Division of Nuclear Medicine, Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.
J Nucl Med. 2011 May;52(5):726-32. doi: 10.2967/jnumed.110.081828. Epub 2011 Apr 15.
Current noninvasive tests for coronary artery disease detect atherosclerosis or regional ischemia. Global myocardial flow reserve is not routinely identified, although it may be an additional marker of disease development and progression.
For the clinical work-up of suspected or known stable coronary artery disease, 275 individuals had undergone rest-dipyridamole (82)Rb myocardial perfusion imaging using PET. In addition to clinical measures of regional perfusion and function, an experimentally validated approach to quantify global myocardial flow reserve was used. Follow-up was obtained for 362 ± 277 d.
Myocardial blood flow and flow reserve showed significant correlation to systemic and cardiac hemodynamics and a weak association with risk factors such as age and history of hyperlipidemia. Flow reserve was expectedly lower in subjects with regional ischemia (1.70 ± 0.65 vs. 2.31 ± 0.97 in those without; P < 0.0001), but a wide range was observed in those without regional perfusion abnormalities. We used a composite endpoint of hard and soft events to determine that flow reserve below the median was predictive of adverse outcome in the overall population (P = 0.001) and in subjects with normal regional perfusion (n = 178; P = 0.036), whereas stress flow was predictive only in the overall population (P = 0.001). Age-adjusted multivariate analysis confirmed regional perfusion defects (relative hazard, 2.51; 95% confidence interval, 1.24-5.10; P = 0.009) and low global flow reserve (relative hazard, 2.93; 95% confidence interval, 1.30-6.65; P = 0.011) as independent predictors of cardiac events.
In clinical cardiac (82)Rb PET, globally impaired flow reserve is a relevant marker for predicting short-term cardiovascular events. It may be used for integration with currently established functional and morphologic test results and for guidance of preventive measures, especially in the absence of regional flow-limiting disease.
目前，用于检测冠状动脉疾病的非侵入性检查可发现动脉粥样硬化或区域性缺血。尽管整体心肌血流储备可能是疾病发展和进展的另一个标志物，但并未常规确定其储备情况。
为了对疑似或已知稳定型冠状动脉疾病进行临床检查，275 例个体接受了静息-双嘧达莫（82）Rb 心肌灌注成像的 PET 检查。除了区域性灌注和功能的临床测量外，还使用了一种经过实验验证的方法来量化整体心肌血流储备。获得了 362±277 d 的随访。
心肌血流和血流储备与全身和心脏血液动力学有显著相关性，与年龄和高脂血症等危险因素有弱相关性。在有区域性缺血的患者中，血流储备明显较低（1.70±0.65 比无缺血者的 2.31±0.97；P＜0.0001），但在无区域性灌注异常的患者中，血流储备范围较宽。我们使用硬终点和软终点的复合终点来确定，整体人群中血流储备低于中位数预示着不良预后（P=0.001），在区域灌注正常的患者中（n=178；P=0.036）也如此，而应激血流仅在整体人群中具有预测性（P=0.001）。年龄校正后的多变量分析证实，区域性灌注缺陷（相对危险，2.51；95%置信区间，1.245.10；P=0.009）和整体低血流储备（相对危险，2.93；95%置信区间，1.306.65；P=0.011）是心脏事件的独立预测因子。
在临床心脏（82）Rb PET 中，整体受损的血流储备是预测短期心血管事件的一个相关标志物。它可用于与目前建立的功能和形态学测试结果相结合，并指导预防措施，特别是在没有区域性血流受限疾病的情况下。
