Abstract 11060: Regadenoson Positron Emission Tomography (PET) is Safe to Guide Coronary Revascularization In High-risk Patients With Severe Symptomatic Aortic Stenosis (AS) Being Considered for Transcatheter Aortic Valve Replacement (TAVR)
The safety of regadenoson PET stress testing in patients with severe AS has not been ascertained. Moreover, in patients being considered for TAVR, symptoms may be related to coronary artery disease (CAD) and/or AS, and appropriate revascularization prior to TAVR is imperative. We sought to establish the safety of regadenoson PET in this setting from a retrospective cohort at our institution.
Between May 2010 and May 2013, we identified 44 patients from our cardiac PET database who were undergoing evaluation for TAVR. Our patients were high-risk with a median age of 72 ± 17, mean STS mortality of 11.5 ± 7.8%, and a median GFR of 42 ± 27ml/min/1.73m2. 93% of patients had a previous diagnosis of CAD; 41% had a previous percutaneous coronary intervention, and 61% had undergone a prior coronary artery bypass grafting.
On echocardiography, mean ejection fraction (EF) was 38 ± 16% with a mean aortic valve area of 0.78 ± 0.26 cm2. Peak and mean gradients were 52 ± 19 and 31 ± 12 mmHg, respectively, with a mean dimensionless index of 0.23 ± 0.06.
There were no major adverse events. A significant transient drop in blood pressure, defined as decrease in systolic blood pressure (BP) by 20 mmHg and a nadir less than 90 mmHg, was relatively common (16%). There was a non-significant trend between reduced EF and a significant decrease in BP (mean EF 40 ± 16 v 28 ± 11%, p = 0.07). There was no association between measures of AS severity and a significant decrease in BP. One patient with hypotension became light-headed, but symptoms spontaneously resolved. Another patient had an episode of non-sustained ventricular tachycardia.
PET abnormalities were present in 93%. 68% had ischemia, and 70% had fixed perfusion defects. Average resting and stress EF on PET were 36 ± 18% and 33 ± 16%, respectively. 55% of patients with abnormal tests underwent coronary angiography. 87% of these patients had ischemia or evidence of hibernating myocardium. 34% of our patients underwent revascularization, and 93% of these had revascularization guided by PET results.
In high-risk patients being considered for TAVR, regadenoson PET is safe to guide coronary revascularization. This modality may be particularly useful in patients with renal insufficiency, known CAD, and prior revascularization.
- © 2013 by American Heart Association, Inc.