[TCT2007]OAT试验对CTO再通没有临床指导意义

　　                                                   ------------呼吁糖尿病多支病变在何时应考虑再血管化治疗
OAT: No Clinical Relevance for CTO Recanalization

　　最近公布的OAT试验临床试验对于慢性完全血管闭塞（CTO）的再通可能没有指导意义。因为入选该试验患者不符合传统CTO病变开通的条件。

　　来自哥伦比亚大学医学中心的Jeffrey W. Moses 医生说：OAT试验入选的患者没有任何进行PCI的指征。即使这些闭塞是慢性的，因此，他所得出的结果，对于现在CTO的治疗的指导，是没有实际意义的。

　　证据不足

　　OAT试验入选的是相对年轻的（平均年龄58岁）、稳定性心绞痛（83%患者心绞痛分级Ⅰ级）患者。20%患者进行了抗血栓治疗，随机入PCI加药物组或药物单独治疗组是在心肌梗死发生后平均8天才完成。2166例患者中，90%没有心肌缺血，82%为单支病变。50%病变位于右冠，这些患者的冠状动脉没有慢性闭塞发生。

　　OAT研究对于CTO合并急性心梗或多支病变患者治疗没有提供临床指导意义，慢性患者可能在进入试验之前就进行了治疗。研究者在报告中提到：“开通我们觉得应该开通的病变，其余患者入选了OAT试验。”

　　Moses 特别强调，开通CTO要在一定的条件下进行。特别在糖尿病患者合并多支病变、前降支近段病变、多处CTO情况下，更应该开通。

　　如果有下列情况：长而弯曲的CTO、钙化严重的CTO，远端血管显影差，无法用逆行方法到达病变处。则开通前要慎重考虑。

　　来自荷兰鹿特丹的Angela Hoye医生指出：缓解症状是开通CTO的强适应证，他引用他领导的研究小组最近发表在欧洲心脏病杂志上的结果，成功的开通CTO能使84.5%的患者在五年之内免于CABG手术，而不成功患者5年内只有61.5%患者免于CABG手术。Hoye及同事也发现在开通和未开通CTO患者之间，生存率也有明显的差别，5年生存率在成功开通患者为93.5% ，而在不成功者仅为88%。在多支血管患者，这种差别更大：5年生存成功者为92.5%。不成功患者为86.3%。

　　Hoye 强调我们不能低估完全血运重建的意义，成功进行完全血运重建的CTO患者与无CTO患者进行介入治疗其生存率是相似的。

　　（阜外心血管病医院　陈俊　高立建　编译）

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OAT: No Clinical Relevance for CTO Recanalization

Caution urged when considering revascularization in diabetic patients with multivessel occlusions.

The results of the Occluded Artery Trial (OAT) may have little to no clinical relevance for CTO revascularization because the patient population did not meet traditional requirements for PCI or recanalization.

Jeffrey W. Moses, MD, of the Columbia University Medical Center, said the “OAT population did not have any indication for PCI, even if the occlusion was chronic, so any allusion to the relevance of them in the rationale of CTO recanalization … would be specious.”

Lacking qualifications

The OAT population included patients who were relatively young (average age, 58 years) and stable (83% were class I). Twenty percent were being treated with thrombotic therapy and, on average, 8 days passed between MI and randomization to either PCI with medical therapy or medical therapy alone (Figure). 

Ninety percent of the 2,166 patients were nonischemic and 82% had single-vessel disease, 50% in the right coronary artery. These patients did not have chronic occlusions.

The trial has no clinical relevance about the prognostic impact of CTO with acute MI and multivessel disease, Moses said. More chronic patients may have been treated outside of the trial.

One investigator reported that his center “opened those patients that we thought should be opened, and any patients left went into OAT.”

Caution needed

Moses urged caution about performing a revascularization procedure under certain conditions, especially in diabetic patients with multivessel occlusions, proximal left anterior descending, and multiple CTOs.

If there is any combination of a long, tortuous CTO, heavy calcium, poor distal visualization, and no prospect of retrograde approach, “you should really think twice about revascularization,” he added.

The relief of symptoms is the “strongest current indication for CTO with angiography,” said Angela Hoye, MB, ChB, PhD, of the Erasmus Medical Center, Rotterdam, The Netherlands. Successful CTO recanalization allowed 87.4% of patients to live free of CABG for 5 years compared with 61.5% of those with unsuccessful recanalization, she said referring to a recent study published by her group in the European Heart Journal.

Hoye and colleagues found significant differences in survival in successful and unsuccessful CTO procedures. Overall, 93.5% of patients with successful PCI survived for 5 years compared with 88.0% of those with unsuccessful PCI. In patients with multivessel occlusions, the difference was greater: 92.5% of patients who had successful procedures survived to 5-year follow-up compared with 86.3% of those who underwent unsuccessful procedures.

“We can’t underestimate the importance of complete revascularization,” Hoye said. “The survival rate for patients treated successfully is similar to that for patients who do not have a CTO and undergo angioplasty.”