Long-term treatment of angina pectoris with bisoprolol or atenolol in patients with chronic obstructive bronchitis: a randomized, double-blind crossover study.

Forty outpatients suffering from angina pectoris due to coronary artery disease and concomitant reversible. chronic obstructive bronchitis were treated with the beta1-selective beta-blockers atenolol (50 mg) and bisoprolol (5 mg) for 6 months in each case, following a randomized, double-blind crossover study design. Lung function tests were carried out by means of whole-body plethysmography before and then several times during treatment. 2 to 4 h after drug intake (once daily in the morning). The main target variables for the factorial analysis of variance for comparison of the two beta-blockers were the airway resistance (AWR), the forced expiratory volume in the first second (FEV1), and the peak expiratory flow rate (PEFR). Bicycle ergometry was performed before and after therapy in order to check the cardiovascular effects of the two beta-blockers. The patients were questioned as to their angina pectoris and bronchitis symptoms at the monthly check-ups. There was no difference between the two beta-blockers (p > 0.05), both causing a slight increase in AWR, which increased with therapy duration, and a small but significant decrease in FEV1 and PEFR (p < 0.01). The bronchitis symptoms were not affected; however, seasonal influences were detected. Atenolol and bisoprolol had comparably pronounced effects on the cardiovascular parameters during ergometry (blood pressure, heart rate, W x min product, and ST-segment depression) and the frequency of angina pectoris attacks. Even beta1-selective beta-blockers may cause an impairment of lung function in patients with chronic obstructive bronchitis. This may be due to the presence of beta1-adrenoceptors in the bronchial tissue. Fifty milligrams of atenolol and 5 mg of bisoprolol once per day are effective in the treatment of angina pectoris.