Spirapril, an ACE-inhibitor without the SH group was tested in a randomized double-blind multicentric study in patients with chronic symptomatic heart failure (NYHA II-IV). After a 1-4-week initial stage with placebo the patients were randomized into five groups: the first was given placebo, the second one spirapril 1.5 mg, the third one spirapril 3 mg, the fourth one spirapril 6 mg and the fifth one 5 and later 10 mg for a period of 12 weeks. The number of patients in different groups was in the following order: 48, 48, 53, 51 and 48. The condition for admission into the study was chronic heart failure not responding adequately to treatment with digoxin and diuretics, IHD or dilatation cardiomyopathy with the left ventricular ejection fraction (% tolerating a basic ergometric load for two minutes. The primary criterium was an increment during the period of the load, secondary criteria comprised objective and subjective cardiac symptoms, changes in the left ventricular ejection fraction, cardiothoracic index/heart size and quality of life. The load tolerance increased in all groups, however, no significant differences between groups were found. The authors also found regression of signs of pulmonary congestion during active spirapril treatment and diminution of the cardiac shadow. Moreover the authors proved a significant reduction of the mortality in the actively treated patients as compared with those receiving placebo, a lower frequency of hospital admissions and reduction of serious undesirable cardiovascular symptoms during active treatment. In patients with medium severe and severe cardiac failure with IHD, combination with short acting calcium channel blockers had an unfavourable effect on the load tolerance and clinical parameters. Sprirapril, combined with diuretics and digoxin is a suitable drug also in chronic cardiac failure. Questionable remains the importance of loading tests when verifying the effectiveness of ACE-inhibitors. Treatment with short-time acting calcium antagonists cannot be recommended in symptomatic chronic cardiac failure.