Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands.
Department of Radiology, Nuclear Medicine & PET Research, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Eur Heart J Cardiovasc Imaging. 2021 May 10;22(6):638-646. doi: 10.1093/ehjci/jeaa305.
Myocardial ischaemic burden (IB) is used for the risk stratification of patients with coronary artery disease (CAD). This study sought to define a prognostic threshold for quantitative [15O]H2O positron emission tomography (PET)-derived IB.
A total of 623 patients with suspected or known CAD who underwent [15O]H2O PET perfusion imaging were included. The endpoint was a composite of death and non-fatal myocardial infarction (MI). A hyperaemic myocardial blood flow (hMBF) and myocardial flow reserve (MFR)-derived IB were determined. During a median follow-up time of 6.7 years, 62 patients experienced an endpoint. A hMBF IB of 24% and MFR IB of 28% were identified as prognostic thresholds. Patients with a high hMBF or MFR IB (above threshold) had worse outcome compared to patients with a low hMBF IB [annualized event rates (AER): 2.8% vs. 0.6%, P < 0.001] or low MFR IB [AER: 2.4% vs. 0.6%, P < 0.001]. Patients with a concordant high IB had the worst outcome (AER: 3.1%), whereas patients with a concordant low or discordant IB result had similar and low AERs of 0.5% and 0.9% (P = 0.953), respectively. Both thresholds were of prognostic value beyond clinical characteristics, however, only the hMBF IB threshold remained predictive when adjusted for clinical characteristics and combined use of the hMBF and MFR thresholds.
A hMBF IB ≥24% was a stronger predictor of adverse outcome than an MFR IB ≥28%. Nevertheless, classifying patients according to concordance of IB result allowed for the identification of low- and high-risk patients.
心肌缺血负担（IB）用于冠状动脉疾病（CAD）患者的风险分层。本研究旨在确定定量 [15O]H2O 正电子发射断层扫描（PET）衍生 IB 的预后阈值。
共纳入 623 例疑似或已知 CAD 患者，行 [15O]H2O PET 灌注成像。终点是死亡和非致死性心肌梗死（MI）的复合终点。测定充血性心肌血流（hMBF）和心肌血流储备（MFR）衍生的 IB。在中位数为 6.7 年的随访期间，62 例患者发生终点事件。确定 hMBF IB 为 24%和 MFR IB 为 28%为预后阈值。与 hMBF IB 低的患者相比（年发生率[AER]：2.8%比 0.6%，P<0.001）或 MFR IB 低的患者（AER：2.4%比 0.6%，P<0.001），hMBF 或 MFR IB 高（高于阈值）的患者预后更差。具有一致高 IB 的患者的结局最差（AER：3.1%），而具有一致低或不一致 IB 结果的患者的 AER 相似且较低，分别为 0.5%和 0.9%（P=0.953）。两个阈值均具有预后价值，超过临床特征，然而，仅 hMBF IB 阈值在调整临床特征和联合使用 hMBF 和 MFR 阈值后仍具有预测价值。
hMBF IB≥24%是不良预后的更强预测因素，而 MFR IB≥28%则不是。然而，根据 IB 结果的一致性对患者进行分类，可以识别低危和高危患者。
