TY - JOUR T1 - Myocardial Energetics in AL and ATTR Cardiac Amyloidosis: A C-11 Acetate PET/CT Study JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 228 LP - 228 VL - 59 IS - supplement 1 AU - M. Samir El-Sady AU - Marie Kijewski AU - Sophia Jacob AU - Paco Bravo AU - Shipra Dubey AU - Ariana Nodoushani AU - Anthony Belanger AU - Mi-Ae Park AU - Rodney Falk AU - Marcelo Di Carli AU - Sharmila Dorbala Y1 - 2018/05/01 UR - http://jnm.snmjournals.org/content/59/supplement_1/228.abstract N2 - 228Background: Myocardial energy consumption and efficiency are reduced in patients with heart failure and reduced ejection fraction. Preclinical work suggests that AL-cardiomyopathy (AL-CMP) is characterized by increased oxidative stress from mitochondrial dysfunction and impaired mitophagy. Our goal was to determine whether myocardial energy efficiency is lower in patients with AL-cardiomyopathy (AL-CMP) compared to those with ATTR cardiomyopathy. Methods: We prospectively studied 23 subjects with cardiac amyloidosis diagnosed by systemic or endomyocardial biopsy and elevated cardiac biomarkers (troponin T or age-adjusted NT pro BNP). All subjects underwent echocardiography and rest PET/CT imaging using 3D list mode acquisition after intravenous injection of ~740 MBq of C-11 acetate. Global left ventricular (LV) myocardial blood flow and k2 values were obtained using PMOD and kmono values were obtained by fitting the time-activity curves between 5 and 32 minutes post-injection to an exponential function. Myocardial k2 was obtained using PMOD. Myocardial wall thickness and LV mass were measured by echocardiography. Myocardial stroke volume was measured by C-11 acetate PET/CT and indexed to body surface area. Myocardial work was defined as the product of stroke volume index, heart rate, and systolic blood pressure (x105). Myocardial energy efficiency (x106) was calculated as the ratio of myocardial work to MVO2 (kmono). Results: The study cohort included 20 AL-CMP and 3 ATTR-CMP subjects. Mean left ventricular ejection fraction did not differ between subjects with AL-CMP (46±12%) and ATTR-CMP (38±8%, P=0.19). Compared to patients with ATTR-CMP, those with AL-CMP differed in several demographic, cardiac structure, and myocardial metabolic features (Table). Patients with AL-CMP were younger, with smaller body surface area, higher LVEF, smaller LV mass, and lower stroke volume index. Rest myocardial blood flow, kmono, k2, and myocardial work were lower in ATTR compared to AL subjects. Myocardial energy efficiency was higher in patients with ATTR-CMP compared to AL-CMP. Conclusions: These results suggest that myocardial structure and energy utilization patterns differ between patients with AL-CMP and ATTR-CMP. Patients with AL-CMP have much lower myocardial mass and lower energy efficiency compared to patients with ATTR-CMP, suggesting better myocardial metabolic adaptation in ATTR-CMP. These findings if confirmed in a larger cohort suggest a role for novel therapeutics to manipulate substrate utilization in AL-CMP. View this table: ER -