Abstract 16939: Scar/EF Assessed by Delayed Hyperenhancement Cardiac MRI is a Novel Viability Index Which Independently Predicts Survival in Patients with Severe Ischemic Cardiomyopathy
Introduction: Myocardial scar burden (MSB) is an independent predictor of mortality in ischemic cardiomyopathy (ICM). However, the integration of MSB with resultant EF has not previously been assessed as a predictor of outcomes in severe ischemic cardiomyopathy.
Purpose: We sought to compare the association of scar/EF and other traditional viability indexes with outcomes in severe ICM.
Methods: 335 patients with > 70% stenosis in ≥1 epicardial coronary artery (75% men, median age 64 years, median LV ejection fraction (EF) 22 %, median ESVi 109cc) underwent delayed hyperenhancement(DHE)-MRI between 2003-2007. Scar was defined as > 2 SD above normal myocardium. . LV scar score (summed segmental scar score per patient divided by 17) was recorded as: 0 = none, 1 = 1-25%, 2 = 26-50%, 3 = 51-75%, and 4 = > 75%. LV volumes and LV ejection fraction were calculated Scar/EF was defined as scar score/EF. Cox proportional hazards survival modeling of a composite end-point (CE; cardiac transplantation, all-cause mortality) was used to risk-adjust comparisons.
Results: Over a follow-up of up to 8 years[mean 5.5 years], 131 events occurred (126 deaths, 5 cardiac transplantations). Revascularization within 90 days after testing (REV) occurred in 168 patients and was modeled with logistic regression to develop a propensity score. Survival analysis revealed that after adjusting for prior CABG/PCI, sex, diabetes, age, use of CRT, ICD, mitral valve or aortic valve procedures, scar/EF(χ2 18.4, Global χ253), scar score(χ2 9, Global χ244.9), EF(χ2 4.5, Global χ240), ESVi (χ2 4.5, Global χ2 40) were predictors of CE. However, scar/EF was the most powerful, independent predictor of CE in the global model. For each of these models, only the addition of scar/EF further increased the χ2 power.
Conclusions: Scar/EF assessed by DHE-MRI is a novel powerful incremental prognostic viability index in patients with severe ICM and has superior prognostic power compared to traditional viability indexes.
- © 2011 by American Heart Association, Inc.