Removal of β-1 autoantibodies in patients with idiopathic dilated cardiomyopathy: long-term efficacy as bridge-to-transplant therapy

Objectives: With increasing heart transplant (HTx) waiting-times, improvement of bridge-to-transplant therapies is paramount. Previously we showed that immunoadsorbtion (IA) is superior to standard medication for treatment of idiopathic dilated cardiomyopathy (IDCM) with evidence of serum β₁-autoantibodies (β₁-AAB). Now we assessed the long-term efficacy of IA in HTx-candidates with IDCM.

Methods: Cardiac function and survival without HTx or ventricular assist device (VAD) implantation were evaluated in β₁-AAB positive patients with end-stage IDCM who underwent IA between 5/1995 and 5/2003 (follow-up: 6–14 years). Additionally we looked for differences in efficacy between unselective (unspecific IA) and selective (specific IA) β₁-AAB removal.

Results: At 6 months after IA, the 105 evaluated patients showed LV diameter decrease from 73±8mm to 67±9mm and LVEF improvement from 23±5% to 29±8% (p<0.01). There were no differences in cardiac improvement between patients with unspecific and those with specific IA. HTx or VAD free survival was reached at 3 years and 5 years by 77.3% and 69.3% of patients with unspecific IA and by 95% and 89.1% of those with specific IA, respectively. Of 54 patients who underwent unspecific IA ≥10 years ago, 27 (50%) survived for ≥8 years without HTx or VADs. Early reappearances of β₁-AABs in 9 (8.6%) of the patients were associated with cardiac worsening.

Conclusions: In a high proportion of IDCM patients referred for HTx, the use of IA allows evident and long-term stable improvement of cardiac function which provides not only efficient bridge-to-transplant but can also delay patients' listing for HTx for many years.