The aim of this study was to investigate the effectiveness of ST 567 in patients suffering from ischaemic heart disease and to compare the effects of this drug with those of propranolol. The study group consisted of 48 male patients, mean age 53, with stable, exercise-induced angina pectoris. After a two-week run-in-placebo period, the patients were randomized to treatment with ST 567 3 X 30 mg (N = 24) and propranolol, 3 X 40 mg (N = 24). The drugs were administered in a double blind fashion during four weeks. Heart rate at rest was decreased by ST 567 from 76 to 65 (P less than 0.005) by propranolol from 76 to 62 (P less than 0.001). Systolic blood pressure was lowered by ST 567 from 131 to 121 (NS) and by propranolol from 133 to 118 (P less than 0.05). Exercise tolerance was increased by ST 567 from 20 X 10(3) to 34 X 10(3) J (P less than 0.05), by propranolol from 26 X 10(3) to 32 X 10(3) J (P less than 0.01) (mean values). Anginal attacks (no. per week) were reduced by ST 567 from 14 to 7 (P less than 0.05) and by propranolol from 14 to 5 (P less than 0.01). Nitroglycerin consumption in no. of tablets per week decreased in ST 567 from 12 to 7 (P less than 0.01), in propranolol from 11 to 4 (P less than 0.0). There were 7 drop outs during treatment with ST 567:2 cases of myocardial infarction, exacerbation of angina in 2 patients, visual disturbances in 2 patients, vertigo in 1 patient. With propranolol we observed worsening of angina in 1 patient, with disturbances in sexual potency in 1.
In conclusion: ST 567 is an effective agent in chronic angina but slightly less effective than propranolol in the dosages studied.