Background: Previous studies in the prethrombolytic or thrombolytic era have reported that right bundle-branch block (RBBB) is associated with poor clinical outcome in patients with acute myocardial infarction (AMI).
Methods and results: The purpose of this study was to examine the relations between RBBB and angiographic findings or clinical outcomes in patients with AMI in the coronary intervention era. A total of 430 patients with a first anterior AMI who underwent coronary angiography within 12 h after the onset were enrolled in this study. Seventy-one patients (17%) had RBBB documented during their hospital stay. RBBB was documented on admission in 35 patients. Patients with RBBB were older (p<0.01) and had prodromal angina less frequently (p=0.03) than those without. On the initial angiograms, patients with RBBB had an occluded left anterior descending artery (p<0.01) and multivessel disease (p=0.01) more frequently than those without. Thirty-day mortality rate was significantly higher in patients with RBBB than in those without (14.0% vs 1.9%, p<0.01). Multiple logistic-regression analysis demonstrated that RBBB (odds ratio 5.89, p<0.01) and multivessel disease (odds ratio 4.36, p=0.01) were independent predictors of 30-day mortality.
Conclusions: Our data suggested that RBBB was still associated with poor clinical outcome in patients with anterior AMI even in the coronary intervention era.