OBJECTIVE. The purpose of this study was to assess the safety of heart rate optimization by use of β-adrenergic blockade solely by the IV route before coronary CT angiography. MATERIALS AND METHODS. The records of 679 patients undergoing CT coronary angiography after receiving IV β-adrenergic blockade were retrospectively analyzed. Health screening was completed before scanning, and heart rate was optimized by administration of IV metoprolol titrated to a maximum of 70 mg to achieve a heart rate less than 65 beats/min. RESULTS. The median IV dose was 20 mg (range, 5-70 mg). The 679 patients analyzed had a total of 10 complications (1.47%). Major complications, defined as not resolving with observation and analgesia alone, occurred in only three patients (0.44%). These complications included a second-degree atrioventricular block. A total of 299 patients (44.0%) needed more than 20 mg of IV metoprolol to achieve target heart rate. Only three patients needed the maximum IV dose of 70 mg metoprolol. Target heart rate was reached successfully in 666 patients (98.1%) with doses of less than 70 mg. This study did not show a statistically significant association between increasing complication frequency and increasing dose. CONCLUSION. This study showed that high doses of IV metoprolol can be used effectively and with a low rate of major complications to control heart rate before coronary CT angiography in correctly screened patients.