908-108 Outcome of Patients with Acute Myocardial Infarction and Bundle Branch Block in the Thrombolytic Era: Observations from GUSTO

• Published in: Journal of the American College of Cardiology 1995-02, Vol.25 (2), p.59A-60A
• Main Authors: Sgarbossa, Elena B., Pinski, Sergio L., Gates, Kathy B., Robinson, Killian, Stein, Susan, Woodlief, Lynn H., Barbagelata, Alejandro, Wagner, Galen S., Topol, Eric J.
• Format: Article
• Language: English
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/0735-1097(95)91700-8

The presence of bundle branch block (BBB) in the admission ECG during acute MI has been recognized as a powerful prognostic factor. Occasional case reports have suggested that timely reperfusion of the infarct-related artery may revert the injury to the conduction system. However, the outcome of pts presenting with acute MI and BBB has not been scrutinized in the thrombolytic era. We compared all North American GUSTO-l patients who had BBB in the admission ECG (n=420; 0.017%) with an equal number of GUSTO-l North American pts without BBB matched for age and Killip class at admission. One hundred and thirty-one pts presented with LBBB and 289 pts presented with RBBB (isolated RBBB: 133 pts; RBBB+LAH: 145 pts; RBBB + LPH: 11 pts) Mean age was 68.3 and mean Killip class was 1.32 for both groups. Pts admitted with BBB had higher event rates for 30-day mortality 122% vs 10%; p=0.003), asystole during hospitalization (18% vs 8%; p<0.001). and need for pacing (22% vs 13%; p=0.006) than their matched controls After adjusting for all additional baseline prognostic variables, BBB remained an independent predictor for 30-day mortality (p=0.036; Odds Ratio=1.58; 95% CI=103-2.43). 1) Although in the thrombolytic era the incidence of BBB at presentation of acute MI may have decreased, this group of pts are at high risk for 3D-day mortality; 2) Their poor prognosis does not seem to be related to a larger infarct size or more severe CHF. The role of septal asynergy, late bradyarrhythmias, and electrical instability (perhaps related to autonomic denervation of the conduction system) deserve further study; 3) Pts presenting with BBB during acute MI warrant especial surveillance and aggressive management, which should probably include prophylactic pacing.