Effect of flosequinan on exercise capacity and cardiac function in patients with chronic mild heart failure: A double-blind placebo-controlled study

Summary Although beneficial effects of a new vasodilating agent, flosequinan, have been demonstrated in patients with severe heart failure, its efficacy has not been studied in patients with a less severe form of chronic heart failure. In this study, the effects of 4 weeks' administration of flosequinan, 50mg daily, and placebo on exercise capacity, cardiac function, and symptoms of heart failure were investigated in 24 patients with chronic mild heart failure (New York Heart Association functional class, mainly class II) in a double-blind clinical trial. When the parameter changes during the treatment period of the flosequinan and placebo groups were compared, no significant difference was found in any of the measurements except for left ventricular fractional shortening determined from M-mode echocardiograms; it was increased by 2.9 ± 1.3% in the flosequinan group whereas it was decreased by 1.3 ± 0.9% in the placebo group (P < 0.05 vs flosequinan treatment). However, when compared to baseline values, flosequinan significantly increased exercise time in the symptom-limited maximal exercise test (704 ± 103 to 763 ± 107 s,P < 0.05) and the oxygen uptake at the anaerobic threshold (13.8 ± 1.3 to 16.7 ± 1.4ml/min kg,P < 0.05), and improved symptoms assessed with a new heart failure severity classification (a median value of 2.0–1.5,P < 0.05). These improvements were not observed in the placebo group. Serious adverse effects were not observed in either group. These results suggest that flosequinan is useful for the treatment of chronic mild heart failure as well as severe heart failure.Authors for the Osaka Flosequinan Multicenter Trial Group, members of which are listed in the Appendix