Emmett Louise, Magee Michael, Freedman S Ben, Van der Wall Hans, Bush Vivienne, Trieu Joseph, Van Gaal William, Allman Kevin C, Kritharides Leonard
Department of Nuclear Medicine, Concord Hospital, University of Sydney, Sydney, Australia.
J Nucl Med. 2005 Oct;46(10):1596-601.
Transient ischemic dilation of the left ventricle found on SPECT myocardial perfusion imaging (MPI) is an accepted marker of severe and extensive coronary artery disease (CAD) and poor prognosis. The influence of other clinical variables on the incidence of transient ischemic dilation is less certain. The aim of this study was to investigate clinical factors that may influence the incidence of transient ischemic dilation. In particular, we looked at factors that may independently affect subendocardial perfusion, such as left ventricular hypertrophy (LVH) and diabetes.
MPI studies of 103 consecutive patients who had undergone recent coronary angiography (< or =6 mo) and transthoracic echocardiography within a year of stress electrocardiography-gated MPI were retrospectively analyzed. Transient ischemic dilation was assessed quantitatively using a software program. A ratio cutoff of > or =1.22 was considered to represent transient ischemic dilation. Summed stress score and summed difference score (ischemia score) were determined using the standard 17-segment 5-point scoring system to quantify myocardial ischemia. LVH was defined as a left ventricular wall thickness of >11 mm on M-mode echocardiography. Severe CAD was defined as severe stenosis (> or =90%) of either the left anterior descending artery or both the right coronary and lateral circumflex arteries.
Nineteen (18%) of the 103 patients had transient ischemic dilation, 19 (18%) had LVH, and 23 (22%) were diabetic. A high percentage had severe CAD (46/103 [45%]), whereas 57 of 103 (55%) had less severe CAD (30/103 [29%]) or nonsignificant CAD (26/103 [25%]). Severe CAD (P < 0.001), diabetes (P < 0.0001), LVH (P < 0.003), and the ischemia score (P < 0.023) were independent predictors of transient ischemic dilation by multivariate logistic regression. In patients with severe CAD, the effect of LVH on the incidence of transient ischemic dilation was additive, increasing the incidence from 21% (8/38) without LVH to 75% (6/8) with LVH (P < 0.006). Likewise, with severe CAD, the incidence of transient ischemic dilation rose from 21% (7/33) in patients without diabetes to 54% (7/13) in those with diabetes (P < 0.04).
The presence of transient ischemic dilation on myocardial perfusion SPECT is associated with the presence of severe CAD, but this association is modified by the presence of LVH and diabetes.
单光子发射计算机断层扫描心肌灌注成像（MPI）发现的左心室短暂性缺血性扩张是严重广泛冠状动脉疾病（CAD）和预后不良的公认标志物。其他临床变量对短暂性缺血性扩张发生率的影响尚不确定。本研究的目的是调查可能影响短暂性缺血性扩张发生率的临床因素。特别是，我们研究了可能独立影响心内膜下灌注的因素，如左心室肥厚（LVH）和糖尿病。
回顾性分析了103例连续患者的MPI研究，这些患者在应激心电图门控MPI检查后一年内接受了近期冠状动脉造影（≤6个月）和经胸超声心动图检查。使用软件程序对短暂性缺血性扩张进行定量评估。比率截断值≥1.22被认为代表短暂性缺血性扩张。采用标准的17节段5分评分系统确定应激总分和差异总分（缺血评分）以量化心肌缺血。LVH定义为M型超声心动图显示左心室壁厚度>11mm。严重CAD定义为左前降支或右冠状动脉和左旋支均严重狭窄（≥90%）。
103例患者中有19例（18%）出现短暂性缺血性扩张，有19例（18%）出现LVH, 23例（22%）患有糖尿病。高比例患者患有严重CAD（46/103 [45%]），而103例中有57例（55%）患有较轻CAD（30/103 [29%]）或非显著性CAD（26/103 [25%]）。多因素逻辑回归分析显示，严重CAD（P<0.001）、糖尿病（P<0.0001）、LVH（P<0.003）和缺血评分（P<0.023）是短暂性缺血性扩张的独立预测因素。在严重CAD患者中，LVH对短暂性缺血性扩张发生率的影响是相加的，使发生率从无LVH时的21%（8/38）增加到有LVH时的75%（6/8）（P<0.006）。同样，在严重CAD患者中，短暂性缺血性扩张的发生率从无糖尿病患者的21%（7/33）升至有糖尿病患者的54%（7/13）（P<0.04）。
心肌灌注SPECT上出现短暂性缺血性扩张与严重CAD的存在相关，但这种关联会因LVH和糖尿病的存在而改变。
