Goldstein L B, McCrory D C, Landsman P B, Samsa G P, Ancukiewicz M, Oddone E Z, Matchar D B
Center for Health Policy Research and Education, Duke University, Durham, NC.
Stroke. 1994 Jun;25(6):1116-21. doi: 10.1161/01.str.25.6.1116.
Randomized clinical trials have shown that carotid endarterectomy decreases the risk of subsequent stroke in patients with high-grade carotid stenosis and ipsilateral transient ischemic attack or minor stroke. The benefit of surgery is highly dependent on surgical risk. We previously found that patients with ipsilateral hemispheric symptoms were at greater risk of carotid endarterectomy complications compared with those who were asymptomatic or had nonipsilateral symptoms. The goals of the present study were (1) to identify preoperative clinical factors that may increase the risk of complications after carotid endarterectomy in patients with ipsilateral hemispheric symptoms and (2) to develop a risk index based on this patient-level data.
Records from 1160 carotid endarterectomies performed at 12 academic medical centers composed the primary data set. Hospital charts for the admission during which carotid endarterectomy was performed were systematically reviewed by abstractors using a defined protocol. The present analysis was carried out on data from the subset of patients who had carotid endarterectomy for ipsilateral hemispheric symptoms. Candidate variables were identified based on univariate Fisher's exact tests or chi 2 tests. A risk index was then developed using those variables with a greater than 90% probability of being associated with adverse outcomes.
Of the 697 patients with ipsilateral symptoms, 8.5% had either stroke, myocardial infarction, or died during the postoperative period of hospitalization. Those over the age of 75 had a greater risk of myocardial infarction (6.6% versus 2.3%, P = .024) but not of stroke or death (P > .10). The overall frequencies of adverse outcomes were also higher in the 5 patients with complete ipsilateral carotid occlusions (40% versus 8.2%, P < .01), the 28 patients with ipsilateral intraluminal thrombus (17.9% versus 8.1%, P = .07), and the 65 patients with ipsilateral carotid siphon stenosis (13.9% versus 7.9%, P = .10). There were no differences in adverse outcomes among those with different degrees of ipsilateral stenosis (30% to 49%, 50% to 69%, and 70% to 99%). Adverse outcome rates were similar regardless of the type of symptom (transient ischemic attack, recent ipsilateral minor stroke, remote ipsilateral minor stroke). There were no significant differences in adverse outcome rates based on sex, race, history of angina, recent myocardial infarction, congestive heart failure, chronic obstructive pulmonary disease, hypertension, degree of stenosis of the contralateral carotid artery, or presence of ulceration in the ipsilateral artery (Fisher's exact tests, P > .10). A count of variables with greater than 90% probability of being associated with adverse outcomes (age > or = 75 years or angiographic evidence of ipsilateral carotid occlusion, stenosis in the region of the carotid siphon, or intraluminal thrombus) was used to form a simple risk index. "High-risk" patients (one or more risk factors) had more than two times the risk of complications compared with "low-risk" patients who had no risk factors (odds ratio, 2.18; 95% confidence interval, 1.25 to 3.81).
Certain preoperative clinical variables may place patients with ipsilateral symptoms at greater risk of perioperative complications after carotid endarterectomy. Prospective validation of a simple risk index would provide an additional method for assessing preoperative risk in endarterectomy candidates.
随机临床试验表明，颈动脉内膜切除术可降低重度颈动脉狭窄且伴有同侧短暂性脑缺血发作或轻度卒中患者后续发生卒中的风险。手术的获益高度依赖于手术风险。我们之前发现，与无症状或有非同侧症状的患者相比，有同侧半球症状的患者发生颈动脉内膜切除术并发症的风险更高。本研究的目的是：（1）确定术前临床因素，这些因素可能增加有同侧半球症状的患者行颈动脉内膜切除术后发生并发症的风险；（2）基于这些患者层面的数据制定一个风险指数。
来自12家学术医疗中心进行的1160例颈动脉内膜切除术的记录构成了主要数据集。使用既定方案，由摘要提取人员系统回顾了行颈动脉内膜切除术期间的住院病历。本分析是基于因同侧半球症状而行颈动脉内膜切除术的患者亚组数据进行的。基于单因素Fisher精确检验或卡方检验确定候选变量。然后使用那些与不良结局关联概率大于90%的变量制定一个风险指数。
在697例有同侧症状的患者中，8.5%在术后住院期间发生了卒中、心肌梗死或死亡。75岁以上的患者发生心肌梗死的风险更高（6.6%对2.3%，P = 0.024），但发生卒中和死亡的风险无差异（P > 0.10）。5例同侧颈动脉完全闭塞的患者、28例有同侧管腔内血栓的患者和65例有同侧颈动脉虹吸部狭窄的患者，不良结局的总体发生率也更高（分别为40%对8.2%，P < 0.01；17.9%对8.1%，P = 0.07；13.9%对7.9%，P = 0.10）。不同程度同侧狭窄（30%至49%、50%至69%和70%至99%）的患者不良结局无差异。无论症状类型（短暂性脑缺血发作、近期同侧轻度卒中、既往同侧轻度卒中）如何，不良结局发生率相似。基于性别、种族、心绞痛病史、近期心肌梗死、充血性心力衰竭、慢性阻塞性肺疾病、高血压、对侧颈动脉狭窄程度或同侧动脉有无溃疡形成，不良结局发生率无显著差异（Fisher精确检验，P > 0.10）。使用与不良结局关联概率大于90%的变量计数（年龄≥75岁或同侧颈动脉闭塞、颈动脉虹吸部区域狭窄或管腔内血栓的血管造影证据）来形成一个简单的风险指数。“高危”患者（有一个或多个风险因素）发生并发症的风险是无风险因素的“低危”患者的两倍多（优势比，2.18；95%置信区间，1.25至3.81）。
某些术前临床变量可能使有同侧症状的患者在颈动脉内膜切除术后发生围手术期并发症的风险更高。对一个简单风险指数进行前瞻性验证将为评估内膜切除术候选患者的术前风险提供一种额外的方法。
