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

Area of Science:

• Cardiology
• Transplantation Medicine
• Medical Systems Analysis

Background:

• The 2018 US heart allocation system aimed to optimize organ distribution.
• Hypertrophic cardiomyopathy (HCM) patients experienced increased heart transplants (HT) post-system implementation.
• The impact of the new system on medium-term HT outcomes in HCM patients was previously unclear.

Purpose of the Study:

• To evaluate the effect of the 2018 heart allocation system on medium-term post-transplant outcomes in adult HCM patients.
• To compare outcomes between patients transplanted before and after the system change.
• To identify changes in transplant characteristics and patient status associated with the new system.

Main Methods:

• Analysis of the United Network for Organ Sharing Transplant Database (2015-2021).
• Inclusion of adult patients with HCM undergoing heart transplantation.
• Division into two equal-duration eras: pre- (Era 1) and post- (Era 2) allocation system implementation.

Main Results:

• 444 HCM patients underwent HT (204 Era 1, 240 Era 2).
• Era 2 showed shorter wait times, higher transplant rates, less inotrope use, more IABP support, longer ischemic times, and greater donor-recipient distance.
• Pre- and post-transplant functional status remained comparable; pre-HT employment increased in Era 2.
• Three-year survival was unchanged between eras.

Conclusions:

• The new heart allocation system facilitated increased HT for HCM patients.
• Despite challenges like longer ischemic times and increased mechanical circulatory support, medium-term outcomes for HCM patients post-HT remain favorable.
• The system appears effective in maintaining positive results for this patient population.