动脉症状的患者接受[ ¹⁵ O]H ₂ O PET 和FFR 侵入性冠状动脉造影。根据性别和年龄确定了有或无既往 CAD 患者以及亚群的最佳截止值。结果：这项多中心研究纳入了 560 名患者。对于既往患有 CAD 的患者 ( n = 186) 和无 CAD患者的最佳截止值相似（hMBF，2.3 vs. 2.3 mL·min ⁻¹ ·g ⁻¹；CFR，2.7 vs. 2.6）。女性 ( n = 190) 的 hMBF 截止值高于男性 (2.8 vs. 2.3 mL·min ^-1 ·g ^-1 )，而 CFR 相当 (2.6 vs. 2.7)。然而，与 2.3 mL·min ^-1 ·g ^-1的截止值相比，女性性别特异性 hMBF 截止值的实施降低了诊断准确性（72% vs. 82%，P < 0.001）。 70 岁以上患者 ( n = 79) 的 hMBF (1.7 mL·min ⁻¹ ·g ⁻¹ ) 和 CFR (2.3) 临界值低于 50 岁或以下、51–60 岁和 61–70 岁患者y（hMBF，2.3–2.4 mL·min ^-1 ·g ^-1；CFR，2.7）。 70 岁以上患者的年龄特异性截止值与之前建立的截止值具有相当的准确性（hMBF，72% vs. 76%，P = 0.664；CFR，80% vs. 75%，P = 0.289）。结论：既往患有和未患有 CAD 的患者在检测 FFR 定义的显着 CAD 方面具有相似的 [ ¹⁵ O]H ₂ O PET 临界值。根据性别和年龄对患者进行分层会导致不同的最佳截止值；然而，与之前建立的 MBF 阈值相比，这些值并没有转化为整体准确性的提高。