How does isosorbide dinitrate and hydralazine work in treating congestive heart failure?

A-HEFT Trial: A large trial looked at the combination of hydralazien and Isordil (isosorbide dinitrate) with african american patients and showed a benefit of improving heart failure status, on top of standard medical therapy. It is thought to be believed due to lack of Nitric Oxide delivery to endothelium in african americans, that is improved by this therapy. Blood pressure tends to be higher in the first place, which improves.