Objectives The purpose of this study was to evaluate the prognostic value of sequential hybrid imaging strategy in which positron emission tomography (PET) perfusion imaging is performed selectively in patients with suspected obstructive coronary artery disease (CAD) on coronary computed tomography angiography (CTA).

Background Coronary CTA is an accurate diagnostic test for excluding obstructive CAD. However, the positive predictive value is suboptimal.

Methods We investigated 864 consecutive symptomatic patients with intermediate probability of CAD who adhered to the sequential imaging approach. PET myocardial perfusion imaging using ¹⁵O-labeled water during adenosine stress was performed when suspected obstructive stenosis was present on coronary CTA. The major adverse events (AEs) including all-cause mortality, myocardial infarction (MI), and unstable angina pectoris (UAP) were recorded.

Results During a median follow-up of 3.6 years, 16 deaths, 10 MIs, and 5 UAPs occurred. Obstructive CAD was excluded by coronary CTA in 462 (53%) patients who had significantly lower annual AE rate than did patients with suspected obstructive stenosis on coronary CTA (0.4% vs. 1.5%; p = 0.003). The latter underwent PET study, on which 195 (49%) had normal and 207 had abnormal perfusion. The annual rate of AEs was 5 times higher in those with abnormal perfusion than with normal perfusion (2.5% vs. 0.5%; p = 0.004). Patients with normal perfusion had AE rate comparable to patients without obstructive CAD on coronary CTA (p = 0.77).

Conclusions In patients with suspected CAD obstructive disease can be excluded in 53% of patients by coronary CTA, and these patients have good outcome. About one-half (49%) of the remaining patients have normal perfusion and event rate comparable to patients without obstructive CAD on coronary CTA while patients with ischemia have clearly worse outcome. Sequential approach utilizing anatomical imaging by coronary CTA followed by selective functional perfusion imaging is a feasible strategy to diagnose and risk-stratify patients with suspected CAD.

目的这项研究的目的是评估顺序混合成像策略的预后价值，在可疑阻塞性冠状动脉疾病（CAD）的患者中，有选择地进行正电子发射断层扫描（PET）灌注成像，以进行冠状动脉计算机断层扫描血管造影（CTA）。

背景冠状动脉CTA是排除阻塞性CAD的准确诊断测试。但是，阳性预测值不是最佳的。

方法我们调查了864例有序冠心病的连续症状患者，他们均遵循顺序成像方法。当怀疑冠状动脉CTA存在阻塞性狭窄时，在腺苷应激期间使用¹⁵ O标记水进行PET心肌灌注显像。记录主要不良事件（AE），包括全因死亡率，心肌梗塞（MI）和不稳定型心绞痛（UAP）。

结果在3.6年的中位随访期间，发生了16例死亡，10例MIs和5例UAP。462名（53％）年AE率显着低于疑似冠脉CTA阻塞性狭窄的患者（462％（53％））被冠状动脉CTA排除了梗阻性CAD（0.4％vs. 1.5％； p = 0.003）。后者接受了PET研究，其中195例（49％）的灌注正常，而207例的灌注异常。正常灌注者的年AE发生率比正常灌注者高5倍（2.5％vs. 0.5％； p = 0.004）。灌注正常的患者的AE发生率与冠状动脉CTA上无阻塞性CAD的患者相当（p = 0.77）。

结论53％的冠状动脉CTA可以排除疑似CAD阻塞性疾病的患者，这些患者的预后良好。其余患者中约有一半（49％）的正常灌注和事件发生率与冠状动脉CTA上无梗阻性CAD的患者相当，而缺血性患者的预后明显更差。采用冠状动脉CTA解剖学成像，然后进行选择性功能灌注成像的顺序方法，是诊断可疑CAD并对其进行风险分层的可行策略。