Diffuse Myocardial Fibrosis Evaluated by Post-Contrast T1 Mapping Correlates With Left Ventricular Stiffness

Objectives rpose of this study was to use cardiac magnetic resonance (CMR) imaging and invasive left ventricular (LV) pressure-volume (PV) measurements to explore the relationship between diffuse myocardial fibrosis and indexes of diastolic performance in a cohort of cardiac transplant recipients. ound ecise mechanism of LV diastolic dysfunction in the presence of myocardial fibrosis has not previously been established. s formed CMR with T1 mapping and obtained invasive LV PV measurements via a conductance catheter in 20 cardiac transplant recipients at the time of clinically-indicated coronary angiography. s ost-contrast myocardial T1 time and extracellular volume fraction correlated with β, the load-independent passive LV stiffness constant (r = −0.71, p = 0.001, and r = 0.58, p = 0.04, respectively). After multivariate analysis, post-contrast myocardial T1 time remained the only independent predictor of β. No significant associations were observed between myocardial T1 time and τ, the active LV relaxation constant, or other load-dependent parameters of diastolic function. sions e myocardial fibrosis, assessed by post-contrast myocardial T1 time, correlates with invasively-demonstrated LV stiffness in cardiac transplant recipients. In patients with increased diffuse myocardial fibrosis, abnormal passive ventricular stiffness is therefore likely to be a major contributor to diastolic dysfunction.