Ricotta John J, Char Daniel J, Cuadra Salvador A, Bilfinger Thomas V, Wall L Philipp, Giron Fabio, Krukenkamp Irvin B, Seifert Frank C, McLarty Allison J, Saltman Adam E, Komaroff Eugene
Division of Vascular Surgery, Stony Brook University Hospital, NY, USA.
Stroke. 2003 May;34(5):1212-7. doi: 10.1161/01.STR.0000069263.08070.9F. Epub 2003 Apr 10.
The goals of this study were to compare the ability of statewide and institutional models of stroke risk after coronary artery bypass (CAB) to predict institution-specific results and to examine the potential additive stroke risk of combined CAB and carotid endarterectomy (CEA) with these predictive models.
An institution-specific model of stroke risk after CAB was developed from 1975 consecutive patients who underwent nonemergent CAB from 1994 to 1999 in whom severe carotid stenosis was excluded by preoperative duplex screening. Variables recorded in the New York State Cardiac Surgery Program database were analyzed. This model (model I) was compared with a published model (model II) derived from analysis of the same variables using New York statewide data from 1995. Predicted and observed stroke risks were compared. These formulas were applied to 154 consecutive combined CAB/CEA patients operated on between 1994 and 1999 to determine the predicted stroke risk from CAB alone and thereby deduce the maximal added risk imputed to CEA.
Risk factors common to both models included age, peripheral vascular disease, cardiopulmonary bypass time, and calcified aorta. Additional risk factors in model I also included left ventricular hypertrophy and hypertension. Risk factors exclusive to model II included diabetes, renal failure, smoking, and prior cerebrovascular disease. Our observed stroke rate for isolated CAB was 1.7% compared with a rate predicted with model II (statewide data) of 1.56%. The observed stroke rate for combined CEA/CAB was 3.9%. When the Stony Brook model (model I) based on patients without carotid stenosis was used, the predicted stroke rate was 2.8%. When the statewide model (model II), which included some patients with extracranial vascular disease, was used, the predicted stroke rate was 3.4%. The differences between observed and predicted stroke rates were not statistically significant.
Estimation of stroke risk after CAB was similar whether statewide data or institution-specific data were used. The statewide model was applicable to institution-specific data collected over several years. Common risk factors included age, aortic calcification, and peripheral vascular disease. The observed differences in the predicted stroke rates between models I and II may be due to the fact that carotid stenosis was specifically excluded by duplex ultrasound from the patient population used to develop model I. Modeling stroke risk after CAB is possible. When these models were applied to patients undergoing combined CAB/CEA, no additional stroke risk could be ascribed to the addition of CEA. Such models may be used to identify groups at increased risk for stroke after both CAB and combined CAB/CEA. The ultimate place for CEA in patients undergoing CAB will be defined by prospective randomized trials.
本研究的目的是比较冠状动脉搭桥术（CAB）后全州范围和机构模型预测机构特定结果的能力，并使用这些预测模型研究CAB与颈动脉内膜切除术（CEA）联合手术潜在的额外中风风险。
从1994年至1999年接受非急诊CAB手术的1975例连续患者中开发了一个机构特定的CAB术后中风风险模型，这些患者术前经双功超声筛查排除了严重颈动脉狭窄。分析了纽约州心脏外科手术项目数据库中记录的变量。将该模型（模型I）与使用1995年纽约州全州数据对相同变量进行分析得出的已发表模型（模型II）进行比较。比较预测的和观察到的中风风险。将这些公式应用于1994年至1999年期间接受CAB/CEA联合手术的154例连续患者，以确定单独CAB的预测中风风险，从而推断出归因于CEA的最大额外风险。
两个模型共有的风险因素包括年龄、外周血管疾病、体外循环时间和主动脉钙化。模型I中的其他风险因素还包括左心室肥厚和高血压。模型II独有的风险因素包括糖尿病、肾衰竭、吸烟和既往脑血管疾病。我们观察到单纯CAB的中风发生率为1.7%，而模型II（全州数据）预测的发生率为1.56%。CEA/CAB联合手术的观察到的中风发生率为3.9%。当使用基于无颈动脉狭窄患者的斯托尼布鲁克模型（模型I）时，预测的中风发生率为2.8%。当使用包括一些颅外血管疾病患者的全州模型（模型II）时，预测的中风发生率为3.4%。观察到的和预测的中风发生率之间的差异无统计学意义。
无论使用全州范围的数据还是机构特定的数据，CAB术后中风风险的估计相似。全州模型适用于多年来收集的机构特定数据。常见的风险因素包括年龄、主动脉钙化和外周血管疾病。模型I和模型II预测中风发生率的观察到的差异可能是由于在用于开发模型I的患者群体中，双功超声特意排除了颈动脉狭窄。建立CAB术后中风风险模型是可行的。当将这些模型应用于接受CAB/CEA联合手术的患者时，不能将额外的中风风险归因于CEA的增加。此类模型可用于识别CAB以及CAB/CEA联合手术后中风风险增加的群体。CEA在接受CAB手术患者中的最终地位将由前瞻性随机试验确定。
