Review: Defining a Unified Vascular Phenotype in Systemic Sclerosis

Microcirculation impairment and related vasculopathy are hallmarks of systemic sclerosis (SSc). Digital ulceration is second only to Raynaud's phenomenon as a vascular complication occurring in patients with SSc. Digital ulcers are painful and generate disability. Furthermore, patients may develop recurrent digital ulcers, and it is reasonable to question whether the outcomes of such patients might be different from those of patients who are not affected. Recently, several registries have provided relevant information about digital ulcers. Male sex and severe skin disease appear to be the main associated factors observed in several registries. However, limitations of those studies are the differences in the definitions of digital ulcers and organ involvement. Few longitudinal studies are available, and the more robust data from the European League Against Rheumatism Scleroderma Trial and Research cohort suggested worse outcomes in patients with a history of digital ulcers but could not demonstrate that a history of digital ulcers can predict additional vascular complications such as pulmonary arterial hypertension, heart failure, or renal crisis. Nevertheless, the autopsy studies published many years ago and the more recent longitudinal biomarker studies support the concept of generalized vasculopathy and a potential association between various cardiovascular complications. It is expected that with the availability of several structured registries, identification of a vascular profile or vascular phenotype will be addressed using more robust data in the near future.