The complex diagnosis of primary heart involvement in systemic sclerosis: red flags to drive the choice of cardiac magnetic resonance.

Objectives: To analyse clinical features and biomarkers associated with primary heart involvement (pHI) confirmed at cardiac magnetic resonance (CMR) in a monocentric cohort of SSc patients.

Methods: A retrospective study. SSc patients who underwent CMR for clinically suspected pHI were identified. SSc-pHI at CMR was defined by the presence of at least one abnormality among: non-ischaemic late gadolinium enhancement (LGE), myocardial oedema (STIR), increased extracellular volume (ECV), native T1 or T2-mapping. Clinical, laboratory and instrumental features were compared between pHI-SSc and non-pHI-SSc patients, and between CMR-positive and CMR-negative patients.

Results: 259 SSc patients (females 89.6%; median age 49 [39-61] years) were included. CMR was performed in 56 (21%) and pHI detected in 37 patients (14%). At univariate analysis, age at SSc onset, diffuse cutaneous subset, increased inflammatory markers and cardiac enzymes, interstitial lung disease (ILD) and myositis were significantly associated with SSc-pHI at CMR; an inverse correlation emerged with anti-centromere antibodies, VEDOSS and female gender. At multivariate analysis, increased troponin T(TnT) [OR 14.108, CI 2.772-71.808, P = 0.014], CRP [OR 11.237, CI 2.265-55.763, P = 0.0031] and the presence of ILD [OR 6.275, CI 1.240-31.763, P = 0.0264] were significantly associated with a positive CMR for SSc-pHI. Considering the 56 patients who underwent CMR, arrhythmias at 24 h-ECG-Holter were associated at univariate analysis to the presence of SSc-pHI at CMR [OR 3.75, CI 1.041-13.5, P = 0.04].

Conclusion: This retrospective analysis identified biomarkers and disease features associated with SSc-pHI confirmed at CMR. Our preliminary data suggest that increased serum levels of TnT and CRP, as well as the presence of ILD and arrhythmias might be considered as red flags suggesting to promptly proceed with a comprehensive cardiac evaluation, including CMR, to diagnose SSc-pHI.