Department of Imaging, Cedars-Sinai Medical Center, 8700 Beverly Blvd, Taper #A238, Los Angeles, CA 90048, USA.
J Nucl Cardiol. 2012 Jun;19(3):465-73. doi: 10.1007/s12350-012-9527-8. Epub 2012 Mar 8.
Transient ischemic dilation (TID) of the left ventricle in myocardial perfusion SPECT (MPS) has been shown to be a clinically useful marker of severe coronary artery disease (CAD). However, TID has not been evaluated for 99mTc-sestamibi rest/stress protocols (Mibi-Mibi). We aimed to develop normal limits and evaluate diagnostic power of TID ratio for Mibi-Mibi scans.
TID ratios were automatically derived from static rest/stress MPS (TID) and gated rest/stress MPS from the end-diastolic phase (TID(ed)) in 547 patients who underwent Mibi-Mibi scans [215 patients with correlating coronary angiography and 332 patients with low likelihood (LLk) of CAD]. Scans were classified as severe (≥ 70% stenosis in proximal left anterior descending (pLAD) artery or left main (LM), or ≥ 90% in ≥ 2 vessels), mild to moderate (≥ 90% stenosis in 1 vessel or ≥ 70%-90% in ≥ 1 vessel except pLAD or LM), and normal (<70% stenosis or LLk group). Another classification based on the angiographic Duke prognostic CAD index (DI) was also applied: DI ≥ 50, 30 ≤ DI < 50 and DI < 30 or LLk group.
The upper normal limits were 1.19 for TID and 1.23 for TID(ed) as established in 259 LLk patients. Both ratios increased with disease severity (P < .0001). Incidence of abnormal TID increased from 2% in normal patients to >36% in patients with severe CAD. Similarly, when DI was used to classify disease severity, the average ratios showed significant increasing trend with DI increase (P < .003); incidence of abnormal TID also increased with increasing DI. The incidence of abnormal TID in the group with high perfusion scores significantly increased compared to the group with low perfusion scores (stress total perfusion deficit, TPD < 3%) (P < .0001). The sensitivity for detecting severe CAD improved for TID when added to mild to moderate perfusion abnormality (3% ≤ TPD < 10%): 71% vs 64%, P < .05; and trended to improve for TID(ed)/TID(es): 69% vs 64%, P = .08, while the accuracy remained consistent if abnormal TID was considered as a marker in addition to stress TPD. Similar results were obtained when DI was used for the definition of severe CAD (sensitivity: 76% vs 66%, P < .05 when TID was combined with stress TPD).
TID ratios obtained from gated or ungated Mibi-Mibi MPS and are useful markers of severe CAD.
心肌灌注单光子发射计算机断层扫描（MPS）中的短暂性缺血扩张（TID）已被证明是严重冠状动脉疾病（CAD）的一种临床有用的标志物。然而，尚未对 99mTc- sestamibi 静息/应激方案（Mibi-Mibi）进行 TID 评估。我们旨在为 Mibi-Mibi 扫描建立正常范围并评估 TID 比值的诊断能力。
在 547 名接受 Mibi-Mibi 扫描的患者中（215 名与相关冠状动脉造影患者和 332 名 CAD 可能性低（LLk）患者），自动从静态静息/应激 MPS（TID）和门控静息/应激 MPS 从舒张末期阶段（TID（ed））获得 TID 比值。扫描分为严重（近端前降支（pLAD）或左主干（LM）中≥70%狭窄，或≥2 个血管中≥90%狭窄）、轻度至中度（1 个血管中≥90%狭窄或≥70%-90%狭窄≥1 个血管，但 pLAD 或 LM 除外）和正常（<70%狭窄或 LLk 组）。还应用了另一种基于血管造影 Duke 预后 CAD 指数（DI）的分类：DI≥50、30≤DI<50 和 DI<30 或 LLk 组。
在 259 名 LLk 患者中，TID 的上限正常范围为 1.19，TID（ed）为 1.23。随着疾病严重程度的增加，这两个比值均增加（P<0.0001）。异常 TID 的发生率从正常患者的 2%增加到严重 CAD 患者的>36%。同样，当使用 DI 对疾病严重程度进行分类时，随着 DI 的增加，平均比值显示出明显的上升趋势（P<0.003）；异常 TID 的发生率也随着 DI 的增加而增加。与灌注评分低的患者相比，灌注评分高的患者的异常 TID 发生率显著增加（应激总灌注缺损，TPD<3%）（P<0.0001）。当 TID 与轻度至中度灌注异常（3%≤TPD<10%）相结合时，检测严重 CAD 的 TID 敏感性提高：71%对 64%，P<0.05；并且 TID（ed）/TID（es）的趋势也有所提高：69%对 64%，P=0.08，而如果将异常 TID 视为应激 TPD 之外的标志物，则准确性保持一致。当使用 DI 定义严重 CAD 时，也得到了类似的结果（当 TID 与应激 TPD 相结合时，敏感性：76%对 66%，P<0.05）。
从门控或非门控 Mibi-Mibi MPS 获得的 TID 比值是严重 CAD 的有用标志物。
