Altered myocardial perfusion in patients with angina pectoris or silent ischemia during exercise as assessed by quantitative thallium-201 single-photon emission computed tomography.

Abstract

The extent of abnormally perfused myocardium was compared in patients with and without chest pain during treadmill exercise from a large, relatively low-risk consecutive patient population (n=356) referred for quantitative thallium-201 single-photon emission computed tomography (SPECT). All patients had concurrent coronary angiography. Patients were excluded if they had prior coronary angioplasty or bypass surgery. Tomographic images were assessed visually and from computer-generated polar maps. Chest pain during exercise was as frequent in patients with normal coronary arteries (12%) as in those with significant (>50%o stenosis) coronary artery disease (CAD) (14%). In the 219 patients with significant CAD, silent ischemia was fivefold more common than symptomatic ischemia (83% versus 17%, p=0.0001).However, there were no differences in the extent, severity, or distribution of coronary stenoses in patients with silent or symptomatic ischemia. Our major observation was that the extent of quantified SPECT perfusion defects was nearly identical in patients with (20.9±15.9%Yo) and without (20.5±15.6%) exertional chest pain. The sensitivity for detecting the presence of CAD was significantly improved with quantitative SPECT compared with stress electrocardiography (87% versus 65%, p=0.0001). Although scintigraphic and electrocardiographic evidence of exercise-induced ischemia were comparable in patients with chest pain (67% versus 73%, respectively; p=NS), SPECT was superior to stress electrocardiography for detecting silent myocardial ischemia (52% versus 35%, respectively; p=0.01). The majority of patients in this study with CAD who developed ischemia during exercise testing were asymptomatic, although they exhibited an angiographic profile and extent of abnormally perfused myocardium similar to those of patients with symptomatic ischemia. The prognostic significance of quantified perfusion defects detected by SPECT remains to be assessed. (Circulation 1990;82:1305-1315 Since the original description of asymptomatic myocardial ischemia in patients with coronary artery disease, there has been a rapid expansion of the literature regarding silent ischemia to

Long term outcome in patients with silent versus symptomatic ischaemia during dobutamine stress echocardiography

“…Some investigators have reported a greater extent and severity of ischaemia in symptomatic patients than in those with silent myocardial ischaemia, [11][12][13][14][15][16] whereas other studies reported no difference in the amount of ischaemic myocardium between patients with and patients without symptomatic myocardial ischaemia during exercise or pharmacological stress testing. [4][5][6][7][8][9][10] In the present study there are no significant differences between dysfunctional segments at rest and the number of ischaemic segments at peak in patients with and without symptomatic myocardial ischaemia. Moreover, the extent of ischaemia during DSE was an independent predictor of cardiac death and myocardial infarction, and the number of diseased vessels was related to an increased rate of cardiac events, particularly in patients with symptomatic ischaemia.…”

Altered myocardial perfusion during dobutamine stress testing in silent versus symptomatic myocardial ischaemia assessed by quantitative MIBI SPET imaging

“…Discordant results have been published on the functional significance of silent versus symptomatic ischaemia during exercise stress testing [15][16][17][18][19][20]. Re-versible exercise-thallium defects were reported to be more extensive and severe in patients with compared to those without angina in the studies of Klein et al [15] and Travin et al [16], while others failed to demonstrate such a difference [17][18][19][20]. Klein et al [15] concluded that the induction of pain is associated with substantially more functional abnormalities when patients with a broad spectrum of coronary artery disease are evaluated.…”

“…Additionally, in patients with myocardial infarction and stress-induced ST-segment elevation, concomitant ST-segment depression may represent reciprocal changes without true ischaemia. Hecht et al [20] and Mahmarian et al [19] reported that in patients with coronary artery disease, positive and negative exercise electrocardiographic findings were associated with a similar amount of ischaemia on exercise thallium scintigraphy. Conversely, Hecht et al [25] concluded that exercise-induced STsegment depression is the single most significant variable in relation to the amount of ischaemic myocardium assessed by exercise echocardiography.…”

Comparison of S–T Segment/Heart Rate Slope with Exercise Thallium Imaging and Conventional S–T Segment Criteria in Detecting Coronary Artery Disease: Effect of Exercise Level on Accuracy

“…However, no other similar results have been reported. Because physiologically a perfusion defect must precede an electrocardiographic change [7] and many studies have indicated that exercise thallium imaging is more accurate than conventional exercise electrocardiogram [8,9], we hypothesized that thallium single-photon emission computed tomography (SPECT) is a better imaging modality than the ST/HR slope in the detection of coronary artery disease. The current study was undertaken to (1) test our hypothesis and (2) evaluate the effect of exercise level on the sensitivity and specificity of the ST/HR slope, conventional electrocardiographic criteria and thallium SPECT.…”