Cinaciguat (BAY 58-2667) is the first of a new class of soluble guanylate cyclase (sGC) activators in clinical development for acute decompensated heart failure. Cinaciguat has potent preload- and afterload-reducing effects, increasing cardiac output. Cinaciguat causes potent and sustained fetal pulmonary vasodilation that is augmented in the presence of oxidized sGC and speculate that Cinaciguat may have therapeutic potential for severe neonatal pulmonary hypertension.