Usefulness of exercise electrocardiography and thallium scintigraphy in unstable angina pectoris in predicting the extent and severity of coronary artery disease

• Published in: The American journal of cardiology Vol. 62; no. 17; pp. 1164 - 1170
• Main Authors: Freeman, Michael R., Chisholm, Robert J., Armstrong, Paul W.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.12.1988; Elsevier
• Subjects: Adult; Aged; Angina Pectoris - physiopathology; Angina, Unstable - diagnostic imaging; Angina, Unstable - physiopathology; Biological and medical sciences; Blood Pressure; Cardiology. Vascular system; Coronary Disease - classification; Coronary Disease - diagnosis; Coronary Disease - diagnostic imaging; Coronary heart disease; Electrocardiography; Exercise Test; Female; Heart; Heart Rate; Humans; Male; Medical sciences; Middle Aged; Myocardial Infarction - diagnostic imaging; Myocardial Infarction - physiopathology; Prospective Studies; Radionuclide Imaging; Risk Factors; Thallium Radioisotopes; Radionuclide study; Human; Electrodiagnosis; Prognosis; Electrocardiography; Myocardium; Cardiovascular disease; Exercise tolerance test; Scintigraphy; Variant angina; Coronary heart disease
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/0002-9149(88)90253-6

The safety and efficacy of exercise electrocardiography and thallium scintigraphy early in the course of unstable angina pectoris were assessed 4.6 ± 1.6 days after admission in 67 patients with unstable angina that stabilized after medical therapy. Coronary arteribgraphy was performed in all patients 5.4 ± 2.4 days after admission. There was no difference in clinical, exercise or scintigraphic variables between patients with stenoses <50% and patients with 1-vessel coronary artery disease (CAD) defined as a diameter stenosis ≥50.%. Patients with 3-vessel CAD had a significantly shorter exercise duration than patients with <50%-diameter narrowing (5.5 ± 2.2 vs 8.3 ± 3.3 minutes, respectively), lower exercise heart rate (119 ± 20 vs 149 ± 22 beats/min) and systolic blood pressure (156 ± 29 vs 166 ± 33 mm Hg), more frequent chest pain (76 vs 20%) and more pronounced ST depression (−1.48 ± 1.37 vs −0.33 ± 0.72 mm). In addition, thallium defect size on exercise was greater in the patients with 2-vessel CAD (159 ± 132 °) and 3-vessel CAD (255 ± 132 °) than in patients with no CAD (28 ± 319 °) or 1-vessel CAD (73 ± 78 °), p ≥0.05. Multiple regression analysis demonstrated that thallium defect size was the best predictor of extent of CAD, with exercise heart rate and presence of chest pain during exercise also predictive of extent of CAD. Exercise testing was deemed safe in patients with unstable angina who have been medically stabilized and thallium defect size was considered the best predictor of extent of CAD.