Faculty Bibliography

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)

OBJECTIVES: We sought to evaluate the risk stratification ability and incremental prognostic value of stress echocardiography over historic, clinical, and stress electrocardiographic (ECG) variables, over a wide spectrum of bayesian pretest probabilities of coronary artery disease (CAD). BACKGROUND: Stress echocardiography is an established technique for the diagnosis of CAD. However, data on incremental prognostic value of stress echocardiography over historic, clinical, and stress ECG variables in patients with known or suggested CAD is limited. METHODS: We evaluated 3259 patients (60 +/- 13 years, 48% men) undergoing stress echocardiography. Patients were grouped into low (<15%), intermediate (15-85%), and high (>85%) pretest CAD likelihood subgroups using standard software. The historical, clinical, stress ECG, and stress echocardiographic variables were recorded for the entire cohort. Follow-up (2.7 +/- 1.1 years) for confirmed myocardial infarction (n = 66) and cardiac death (n = 105) was obtained. RESULTS: For the entire cohort, an ischemic stress echocardiography study confers a 5.0 times higher cardiac event rate than the normal stress echocardiography group (4.0% vs 0.8%/y, P < .0001). Furthermore, Cox proportional hazard regression model showed incremental prognostic value of stress echocardiography variables over historic, clinical, and stress ECG variables across all pretest probability subgroups (global chi2 increased from 5.1 to 8.5 to 20.1 in the low pretest group, P = .44 and P = .01; from 20.9 to 28.2 to 116 in the intermediate pretest group, P = .47 and P < .0001; and from 17.5 to 36.6 to 61.4 in the high pretest group, P < .0001 for both groups). CONCLUSIONS: A normal stress echocardiography portends a benign prognosis (<1% event rate/y) in all pretest probability subgroups and even in patients with high pretest probability and yields incremental prognostic value over historic, clinical, and stress ECG variables across all pretest probability subgroups. The best incremental value is, however, in the intermediate pretest probability subgroup