Magnetic resonance low-dose dobutamine test is superior to SCAR quantification for the prediction of functional recovery.

BACKGROUND: Low-dose dobutamine challenge (DSMR) by MRI was compared with delayed enhancement imaging with Gd-DTPA (SCAR) as a predictor of improvement of wall motion after revascularization (RECOVERY).

METHODS AND RESULTS: In 29 patients with coronary artery disease (68+/-7 years of age, 2 women, 32+/-8% ejection fraction), wall motion was evaluated semiquantitatively by MRI before and 3 months after revascularization. SCAR and DSMR were performed before revascularization. The transmural extent of scar was assessed semiquantitatively. Binary prediction of RECOVERY was performed by logistic regression in 288 segments with wall motion abnormalities at rest. Receiver operating characteristic-area under curve (AUC) statistics were used to compare different models. Low-dose DSMR (AUC 0.838) was superior to SCAR (AUC 0.728) in predicting RECOVERY. SCAR did not improve accuracy of prediction by DSMR. Subgroup analysis showed superiority of DSMR for 1% to 74% transmural extent of infarction.

CONCLUSIONS: Low-dose DSMR is superior to SCAR in predicting RECOVERY. This advantage is largest in segments with a delayed enhancement of 1% to 74%.