Department of Medicine, University of Texas Medical School, Houston, TX, USA.
JACC Cardiovasc Imaging. 2011 Apr;4(4):402-12. doi: 10.1016/j.jcmg.2011.02.008.
We sought to quantify ranges of normal myocardial perfusion and flow reserve in young, asymptomatic volunteers after systematic historical and laboratory screening for unexpected factors affecting coronary flow.
Noninvasive cardiac positron emission tomography (PET) quantifies absolute flow and coronary flow reserve (CFR), thereby defining physiological severity of coronary artery disease for clinical studies or management. Defining "normal" coronary flow is a necessary prerequisite to its broad clinical application.
Volunteers aged 20 to 40 years of age without cardiac disease or other conditions underwent rest-dipyridamole stress cardiac PET with absolute quantitative flow measurements using Rb-82 in paired studies at least 7 days apart for reproducibility. The presence of coronary calcium, detectable blood nicotine or caffeine, dyslipidemia, and an extended family history of early clinical atherosclerosis were objectively and systematically examined for grouping subjects as true normal or not normal.
We enrolled 125 volunteers, 107 (86%) underwent 2 PET scans. Fifty-six (45%) were classified as true normal, whereas 69 (55%) were classified as not normal. True normals had higher high-density lipoprotein and less PET scan heterogeneity. Hemodynamic responses to dipyridamole stress were similar. Rest flow was the same in both groups (0.72 ± 0.17 ml/min/g vs. 0.69 ± 0.14 ml/min/g, p = 0.164). However, stress flow (2.89 ± 0.50 ml/min/g vs. 2.63 ± 0.61 ml/min/g, p = 0.005) and CFR (4.17 ± 0.80 vs. 3.91 ± 0.86, p = 0.047) were higher in true normals. Paired studies were performed a median of 22 days (interquartile range: 15 to 39) apart. Reproducibility was improved in the true normal group.
One-half of young, asymptomatic volunteers from the community harbor unexpected factors that mildly but systematically reduce stress flow, CFR, and reproducibility. This study establishes normal ranges and reproducibility for flow and CFR as the basis for clinical applications.
我们旨在通过系统地历史和实验室筛查影响冠脉血流的意外因素，对年轻无症状志愿者的正常心肌灌注和血流储备范围进行量化。
非侵入性心脏正电子发射断层扫描（PET）可定量评估绝对血流量和冠脉血流储备（CFR），从而为临床研究或管理定义冠心病的生理严重程度。定义“正常”冠脉血流是其广泛临床应用的必要前提。
年龄在 20 至 40 岁之间、无心脏病或其他疾病的志愿者，在至少相隔 7 天的两次配对研究中接受静息-双嘧达莫负荷心脏 PET，并用 Rb-82 进行绝对定量血流测量，以评估重复性。客观且系统地检查有无冠脉钙化、可检测的血液尼古丁或咖啡因、血脂异常，以及早发临床动脉粥样硬化的家族史，将受试者分为真正正常或不正常。
我们共纳入 125 名志愿者，其中 107 名（86%）完成了 2 次 PET 扫描。56 名（45%）被归类为真正正常，69 名（55%）为异常。真正正常组的高密度脂蛋白水平较高，PET 扫描异质性较小。双嘧达莫应激的血液动力学反应相似。两组的静息血流量相同（0.72±0.17ml/min/g 比 0.69±0.14ml/min/g，p=0.164）。然而，真正常组的应激血流量（2.89±0.50ml/min/g 比 2.63±0.61ml/min/g，p=0.005）和 CFR（4.17±0.80 比 3.91±0.86，p=0.047）更高。中位时间间隔为 22 天（四分位距：15 至 39）进行了两次配对研究。真正常组的重复性提高。
来自社区的一半年轻无症状志愿者存在意外因素，这些因素轻微但系统地降低了应激血流量、CFR 和重复性。本研究建立了血流和 CFR 的正常范围和重复性，为临床应用奠定了基础。
