Impact of the New Heart Allocation System on the Medium-Term Outcomes in Patients With Hypertrophic Cardiomyopathy.

Abstract

The introduction of the new heart allocation system in the United States in 2018 resulted in an increase in the number of heart transplants (HT) performed among patients with hypertrophic cardiomyopathy (HCM). However, whether that affected medium-term post-HT outcomes in this group of patients remains unknown. We conducted an analysis of the United Network for Organ Sharing Transplant Database, including adults with HCM who underwent heart transplantation between 2015 and 2021. Patients were divided into two equal-duration eras: Era 1 (October 17, 2015, to October 17, 2018) and Era 2 (October 18, 2018, to October 18, 2021). In the studied period, 444 patients with HCM underwent HT: 204 in Era 1 and 240 in Era 2. In Era 2, the waitlist time was shorter, transplant rates were higher, patients were less frequently supported with inotropes but more often with an IABP, ischemic time was longer, and donor-to-recipient distance larger. Pre- and post-transplant functional status was comparable across the two eras, while the pre-HT employment rate was higher in the new system. The 3 year survival was unchanged across eras. In the new allocation system, despite more frequent mechanical circulatory support (MCS) use and increased ischemic time, the medium-term outcomes of patients with HCM remained favorable.