Cardiac autonomic dysfunction in systemic sclerosis: a systematic review

Aim . To summarize the findings of studies investigating the clinical and prognostic significance of cardiac autonomic dysfunction (CAD) in patients with systemic sclerosis (SSc) in a systematic review. Material and methods. A literature search was performed in the eLIBRARY.ru and MEDLINE (PubMed) electronic bibliographic databases. The systematic review was reported in accordance with the PRISMA guidelines. No restrictions on the year of publication were applied during the literature search and study selection. A qualitative synthesis of the findings was performed. Results . The review included 29 studies reported in 32 publications. The number of patients with SSc ranged from 10 to 86. Two publications described prospective studies, whereas the remaining studies had a cross-sectional design. CAD was primarily assessed by heart rate variability (HRV) analysis; Ewing cardiovascular autonomic tests, questionnaires, and heart rate turbulence (HRT) analysis were used less frequently. Most studies demonstrated reduced time- and frequency-domain HRV indices, impaired parasympathetic regulation, and a relative predominance of sympathetic activity in patients with SSc. CAD parameters were associated with diffuse cutaneous disease, the severity of skin and microvascular involvement, pulmonary hypertension, structural and functional cardiac abnormalities, and ventricular arrhythmias. In several studies, reduced HRV and abnormal HRT parameters were associated with adverse outcomes. Conclusion . CAD in patients with SSc is characterised by impaired parasympathetic regulation, a relative predominance of sympathetic influences, reduced HRV, and abnormal HRT parameters. CAD indices were associated with clinical and laboratory characteristics of SSc reflecting disease severity and activity. The available evidence suggests that CAD may have adverse prognostic implications in patients with SSc, which requires further investigation in large prospective studies.