The effect of flosequinan in patients with heart failure of acute onset complicating acute myocardial infarction.

We studied the hemodynamic effect of a single dose of the new direct-acting vasodilator, flosequinan, in 18 patients with severe heart failure of acute onset complicating acute myocardial infarction, which was resistant to high doses of diuretics, nitrates and dobutamine given intravenously. Flosequinan was added to conventional therapy at 3.5 +/- 0.8 days from the infarction, in the form of a single oral dose of 100 mg. Hemodynamic measurements were performed every hour for 4 hours after the administration, without any other drug being added. The infusion rate of nitrates was kept constant. Flosequinan produced hemodynamic improvement in this group. The effect peaked at 2 hours and remained at this level at 4 hours. Pulmonary capillary wedge pressure decreased from 27.6 +/- 4.3 to 16.8 +/- 2.8 mm Hg and cardiac output increased from 3.5 +/- 0.3 to 4.1 +/- 0.4 l/min (P less than 0.001). Pulmonary arterial and right atrial pressures and systemic and pulmonary vascular resistances were also significantly reduced. Heart rate and mean systemic arterial pressure were not significantly altered. Administration of flosequinan was not associated with symptomatic hypotension, cardiac arrhythmias or other adverse events. We conclude that flosequinan is effective in producing acute hemodynamic improvement in patients with heart failure, complicating acute myocardial infarction, which is resistant to conventional therapy. Flosequinan is safe and well tolerated. Studies for longer time periods are indicated.