Management of chronic stable angina with once-daily bisoprolol or atenolol and long-term efficacy of bisoprolol.

The efficacy of once-daily bisoprolol (10 mg) and atenolol (100 mg) was assessed in 19 patients with stable angina, using a double-blind randomized crossover protocol and computer-assisted treadmill exercise testing with continuous monitoring of leads CM5 and CC5, the test being carried out 22-24 h after the last dose. The mean +/- SEM exercise time on placebo was 6.5 +/- 0.4 min increasing to 7.8 +/- 0.5 min on bisoprolol (p less than 0.02) and 8.6 +/- 0.6 min on atenolol (p less than 0.001). The increase in exercise time with atenolol was significantly greater than with bisoprolol (p less than 0.02). The time to 1 mm ST-depression in CM5 and CC5 was also prolonged significantly with both drugs compared to placebo, but with no difference between the two active treatments. The mean resting heart rate of 84 +/- 4 beats/min decreased to 63 +/- 2 beats/min on bisoprolol (p less than 0.001) and 64 +/- 2 beats/min on atenolol (p less than 0.001) with a significant decrease in the peak exercise heart rate seen with both drugs (p less than 0.001). The peak rate-pressure product (beats/min X mm Hg X 10(-2)) was 175 +/- 8 after placebo, 146 +/- 7 (p less than 0.001) after bisoprolol and 149 +/- 5 (p less than 0.01) after atenolol. One patient was withdrawn because he suffered a myocardial infarction. After completion of the crossover phase, 18 of the patients were prescribed bisoprolol 10 mg once a day for 6 weeks. Twelve patients were treated for 12 weeks. An exercise test was performed at the end of each 6-week period. The effects of bisoprolol on all parameters were maintained. In conclusion, bisoprolol is an effective antianginal agent, comparable in efficacy and duration of action with atenolol, and is suitable for once daily administration.