Background: Transient ischemic dilation (TID) of the left ventricle on stress-redistribution thallium-201 scintigraphy is a marker of severe and extensive coronary artery disease (CAD), and associated with an adverse outcome. The significance of transient ischemic dilation during stress echocardiography is not well defined.
Methods: We assessed 155 patients undergoing stress echocardiography (61% treadmill exercise, 39% dobutamine) with confirmed follow-up (mean 2.8 +/- 1.1 years) for hard events (myocardial infarction, n = 14, and cardiac death, n = 9).
Results: Normal limits for TID ratio were developed using data from 39 patients with a low likelihood (<5%) of CAD and normal stress echocardiography study findings. The criteria for abnormality was developed based on data from 116 patients who underwent coronary angiography after and within 3 months of an abnormal ischemic stress echocardiography study result. For normal limits, receiver operating characteristic curve analysis showed that abnormal TID ratio values corresponded to left ventricular volume ratios greater than 1.17 (mean +/- 2SD). TID assessment using these criteria for abnormality showed high sensitivity (100%) and moderate specificity (54%) for detection of severe and extensive angiographic CAD. Patients with TID had a greater extent and severity of stress induced wall-motion abnormalities, higher peak wall-motion score index, and worse prognosis than patients without TID.
Conclusions: TID during stress echocardiography is a sensitive marker of severe and extensive angiographic CAD and is associated with a high risk of cardiac events (19.7%/y event rate).