Liu Yihua, Jiang Yefan, Yang Xiaoxi, Geng Bingchuan, Liu Yi, Shang Xiaoke, Liu Jinping, Lan Xiaoli, Dong Nianguo
Department of Cardiovascular Surgery and Heart Transplantation, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Department of Radiation and Medical Oncology, Zhongnan Hospital, Wuhan University, Wuhan 430071, China.
J Thorac Dis. 2018 Apr;10(4):2249-2255. doi: 10.21037/jtd.2018.04.03.
Myocardial viability assessment is typically performed in patients with coronary artery disease (CAD) and severe left ventricular (LV) dysfunction to identify those who might benefit from revascularization and assist in decision making process. However, the prognostic value of myocardial viability testing remains a debating issue.
Positron Emission Tomography using F-fluorodeoxyglucose (FDG-PET) was performed in 81 patients with ischemic LV dysfunction [ejection fraction (EF) ≤35%] for myocardial viability assessment prior to coronary artery bypass surgery. Fifty-three of them received finally coronary artery bypass grafting and were divided into two groups according to the extent of myocardial scar: one group with scar burden ≥10% (n=30) and the other with scar burden <10% (n=23). The remaining patients were contraindicated for CABG and received optimal medical treatment (OMT, n=28). All patients were followed up and the primary endpoint was all-cause mortality and the secondary endpoint was a composite of all-cause mortality and major adverse cardiovascular and cerebrovascular events (MACCE).
FDG-PET revealed a different profile of myocardial viability among three groups with respect to the extent of myocardial scar, the hibernating myocardium (both P<0.01), some echocardiographic parameters such as left ventricular diastolic dimension (LVDD) and EF were also significantly different (both P<0.05). Nevertheless, the baseline prevalence of comorbidities and functional classifications were comparable. The per-procedural parameters were not significantly different between two CABG groups. In a median follow-up time of 32 months, Kaplan Meier analysis uncovered no significant difference in terms of overall survival (P=0.74) and MACCE-free survival (P=0.66) among three groups.
Myocardial viability assessment using FDG-PET is of limited prognostic value in patients with CAD and severe LV dysfunction. In patients with substantial myocardial scar burden despite the existence of considerable hibernating myocardium, functional recovery following surgical revascularization is not necessarily translated to survival benefits.
心肌活力评估通常在冠状动脉疾病（CAD）和严重左心室（LV）功能障碍的患者中进行，以确定那些可能从血运重建中获益的患者，并协助决策过程。然而，心肌活力测试的预后价值仍然是一个有争议的问题。
对81例缺血性左心室功能障碍[射血分数（EF）≤35%]患者在冠状动脉搭桥手术前行心肌活力评估，采用F-氟脱氧葡萄糖正电子发射断层扫描（FDG-PET）。其中53例最终接受冠状动脉搭桥术，并根据心肌瘢痕范围分为两组：瘢痕负荷≥10%组（n=30）和瘢痕负荷<10%组（n=23）。其余患者因冠状动脉搭桥术禁忌而接受最佳药物治疗（OMT，n=28）。所有患者均进行随访，主要终点为全因死亡率，次要终点为全因死亡率和主要不良心血管和脑血管事件（MACCE）的复合终点。
FDG-PET显示三组之间在心肌瘢痕范围、冬眠心肌方面心肌活力情况不同（均P<0.01），一些超声心动图参数如左心室舒张内径（LVDD）和EF也有显著差异（均P<0.05）。然而，合并症的基线患病率和功能分级具有可比性。两个冠状动脉搭桥术组之间的围手术期参数无显著差异。在中位随访时间32个月时，Kaplan Meier分析发现三组之间在总生存率（P=0.74）和无MACCE生存率（P=0.66）方面无显著差异。
对于CAD和严重LV功能障碍患者，使用FDG-PET进行心肌活力评估的预后价值有限。在存在大量冬眠心肌但心肌瘢痕负荷较大的患者中，手术血运重建后的功能恢复不一定能转化为生存获益。
