Abstract 2417: Short-Term Experience of Immunoadsorption Therapy for Refractory Heart Failure Due to Dilated Cardiomyopathy
Background: Dilated cardiomyopathy (DCM) is the predominant cause of end-stage heart failure (HF) resulting in heart transplantation in Japan. Autoimmune disorder is one of the features characterizing DCM. Various anticardiac autoantibodies are found in approximately 85% of such patients, and some autoantibodies play a role in mediating myocardial damage and fatal arrhythmias resulting in sudden death. Immunoadsorption technique (IA) is one of the potentially promising therapeutic measures to remove these autoantibodies. High-profile tryptophan column has low antigenecity and specificity for IgG subclass 3, which appears to contain most pathophysiologically relevant autoantibodies. The goal of this study is to determine if the IA therapy using the tryptophan column has beneficial effect on cardiac function, neurohormones and cytokines in patients with severe HF who are refractory to conventional therapy.
Methods and Results: IA therapy was conducted in 17 patients with DCM (age 53 ± 3, male 8, NYHA III/IV, mean ejection fraction 18 ± 2%), who were refractory to conventional medical therapy including β-blockers and cardiac resynchronization therapy. Study subjects had autoantibodies directed against either β1 adrenergic or M2 muscarinic receptors, which were screened by ELISA. IA was performed for 2 hours each session, and repeated 3 to 5 times. All 17 cases completed IA without any complications. We confirmed that autoantibody titers for β1 adrenergic and M2 muscarinic receptors decreased or became undetectable after the sessions of IA. Plasma BNP levels were significantly decreased after completion of IA (from 884 ± 181 pg/ml to 520 ± 128 pg/ml, p = 0.002). Plasma inflammatory cytokines including interleukin-6 and tumor necrosis factor-α showed no significant changes after each session of IA. Six minutes walk distance was significantly increased (from 313 ± 39 m to 360 ± 29 m, p = 0.01). LVEF measured by radionuclide ventriculography tended to increase 3– 6 months after completion of IA (from 18 ± 2% to 21 ± 2%, p = 0.08).
Conclusions: Our initial experience demonstrated safety and efficacy of IA for patients with advanced HF due to DCM. Long-term follow-up is needed to confirm the effects on cardiac function and morbidity/mortality in such patients.