Background:
The use of ventricular assist devices (VADs) as bridge to transplantation (Tx) has become a standard therapeutic option in end-stage heart failure (HF). During unloading clinical recovery which allows reliable weaning from VADs is possible. After 12 years of weaning experience, we searched for parameters that are predictive for post-weaning cardiac stability and thus helpful for future weaning decisions.
Methods:
With regard to potential prediction of weaning success we evaluated echocardiographic parameters obtained during final ``off pump” trials before VAD explantation, histological changes and serum anti-ß1-adrenoreceptor autoantibody disappearance during unloading, duration of mechanical support and duration of HF. Among 79 patients weaned since 3/1995, a homogenous group of 35 patients with idiopathic dilated cardiomyopathy (IDCM) weaned from LVADs were selected for evaluation.
Results:
The 8-year post-weaning survival reached 78.1 ±8.2%. Freedom from HF recurrence at 4 years after weaning was 69.3 ±8.1%. Patients with post-weaning cardiac stability were younger, history of HF and recovery time during unloading shorter, LV short/long axis ratio lower (less spherical) and systolic wall motion velocity (measured by tissue Doppler) higher (p< 0.05). For LVEF ≥ 45% at LV enddiastolic diameter (LVEDD) ≤ 55mm the positive predictive value for ≥ 4 years cardiac stability reached 90.5%. There was no HF recurrence during the first 4 years in patients with LVEF ≥ 45%, LVEDD ≤ 55% and history of HF < 5 years. The time course of LVEF during the first 6 months also appeared predictive for long-term stability after weaning. History of HF > 5 years showed a predictive value of 90% for HF recurrence during the first 3 years. Neither reduction in myocardial hypertrophy and fibrosis nor serum anti-ß1-adrenoreceptor autoantibody disappearance during unloading appeared predictive for post-weaning stability.
Conclusions:
Off-pump LVEF and LVEDD, time course of LVEF during the first 6 months after weaning and duration of HF are predictive for the outcome after LVAD removal in IDCM patients. Patients’ age, altered LV geometry, low wall motion velocity and prolonged LVAD support until improvement (> 6 months) appeared to be risk factors for HF recurrence.
Natural history of idiopathic dilated cardiomyopathy: effect of referral bias and secular trend
