Background: Several clinical risk factors for death and heart transplantation have been identified in patients with Fontan circulation. It is unknown whether cardiac magnetic resonance (CMR) measurements of ventricular size and function are independently associated with these outcomes and further improve risk stratification.
Methods and results: Data on patients with Fontan circulation who had a CMR study from January 2002 to January 2011 were retrospectively reviewed. The end point was time to death or listing for heart transplantation after the CMR study. The median age of the 215 patients was 18.3 years (25th, 75th percentiles: 14, 26) with a median age at Fontan of 3.6 years (2.3, 7.1). During a median post-CMR follow-up period of 4.1 years (2.6, 6.2), 24 patients (11%) reached the end point: 20 deaths, 3 transplantations, and 1 transplantation listing. In a multivariable Cox regression model with clinical parameters only, protein-losing enteropathy was associated with death or listing for transplant. A multivariable model, including clinical and CMR parameters, showed that in addition to protein-losing enteropathy, ventricular indexed end-diastolic volume >125 mL/body surface area raised to the 1.3 power was associated with the endpoint. A likelihood-ratio test comparing the 2 models showed that the addition of indexed end-diastolic volume resulted in a significantly improved end point prediction (P<0.001)-C-index increased from 0.63 to 0.79.
Conclusions: CMR-derived ventricular indexed end-diastolic volume is an independent predictor of death or transplant in patients late after the Fontan operation and adds incremental value over clinical symptoms alone for risk stratification.
Keywords: Fontan procedure; heart defects, congenital; magnetic resonance imaging.
© 2014 American Heart Association, Inc.