Neurovascular dysregulation in systemic sclerosis: novel insights into pathophysiology, diagnosis, and treatment utilizing invasive cardiopulmonary exercise testing.

Abstract

Purpose of review: Pathologic abnormalities in skeletal muscle and the systemic vasculature are common in patients with systemic sclerosis (SSc). These abnormalities may lead to impaired systemic peripheral oxygen extraction (EO 2 ), known as neurovascular dysregulation, which may be because of abnormal blood flow distribution in the vasculature, microvascular shunting, and/or skeletal muscle mitochondrial dysfunction. Findings from invasive cardiopulmonary exercising testing (iCPET) provide important insights and enable diagnosis and treatment of this SSc disease manifestation.

Recent findings: Recent findings from noninvasive cardiopulmonary exercise testing (niCPET) support the existence of neurovascular dysregulation in patients with SSc. Invasive cardiopulmonary exercise testing (iCPET) has pointed to reduced systemic vascular distensibility as a possible mechanism for neurovascular dysregulation in patients with connective tissue diseases, including SSc.

Summary: Neurovascular dysregulation is likely an underappreciated cause of exercise impairment and dyspnea in patients with SSc in the presence or absence of underlying cardiopulmonary disease. It is posited to be related to microcirculatory and muscle dysfunction. Further studies are needed to clarify the pathophysiology of neurovascular dysregulation in SSc and to identify novel treatment targets and additional therapies.