Background Cardiac involvement in systemic sclerosis (SSc) is the second most frequent SSc-related cause of death. It remains mostly asymptomatic in early stages and is underdiagnosed with routine non-invasive screening. Cardiac magnetic resonance imaging (CMR) is becoming a key actor as it has a better sensitivity than echocardiography (echo). CMR can detect diffuse myocardial fibrosis (DMF) by native T1 mapping, myocardial edema (ME) by T2 mapping and focal fibrosis by late gadolinium enhancement (LGE). Ntusi et al. reported an increase of 5% of T1 value suggestive of DMF in 10 of 19 SSc patients.
Objectives To determine the prevalence of cardiac involvement by CMR native T1 and T2 mapping and its correlation with echo data and non-cardiac manifestations in SSc patients.
Methods 72 patients fulfilling ACR/EULAR classification criteria were prospectively included between 2013–2016. They underwent CMR at 1.5T, including native T1 and T2 mapping, and LGE. Normal T1 value determined in our center was 1032±39 msec. In the present study an elevated native T1>1082 msec was likely representing ventricle (especially left) DMF and T2>55 msec representing ME .
Results Patients characteristics: mean age: 56±14.8; diffuse disease: 38 (52.8%); anti-Scl70 positivity: 29 (40.3%); anti-RNApolIII positivity: 6 (8.3%); 21 (29.2%) patients had early disease (<2 years from first non-Raynaud symptom). The mean T1 was 1064±41.6 msec and T2 was 51.8±2.9 msec. 36 patients (50%) had DMF but only 6 (8.3%) had ME. The mean T1 in DMF cases was 1097±14, and the T2 in ME cases was 58.2±1.6 msec. LGE was reported in 25.7% of patients. Although LGE was more frequent in patients with DMF than in those without DMF (13 vs 5, p=0.024), only 13 (36.1%) DMF patients had LGE. Left ventricular ejection fraction (L-VEF), left ventricular telediastolic volume (L-VTDV), Right-VEF and Right-VTDV were similar in DMF and non-DMF (N-DMF) groups. Echo was normal in 18 (50%) patients with DMF and in 25 (69.4%) of N-DMF group (p=0.09). DMF and N-DMF groups were similar for sex ratio, age, cardiovascular risk factors and ischemic heart disease. DMF was more frequent in patients with late disease (27 vs 9, p=0.05). T1 value was positively correlated to pulmonary arterial hypertension and digital ulcerations together (r=0.31, p=0.008) but not with Rodnan skin score. Six patients (8.3%) died during the inclusion period: 5 were in DMF group (p=0.09). The alterations of L-VEF and R-VEF were correlated (r=0.45, p=0.009). DMF was not associated with skin subsets, interstitial lung disease, auto-antibody profile, all echo parameters, CRP and BNP.
Conclusions Native T1 mapping detects left ventricular DMF in 50% of patients with SSc including 43% (9/21) of the patients with early disease. Among them, 36% had normal echocardiography and CMR L-VEF and no LGE.
Ntusi NA, Piechnik SK, Francis JM, et al. Subclinical myocardial inflammation and diffuse fibrosis are common in systemic sclerosis a clinical study using myocardial T1-mapping and extracellular volume quantification.J Cardiovasc Magn Reson 2014;16:21.
Germain P, El Ghannudi S, Jeung MY et al. Native T1 mapping of the heart - a pictorial review. Clin Med Insights Cardiol 2014;8:1.
Disclosure of Interest None declared