Related Experiment Videos
Safety and diagnostic accuracy of dipyridamole-thallium imaging in the elderly
J Y Lam1, B R Chaitman, M Glaenzer
1Department of Medicine, St. Louis, University School of Medicine, Missouri 63104.
Insights
Intravenous dipyridamole-thallium imaging is a safe and effective noninvasive diagnostic tool for assessing coronary artery disease in elderly patients. Its safety profile and diagnostic accuracy are comparable to those in younger individuals.
Area of Science:
- Cardiology
- Nuclear Medicine
- Geriatric Medicine
Background:
- Noninvasive diagnosis of coronary artery disease (CAD) in the elderly presents challenges.
- Intravenous dipyridamole-thallium imaging is a potential diagnostic method for CAD.
- The safety of this imaging technique in older populations requires evaluation.
Purpose of the Study:
- To compare the safety and side effect profile of intravenous dipyridamole-thallium imaging in patients aged 70 years and older versus younger patients.
- To assess the frequency of severe ischemic responses in both age groups.
- To evaluate the diagnostic accuracy (sensitivity and specificity) of the procedure in older adults.
Main Methods:
- A comparative study involving 101 patients aged >= 70 years and 236 patients < 70 years.
- Intravenous dipyridamole (0.56 mg/kg) followed by thallium imaging was administered.
- Side effects, severe ischemic responses, and diagnostic accuracy for obstructive CAD were recorded and compared between the age groups.
Main Results:
- No significant differences in the overall side effect profile or need for aminophylline reversal between older and younger patients.
- No myocardial infarction or death occurred in any patient.
- Severe ischemic responses were infrequent (2% in older vs. 2.5% in younger patients).
- Sensitivity (86% vs. 83%) and specificity (75% vs. 70%) for CAD were similar in both groups.
Conclusions:
- Intravenous dipyridamole-thallium imaging is a safe noninvasive method for assessing obstructive coronary artery disease in elderly patients.
- The procedure demonstrates a similar side effect profile and diagnostic accuracy in older adults compared to younger individuals.
- The risk of severe ischemic events is low in all patient groups.
Abstract:
The noninvasive diagnosis of coronary artery disease in the elderly can occasionally be difficult. Intravenous dipyridamole-thallium imaging is a potentially useful diagnostic test to determine presence and severity of coronary disease; however, the safety of the procedure has not been determined in an older population. The side effect profile and frequency of severe ischemic responses after 0.56 mg/kg of intravenous dipyridamole were compared in 101 patients greater than or equal to 70 years old and 236 patients less than 70 years old. There were no side effects in 64% and 62% of patients greater than or equal to 70 and less than 70 years old, respectively (p = NS). Among the 337 patients tested, there were no complications of myocardial infarction or death. The most common cardiac side effect was chest pain, which occurred in 21 (21%) of the 101 patients aged greater than or equal to 70 years and in 64 (27%) of the 236 patients less than 70 years (p = NS). Aminophylline was required to reverse cardiac or noncardiac side effects in 15 (15%) and 36 (15%) of the patients greater than or equal to 70 and less than 70 years old, respectively (p = NS). A severe ischemic response occurred in 2% and 2.5% of patients greater than or equal to 70 and less than 70 years old, respectively (p = NS). The sensitivity of intravenous dipyridamole-thallium imaging for obstructive coronary artery disease was 86% (25 of 29) and 83% (68 of 82) in older and younger patients, respectively (p = NS); the specificity was 75% (6 of 8) and 70% (16 of 23), respectively (p = NS). Thus, intravenous dipyridamole-thallium imaging is a safe noninvasive method for assessment of older patients with obstructive coronary disease; its side effect profile and diagnostic accuracy are similar to those seen in younger patients. The technique is associated with severe ischemic responses in only a small minority of patients.