Does the presence of right or left bundle branch block predict long-term mortality in patients following myocardial infarction?
Following myocardial infarction, RBBB is a predictor of increased long-term mortality in patients with reduced LV systolic function, whereas LBBB predicts mortality in those with preserved LV systolic function.
AIMS: Patients with acute myocardial infarction (MI) with bundle branch block (BBB) have a poor prognosis, but distinction between left (L)- and right (R)-sided BBB is seldom made in epidemiological studies. We studied long-term mortality associated with RBBB and LBBB in the TRAndolapril Cardiac Evaluation (TRACE) study. METHODS AND RESULTS: TRACE screened consecutive patients presenting with an MI and recorded clinical, electro- and echo-cardiographic variables. Subsequently, deaths were recorded during a minimum follow-up of 15 years. In total, 6676 consecutive patients with MI were hospitalized at 27 centres in Denmark. Of these, 533 (8%) had BBB, of whom 260 (4%) had RBBB and 273 (4%) had LBBB. Overall, 5196 (78%) patients died, 256 (94%) with LBBB and 235 (90%) with RBBB compared with 4705 (77%) of those without BBB (P 1.5, 1.70; 95% CI, 1.12-2.57). CONCLUSIONS: Right BBB was a predictor of increased mortality in patients with reduced LV systolic function, whereas LBBB was a marker of increased mortality in patients with preserved LV systolic function.
Lewinter et al. (Tue,) studied this question.