Abstract 18985: Extracellular Volume Fraction Evaluated by T1-Mapping Determines Left Ventricular Stiffness and is Associated With Exercise Capacity in Patients With Heart Failure With Preserved Ejection Fraction
Introduction: In patients with heart failure with preserved ejection fraction (HFpEF), increased left ventricular (LV) stiffness can be a potential therapeutic target. However, noninvasive assessment of this parameter has not been established yet.
Hypothesis: We assumed that diffuse myocardial fibrosis, measured as extracellular volume fraction (ECV) of the myocardium by using cardiac magnetic resonance (CMR) T1 mapping, can determine passive LV stiffness, and evaluated the relationship between ECV and exercise capacity.
Methods: A total of 14 HFpEF (4 male, 66±15 years) patients who revealed a typical clinical presentation with heart failure NYHA classes III-III were prospectively enrolled. HFpEF was defined as LV ejection fraction greater than 50% on echocardiography, the ratio of early transmitral velocity to tissue Doppler mitral annular early diastolic velocity (E/Ea) >8 and plasma BNP level >35pg/ml. All patients underwent CMR at 3T and cardiac catheterization with pressure-volume loop catheters. ECV was quantified using hematocrit-adjusted myocardial and blood T1 values measured before and after administration of gadolinium contrast medium. LV stiffness was assessed by the slope of the end-diastolic pressure-volume curve during vena cava occlusion. Exercise capacity was determined by maximal cardiopulmonary exercise testing.
Results: Twelve patients (86%) had hypertension and 5 patients (36%) showed late gadolinium enhancement (LGE). ECV was significantly correlated with LV stiffness constant β and was the strongest independent predictor for LV stiffness constant β (β=0.56, p<0.01). LV stiffness constant β had no correlation with E/Ea, plasma BNP level, LV mass index or cardiac index. In addition, ECV had an inverse weak correlation with peak oxygen uptake peak VO2 (r=–0.49. p=0.15).
Conclusions: CMR quantification of ECV has great potential for the noninvasive assessment of LV stiffness and can be useful as an indicator of exercise capacity in HFpEF.
Author Disclosures: T. Omori: None. K. Dohi: None. N. Fujimoto: None. S. Nakamori: None. M. Ishida: None. N. Kumagai: None. Y. Ichikawa: None. K. Kitagawa: None. N. Yamada: None. H. Sakuma: None. M. Ito: None.
- © 2016 by American Heart Association, Inc.