Abstract 14181: Diffuse Interstitial Myocardial Fibrosis Detected by T1 Mapping is Increased in Patients With Heart Failure With Preserved Ejection Fraction, and Correlates With Diastolic Dysfunction and Severity of Heart Failure
Introduction: Diffuse interstitial myocardial fibrosis (IMF) plays a key role in heart failure with preserved ejection fraction (HFPEF). T1 mapping, a novel magnetic resonance (MRI) technique, has recently been used to quantify IMF non-invasively. The aim of our study was to assess IMF by T1 mapping in HFPEF patients compared with controls, and evaluate its relationship to the severity of diastolic dysfunction and of heart failure
Methods: We performed 3 Tesla MRI in 45 HFPEF patients and in 25 controls. HFPEF was defined as symptoms and signs of HF in the presence of left ventricular (LV) ejection fraction (LVEF) >50%, evidence of diastolic dysfunction, and the absence of other causes. T1 mapping with a Look -Locker sequence was performed 9±3 minutes after infusion of 0.2 mmol/Kg of gadolinium. We calculated post-contrast T1 relaxation time as a surrogate for IMF using previously validated in-house custom-made software. Feature tracking derived longitudinal strain (FT-LS) and circumferential strain (FT-CS) were analyzed from the MRI cine images. Diastolic function was assessed by echocardiography. LV filling pressures were obtained from cardiac catheterization.
Results: There were no differences in age (58±15 vs. 57±17 years, p=NS), gender or anthropometric measures between both groups. Post-contrast T1 relaxation times were significantly shorter in HFPEF patients vs. controls (413±51 vs. 474±37ms, p<.01), suggesting a higher degree of IMF in HFPEF. LVEF and T1 times did not correlate, but there was significant correlation between T1 values and FT-LS (r=-0.52, p<.05), a more sensitive measure of LV systolic function. Also, T1 times correlated with diastolic function: E′, E/E′ratio, and left atrial size (r=0.42-0.52, p<.05 for all), as well as with invasively determined LV end-diastolic pressure (r=-0.59, p<.05). Finally, T1 times also correlated with severity of HF based on brain natriuretic peptide levels, NYHA class at admission, and O2 saturation (r=0.42-0.5, p<.05 for all).
Conclusions: HFPEF patients had significantly shorter T1 times consistent with greater IMF compared with controls. T1 times correlates with and probably contributes to worse diastolic function and severity of HF in HFPEF. T1 mapping is a promising tool for the evaluation of HFPEF
- © 2013 by American Heart Association, Inc.