Abstract 15700: [11C]PIB and [11C]Acetate in Positron Emission Tomography: A New Method to Diagnose and Evaluate Cardiac Function in Patients With Cardiac Amyloidosis
Introduction: Cardiac amyloidosis is an important and serious manifestation of systemic amyloidosis. Diagnosis is often delayed and requires several diagnostic procedures including echocardiography, right heart catheterization and myocardial biopsy. We hypothesized that Positron Emission Tomography (PET) can be used to visualize amyloid deposits in the myocardium and also to evaluate cardiac function non-invasively.
Methods: Ten patients with confirmed AL, transthyretin (familial or senile systemic) and three healthy controls were scanned with PET using tracers [11C]PIB (Pitsburg Compound B) and [11C]acetate. PIB binds to amyloid and when combined with 11C, it functions as an amyloid imaging agent. [11C]acetate is used to measure perfusion and oxygen consumption in the myocardium as well as stroke volume. Cardiac involvement was diagnosed either by myocardial biopsy or by echocardiography Results consistent with restrictive cardiomyopathy combined with the established systemic amyloidosis diagnosis by immunohistochemistry or western blot.
Results: All patients showed [11C]PIB retention in the myocardium (as seen in figure 1) whereas there were no signs of retention in the control group. This indicates that we can visualize myocardial amyloid deposits in patients with cardiac amyloidosis measured as uptake and retention of [11C]PIB. [11C]PIB and [11C]acetate had different uptake patterns in patients which show that [11C]PIB uptake is not representing blood flow and probably is a measure of binding to amyloid. By measuring [11C]acetate kinetics we can derive that the patients both had lower stroke volumes and higher oxygen consumption in the right ventricle compared to their healthy counterparts, consistent with restrictive cardiomyopathy.
Conclusions: [11C]PIB and [11C]acetate PET is a new method to diagnose and evaluate cardiac function in patients with cardiac amyloidosis.
- © 2010 by American Heart Association, Inc.