P0412 - Systemic Ventricular Strain Predicts Transplant Free Survival in Fontan Patients with Hypoplastic Left Heart Syndrome

Background:
Despite improvements in the clinical management of hypoplastic left heart syndrome patients with Fontan palliation, this patient population is highly vulnerable to complications and mortality. Many will require heart transplant due to either inefficiencies of systemic ventricular dysfunction. Limited data exists to help determine an appropriate time for transplant referral. This study aims to determine if systemic ventricular strain by echocardiography would predict transplant free survival.

Methods:
Hypoplastic left heart patients who had undergone Fontan palliation at our institution since 1994 and had echocardiograms done between 2011 and 2019 were included in the study. Patients were divided into: 1) those who required transplant or experienced death; and 2) those who did not require transplant or experience death. For those who did experience the composite endpoint, the last echocardiogram prior to the composite outcome was used while for those who did not experience the composite endpoint the last echocardiogram done was used. Global longitudinal strain (GLS) and global circumferential strain (GCS) were then compared between the two groups in univariate fashion. A receiver operator curve analysis was used to determine whether GLS and GCS were predictive of the composite outcome.

Results:
A total of 89 patients with hypoplastic left heart syndrome where identified, of whom 33 patients with adequate images were included in this initial analysis. Of these, 6 (18%), experienced the composite outcome. GLS was worse in those with the composite outcome (-7.0% versus -15.7%, p< 0.01) as was GCS (-5.6% versus -16.9%, p= 0.01).

Receiver operator curve analysis for GLS resulted in an area under the curve of 83.7%, demonstrating good predictive value. GLS of -7.3% was 83% sensitive and 89% specific for predicting the composite outcome.

Receiver operator curve analyses for GCS resulted in an area under the curve of 86.0%, demonstrating good predictive value. GCS of -10.0% was 100% sensitive and 80% specific for the predicting the composite outcome.

Conclusion:
GLS and GCS can help predict transplant free survival in patients with hypoplastic left heart syndrome having undergone Fontan palliation. Worsening strain may be a helpful tool in determining when transplant evaluation is warranted in these patients.