Weintraub W S, Kosinski A S, Brown C L, King S B
Andreas Gruentzig Cardiovascular Center, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.
J Am Coll Cardiol. 1993 Jan;21(1):6-14. doi: 10.1016/0735-1097(93)90711-9.
The purpose of this study was to determine whether variables shown to correlate with restenosis in one group (learning group) could be shown to predict recurrent stenosis in a second group (validation group).
Restenosis remains a critical limitation after percutaneous transluminal coronary angioplasty. Although several clinical variables have been shown to correlate with restenosis, there are few data concerning attempts to predict recurrent stenosis.
The source of data was the clinical data base at Emory University. Patients who had had previous coronary surgery and patients who underwent coronary angioplasty in the setting of acute myocardial infarction were excluded. A total of 4,006 patients with angiographic restudy after successful angioplasty were identified. They were classified into a learning group of 2,500 patients and a validation group of 1,506 patients. The correlates of restenosis in the learning group were determined by stepwise logistic regression, and a model was developed to predict the probability of restenosis and was tested in the validation group. By using various cut points for the predicted probability of restenosis, a receiver operating characteristic curve was created. Goodness of fit of the model was evaluated by comparing average predicted probabilities with average observed probabilities within subgroups on the basis of risk level determined by linear regression analysis.
In the learning group 1,145 patients had restenosis and 1,355 did not. Correlates of restenosis were severe angina, severe diameter stenosis before angioplasty, left anterior descending coronary artery dilation, diabetes, greater diameter stenosis after angioplasty, hypertension, absence of an intimal tear, eccentric morphology and older patient age. The model derived from the learning group was used to predict restenosis in the validation group. By varying the cut point for the predicted probability of restenosis above which restenosis is diagnosed and below which it is not, a receiver operating characteristic curve was created. The curve was close to the line of identity, reflecting a poor predictive ability. However, the model was shown to fit well with the predicted probability of restenosis correlating well with the observed probability (r = 0.98, p = 0.0001).
Clinical variables provide limited ability to predict definitively whether a particular patient will have restenosis. However, the current model may be used to predict the probability of restenosis, with some uncertainty, at least in well characterized patients who have already had angioplasty.
本研究旨在确定在一组患者（学习组）中显示与再狭窄相关的变量是否能预测另一组患者（验证组）的复发性狭窄。
经皮腔内冠状动脉成形术后，再狭窄仍然是一个关键的限制因素。虽然已经显示一些临床变量与再狭窄相关，但关于预测复发性狭窄的尝试的数据很少。
数据来源是埃默里大学的临床数据库。排除曾接受过冠状动脉手术的患者以及在急性心肌梗死情况下接受冠状动脉成形术的患者。共确定了4006例成功进行血管成形术后接受血管造影复查的患者。他们被分为一个由2500例患者组成的学习组和一个由1506例患者组成的验证组。通过逐步逻辑回归确定学习组中再狭窄的相关因素，并建立一个模型来预测再狭窄的概率，并在验证组中进行测试。通过使用再狭窄预测概率的各种切点，创建了一个受试者操作特征曲线。通过将基于线性回归分析确定的风险水平的亚组内平均预测概率与平均观察概率进行比较，评估模型的拟合优度。
在学习组中，1145例患者发生再狭窄，1355例未发生。再狭窄的相关因素包括严重心绞痛、血管成形术前严重直径狭窄、左前降支冠状动脉扩张、糖尿病、血管成形术后更大直径狭窄、高血压、无内膜撕裂、偏心形态和患者年龄较大。从学习组得出的模型用于预测验证组中的再狭窄。通过改变再狭窄预测概率的切点（高于该切点诊断为再狭窄，低于该切点则不是），创建了一个受试者操作特征曲线。该曲线接近恒等线，反映出预测能力较差。然而，该模型显示与再狭窄预测概率与观察概率相关性良好（r = 0.98，p = 0.0001）。
临床变量在明确预测特定患者是否会发生再狭窄方面能力有限。然而，当前模型可用于预测再狭窄的概率，至少在已经接受血管成形术的特征明确的患者中存在一定不确定性。
