Abstract 12640: Prognostic Utility of Myocardial Fatty Acid Imaging in Risk Stratification for Sudden Cardiac Death in Patients with Ischemic Cardiomyopathy
Background: The introduction of the implantable cardioverter defibrillator (ICD) has a major impact on the prevention of sudden cardiac death (SCD) in patients with ischemic cardiomyopathy (ICM). However, revascularization is necessary and has been demonstrated to reduce arrhythmia recurrences, although some ICM patients remained at high risk for ventricular arrhythmias (VA) even after revascularization. Scar tissue after myocardial infarction is traditionally considered to be responsible for the occurrence of VA, but scar border zone, like stunning or hibernation, may function as a substrate for VA. lodine-123-beta-methyliodophenyl-pentadecanoic acid (BMIPP) SPECT can assess myocardial fatty acid utilization. The aim of this study was to evaluate the risk stratification for SCD in ICM using BMIPP imaging.
Method: We retrospectively studied 100 ICM patients who underwent revascularization followed by ICD implantation, and had undergone dual SPECT using 123 I-BMIPP and 201 thallium chloride (Tl). Comparisons were made between subjects who did and those who did not receive an appropriate ICD shock therapy. Dual myocardial SPECT findings were analyzed qualitatively and quantitatively in a blind manner, and abnormal uptake on BMIPP images were interpreted from comparison with the findings of Tl perfusion images. A multivariable logistic regression was used to identify variables associated with shock therapy.
Result: During follow-up of 40.8 ± 25.9 months, 19 patients (19%) received appropriate shock therapies. After multivariable adjustment, mismatching of BMIPP and Tl uptake remained a significant predictor of future shock therapies (OR 2.99; 95% Cl 1.03-8.67, p<0.05). Other variables including age, gender, ejection fraction, maximum beats and rates of ventricular tachycardia on Holter ECG, and medication (beta-blocker, ACE-I/ARB, statin, amiodarone) were not associated with shock therapy.
Conclusion: BMIPP and Tl dual myocardial imaging is a useful modality for predicting SCD after revascularization in patients with ICM, which should be considered in ICD implantation decision.
- Implantable cardioconvert defibrillator
- Radionuclide imaging
- Ischemic heart disease
- Sudden cardiac death
- © 2011 by American Heart Association, Inc.