WEANING FROM MECHANICAL CARDIAC SUPPORT IN PATIENTS WITH IDIOPATHIC DILATED CARDIOMYOPATHY

Background Implantation of mechanical cardiac support systems (MCSS) i n patients with idiopathic dilated cardiomyopathy (IDC) may improve ca rdiac function and allow explantation of the device. We report of long -term effects of ventricular unloading on cardiac function, humoral an ti-beta 1-adrenoceptor autoantibodies (A-beta(1)-AABs), and myocardial fibrosis. Methods and Results Seventeen patients in New York Heart As sociation functional class IV with nonischemic IDC received MCSS. All had a cardiac index of <1.6 L.min(-1).m(-2) of body surface area, a le ft ventricular ejection fraction (LVEF) of <16%, and a left ventricula r internal diameter in diastole (LVIDd) of >68 mm and tested positive for A-beta(1)-AABs. Echocardiographic evaluation, serum tests for A-be ta(1)-AABs, and histological assessment of myocardial fibrosis were pe rformed before and after MCSS implantation. The mean support duration was 230+/-201 days. Six patients died, four were transplanted, and two are still on MCSS. Five patients with significant cardiac recovery (m ean LVIDd, 54+/-2.3 mm; LVEF, 47+/-3.7%) were weaned after 160 to 794 days and are now device free for 51 to 592 days. A-beta(1)-AABs disapp eared gradually during MCSS without increase after weaning; cardiac fu nction and volume density of fibrosis remained normal. Nine patients' cardiac function hardly improved during ventricular unloading. Conclus ions Cardiac function can be normalized in selected patients with end- stage IDC by MCSS. The degree of preoperative myocardial fibrosis may be an indicator for outcome; A-beta(1)-AABs can be used to monitor myo cyte recovery. Weaning from MCSS offers an alternative to cardiac tran splantation in certain patients.