Abstract 17393: Functional Molecular Imaging Characteristics of Ischemic and Non-Ischemic Scar Substrate and successful VT Ablation Sites using 18F-Fluorodeoxyglucose (FDG) Positron Emission Tomography
Background: Molecular imaging techniques such as 18 FDG PET enables a functional assessment of the anatomic scar substrate and may provide complementary insights in the complex scar substrate of ischemic and non-ischemic patients presenting for ablation of drug-refractory ventricular tachycardia.
Method: Out of 68 patients with drug refractory VT undergoing VT ablation 10 patients with ischemic cardiomyopathy with pre-procedural FDG PET/perfusion imaging and well-defined successful VT ablation sites were identified. Metabolic FDG-PET maps were normalized to perfusion maps and reconstructed as 757 segment polar plot and compared to co-registered high-resolution voltage map for each patient.
Result: A total of 4194 mapping points were analyzed for metabolic activity. Voltage defined scar (<0.5mV; n=1546 mapping points) demonstrated a metabolic activity of 57±42%, which significantly increased to 72±47% in the border zone (0.5-1.5mV; n=1296 mapping points; p1.5mV; n=1352 mapping points) with 88±43% (p<0.001). The 15 ablation sites demonstrated an abnormal metabolic activity (56±33%). While the tracer uptake was reduced in the 10 ablation lesions located in the voltage defined scar or border zone (<1.5mV; 52±34%), even 40% (2/5) of the successful ablation sites with preserved voltage (>1.5mV) demonstrated a decreased metabolic uptake (33±29% vs. 85±8%).
Conclusion: Molecular imaging demonstrated significant quantitative, functional differences in scar, border zone and normal myocardium. Successful ablation sites showed a decreased tracer uptake and demonstrated a decreased tracer uptake even in 40% of the ablation sites with preserved bipolar voltage. This may possibly facilitate VT ablation in ischemic patients.
Author Disclosures: M.S. Abdulghani: None. R. Asoglu: None. M. Smith: None. W. Chen: None. R. Vunnam: None. T. Klein: None. A. Saliaris: None. V. See: None. S. Shorofsky: None. V. Dilsizian: Research Grant; Modest; GE. T. Dickfeld: Research Grant; Modest; Biosense and GE research grant. Consultant/Advisory Board; Modest; Biosense.
- © 2014 by American Heart Association, Inc.