Effect of metoprolol succinate in patients with stable angina and elevated heart rate receiving low dose β-blocker therapy

β-blockers are underused in Chinese patients with coronary heart disease. The prescribed dose is often low. The aim of this study was to investigate the effect of metoprolol succinate doses of 95 mg and 190 mg on heart rate (HR) control, as well as drug tolerance, in Chinese patients with stable angina, low-dose β-blocker use and unsatisfactory HR control