Abstract 16829: Myocardial Extracellular Volume Fraction and Survival in Systemic AL Amyloidosis
Introduction: The prognosis in Systemic AL Amyloidosis is largely driven by cardiac involvement. Using Cardiovascular Magnetic Resonance T1 mapping, we can measure the native myocardial T1 and Myocardial Extracellular Volume (ECV).
Hypothesis: We hypothesise that ECV reflects myocardial amyloidosis burden and can determine prognosis.
Methods: 92 patients underwent CMR and T1 mapping pre- and post contrast. Myocardial ECV was calculated at equilibrium. 54 healthy volunteers acted as controls. Patients were followed up for a mean duration of 18 months and survival analysis was performed. Further analysis compared the performance of ECV and native myocardial T1 as models for predicting survival.
Results: Mean ECV was raised at 0.45 compared to 0.25 for healthy volunteers (P<0.001). ECV also tracked pre-test probability of cardiac involvement (see image 1), cardiac biomarkers and systolic and diastolic dysfunction. After mean duration of follow up of 18 months, an ECV of >0.45 carried a hazard ratio of 3.83 (95% CI: 1.40 - 19.47), P=0.009. Kaplan Meier analysis was also performed (see image 2). Native myocardial T1 of >1086ms carried a hazard ratio of 4.55 (95% CI: 1.03 - 20.07), P=0.05. When ECV and native myocardial T1 were compared head to head using the Harrell’s C statistic, ECV was the stronger predictor of survival .
Conclusion: In conclusion, myocardial ECV in cardiac AL amyloidosis is a strong predictor of outcome, despite therapy.
- © 2013 by American Heart Association, Inc.