AB0560 CLINICAL, SEROLOGICAL AND IMAGING CHARACTERISTICS OF LATIN AMERICAN PATIENTS WITH LUPUS MYOCARDITIS: A CASE-CONTROL STUDY

Abstract

BackgroundLupus myocarditis (LM) is an uncommon manifestation of systemic lupus erythematosus (SLE),with a prevalence of 9% that tends to be lower in recent studies; it can range from subclinical to life-threatening manifestations (1). The clinical and immunological characteristics of LM have not been established in Latin American patients.ObjectivesTo determine the clinical, serological, and imaging characteristics of patients with LM.MethodsWe conducted a single-center, case-control study that enrolled hospitalized patients between 2012 and 2020 in Colombia. Fifteen LM patients (cases) were matched by age and sex with thirty non-LM patients (controls). Descriptive, comparative, and logistic regression analyses were performed.ResultsPatients with LM were mostly females (93.3%) with a mean age of 28.2 years. The major affected clinical domains associated was renal (80%). Myocardial involvement occurred after SLE diagnosis with a mean of 5.1 years. Dyspnea (73.3%) was the main clinical manifestation. Troponin was high in 92.3% and echocardiographic findings included decreased left ventricular ejection fraction (LVEF) in the 60% of cases (mean 40%), diastolic dysfunction (61.5%), left ventricular dilatation (53.3%) and global hypokinesia 35.7%. The most common valvulopathy was mild mitral regurgitation. Nine LM patients underwent cardiac magnetic resonance. In this modality, mean LVEF was 38%, increased regional intensity on T2-weighted images, increased myocardial potentiation ratio on T1, and non-ischemic enhancement (mainly epicardial) was presented on 85.7%, 60%, and 57.1%, respectively. All patients received glucocorticoids and cyclophosphamide. Comparisons of the demographic, clinical, serological between LM and non-LM groups are shown in Table 1.Table 1.Demographic, clinical and serological characteristics.VariableLM (n=15)Non-LMP-valueFemale93.3%100%0.333Age SLE24.9 (SD 12)28.3 (SD 13.9)0.515Clinical domainsCutaneous46.7%90%0.003Articular60%76.7%0.245Hematological60%83.3%0.086Serosal53.3%36.7%0.227Renal80%76.7%0.560Neuropsyquiatric6.7%26.7%0.115Vascular13.3%50%0.017PCR mg/dL10.1 (SD 9.3)2.8 (SD 4.6)0.0004Erythrocyte sedimentation rate mm/H52.9 (SD 25.7)43.9 (SD 32.9)0.267Creatinine mg/dL1.4 (SD 0.9)1.9 (SD 2.5)0.294C3 mg/dL57.4 (SD 22.4)86.2 (SD 29.9)0.002C4 mg/dL9.6 (SD 8.3)16.4 (SD 9.3)0.009Anti-dsDNA86.7%52.4%0.034SLEDAI score14.7 (SD 5.7)6.8 (SD 7.6)0.0003SD: Standard deviationBivariate logistic regression showed that LM was independently associated with anti-dsDNA (OR 1.17, IC 1.04 – 1.31, p= 0.004), higher SLEDAI score (OR 1.17, IC 1.04 – 1.31, p=0,006), higher RCP (OR 1.21, IC 1.04 – 1.4, p=0.013), lower C3 (OR 0.96, IC 0.93 – 0.98, p:0,06) and lower C4 (OR 0.90 IC 0.82 – 0.99 P=0,036), highlighting its relationship with disease activity.ConclusionLM is a potentially severe manifestation and occurs in patients with higher disease activity, as was evidenced in the present study by low complement, anti-dsDNA and SLEDAI score. In the proper clinical context, noninvasive diagnostic tests should detect myocardial involvement in SLE.References[1]du Toit, Riette et al. “Outcome of clinical and subclinical myocardial injury in systemic lupus erythematosus - A prospective cohort study.” Lupus vol. 30,2 (2021): 256-268. doi:10.1177/0961203320976960Disclosure of InterestsNone declared