Primary myocardial involvement in systemic sclerosis: pathophysiology, clinical manifestations, and advances in cardiac imaging

Abstract Systemic sclerosis (SSc) is a rare systemic autoimmune rheumatic disease associated with the highest cardiovascular risk among autoimmune conditions. Beyond pulmonary complications, primary heart involvement (pHI) represents a major cause of morbidity and mortality yet frequently remains asymptomatic and under-recognised. Microvascular dysfunction, myocardial inflammation and progressive interstitial and replacement fibrosis are central mechanisms. Clinical manifestations range from myocarditis to heart failure, arrhythmias, and sudden cardiac death, while subclinical myocardial involvement is common and prognosis remains poor once overt disease develops. Advanced cardiovascular imaging, particularly cardiovascular magnetic resonance has transformed detection through sensitive assessment of myocardial structure, function and myocardial tissue characterisation, while positron emission tomography may offer complementary insights. However, optimal screening strategies, imaging application and disease-specific therapies remain unmet needs. This review summarises current understanding of SSc-pHI pathophysiology, clinical presentations and management, with a focus on the evolving role of multimodality imaging in early detection, risk stratification.