Durable Mechanical Circulatory Support in Patients with Amyloid Cardiomyopathy: Insights from INTERMACS

Background: Many patients with amyloid cardiomyopathy (ACM) develop advanced heart failure, and durable mechanical circulatory support (MCS) may be a consideration. However, data describing clinical outcomes after MCS in this population are limited. Methods: Adult patients in the Interagency Registry for Mechanically Assisted Circulatory Support with dilated cardiomyopathy (DCM, n=19 921), nonamyloid restrictive cardiomyopathy (RCM, n=248), or ACM (n=46) between 2005 and 2017 were included. Patient and device characteristics were compared between cardiomyopathy groups. The primary end point was the cumulative incidence of death with heart transplantation as a competing risk. Results: Patients with ACM (n=46) were older (61 years [interquartile range, 55-69 years] versus 58 years [interquartile range, 49-66 years] for DCM and 55 years [interquartile range, 46-62 years] for nonamyloid RCM, P<0.001) and were more commonly Interagency Registry for Mechanically Assisted Circulatory Support profile 1 (30.4% versus 17.9% for DCM and 21.0% for nonamyloid RCM, P=0.04) at device implantation. Use of biventricular support (biventricular assist device or total artificial heart) was the highest for patients with ACM (41.3% versus 6.7% and 19.4% for patients with DCM and nonamyloid RCM, respectively, P=0.014). The cumulative incidence of death was highest for patients with ACM relative to those with DCM or nonamyloid RCM (P<0.001) but did not differ significantly between groups for those who required biventricular MCS. Conclusions: Compared with patients with DCM or nonamyloid RCM who received durable MCS, those with ACM experienced the highest use of biventricular support and the worst survival. These data highlight concerns with the use of durable MCS for patients with ACM.