Abstract 13126: The Optimal Timing for Detection of Perfusion and Wall Motion Abnormalities Following Regadenoson Bolus Real Time Perfusion Stress Echocardiography
Background: Regadenoson (Reg) is a selective A2a adenosine receptor agonist which has been approved as a stress perfusion agent. Although the agent is given as a bolus with rapid onset, the optimal timing for detection of myocardial perfusion (MP) or wall motion (WM) abnormalities due to coronary artery disease (CAD) is not known. Real time perfusion echocardiography (RTPE) has the ability, unlike other imaging techniques, to rapidly assess both MP and WM as a continuum at multiple time points. The purpose of this study was to determine the optimal time period for assessing MP and WM during Reg stress imaging.
Methods: In 70 patients (mean age 62 years; 30 women) with suspected CAD, RTPE (using either Siemens Acuson Sequoia or Philips IE 33) was performed during a continuous intravenous infusion of 5% Definity (Lantheus) contrast at baseline, and then at three time periods (<3, 3–6, and >6 min) following a 400 microgram bolus injection of Reg. Analysis of MP and WM was during the replenishment phase of contrast following a high mechanical index impulse. All studies were read by a blinded reviewer without knowledge of patient history or demographics. Sensitivity (Sens) and Specificity (Spec) were determined at each time period, using quantitative coronary angiography (QCA) as a reference(>50% diameter stenosis considered significant).
Results: There was a progressive decline in MP sensitivity with time (78% at <3 minutes, 59% at >6 min), with only one patient developing a MP abnormality at > 3 minutes. WM sensitivity was lower, but did not change at any time following Reg bolus (Figure). Specificity of MP analysis was the same at all three time periods.
Conclusions: The optimal time period for detection of MP abnormalities is within the first six minutes of the Reg bolus. Reg-induced WM abnormalities are less sensitive than MP abnormalities, but persist for longer time periods.
- © 2010 by American Heart Association, Inc.