Background: It is still controversial whether intravenous administration of β-blocker in the very acute phase of acute myocardial infarction (AMI) is beneficial. Landiolol is an ultra-short-acting β-blocker that has less effect on blood pressure, but little is known about its efficacy and safety for patients with AMI undergoing primary percutaneous coronary intervention (PCI).
Methods and results: A consecutive 96 patients with AMI not manifesting cardiogenic shock were prospectively randomized to landiolol (n = 47) or a control group (n = 49). Continuous administration of landiolol (3 µg·kg(-1)·min(-1) for 24 h) was done just after PCI in the landiolol group, but not in the control group. Heart rate decreased by 9.4 ± 1.7 beats/min after initiation of landiolol (P<0.01), but was unchanged in the control group. Left ventricular ejection fraction assessed 6 months later was greater than that at 2 weeks in the landiolol group (52.0 ± 1.5 vs. 49.1 ± 1.5%, P = 0.01), but remained unchanged in the control group. Left ventricular end-diastolic volume index assessed 6 months later was increased compared with that at 2 weeks in the control group (78.0 ± 2.7 vs. 72.5 ± 2.8 ml/m(2), P = 0.02), whereas it was unchanged in the landiolol group.
Conclusions: Early intravenous administration of landiolol in patients with AMI undergoing PCI is safe and has the potential to improve cardiac function and inhibit cardiac remodeling in the chronic phase.