The primary study hypothesis is that inhibition of factor Xa with rivaroxaban will reduce
inflammation, coagulation and endothelial cell activation, and improve microvascular blood
flow in patients with sickle cell disease (SCD) during the non-crisis, steady state. To test
this hypothesis, this study will evaluate the effects of rivaroxaban on:
- plasma markers of inflammation;
- plasma markers of endothelial activation;
- plasma markers of thrombin generation; and
- microvascular blood flow assessed using laser Doppler velocimetry (LDV) of
post-occlusive reactive hyperemia (PORH).
In a cross-over design, subjects will receive rivaroxaban 20 mg/day and placebo for 4 weeks
each, separated by a 2-week washout phase.