Objectives: The clinical value of cine magnetic resonance imaging (MRI) during dobutamine stress for detection of coronary artery disease was evaluated in 45 patients with chest pain who were admitted for coronary arteriography.
Background: Development of stress-induced wall motion asynergy is considered an early and reliable sign of myocardial ischemia preceding electrocardiographic (ECG) changes and angina. As physical exercise during MRI is difficult because of motion artifacts and space restriction, dobutamine infusion was used to induce cardiovascular stress.
Methods: Cine MRI tomograms were obtained in six adjacent short-axis planes. After baseline acquisition, dobutamine was administered to a maximal dose of 20 micrograms/kg per min. Both at rest and during peak dobutamine stress, magnetic resonance images were displayed in a cinematographic loop to assess regional wall motion qualitatively. Results of dobutamine MRI were considered positive for coronary artery disease if any new or worsening wall motion abnormality developed. Immediately after MRI at peak dobutamine infusion, dobutamine electrocardiography was performed outside the magnetic environment. In addition, all patients performed symptom-limited exercise electrocardiography.
Results: Significant coronary artery disease (> 50% diameter stenosis) was present in 37 patients. During peak dobutamine stress, wall motion asynergy developed or worsened in 30 patients, yielding an overall sensitivity for detection of coronary artery disease of 81% and a specificity of 100%. Corresponding data were 51% and 63% for dobutamine electrocardiography and 70% and 63% for exercise electrocardiography. The sensitivity of dobutamine MRI for the detection of coronary artery disease in patients with single-, double- and triple-vessel disease was 75% (15 of 20 patients), 80% (8 of 10) and 100% (7 of 7), respectively.
Conclusion: Dobutamine MRI is an accurate nonexercise-dependent method for the assessment of myocardial ischemia in patients with coronary artery disease.