Abstract 13411: Vasodilatory Capacity With Regadenoson Myocardial Perfusion Imaging In Patients With End Stage Liver Disease

Abstract

Introduction: The sensitivity and specificity of myocardial perfusion imaging in end stage liver disease (ESLD) patients ranges between 35-37% and 63-88%, respectively. Despite high levels of endogenous catecholamines and angiotensin, ESLD induced arterial vasodilation may exhaust the vasodilatory capacity of common pharmacologic stress agents. Reduced heart rate (HR) response to vasodilator stress test has been associated with increased major adverse cardiac events (MACE) in pre-transplant end stage renal disease patients but there is limited data in ESLD. We hypothesize that the hemodynamic response, measured as a change in HR and systolic blood pressure (SBP), during regadenoson stress test will be more robust when associated with low level exercise. Method: Forty-five subjects with ESLD referred for pre-transplant risk stratification were assigned to 1 of 3 groups: regadenoson alone or associated with low level treadmill or bicycle maneuver. Regadenoson was injected 2 minutes after low level exercise in the treadmill and bicycle groups. Myocardial perfusion images and hemodynamic changes were performed and interpreted as part of the standard clinical protocol. Results: There were 21 subjects in the regadenoson alone group, 10 in the low level treadmill group, and 14 in the bicycle maneuver group. There were no perfusion abnormalities in any of the groups and LVEF were greater than 50%. There was a statistically significant difference in HR response between the 3 groups (p = 0.015), but not in percentage SBP change between the 3 groups (p = 0.4). Pairwise comparison of regadenoson alone vs. low level treadmill percentage HR change showed statistical significance (p = 0.011). There was no MACE at 6-month follow-up. Conclusions: Low level exercise achieved a higher HR response than the other groups with a similar SBP response. The increased HR response may represent a more physiologic assessment of the true vasodilatory capacity remaining in ESLD patients.