Abstract 16281: A Diagnosis and Treatment Algorithm for Suspected Myocardial Infarction and New Left Bundle Branch Block
Introduction: Patients presenting with ischemic symptoms and new LBBB (nLBBB) pose a unique diagnostic and management challenge. ACCF/AHA guidelines recently removed the recommendation for emergency reperfusion therapy in this important subgroup.
Methods: Using a comprehensive prospective regional STEMI program database, we evaluated the prevalence, clinical and angiographic characteristics, and outcomes in nLBBB patients and validated a simplified hierarchical algorithm incorporating clinical and EKG data.(Figure)
Results: Of the 3,903 consecutive STEMI patients who presented between 2003 and 2013, 131 (3.3%) patients had nLBBB. These patients had fewer acute culprit arteries (54% vs. 86%; p<0.001), were older (70.7 vs 62.4, p<0.001), more commonly female (43% vs 28%; p< 0.001), with a lower ejection fraction (41% vs 47%; p<0.001) and presented with cardiac arrest or heart failure more often (16% and 23% vs 9% and 13%; p<0.01) than those without nLBBB. At 1 year follow-up all-cause mortality, adjusted for differences in comorbidities, was higher with nLBBB than without nLBBB (12% vs. 6%; p=0.014). The overall MACE rate (a composite of death, revascularization, re-infarction or stroke) was higher with nLBBB both at 30 days (14% vs. 9%; p=0.038) and at 1 year (24% vs. 14%; p=0.002).
Classification of the nLBBB patients using the algorithm led to 45% with STEMI-equivalent undergoing emergent intervention; 31% ACS undergoing urgent intervention and 24% felt not to be acute, therefore no angiography. Based on the identification of a culprit artery, the algorithm yielded a high sensitivity (97%) and negative predictive value (94%).(Figure)
Conclusions: Patients with acute ischemic symptoms and nLBBB represent a high-risk population with significant risk of cardiac arrest, death and re-infarction. An algorithm using simplified clinical and ECG criteria may improve the diagnostic accuracy regarding reperfusion strategies for nLBBB patients.
Author Disclosures: V.K. Pera: None. D.M. Larson: None. S.W. Sharkey: None. R.F. Garberich: None. C.J. Solie: None. Y.L. Wang: None. J.H. Traverse: Research Grant; Modest; NHLBI. Research Grant; Significant; modest. A.K. Poulose: None. T.D. Henry: None.
- © 2014 by American Heart Association, Inc.