Abstract 18020: Cardiac Autoantibodies Negatively Affect Diastolic Function In Dilated Cardiomyopathy
Background: Disturbances of the humoral immune system have been described in patients with dilated cardiomyopathy (DCM). Immunoadsorption has been evaluated as a new treatment option in DCM with favourable influence on left ventricular systolic function. It is not known, whether these autoantibodies also influence diastolic properties. These studies aimed to evaluate the effect of cardiotropic antibodies and their removal by immunoadsorption (IA) on diastolic function in DCM.
Methods: 15 Patients with DCM (LVEF < 45%, NYHA II-IV) were treated by means of IA for 5 consecutive days with subsequent IgG substitution. Diastolic parameters were recorded by means of echocardiography before and 6 months after IA. Before IA, total IgG from serum of patients was isolated by means of mini-column apheresis. IgG was then added to isolated rat cardiac myocytes. Cell relaxation properties were recorded by means of single cell video edge detection under continuous 1Hz excitation.
Results: Patients showed signs of impaired ventricular relaxation and increased atrial pressure before IA/IgG (deceleration time (DT): 184 ± 16ms; isovolumic relaxation time (IVRT): 112 ± 15ms; atrial reversal flow velocity (AR): 41.2 ± 2.8cm/s). Parameters of diastolic relaxation improved 6 months after IA (DT: 232 ± 19ms, p<0.05; IVRT: 59 ± 5ms, p<0.01; AR: 31.1 ± 1.7cm/s, p<0.01). Relaxation velocity of isolated cardiomyocytes was concentration-dependently reduced after addition of patient IgG (300μg: −10.3 ± 2.8%, p<0.05 vs. baseline recordings).
Conclusion: Besides influencing systolic properties, antibodies binding to isolated cardiomyocytes manipulate relaxation of isolated cardiomyocytes. Treatment with IA/IgG reduces impaired ventricular relaxation and increased atrial pressure.
- © 2010 by American Heart Association, Inc.