Myocardial T1-mapping for early detection of left ventricular myocardial fibrosis in systemic sclerosis

Abstract

Background Subclinical primary left ventricular (LV) dysfunction is a complication of systemic sclerosis (SSc) related to progressive diffuse myocardial fibrosis. Myocardial T1-mapping has recently been proposed as a cardiac magnetic resonance (CMR) method to quantify interstitial fibrosis early in the disease course whereas late-gadolinium enhancement (LGE) imaging remains normal. Objective We aimed to evaluate whether myocardial T1-mapping could detect subclinical abnormalities in SSc patients with normal standard parameters of LV function and normal LGE imaging. Methods We prospectively studied 37 patients (52±12 years) presenting with SSc with no history of heart disease, no pulmonary hypertension at rest, a normal LV assessed by conventional echocardiography (normal volumes, ejection fraction and wall motion), and no LGE. SSc patients were compared to16 matched controls healthy volunteers (47±7 years old). T1 quantification was performed using a Modified Look-Locker Inversionrecovery (MOLLI) sequence at 1.5T (Siemens) on a LV short axis before, 5min and 15 min after 0.2 mmol/Kg gadolinium injection. Imaging protocol included also standard Cine-SSFP imaging, and LGE imaging. LV diastolic function (mitral inflow pattern) was further assessed using echocardiography. Results A non significant shorter mean T1 time (ms, mean± SEM) was observed in SSc patients compared to controls both at 5 (357±5 vs. 361±6, p=0.65) and 15 (448±5 vs. 456±5, p=0.34) minutes after gadolinium injection. Echocardiography displayed a LV diastolic dysfunction in 47% of SSc patients and in 25% of controls (p=0.04). The SSc patients with a LV diastolic dysfunction had a shorter 15 minutes post-contrast T1 time (ms) than those with a normal diastolic function (431±7 vs. 464±8, p=0.01).