Abstract 12505: Prognostic Significance of Myocardial Extracellular Volume Fraction
Background: Cardiac magnetic resonance (CMR) techniques permit quantification of cardiac extracellular volume fraction (ECV), inclusive of interstitial fibrosis. ECV and late gadolinium enhancement (LGE), suggestive of cardiac replacement fibrosis, have been independently linked with heart failure (HF) events. Non-coronary artery disease type LGE has not been excluded in ECV measures. We examined associations between ECV censored for LGE-involved segments, LGE presence, and HF events.
Methods: Mid short axis T1 maps were divided into 6 cardiac segments, each classified as LGE absent or present. Global ECV was derived from T1 maps using the area-weighted average of only LGE-absent segments. ECV was considered elevated if measured >30%, the upper 95% bounds of a healthy group without known cardiac disease (n=28). Patients were divided into 4 groups based on presence of elevated ECV and of any LGE. Subsequent HF admission and any death were ascertained. Their relationship with ECV was examined separately and as a composite with Cox proportional hazard models.
Results: Of 1,604 serial patients with T1 maps, 1,047 were eligible after exclusions and followed over a median 10.5 (interquartile range 5.4, 21.4) months. Patients with elevated ECV had an increased risk for death (hazard ratio [HR] 2.60, 95% confidence interval [CI] 1.78 to 3.79)), HF admissions (HR 1.97, 95% CI 1.48 to 2.61), and combined endpoint (HR 2.14, 95% CI 1.69 to 2.70) regardless of LGE presence (Table). After adjustments for covariates, the relationship persisted for death (HR 1.86, 95% CI 1.24 to 2.79), hospitalization (HR 1.54, 95% CI 1.13 to 2.10), and combined endpoints (HR 1.60, 95% CI 1.24 to 2.07).
Conclusion: Extracellular volume fraction measures were associated with heart failure outcomes, despite censoring of replacement fibrosis segments and even among patients without any replacement fibrosis. ECV may have a synergistic role with replacement fibrosis in heart failure risk assessment.
Author Disclosures: E.Y. Yang: None. M. Ghosn: None. M.A. Khan: None. N.L. Gramze: None. G.W. Pickett: None. S.J. Pickett: None. P.W. Green: None. G. Brunner: None. F. Nabi: None. W. Chan: None. V. Nambi: None. C.M. Ballantyne: Consultant/Advisory Board; Modest; Abbott Diagnostics, Amarin, Amgen, Eli Lilly, Esperion, Ionis, Matinas BioPharma Inc, Novartis, Regeneron, Roche Diagnostic. Research Grant; Significant; NIH, AHA, ADA. Other Research Support; Significant; Abbott Diagnostic, Amarin, Amgen, Eli Lilly, Esperion, Ionis, Novartis, Pfizer, Regeneron, Roche Diagnostic, Sanofi-Synthelabo. Consultant/Advisory Board; Significant; Astra Zeneca, Merck, Pfizer, Sanofi-Synthelabo. D.J. Shah: None.
- © 2016 by American Heart Association, Inc.