Objectives: To assess the efficacy of early invasive strategy for the treatment of Braunwald III-B type unstable angina pectoris.
Methods: This study included 573 consecutive patients of whom 267 underwent percutaneous coronary intervention (PCI) (312 lesions). The patients were divided into two groups, 95 treated with the early invasive strategy of coronary angiography within 24 hr of admission (Group PCI-I) and the remaining 172 treated with the early conservative strategy of coronary angiography 24 hr after admission (Group PCI-C).
Results: No significant differences were noted in the baseline characteristics of the two groups except for ST segment elevation on electrocardiography at presentation, which occurred significantly less frequently in Group PCI-C (36.8% vs 8.1%, p < 0.0001). The initial success rate of percutaneous coronary intervention was sufficiently high in both groups (Group PCI-I: 96.9% vs Group PCI-C: 97.7%, NS). Acute myocardial infarction occurred in six patients of Group PCI-C (3.5%) because of the side branch occlusion. There was no in-hospital death or emergent coronary artery bypass grafting. During the 6-month follow-up, there were no significant differences in the death rates (2.1% vs 1.7%), the death or myocardial infarction rates (5.3% vs 5.8%) and the target lesion revascularization ratio (26.0% vs 25.7%) between Group PCI-I and Group PCI-C.
Conclusions: The clinical outcomes of the early invasive strategy for unstable angina pectoris were almost equivalent to those of the early conservative strategy, despite more frequent ST segmental elevation at admission in Group PCI-I. These findings suggest that the early invasive strategy for unstable angina pectoris may be acceptable even in the current Japanese clinical setting without the use of GP IIb/IIIa receptor antagonist, low molecular weight heparin or clopidogrel.