Prognostic implications of bundle branch block in patients undergoing primary coronary angioplasty in the stent era

The presence of bundle branch block (BBB) in patients with ST-segment elevation myocardial infarction has been associated with a poor outcome. However, the implications of BBB in patients undergoing primary angioplasty in the stent era are poorly established. Furthermore, the prognostic implications of BBB type (right vs left and previous vs transient or persistent) remain unknown. We analyzed the data from 913 consecutive patients with ST-segment elevation myocardial infarction treated with primary angioplasty. All clinical, electrocardiographic, and angiographic data were prospectively collected. The median follow-up period was 19 months. The primary end point was the combined outcome of death and reinfarction. BBB was documented in 140 patients (15%). Right BBB (RBBB) was present in 119 patients (13%) and was previous in 27 (23%), persistent in 45 (38%), and transient in 47 (39%). Left BBB (LBBB) was present in 21 patients (2%) and was previous in 8 (38%), persistent in 9 (43%), and transient in 4 (19%). Patients with BBB were older, and more frequently had diabetes, anterior infarctions, a greater Killip class, a lower left ventricular ejection fraction, and greater mortality (all p <0.005) than patients without BBB. The short- and long-term primary outcome occurred more frequently in patients with persistent RBBB/LBBB than in those with previous or transient RBBB/LBBB. On multivariate analysis, persistent RBBB/LBBB emerged as an independent predictor of death and reinfarction. In conclusion, in patients undergoing primary angioplasty in the stent era, BBB is associated with poor short- and long-term prognosis. This risk appears to be particularly high among patients with persistent BBB.