Division of Cardiology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.
Division of Cardiology, Department of Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts.
JACC Cardiovasc Imaging. 2019 Aug;12(8 Pt 2):1686-1695. doi: 10.1016/j.jcmg.2018.08.018. Epub 2018 Nov 5.
The aim of this study was to evaluate the incremental prognostic value of global coronary flow reserve (CFR) in patients with known or suspected coronary artery disease who were undergoing stress cardiac magnetic resonance (CMR) imaging.
Coronary microvascular dysfunction results in impaired global CFR and is implicated in the development of both atherosclerosis and heart failure. Although noninvasive assessment of CFR with positron emission tomography provides independent prognostic information, the incremental prognostic value of CMR-derived CFR remains unclear.
Consecutive patients undergoing stress perfusion CMR were prospectively enrolled (n = 507). Coronary sinus flow was measured using phase-contrast imaging at baseline (pre) and immediately after stress (peak) perfusion. CFR was calculated as the ratio of peak to pre-flow. Patients were followed for major adverse cardiac events (MACE): death, nonfatal myocardial infarction, heart failure hospitalization, sustained ventricular tachycardia, and late revascularization. Cox proportional hazards regression modeling was used to examine the association between CFR and MACE. The incremental prognostic value of CFR was assessed in nested models.
Over a median follow-up of 2.1 years, 80 patients experienced MACE. By Kaplan-Meier analysis, the risk of MACE was significantly higher in patients with CFR lower than the median (2.2) (log-rank p < 0.001); this remained significant after adjustment for the presence of ischemia and late gadolinium enhancement (LGE) (log-rank p < 0.001). CFR was significantly associated with the risk of MACE after adjustment for clinical and imaging risk factors, including ischemia extent, ejection fraction, and LGE size (hazard ratio: 1.238; p = 0.018). Addition of CFR in this model resulted in significant improvement in the C-index (from 0.70 to 0.75; p = 0.0087) and a continuous net reclassification improvement of 0.198 (95% confidence interval: 0.120 to 0.288).
CMR-derived CFR is an independent predictor of MACE in patients with known or suspected coronary artery disease, incremental to common clinical and CMR risk factors. These findings suggest a role for CMR-derived CFR in identifying patients at risk of adverse events following stress CMR, even in the absence of ischemia and LGE.
本研究旨在评估在已知或疑似冠心病患者中，行应激心脏磁共振（CMR）成像检查时，整体冠状动脉血流储备（CFR）的增量预后价值。
冠状动脉微血管功能障碍导致整体 CFR 受损，与动脉粥样硬化和心力衰竭的发展均有关。尽管正电子发射断层扫描（PET）无创评估 CFR 可提供独立的预后信息，但 CMR 衍生的 CFR 的增量预后价值仍不清楚。
前瞻性纳入连续行应激灌注 CMR 的患者（n=507）。基线（预）和应激后即刻（峰）灌注时使用相位对比成像测量冠状动脉窦血流。CFR 计算为峰流与预流的比值。患者随访主要不良心脏事件（MACE）：死亡、非致死性心肌梗死、心力衰竭住院、持续性室性心动过速和晚期血运重建。Cox 比例风险回归模型用于评估 CFR 与 MACE 之间的关联。在嵌套模型中评估 CFR 的增量预后价值。
中位随访 2.1 年后，80 例患者发生 MACE。通过 Kaplan-Meier 分析，CFR 低于中位数（2.2）的患者发生 MACE 的风险显著更高（对数秩检验 p<0.001）；校正缺血和晚期钆增强（LGE）后仍然显著（对数秩检验 p<0.001）。校正临床和影像学危险因素后，CFR 与 MACE 风险显著相关，包括缺血程度、射血分数和 LGE 大小（风险比：1.238；p=0.018）。在该模型中加入 CFR 可显著提高 C 指数（从 0.70 提高至 0.75；p=0.0087），连续净重新分类改善 0.198（95%置信区间：0.120 至 0.288）。
在已知或疑似冠心病患者中，CMR 衍生的 CFR 是 MACE 的独立预测因子，比常见的临床和 CMR 危险因素更有增量价值。这些发现表明，即使在没有缺血和 LGE 的情况下，CMR 衍生的 CFR 也可用于识别应激 CMR 后发生不良事件的风险患者。
