A Multicenter, Open-Label Study of an Intravenous Short-Acting β(1)-Adrenergic Receptor Antagonist Landiolol Hydrochloride for Coronary Computed Tomography Angiography by 16-Slice Multi-Detector Computed Tomography in Japanese Patients with Suspected Ischemic Cardiac Disease

BACKGROUND: During coronary computed tomography (CT) angiography (CCTA), β-blockers (β-adrenergic receptor antagonists) have commonly been used to lower heart rate and improve image quality. OBJECTIVES: The aim of this study was to investigate the image quality-improving effect as well as the heart rate-lowering effect of landiolol hydrochloride (an intravenous short-acting β(1)-adrenergic receptor antagonist) in CCTA by 16-slice multi-detector CT (MDCT). METHODS: A total of 39 subjects suspected of having ischemic cardiac disease and requiring CCTA received 0.125 mg/kg of landiolol hydrochloride to study the efficacy and safety of landiolol hydrochloride in a multicenter open-label clinical study. The endpoint was the diagnosable proportion (proportion of subjects whose coronary stenosis was diagnosable). RESULTS: The diagnosable proportions for the reconstruction images at mid-diastole were 56.0 %. The diagnosable proportions for the optimal reconstruction images were 65.4 %. The mean heart rate-lowering effect was observed soon after administration of landiolol hydrochloride; the peak of the effect was reached in 3–5 min, and the effect wore off in 30 min after completion of administration. The mean heart rate-lowering proportion at that time was −14.46 ± 8.4 %. CONCLUSIONS: Landiolol hydrochloride was confirmed to reduce heart rate significantly and rapidly after intravenous injection and this suggests that the study drug is a safe and useful agent for improving the image quality of CCTA by 16-slice MDCT.