High-grade atrioventricular block in acute coronary syndrome: Portuguese experience.

Abstract Background: The high-grade atrioventricular block (HAVB) occurrence in acute coronary syndrome (ACS) is a potentially life-threatening complication, that demands a rapid and efficient response regarding reperfusion time and rhythm stabilization. This study aimed to analyse the rate, clinical features, therapeutic approach, complications, in-hospital mortality and follow-up of HAVB in the setting of ACS. Methods: Multicenter retrospective study based on the Acute Coronary Syndrome Portuguese National Registry, including 32157 patients admitted for ACS between 1/10/2010–3/05/2020, classified according to the presence or absence of HAVB during the hospitalization for ACS. Comparison between the two groups was performed. Logistic regression was accomplished to assess predictors of HAVB in ACS patients. Results: Patients with HAVB were older, and had higher rates of females, history of stroke and neoplasia. HAVB patients presented more frequently ST-segment elevation myocardial infarction, syncope as a major symptom, higher Killip-Kimball class and multivessel disease. Furthermore, HAVB patients had more major adverse cardiac events during the hospitalization for ACS, namely heart failure complication, cardiogenic shock complication, new-onset of atrial fibrillation, ACS mechanical complication, sustained ventricular tachycardia, cardiac arrest, stroke complication and in-hospital death. Logistic regression revealed that female gender, age ≥ 75 years old, heart rate I were predictors of HAVB in ACS patients. Also, HAVB patients presented higher rates of all-causes of death at 1-year follow-up (p = 0.011). Conclusions: Using real-life data, patients with HAVB in the setting of ACS had a worse prognosis during hospitalization and in the short-term follow-up period.