Laser speckle contrast analysis predicts major vascular complications and mortality of patients with systemic sclerosis

Abstract

Objectives: The aim of study was to evaluate peripheral blood perfusion and the proximal-distal gradient (PDG) of the hands as biomarkers of SSc major vascular complications (digital ulcers, pulmonary arterial hypertension, scleroderma renal crisis) and mortality by laser speckle contrast analysis.

Methods: In this retrospective observational study, 176 SSc patients [158 female, median age 53 (51-57) years] and 142 healthy controls [115 female, median age 53 (48-55) years] were enrolled. Clinical data were collected at baseline and annually through 5 years of follow-up. Hand dorsum perfusion images were divided into three regions of interest (ROI): ROI1 included the second, third, and fourth fingers distal to the proximal interphalangeal finger joint; ROI2 included the area between the proximal interphalangeal finger joint and the metacarpophalangeal joint; ROI3 included the hand dorsum. PDG was identified when the perfusion mean difference between ROI1 and ROI2 was >30 perfusion units.

Results: Median peripheral blood perfusion was significantly lower for SSc patients than healthy controls. PDG was present in 51.5% of SSc patients and in 98.6% of healthy controls. Using the final multivariate model, nailfold videocapillaroscopy (NVC) pattern [hazard ratio (HR) 0.065 (0.015-0.283), P <0.0001] and PDG [HR 0.376 (0.194-0.727), P <0.01] were found to be risk factors for major vascular complications. By multivariate analysis, age [HR 1.051 (1.014-1.088), P <0.01), NVC pattern [HR 0.001 (0.000-3.111), P >0.05], and PDG [HR 0.207 (0.073-0.589), P <0.01] were found to be risk factors for 5-year SSc mortality.

Conclusion: PDG predicts major vascular complication and 5-year mortality of SSc patients.

Keywords: LASCA; SSc; digital ulcers; peripheral blood flow; vascular complications.