Comparing outcomes for infiltrative and restrictive cardiomyopathies under the new heart transplant allocation system

Area of Science:

• Cardiology
• Transplantation Medicine
• Public Health Policy

Background:

• The introduction of a new heart transplantation (HT) allocation policy on October 18, 2018, prompted an evaluation of its impact.
• Previous allocation systems faced challenges in managing waitlist dynamics and clinical outcomes for specific heart conditions.

Purpose of the Study:

• To compare early outcomes of heart transplantation for patients with restrictive cardiomyopathy, hypertrophic cardiomyopathy, cardiac sarcoidosis, or cardiac amyloidosis under the new policy versus the old system.
• To assess the effects of the revised HT allocation policy on waitlist events and transplantation rates.

Main Methods:

• Utilized the United Network for Organ Sharing (UNOS) registry to analyze data from 1232 HT candidates.
• Categorized patients into two eras: Era 1 (pre-policy, listed before 10/17/2018) and Era 2 (post-policy, listed on or after 10/18/2018).
• The primary endpoint was defined as death on the waitlist or delisting due to clinical deterioration.

Main Results:

• Era 2 demonstrated a significant increase in temporary mechanical circulatory support use.
• A reduction in the primary endpoint was observed in Era 2 (18.6 events per 100 PY) compared to Era 1 (20.9 events per 100 PY).
• Median waitlist time decreased significantly (91 to 58 days), and the transplantation rate increased substantially (119.0 to 204.7 transplants/100 PY).

Conclusions:

• The new heart transplantation allocation policy has successfully decreased waitlist time and mortality/delisting due to clinical deterioration for patients with infiltrative, hypertrophic, and restrictive cardiomyopathies.
• The policy change has led to an increased rate of heart transplantation for these patient groups.
• Importantly, the updated policy did not adversely affect post-transplant 6-month survival rates.