This trial comprised 40 patients with
angina pectoris and reproducible ischaemic ST segment depression in the exercise ECG. Whenever possible the diagnosis of
coronary heart disease was confirmed by coronary angiography. After a preliminary 7-day placebo period, 20 of these patients were treated for 4 weeks with 5-(3-tert-butylamino-2-hydroxy-propoxy)-3, 4-dihydro-2(1H)-quinolinone
hydrochloride (carteolol hydrochloride, Endak, Endak mite), a nonselective beta-receptor blocker, having
adrenergic properties (ISA) up to 30 times more powerful than those of
propranolol. The trial was double-blind and randomized; standard medication (
pindolol) was given to the controls. In general, the results obtained with
carteolol--and also with
pindolol--may be regarded as "good" or "very good". The average weekly incidence of anginal attacks fell from 6 to 4 (p less than 0.05).
Carteolol produced a definite decrease in ST segment depression during exercise, at the end of exercise and in the recovery phase (p less than 0.05). The same was true for the patients treated with
pindolol. There was no statistically significant difference between the treatment groups. Pulse rate and systolic blood pressure--measured before exercise and at the end of the recovery phase--did not change; however, readings made at the end of exercise showed a significant decrease (p less than 0.05). Diastolic pressure remained essentially unaltered. There were no changes in the chest radiograph or resting ECG. Laboratory results remained unchanged in both groups. In one patient of each group treatment needed to be discontinued because of dyspnoea, mainly during exercise. This reaction could probably be related to the beta-blocker
therapy. The overall response to treatment, as assessed by the physician conducting the trial, was "good" or "very good" in 75% of the patients receiving
carteolol and in 70% of those receiving
pindolol. 70% of the patients who had received
carteolol assessed the therapeutic result as "good" or "very good"; in the
pindolol group 55% made the same judgment.