Abstract

JUAREZ-HERRERA, Úrsulo; JERJES SANCHEZ, Carlos; GONZALEZ-PACHECO, Héctor  and  MARTINEZ-SANCHEZ, Carlos. In-hospital outcome in patients with ST elevation myocardial infarction and right bundle branch block: A sub-study from RENASICA II, a national multicenter registryEvolución intrahospitalaria en pacientes con infarto agudo del miocardio con elevación del segmento ST y bloqueo de rama derecha: Sub-estudio de RENASICA II, un registro nacional multicéntrico. Arch. Cardiol. Méx. [online]. 2010, vol.80, n.3, pp.154-158. ISSN 1665-1731.

Objective: Compare in-hospital outcome in patients with ST-elevation myocardial infarction with right versus left bundle branch block. Methods: RENASICA II, a national mexican registry enrolled 8098 patients with final diagnosis of acute coronary syndrome secondary to ischemic heart disease. In 4555 STEMI patients, 545 had bundle branch block, 318 (58.3%) with right and 225 patients with left (41.6%). Both groups were compared in terms of in-hospital outcome through major cardiovascular adverse events; (cardiovascular death, recurrent ischemia and reinfarction). Multivariable analysis was performed to identify in-hospital mortality risk among right and left bundle branch block patients. Results: There were not statistical differences in both groups regarding baseline characteristics, time of ischemia, myocardial infarction location, ventricular dysfunction and reperfusion strategies. In-hospital outcome in bundle branch block group was characterized by a high incidence of major cardiovascular adverse events with a trend to higher mortality in patients with right bundle branch block (OR 1.70, CI 1.19 - 2.42, p < 0.003), compared to left bundle branch block patients. Conclusion: In this sub-study right bundle branch block accompanying ST-elevation myocardial infarction of any location at emergency room presentation was an independent predictor of high in-hospital mortality.

Keywords : Acute coronary syndrome; ST elevation myocardial infarction; Bundle branch block; Right bundle branch block; Mortality; Mexico.