Cardiac Complications in Systemic Lupus Erythematosus: A Systematic Review of Diagnostic and Prognostic Gaps

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with multisystem involvement and fluctuating activity. Among its many complications, cardiovascular disease (CVD) is a leading cause of morbidity and mortality, with up to 25% of patients affected. Cardiac manifestations, such as pericarditis, myocarditis, and accelerated atherosclerosis, are often underdiagnosed due to their subclinical presentation and lack of standardized screening protocols. This systematic review aims to synthesize current evidence on the incidence, detection, and prognostic challenges of cardiac complications in SLE patients and to identify gaps in current risk stratification and diagnostic methods. A comprehensive literature search was conducted across Ovid, CINAHL, EMBASE, and Web of Science using predefined search terms related to SLE, cardiovascular complications, disease flares, and diagnostic tools (e.g., biomarkers, cardiac MRI). English-language studies published between 2015 and 2025 involving adults (≥18 years) were included. Eligible studies focused on cardiac complications in SLE patients and reported outcomes such as incidence, diagnostic markers, or evidence of underdiagnosis. Exclusion criteria included pediatric populations, non-SLE autoimmune diseases, lack of cardiac outcome data, animal/in vitro studies, non-English papers, reviews, and editorials. Across 31 studies encompassing over 7,000 patients with SLE, cardiac symptoms were frequent, ranging from subclinical abnormalities to life-threatening complications. Case reports highlighted severe manifestations, including cardiac tamponade, myocarditis, cardiogenic shock, and myocardial infarction, often mimicking acute coronary syndromes. Observational and retrospective cohorts demonstrated high rates of pericardial effusion (up to 25%), pulmonary hypertension (15-42%), valvular disease (15-32%), and subclinical myocardial dysfunction detected by advanced echocardiographic or PET modalities. Large-scale cohorts identified lupus myocarditis in 1.7%-9% of patients, strongly associated with higher Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores, hypocomplementemia, and anti-nucleosome antibody positivity. Biomarker studies reported elevated troponin, IL-18, IL-1Ra, and interferon-α as predictors of myocardial injury and adverse outcomes. Mortality data linked poor prognosis to myocarditis, pulmonary hypertension, renal disease, and higher comorbidity indices. Outcomes varied, and patients were treated with diverse therapies, including glucocorticoids, immunosuppressants, biologics, and cardiovascular medications. Collectively, findings underscore that cardiac manifestations in SLE are common, multifactorial, and frequently underdiagnosed, with biomarkers and advanced imaging emerging as valuable tools for early detection. Cardiac complications in SLE are prevalent, diverse, and often underrecognized. This review highlights the critical need for improved diagnostic strategies, including the use of emerging biomarkers and advanced imaging techniques, to enable earlier detection and more accurate risk stratification. Standardizing screening protocols and incorporating cardiovascular assessment into routine SLE management may reduce delays in diagnosis and improve patient outcomes. Further research is essential to develop consensus guidelines for early identification and prognostication of cardiac involvement in SLE.