Exercise Thallium Tomography Predicts Future Clinically Manifest Coronary Heart Disease in a High-Risk Asymptomatic Population

Abstract

Exercise thallium scintigraphy appears to be useful in the risk assessment of asymptomatic siblings of patients with premature CHD, particularly in male siblings who are 45 years of age or older.

Severity of Coronary Artery Calcification by Electron Beam Computed Tomography Predicts Silent Myocardial Ischemia

“…The presence and extent of stress-induced myocardial ischemia detected by SPECT are known to predict subsequent outcome. [3][4][5][6][7][8] Our results indicate that most subjects with coronary calcium do not have inducible ischemia but that the likelihood of ischemia increases with total CACS, particularly with scores Ն400. In fact, total CACS Ն400 identified a group in whom a large percentage of subjects (46%) had demonstrable ischemia.…”

“…Our results support previous studies demonstrating that asymptomatic subjects with cardiac risk factors generally have normal ETT and perfusion scans. [7][8][9] In the Lipid Research Clinics trial, 9 only 8.3% of 3775 asymptomatic men with hyperlipidemia had exercise-induced ECG ischemia. In a study of middle-aged siblings of patients with premature CAD, the stress ECG was abnormal in only 10% and thallium imaging in 22%.…”

“…In a study of middle-aged siblings of patients with premature CAD, the stress ECG was abnormal in only 10% and thallium imaging in 22%. 7 In the Baltimore Longitudinal Study on Aging, few asymptomatic subjects had an abnormal stress ECG (16%) or thallium perfusion scan (14%). 8 Although subjects who had abnormal results for both tests had a reduced event-free survival (52%), this was observed in only 5% of individuals screened; likewise, only 4.4% of our subjects had both abnormal ETT and perfusion imaging.…”

“…However, currently available noninvasive techniques, such as exercise treadmill testing (ETT) and myocardial single photon emission computed tomography (SPECT), can identify only patients with advanced CAD who manifest myocardial ischemia. 1,2 Although the presence and extent of left ventricular ischemia can accurately identify individuals at high risk for cardiac events, [3][4][5][6][7][8] the low prevalence of a positive test result among asymptomatic subjects with cardiac risk factors mitigates against this approach. [7][8][9] Electron beam computed tomography (EBCT) is a new noninvasive technique that can detect coronary atherosclerosis even at its earliest stages on the basis of the presence and severity of coronary artery calcification.…”

“…1,2 Although the presence and extent of left ventricular ischemia can accurately identify individuals at high risk for cardiac events, [3][4][5][6][7][8] the low prevalence of a positive test result among asymptomatic subjects with cardiac risk factors mitigates against this approach. [7][8][9] Electron beam computed tomography (EBCT) is a new noninvasive technique that can detect coronary atherosclerosis even at its earliest stages on the basis of the presence and severity of coronary artery calcification. 10 Although calcification severity predicts the presence of significant anatomic CAD, 11,12 there is little information as to whether the coronary artery calcium score (CACS) can identify asymptomatic individuals at high risk for having myocardial ischemia among a larger, asymptomatic, heterogeneous population with cardiac risk factors.…”