Weaning From Mechanical Cardiac Support in Patients With Idiopathic Dilated Cardiomyopathy

Abstract

Background Implantation of mechanical cardiac support systems (MCSS) in patients with idiopathic dilated cardiomyopathy (IDC) may improve cardiac function and allow explantation of the device. We report of long-term effects of ventricular unloading on cardiac function, humoral anti-β1-adrenoceptor autoantibodies (A-β 1 -AABs), and myocardial fibrosis. Methods and Results Seventeen patients in New York Heart Association 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 left ventricular ejection fraction (LVEF) of <16%, and a left ventricular internal diameter in diastole (LVIDd) of >68 mm and tested positive for A-β 1 -AABs. Echocardiographic evaluation, serum tests for A-β 1 -AABs, and histological assessment of myocardial fibrosis were performed 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 (mean 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-β 1 -AABs disappeared gradually during MCSS without increase after weaning; cardiac function and volume density of fibrosis remained normal. Nine patients’ cardiac function hardly improved during ventricular unloading. Conclusions 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-β 1 -AABs can be used to monitor myocyte recovery. Weaning from MCSS offers an alternative to cardiac transplantation in certain patients.