Cardiac involvement in primary Sjögren Syndrome patients and its association with disease activity: a cardiac magnetic resonance study

Cardiac involvement in primary Sjögren Syndrome (pSS) is often subclinical and underdiagnosed. This study aimed to characterize cardiac alterations in asymptomatic pSS patients using cardiac magnetic resonance (CMR) and to investigate their association with disease activity. In this retrospective study, 71 pSS patients (categorized by ESSDAI into low, moderate, and high disease activity groups) and 51 matched controls underwent 3.0T CMR. Assessments included left ventricular (LV) function parameters (ejection fraction [LVEF], global longitudinal, circumferential, and radial strain [GLS, GCS, GRS]) and myocardial tissue characteristics (native T1, T2). Statistical analyses compared groups and evaluated correlations between CMR parameters, ESSDAI scores, and clinical/laboratory markers. Compared to controls, pSS patients exhibited significantly lower LVEF (61% vs. 64%, P = 0.016), reduced GLS (-16% vs. -18%, P < 0.001), elevated global T2 (42.4 vs. 40.5 ms, P < 0.001) and native T1 (1215.0 vs. 1193.0 ms, P = 0.027) values. These abnormalities were most pronounced in the high-activity group. ESSDAI scores showed a moderate negative correlation with GRS ( r =-0.302, P = 0.010) and a weak positive correlation with GCS ( r = 0.288, P = 0.015). Univariable and multivariable analysis identified rheumatoid factor (RF) > 20 IU/mL (β=-3.79, P = 0.016) as an independent factor associated with decreased LVEF. While presence of Raynaud phenomenon (β = 2.04, P = 0.013) was independently associated with increased T2 values. Asymptomatic pSS patients exhibited subclinical myocardial dysfunction and edema detectable by CMR, with severity correlating with disease activity. Elevated RF and presence of Raynaud phenomenon were independently associated with cardiac involvement, suggesting that CMR may be warranted for early cardiac evaluation in pSS patients, particularly those with these risk indicators.