# Cardiac Medication Prescription Pattern and Association With Transplant-free Survival in the Adult Fontan Population

## TL;DR

This study examines how medications affect survival in adults with Fontan circulation, finding that loop diuretics are linked to worse outcomes.

## Contribution

The study provides one of the first large-scale analyses of medication patterns and survival in adult Fontan patients.

## Key findings

- Loop diuretic prescriptions were associated with significantly worse transplant-free survival.
- Antiplatelet agents were the most commonly prescribed medication class.
- The study reports detailed medication patterns in a large cohort of adult Fontan patients.

## Abstract

There are limited data on the cardiac medications taken by patients with Fontan circulation in adult congenital heart disease (ACHD) clinics.

The objectives of the study were to describe the type and frequency of cardiac medications prescribed to adults with Fontan circulation and assess for association between medication prescriptions/burden and transplant-free survival.

A retrospective cohort study of adults with Fontan circulation followed in an outpatient ACHD clinic between 2009 and 2023 was performed. Demographics, clinical variables, and all prescribed outpatient cardiac medications were abstracted from the electronic medical record. The outcome of interest was transplant-free survival. Cox proportional hazards analysis was performed to determine the association between the medication type/burden and transplant-free survival.

There were 429 patients (55.2% male, 72.5% White, and 49.7% single left ventricle morphology) with median age 24 years (IQR: 22-29) at time of first clinic visit. The most prescribed medication classes were antiplatelet agents (74.6%) followed by angiotensin converting enzyme inhibitors or angiotensin receptor blockers (59.0%), anticoagulants (44.1%), loop diuretics (39.6%), metoprolol (32.2%), mineralocorticoid receptor antagonists (31.5%), antiarrhythmics (27.5%), and pulmonary vasodilators (16.1%). Being prescribed loop diuretic agents was associated with worse transplant-free survival (HR: 9.49, P < 0.001).

We report one of the first large-scale studies of prescription patterns in adult patients with Fontan circulation in a single ACHD clinic. We demonstrate an inverse association between loop diuretic prescriptions and transplant-free survival.