Sporadic inclusion body myositis: no specific cardiac involvement in cardiac magnetic resonance tomography

Cardiovascular manifestations in idiopathic inflammatory myopathies

Cardiovascular involvement in idiopathic inflammatory myopathies (IIM) is an understudied area which is gaining increasing recognition in recent times. Recent advances in imaging modalities and biomarkers have allowed the detection of subclinical cardiovascular manifestations in IIM. However, despite the availability of these tools, the diagnostic challenges and underestimated prevalence of cardiovascular involvement in these patients remain significant. Notably, cardiovascular involvement remains one of the leading causes of mortality in patients with IIM. In this narrative literature review, we outline the prevalence and characteristics of cardiovascular involvement in IIM. Additionally, we explore investigational modalities for early detection of cardiovascular involvement, as well as newer approaches in screening to facilitate timely management. Key points • Cardiac involvement in IIM in majority cases is subclinical and a major cause of mortality. • Cardiac magnetic resonance imaging is sensitive for detection of subclinical cardiac involvement.

Defining cardiac involvement in idiopathic inflammatory myopathies: a systematic review

OBJECTIVE

Recent advances in cardiac magnetic resonance imaging (CMR) and other diagnostic techniques have made it easier to identify subclinical cardiac inflammation and dysfunction in the idiopathic inflammatory myopathies (IIM). Herein, we systematically review the literature regarding cardiac involvement in IIM.

METHODS

We searched Medline and EMBASE from 1990-2020 using keywords related to IIM and cardiac disease. We included English language studies in adults with any immune-mediated, inflammatory muscle pathology.

RESULTS

We identified 10425 potentially relevant abstracts, of which 29 were included. Most frequently these included patients with polymyositis or dermatomyositis without symptomatic myocarditis. Five categories of cardiac investigation were used in these patients: cardiac enzyme testing, electrocardiography (ECG), transthoracic echocardiography (TTE), CMR and nuclear medicine testing. Patients with clinical myocarditis had universally abnormal cardiac troponin levels and ECG. Elevated cardiac troponin T was more common than troponin I (cTnI) and may correlate with disease activity, whereas cTnI was more specific for cardiac involvement. Non-specific ECG changes were common. The major finding on TTE was abnormal ejection fraction. Gross systolic dysfunction was unusual, but subclinical systolic dysfunction was reported in several studies. Abnormal diastolic function was common and may be associated with disease duration. Late gadolinium enhancement (reflecting regional necrosis or scar) and abnormal myocardial mapping parameters (reflecting myocardial inflammation, fibrosis and oedema) were frequently identified on CMR, suggesting significant subclinical myocardial pathology (despite typically normal ejection fraction).

CONCLUSION

Abnormal cardiac investigations are commonly found in asymptomatic IIM patients, which has potential prognostic and treatment implications.