Clinical Trial: Effect of Sildenafil on the Microcirculatory Blood Flow and Endothelial Progenitor Cells in Systemic Sclerosis

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Effect of Sildenafil on the Microcirculatory Blood Flow and on the Endothelial Progenitor Cells in Patients With Systemic Sclerosis: a Randomized, Double-blind, Placebo-controlled Clinical Trial

Brief Summary: Early phases of systemic sclerosis is characterized by inflammatory and microvasculature alterations. Sildenafil citrate has been shown to have vasodilatory effects and to enhance vasculogenesis. The purpose of this study is to evaluate the effect of sildenafil citrate on hand blood flow of patients with systemic sclerosis, using Laser Doppler Imaging.

Detailed Summary: Progressive microangiopathy and endothelial dysfunction are identified in early phases of systemic sclerosis. These alterations may result in progressive reduction of vessel lumen, decreased blood flow, and a state of chronic hypoxia resulting in digital ulcers, digital pitting, and, in more severe cases, gangrene and amputation of the extremities. Few studies aimed to evaluate the effects of Sildenafil on the microcirculatory blood flow in patients with Raynaud's phenomenon secondary to systemic sclerosis (SS). Moreover, no study has evaluated the effect of this drug on the number and function of endothelial progenitor cells in SS patients. The relatively new technique of laser Doppler imaging (LDI) allows an objective measurement of superficial cutaneous microvascular blood flow and constitutes a promising approach in the assessment of the digital microvascular vasoreactivity in response to cold stimulus or in response to treatment in SSc patients.
Sponsor: Federal University of São Paulo

Current Primary Outcome:

  • Digital Skin Microvascular Blood Flow Measured by Laser Doppler Imaging (LDI) Before Cold Stimulus [ Time Frame: 8 weeks ]
    Finger blood flow of the four medial fingers, measured by laser Doppler imaging and expressed in arbitrary perfusion units (p.u.).
  • Digital Skin Microvascular Blood Flow Measured by Laser Doppler Imaging (LDI) After Cold Stimulus. [ Time Frame: 8 weeks ]


Original Primary Outcome: Digital skin microvascular blood flow by means of Laser Doppler Imaging (LDI). [ Time Frame: 8 weeks ]

Current Secondary Outcome: Daily Frequency of Raynaud's Phenomenon Attacks [ Time Frame: 8 weeks ]

Daily frequency of RP attacks as self registered in a 1-week diary. Any episode of pallor or cyanosis of the hand/fingers was considered as a RP attack, and patients were supposed to register the daily amount of such episodes on a 1-week diary, previously to the medical visit.


Original Secondary Outcome:

  • Number and proliferative capacity of endothelial progenitor cells (EPC) [ Time Frame: 8 weeks ]
  • Serum levels of vascular endothelial growth factor (VEGF) [ Time Frame: 8 weeks ]
  • Clinical features of Raynaud's phenomenon and digital ulcers [ Time Frame: 8 weeks ]
    Raynaud's Condition Score, HAQ and specific VAS scales for Raynaud's phenomenon and disability.


Information By: Federal University of São Paulo

Dates:
Date Received: May 2, 2011
Date Started: April 2011
Date Completion:
Last Updated: October 12, 2016
Last Verified: October 2016