Lee K S, Marwick T H, Cook S A, Go R T, Fix J S, James K B, Sapp S K, MacIntyre W J, Thomas J D
Department of Cardiology, Cleveland Clinic Foundation, OH 44195.
Circulation. 1994 Dec;90(6):2687-94. doi: 10.1161/01.cir.90.6.2687.
The uptake of F-18 deoxyglucose into dysfunction segments after myocardial infarction identifies metabolically active (FDG+) or inactive (FDG-) myocardium. Although patients with FDG+ segments have been found to be at risk for adverse events, the prognostic significance of viable myocardium in relation to other influences on postinfarction prognosis, including revascularization, remain ill defined. The purpose of this study was to investigate the relative prognostic significance of FDG+ tissue and to establish whether myocardial revascularization in patients with viable tissue attenuates the risk of adverse outcome.
One hundred thirty-seven patients with left ventricular dysfunction and resting perfusion defects after myocardial infarction underwent positron emission tomography with both dipyridamole stress Rb-82 perfusion imaging and FDG imaging. After the exclusion of 4 patients proceeding to transplantation, 2 with uninterpretable scans and 2 lost to follow-up, 129 patients were followed clinically for 17 +/- 9 months. Four groups were defined: patients with FDG+ dysfunctional myocardium who were revascularized (n = 49) or treated medically (n = 21) and those with FDG- segments who were revascularized (n = 19) or treated medically (n = 40). The groups of patients with FDG+ or FDG- findings, with and without revascularization, did not differ with respect to known determinants of postinfarction prognosis: age, left ventricular ejection fraction, or the prevalence of multivessel disease. Nonfatal ischemic events occurred in 48% of medically treated FDG+ patients compared with 8% of revascularized patients with FDG+ tissue (P < .001) and 5% of patients with FDG- myocardium (P < .001). Thirteen patients died from cardiac causes; 11 (85%) had a left ventricular ejection fraction of < 30%, and these patients were evenly distributed between FDG+ and FDG- groups. Using Cox's proportional hazards model, only the presence of FDG+ myocardium (odds ratio, 12.9; P < .001) and the absence of revascularization (odds ratio, 5.8; P = .002) independently predicted ischemic events, while only age (P = .02) and ejection fraction (P < .001) but not the presence of viable myocardium were predictive of death.
Residual viable myocardium after myocardial infarction may act as an unstable substrate for further events unless it is revascularized. Despite this association, age and left ventricular dysfunction remained the strongest predictors of cardiac death after myocardial infarction in these patients with a spectrum of left ventricular dysfunction.
心肌梗死后，F-18脱氧葡萄糖摄取至功能障碍节段可识别代谢活跃（FDG+）或不活跃（FDG-）心肌。虽然已发现FDG+节段的患者有发生不良事件的风险，但存活心肌相对于其他影响心肌梗死后预后的因素（包括血运重建）的预后意义仍不明确。本研究的目的是探讨FDG+组织的相对预后意义，并确定有存活组织患者的心肌血运重建是否可降低不良结局的风险。
137例心肌梗死后左心室功能障碍且静息灌注缺损的患者接受了双嘧达莫负荷82Rb灌注显像和FDG显像的正电子发射断层扫描。排除4例进行移植的患者、2例扫描结果无法解读的患者和2例失访患者后，129例患者接受了17±9个月的临床随访。定义了四组：FDG+功能障碍心肌且接受血运重建的患者（n = 49）或接受药物治疗的患者（n = 21），以及FDG-节段且接受血运重建的患者（n = 19）或接受药物治疗的患者（n = 40）。FDG+或FDG-结果的患者组，无论是否接受血运重建，在心肌梗死后预后的已知决定因素方面无差异：年龄、左心室射血分数或多支血管病变的患病率。48%接受药物治疗的FDG+患者发生非致命性缺血事件，而FDG+组织接受血运重建的患者为8%（P <.001），FDG-心肌患者为5%（P <.001）。13例患者死于心脏原因；11例（85%）左心室射血分数<30%，这些患者在FDG+和FDG-组中分布均匀。使用Cox比例风险模型，只有FDG+心肌的存在（比值比，12.9；P <.001）和未进行血运重建（比值比，5.8；P =.002）独立预测缺血事件，而只有年龄（P =.02）和射血分数（P <.001）而非存活心肌的存在可预测死亡。
心肌梗死后残留的存活心肌可能是进一步事件的不稳定底物，除非进行血运重建。尽管存在这种关联，但在这些具有一系列左心室功能障碍的患者中，年龄和左心室功能障碍仍然是心肌梗死后心脏死亡的最强预测因素。
