Abstract 19289: Left Bundle Branch Block in Patients With Acute Myocardial Infarction: Presentation, Treatment and 20-Years Trends in Outcome From the Acute Myocardial Infarction in Switzerland (amis) Plus Registry
Introduction: Current guidelines recommend urgent reperfusion therapy, preferably primary percutaneous coronary intervention (pPCI), in patients with ongoing myocardial ischemia and persistent ST-segment elevation (STE) or new or presumed new left bundle branch block (LBBB). Whether new or presumed new LBBB should be managed as a STE-equivalent in contemporary clinical practice remains controversial.
Methods: We analyzed data from on a large, nationwide, prospective, multicenter registry of patients admitted with acute myocardial infarction (AMI) in Switzerland (AMIS). Descriptive statistics and multivariate logistic regression were used to compare baseline characteristics, treatment and outcomes between patients with STE and new or presumed new LBBB.
Results: From 1997 to June 2016, 29114 patients with AMI (STE, 91.8%; LBBB, 6.2%) were included. Compared to the STE patients, patients with LBBB were older, with higher cardiovascular risk profile, greater burden of pre-existing comorbidities, longer reperfusion delays, higher prevalence of cardiogenic shock and worse left ventricular systolic function, but smaller AMI size. After adjustment for age and gender, LBBB patients were less likely to receive evidence-based antithrombotic therapies, and undergo urgent coronary angiography (45.7%) or pPCI (42.4%), compared to patients with STE (p<0.001 for all). LBBB was associated with higher rates of major adverse cardiovascular events (17% vs. 8.2%), in-hospital mortality (15.8% vs. 6.5%), and cardiogenic shock (11.6% vs. 6.4%), compared with patients with STE (p<0.001 for all). On multivariate analysis, LBBB was associated with the same risk of in-hospital mortality as STE (OR 0.98, 95% CI 0.83-1.15). Between 1997 and 2016, we observed an important decrease in in-hospital mortality, more largely in patients with LBBB than with STE.
Conclusions: In a large prospective cohort of patients with AMI, presence of new or presumed new LBBB identifies a high-risk subset of patients with high morbidity and mortality rates. However, our data suggest that LBBB patients have the same adjusted risk of in-hospital mortality than patients with STE. Further studies are needed to identify patients with LBBB that may benefit from an invasive treatment strategy.
Author Disclosures: J. Iglesias: None. S. Degrauwe: None. F. Eberli: None. H. Rickli: None. P. Urban: None. R. Simon: None. D. Radovanovic: None. P. Erne: None.
- © 2016 by American Heart Association, Inc.