Safety and accuracy of cardiac magnetic resonance imaging combined with low-dose dobutamine stress-testing in patients with congenital heart disease

Objective

to report our experiences with low-dose dobutamine stress cardiovascular magnetic resonance (DCMR) imaging in patients with congenital heart disease (CHD) and to assess the intra-observer and interobserver variability of biventricular function, volumes, and mass.

Background

Stress-testing is an important tool to obtain additional information on ventricular and vascular function in patients with acquired or congenital heart disease. Low-dose DCMR imaging in small groups of patients with CHD revealed ventricular and vascular dysfunction that is not apparent at rest. There are no reports in a large series of patients on the safety and accuracy of low-dose DCMR imaging.

Methods

inclusion of all patients who underwent low-dose DCMR in our institution. Acquisition of a short axis set and flow measurements at rest, and during dobutamine administered at 7.5 μg/kg/min maximum. Intra-observer and interobserver variability (coefficient of variation) was determined for biventricular function, volumes, and mass.

Results

In 91 patients 110 studies were performed (63 male subjects, 54 tetralogy of Fallot, 37 Fontan patients, youngest age at study 6.8 years). In 3 patients minor side effects occurred (vertigo, headache, bigeminy). In 10 patients dobutamine was lowered to 5 μg/kg/min because of an increase in heart rate of >150% baseline, although well tolerated. Intra-observer variability was between 2.3 and 8.7% for rest and stress measurements. Interobserver variability was between 3.6 and 10.5% at rest. With stress-testing, the coefficient of variation for biventricular ESV increased significantly to ≥ 15%, while it remained < 10% for the other variables.

Conclusion

In patients with various types of CHD low-dose DCMR imaging is feasible, safe, and can be performed from 7 years of age. Intra-observer variability is low for rest and stress measurements. With stress-testing, interobserver variability of biventricular ESV increases significantly.