Abstract 17410: Small Perfusion Defects during Dobutamine Stress MRI are not Associated with Future Cardiovascular Events in High Risk Patients with Diabetes, Hypertension, or Pre-Existing Coronary Artery Disease

Abstract

Background: Although, large persistent dobutamine stress cardiac magnetic resonance (DCMR) induced perfusion defects forecast future cardiac events, the prognostic significance of small, short duration DCMR perfusion defects is unknown.

Methods: DCMR was performed in 331 individuals (aged 68 + 8 years, 50.4% male) with CAD, diabetes (DM) or hypertension on a 1.5-T Siemans Avanto scanner in which dobutamine/atropine were infused to achieve 85% of the maximum predicted heart rate response for age. Intravenous gadolinium was infused at peak stress. The transmural thickness and persistence of the perfusion defects were assessed by personnel blinded to cardiovascular (CV) events.

Results: There were 156 individuals (47.1%) who exhibited perfusion defects (47.4% of less than 5 frames in duration or less than 25% myocardial thickness and 52.5% of 5 of more frames in duration and greater than 25% myocardial thickness) with 16 experiencing a CV event (cardiac death, nonfatal myocardial infarction (MI), or coronary artery revascularization). In patients with perfusion defects of less than 5 frames or less than 25% of the myocardial thickness, there was an increased incidence of DM compared to those without perfusion defects (p-value 0.019). There was an increased incidence of CAD, prior MI, and left ventricular dysfunction in patients with perfusion defects of 5 or more frames and greater than 25% of the myocardial thickness (p-value < 0.001). There were no clinical outcomes in patients with perfusion defects of less than 5 frames in duration or less than 25% of the myocardial thickness, whereas defects of 5 or more frames in duration and greater than 25% of the myocardial thickness conferred increasing CV risk (Figure).

Conclusion: While large persistent DCMR induced perfusion defects convey a high risk of a future CV event in those with CAD, DM, or hypertension, small, short-lived DCMR induced perfusion defects are associated with a low 2-year risk of a cardiac event.