Cardiac Magnetic Resonance Parameters Predict Transplantation-Free Survival in Patients With Fontan Circulation

Abstract

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 Fontan patients who had a CMR study from 1/2002 to 1/2011 were retrospectively reviewed. The endpoint 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]. Over a median post-CMR follow-up period of 4.1 years [2.6, 6.2], 24 patients (11%) reached the endpoint: 20 deaths, 3 transplants, and 1 transplant listing. In a multivariable Cox regression model with clinical parameters only, protein losing enteropathy (PLE) was associated with transplant-free survival. A multivariable model including clinical and CMR parameters showed that in addition to PLE, ventricular end-diastolic volume (EDVi) >125 mL/BSA1.3 was associated with transplant-free survival. A likelihood-ratio test comparing the 2 models showed that the addition of EDVi resulted in a significantly improved endpoint prediction (P<0.001) — C-index increased from 0.63 to 0.79. Conclusions CMR-derived ventricular EDVi is an independent predictor of transplant-free survival late after the Fontan operation and adds incremental value over clinical symptoms alone for risk stratification.

Ventricular function and cardiac reserve in contemporary Fontan patients

“…Our data on ventricular volumes are remarkably similar to those recently reported in a somewhat older cohort from Boston. In that study CMR-derived ventricular indexed enddiastolic volume was an independent predictor of transplantation-free survival in patients late after the Fontan operation [31]. Direct comparison of these results is difficult, since different methods were used for indexing to body surface area.…”

Factors associated with long-term mortality after Fontan procedures: a systematic review

“…Few studies reported imaging markers predictive of long-term mortality or transplant 31. One study showed that global circumferential strain on transthoracic echocardiogram is predictive of long-term mortality (HR=1.3 per unit change, 95% CI 1.1 to 1.5) 32.…”

Role of cardiac MRI and CT in Fontan circulation

“…Serial assessment of the ventricular volume is important as a dilated ventricle (end-diastolic volume greater than 125 ml/body surface area 1.3 ) is associated with poorer outcomes [25], therefore a standard analysis technique is vital. In addition, it may be worthwhile evaluating the size and function of the secondary Fig.…”