A double-blind, parallel-group comparison of flosequinan and enalapril in the treatment of chronic heart failure.

The effects of flosequinan and enalapril on exercise capacity (bicycle exercise duration), quality-of-life symptomatology (visual analogue scales) and New York Heart Association (NYHA) grading, were compared in 61 patients with chronic heart failure (NYHA, grade III). Bicycle exercise duration improved similarly with flosequinan (+27%) and enalapril (+18%); in patients completing the study, flosequinan produced a significantly greater increase in exercise time at week 12, compared with enalapril (P = 0.02). Improvements in visual analogue scores relating to general health, energy and vitality, ability to perform physical activities and breathing performance, were equivalent for both drugs. Changes in NYHA classification showed that 27 (55%) of 49 patients completing the study had improved by at least one NYHA grade (15 (68%) patients on flosequinan; 12 (44%) on enalapril). The overall safety and tolerability of the two treatments was similar; 18 patients reported adverse effects while on flosequinan, compared with 19 patients on enalapril. Neither treatment was associated with any clinically important changes in haematological or biochemical variables, although some treatment-related effects were observed. This study confirms that flosequinan achieved similar efficacy to enalapril in the symptomatic relief of chronic heart failure. The effect of flosequinan on survival in chronic heart failure has not been tested; pending such studies, our data suggest that it may prove a useful alternative therapy in patients where ACE inhibitors are contraindicated or poorly tolerated.