RESUMO
The choice between beta-blockade or nitrates as first line treatment for stable angina pectoris is based upon the different mechanisms of action and patient characteristics. We performed a clinical trial comparing the efficacy of the longacting beta-blocker bisoprolol once daily and the short acting nitrate, isosorbide dinitrate, three times daily in the reduction of anginal complaints in daily life and under stress. Thirty patients were enrolled in a double-blind randomised cross-over study. Both bisoprolol and isosorbide dinitrate were effective in reducing anginal attacks and nitroglycerin consumption significantly, but bisoprolol was significantly more effective than isosorbide dinitrate. Bisoprolol improved the workload during bicycle exercise testing significantly, but the improvement with isosorbide dinitrate was not significant. Despite the reduction in maximal rate pressure product, bisoprolol was significantly (P < 0.05) more effective at improving total workload and reducing the time to onset of angina than isosorbide dinitrate. The rate pressure product did not change significantly with isosorbide dinitrate. In this study, bisoprolol 10 mg once daily was more effective and caused less side effects than isosorbide dinitrate 20 mg three times a day. It seems questionable if monotherapy of isosorbide dinitrate 20 mg t.i.d is an adequate drug regime for stable angina pectoris.
