Dobutamine versus dipyridamole echocardiography in coronary artery disease

Dobutamine and dipyridamole echocardiography are gaining popularity as exercise-independent stress tests for the diagnosis of coronary artery disease. To compare the feasibility, sensitivity, and specificity of dobutamine echocardiography to dipyridamole echocardiography, we conducted both tests, on different days and in random order, on 35 patients with chest pain and suspected coronary artery disease. Dobutamine was administered in scalar doses up to 40 micrograms/kg per minute and dipyridamole up to 0.84 mg/kg for 10 minutes. Dobutamine echocardiography testing was positive in eight of 16 (50%) patients with single-vessel disease and in 11 of 12 (92%) patients with multivessel disease, resulting in an overall sensitivity of 68% for the presence of coronary artery disease. Dipyridamole echocardiography testing showed the same sensitivity as dobutamine in patients with multivessel disease but a lower sensitivity (31%) in single-vessel disease, resulting in an overall sensitivity of 57%. The specificity of both tests was 100%. An ST segment shift of more than 1 mm compared with baseline was documented in 74% of the positive dobutamine echocardiography tests and in 81% of the positive dipyridamole echocardiography tests. No major complications occurred during both tests. Ventricular arrhythmias occurred in 11 patients with dobutamine and in none with dipyridamole (31% versus 0%, p less than 0.001). Thus, in our selected population dobutamine echocardiography testing demonstrated a similar overall sensitivity and specificity for the diagnosis of coronary artery disease compared with dipyridamole, with a slightly better sensitivity for single-vessel disease but a greater arrhythmogenic potential.