STRIDE I evaluated the selective endothelin A receptor antagonist , sitaxsentan ( SITAX ) , in a 12-week randomized , double-blind , trial ( 178 patients ) employing placebo ( PBO ) , 100 mg or 300 mg SITAX orally once daily in PAH and included patients with NYHA class II , congenital heart disease and a BL 6MW > 450 m , groups often excluded from previous trials .
