冠状动脉临界病变和急性心肌梗死的关系

Relationship between intermediate coronary stenosis at baseline and acute myocardial infarction

目的 通过分析急性心肌梗死前不同的冠状动脉（冠脉）造影基础病变特征和心肌梗死发病时间的关系,进一步探讨急性心肌梗死的发病机制和冠状动脉粥样硬化性心脏病（冠心病）的防治策略.方法 入选2005年6月到2011年11月因急性心肌梗死行介入治疗的患者104例.所有患者心肌梗死前都曾在阜外心血管病医院冠心病诊治中心行冠脉造影术或冠脉支架植入治疗.根据冠脉造影定量分析基础病变的狭窄程度,将患者分成3组（＜50％狭窄程度即轻度病变组,50％～70％狭窄程度即临界病变组,＞70％狭窄程度即严重狭窄组）.比较3组的基础病变特征,分析3组基础病变狭窄程度和心肌梗死发病时间的关系.结果 基础病变为临界病变的患者中有经皮冠状动脉介入治疗病史的较多,3组比较,差异有统计学意义[50％（13/26）vs.82.5％（47/57）vs.66.7％（14/21）,P=0.009].心肌梗死基础病变特征中,＞70％狭窄程度的患者狭窄程度重、病变长度较长、最小血管内径较小（P＜0.001）.12个月内与12个月后进展为心肌梗死的基础病变比较,狭窄程度较重（P=0.002）.基础病变狭窄程度与心肌梗死时间成负相关（r=-0.421,P＜0.001）,基础病变狭窄程度进展与心肌梗死时间成正相关（r=0.467,P＜0.001）.结论 冠脉轻度病变或临界病变,部分是随时间延长不断进展为更严重的狭窄后导致了急性心肌梗死.基础狭窄程度严重的病变（＞70％狭窄程度）,是短时间内发生急性心肌梗死的重要病因.

Objectives To evaluate the angiographic stenosis of coronary lesions responsible for acute myocardial infarction （MI） with a focus on determining the impact of intervals from initial angiogram to subsequent clinical event,and to explore the pathogenic mechanism of acute MI and the strategy for prevention of coronary heart disease （CHD）.Methods From June 2005 to November 2011,104 patients with MI and previous angiogram at Coronary Artery Disease Center,Chinese Academy of Medical Sciences ＆ Peking Union Medical College were enrolled.Angiograms were reanalyzed with quantitative coronary angiography,and relevant clinical data were obtained from medical records.The patients were divided into three groups based on initial coronary stenosis：groups of below 50％,between 50％-70％ and above 70％.The coronary lesion characteristics and time intervals were analyzed.Results Main clinical characteristics of the 3 groups were similar,except that much more patients in group between 50％-70％ experienced percutaneous coronary intervention [50％ （13/26） vs.82.5％ （47/57） vs.66.7％ （14/21）,P=0.009].Underlying diameter stenosis was significantly larger and minimal lumen diameter was significantly smaller in group above 70％ （P＜0.001）.Underlying diameter stenosis that led to MI ＜12 months after evaluation were more severe than that in ＞12 months （P=0.002）.Underlying diameter stenosis and stenosis progression correlated with time intervals from initial angiogram to subsequent MI（r=-0.421,P＜0.001 ;r=0.467,P＜0.001）.Conclusions The progression of mild and intermediate coronary lesions may be another mechanism of acute MI.Severe coronary diameter stenosis （＞70％） may be an important cause of subsequent MI.