Long-term effects of the alpha, beta-blocker arotinolol on stable effort angina pectoris using 24-hour ambulatory electrocardiographic monitoring: Anopen-label, pilot study

Background: Beta-blockers are effective in patients with effort angina pect oris. However, there have been no previous reports on the long-term effects of beta-blocker therapy using ambulatory electrocardiographic (AECG) monit oring according to a MEDLINE(R) search. Objective: This study was undertaken to assess the long-term effects of the alpha, beta-blocker arotinolol in patients with stable effort angina pecto ris using AECG monitoring. Methods: This pilot study involved patients with Canadian Cardiovascular So ciety class I or II stable effort angina pectoris and left ventricular ejec tion fraction >40% assessed using a-dimensional echocardiography in whom pe rcutaneous transluminal coronary angioplasty and coronary artery bypass gra fting had not been performed. Patients were excluded if they were >75 years of age, had congestive heart failure of New York Heart Association class I II or IV, or had a confirmed diagnosis of an illness likely to shorten thei r life span (eg, cancer, cirrhosis). Effort angina pectoris was diagnosed b ased on chest pain on effort and myocardial ischemia as demonstrated by str ess thallium-201 myocardial perfusion scintigraphy and significant ST-segme nt depression on exercise electrocardiogram. The alpha, beta-blocker arotin olol 20 mg/d, divided into 2 doses of 10 mg each, was administered orally f or 2 years. Patients were seen by the same physician at a-week intervals du ring the first 6 weeks of treatment and at 4-week intervals thereafter, at which times chest pain, nitrate consumption, blood pressure, and heart rate were assessed. AECG monitoring was performed before treatment;, at 6 weeks , and after 2 years of treatment. Results: Results were assessable in 12 of 18 patients at 4 institutions (6 withdrew from the study within 4 weeks of treatment) with a mean (+/-SD) ag e of 65 +/- 3 years. The number of episodes per day of chest pain decreased significantly (P < 0.05) at 6 weeks and became rare 2 years after treatmen t. There was significant improvement (P < 0.05) during the daytime at both 6 weeks and 2 years in the number of episodes (0.1 +/- 0.4 and 0.1 +/- 0.3, respectively, vs 0.9 +/- 1.1) and the duration (3.8 +/- 7.0 and 0.4 +/- 1. 6 minutes, respectively, vs 40.9 +/- 27.8 minutes) of ST-segment depression . The incidence and duration of ST-segment depression decreased significant ly (P < 0.05) in the nighttime at a years compared with baseline (0.2 +/- 0 .04 and 0.04 +/- 1.6 minutes vs 1.9 +/- 0.9 and 23.9 +/- 31.5 minutes, resp ectively). Daytime heart rate decreased significantly (P < 0.05), from 84 /- 11 beats/min before treatment to 69 +/- 12 beats/min at 6 weeks and 67 /- 12 beats/min at 2 years; nighttime heart rate also decreased significant ly (P < 0.05), from 70 +/- 11 beats/min before treatment to 65 +/- 9 beats/ min at 6 weeks and 59 +/- 7 beats/min at 2 years. Conclusions: Arotinolol improved the incidence and duration of ST-segment d epression in patients with stable effort angina pectoris on AECG monitoring by decreasing heart rate. Because the improvement; was more marked after 2 years than after 6 weeks, me concluded that arotinolol is beneficial in th e long-term treatment of patients with stable effort angina pectoris, altho ugh a larger study using a control group is needed to confirm our results.