FLOSEQUINAN, A NEW VASODILATOR - SYSTEMIC AND CORONARY HEMODYNAMICS AND NEUROENDOCRINE EFFECTS IN CONGESTIVE-HEART-FAILURE

Objectives. The aim of this study was to evaluate the immediate and long-term systemic and coronary hemodynamic, metabolic and neurohormonal effects of flosequinan in patients with congestive heart failure. Background. Preliminary studies have shown that this new long-acting oral systemic vasodilator may have beneficial effects in patients with heart failure. Methods. Thirteen patients with congestive heart failure were studied. Systemic and coronary hemodynamic, metabolic and neurohormonal effects of flosequinan were assessed acutely with repeat systemic hemodynamic studies after 6 weeks of treatment. Results. The administration of flosequinan acutely and after long-term treatment, resulted in a significant increase in cardiac index, stroke work index and stroke volume index with a reduction in systemic and pulmonary vascular resistances. The improvement in ventricular function was associated with an improvement in left ventricular efficiency without a change in myocardial oxygen consumption or coronary sinus blood flow. Myocardial oxygen extraction and net myocardial lactate extraction also did not change significantly with flosequinan therapy. Systemic catecholamine levels and myocardial catecholamine balance did not change. Plasma arterial and coronary sinus atrial natriuretic factor concentrations were elevated at baseline; the latter concentrations at the level of the great cardiac vein were significantly higher than those of arterial concentrations, indicating increased left ventricular release of atrial natriuretic factor in congestive heart failure. Both arterial and coronary sinus atrial natriuretic factor levels were significantly reduced with the administration of flosequinan at peak effect in association with an improvement in systemic hemodynamics. Conclusions. Flosequinan therapy in patients with congestive heart failure results in a sustained beneficial hemodynamic action and improved cardiac performance without an increase in metabolic demand or activation of the sympathetic nervous system.