Subclinical cardiac dysfunction in idiopathic inflammatory myopathies: the role of global longitudinal strain

Autoimmune diseases are characterized by systemic inflammation that can affect multiple tissues. In idiopathic inflammatory myopathies (IIM), skeletal muscle is primarily involved; however, subclinical cardiac dysfunction may also occur. While left ventricular ejection fraction (EF) is commonly used to assess cardiac function, global longitudinal strain (GLS) has proven more sensitive in detecting early myocardial impairment. This study aimed to evaluate left ventricular GLS (LV GLS) in patients with IIM and no known cardiovascular disease, assessing both the prevalence of reduced GLS values and their associations with clinical and laboratory parameters. We enrolled 37 outpatients from the Department of Internal Medicine at the University Hospital of Verona, who underwent comprehensive clinical and echocardiographic assessment. The mean GLS value observed (- 17.9% ± 2.2%) was below the normal reference range (- 18.2% to - 21.2%) defined by the echocardiographic system. When compared with 37 healthy controls, IIM patients showed significantly impaired GLS despite preserved EF in both groups (- 17.88 ± 2.23% vs. - 19.88 ± 1.72%, p < 0.001). This difference remained significant after adjusting for age and sex (β = +2.25%, p < 0.001). In linear regression models, GLS was independently associated with arthritis (β = 2.165, p = 0.007), lymphocyte count (β = 0.001, p = 0.025), CK levels (β = 0.000, p = 0.024), and age (β = 0.032, p = 0.020). Patients with arthritis showed significantly worse GLS values compared to those without arthritis, despite similar EF. In multivariate analysis, arthritis remained independently associated with impaired GLS and lower CK levels. Overall, our findings suggest that patients with IIM exhibit a global reduction in left ventricular longitudinal function, detectable by GLS, even in the absence of overt cardiac disease. This impairment appears particularly evident in patients presenting with arthritis and is independent of age-related effects. Longitudinal studies are warranted to investigate the progression of GLS alterations and their potential role in guiding therapeutic strategies.