Weaning from mechanical cardiac support in patients with idiopathic dilated cardiomyopathy

Background: Implantation of a mechanical cardiac support system (MCSS) in patients with idiopathic dilated cardiomyopathy (IDC) may improve cardiac function and allow explantation of the device. Our experience now includes 13 patients who have been,,weaned'' from MCSS and we report about the overall results of this treatment as well as the effects of ventricular unloading on cardiac function, anti-p,adrenoceptor-autoantibody (A-beta(1)-AAB) level and the degree of myocardial fibrosis. Methods: 13 patients with non-ischemic IDC who had been admitted here in cardiogenic shock (CI < 1,61.min(-1).m(2), left ventricular ejection fraction [LVEF] < 16% and left ventricular internal diameter in diastole [LVIDd] > 68 mm) and who all tested positive for A-beta(1)-AABs were implanted with an uni-(12 patients) or a biventricular(1 patient) mechanical assist device. Echocardiographic evaluation and A-beta(1)-AAB-level-monitoring was routinely performed after implantation and explantation of the MCSS and the degree of myocardial fibrosis was assessed at the time of implantation and after explantation. Results: During a mean duration of mechanical support of 236 +/- 201 days (range: 30 to 794 days), LV-EF improved to a mean of 46% and LVIDd decreased to a mean value of 56 mm in these 13 patients. A-beta(1)-AABs decreased and disappeared 11,7 weeks after implantation of the device and did not reincrease thereafter. The highly pathologic degree of fibrosis at the time of implantation diminished to normal values about 1 year after explantation. One patient died of anesthesiologic complications and another patient shortly presented with a new episode of cardiac insufficiency 6 months after explantation. He was implanted again with an univentricular assist device was successfully transplanted 3 weeks later. Mean observation period of the remaining 11 patients now amounts to 12,6 +/- 9,77 (range: 3 to 26) months after explantation of the device - as of May, 31, 1997 - with a cumulative observation period of 139 patient months. Conclusion: Temporary implantation of a MCSS may normalize cardiac function in selected patients with IDC. The striking degree of myocardial fibrosis can reduce to normal values after explantation of the device. A-beta(1)-AABs disappear during ventricular unloading and do not increase thereafter. ,,Weaning'' from mechanical device may constitute an alternative treatment to cardiac transplantation in selected patients.