Abstract 17150: Myocardial Fibrosis by T1 Mapping is an Early Indicator of Severe Cardiac Allograft Vasculopathy
Background: Cardiac allograft vasculopathy (CAV) is associated with late graft failure and mortality. Recognition of graft dysfunction due to CAV using current criteria occurs late and implies poor prognosis. We aimed to determine whether myocardial extracellular volume (ECV) with T1 weighted cardiac magnetic resonance (CMR), an indicator of intramyocardial fibrosis, was increased in patients with CAV prior to the onset of left ventricular (LV) dysfunction.
Methods: A cross-sectional study was performed to determine the association between myocardial fibrosis and CAV. Subjects were matched based on age and duration of transplant. All subjects underwent coronary angiogram, right heart catheterization, echocardiogram, and CMR assessment with T1 mapping in single short-axis slice. ECV, scar volume, scar percent, hemodynamics, RV function, and LV systolic and diastolic indices by echo were compared between patients with and without CAV. CAV was graded using current ISHLT criteria.
Results: 12 heart transplant recipients were included, 6 with CAV and 6 without CAV. 11 were male, mean age was 52 yrs, mean duration of transplant 6.1 yrs. Two patients were transplanted for ischemic cardiomyopathy. The cardiac index (CI), pulmonary capillary wedge pressure (PCWP) and mean right atrial pressures (RAP) were similar in both groups. LV ejection fraction (LVEF), right ventricular systolic function (RVEF), diastolic indices assessed by echo, and cardiac mass index assessed by CMR were normal and similar between CAV and no CAV. However, patients with CAV had significantly increased ECV (37±06 vs. 29%±02; p=0.01) and increased scar (13%±8.86 vs. 0%, p=0.005) compared to those without CAV.
Conclusions: Myocardial ECV is elevated in patients with CAV despite preserved systolic and diastolic function. T1 mapping may have the potential to detect early graft dysfunction in CAV. Longitudinal studies are required to assess its prognostic value.
- © 2013 by American Heart Association, Inc.