Prognostic implications of atrio-ventricular block in patients undergoing primary coronary angioplasty in the stent era.

INTRODUCTION: Conduction disorders in patients with ST-segment elevation myocardial infarction (STEMI) are associated with high mortality. Previous studies have analyzed the implications of AVB in acute coronary syndrome treated with fibrinolysis. However, the implications of AVB in patients with STEMI treated with primary angioplasty have not been sufficiently studied.

MATERIAL AND METHODS: 913 patients with STEMI treated with primary angioplasty. All clinical, electrocardiographic and angiographic variables were collected.

RESULTS: AVB was documented in 115 patients (12.6%). On admission, AVB was present in 70 (7.7%), and persistent at hospital discharge in 36 (3.9 %). Within these, first-degree AVB was present in 29 (3.2%), second-degree in 27 (3%) and third-degree in 73 (8%). AVB was more frequent in women, elderly, hypertensive, diabetic, with worse functional class (Killip class > 2) and with higher incidence at inferior infarctions (P < 0.05). AVB in general and, more specifically, third-degree AVB was associated with a higher mortality (20.5% versus 5.7%; P < 0.001), re-infarction (8.2% versus 3.6%; P = 0.06) and a greater incidence of cardiogenic shock (33.3% versus 14%; P < 0.001). Interestingly, these events were more common in patients who had persistent AVB at hospital discharge than in those with transitory AVB or present at admission AVB. In the multivariate analysis, persistent AVB at hospital discharge proved to be an independent predictor of cardiovascular events (death and recurrent infarction), not the rest of AVB.

CONCLUSIONS: AVB in patients who underwent primary angioplasty is associated with a worse prognosis while is in-hospital. This risk is particularly high in patients who had persistent AVB at hospital discharge.