Atrioventricular block in patients with acute myocardial infarction in a state of cardiogenic shock

Abstract

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): University Hospital of Virgen Macarena. Introduction Atrioventricular block (AVB) is a complication to consider in patients with acute myocardial infarction (AMI), constituting a factor in decompensation that can contribute to the shock state in some patients. Purpose The study analyzed the incidence of AVB and its relationship with the culprit artery, mortality, and the final need for device implantation. Methods A single-center, observational, retrospective study included patients admitted to the Coronary Care Unit in a state of cardiogenic shock in the context of AMI between July 2011 and September 2022. Results A total of 298 patients with AMI in a state of shock were included. The average age of the sample was 69 years, with 66.7% being male, 66.8% having hypertension, 55% having dyslipidemia, 50% having diabetes, and 33% being smokers. Nearly half of the patients (47.86%) already presented with a Killip Kimball class IV at the time of admission. The left anterior descending artery (LAD) was responsible for the infarction in 57.4% of cases, and the right coronary artery (RCA) in 24.8%. The incidence of AVB was significantly higher in patients with RCA infarctions compared to LAD (39.1% vs. 3.1%) and compared to other vessels (39.1% vs. 6.69%), with this significance remaining in any type of acute coronary syndrome. The need for device implantation was infrequent. Patients with LAD infarctions required more implantation of implantable cardioverter-defibrillators (ICDs) compared to RCA infarctions (4.43% vs. 0.49%), and RCA infarctions required more conventional pacemaker implantation (2.7% vs. 0%). A better prognosis was observed in RCA involvement with lower mortality compared to other vessels (OR 0.35, 95% CI 0.19-1.6; p=0.01) and compared to LAD involvement (OR 0.44, 95% CI 0.23-0.84; p=0.013). Conclusions The incidence of AVB was a particularly common complication in patients in a state of shock with RCA infarctions. However, the mortality was significantly lower in this subgroup of patients. Regardless of the responsible artery, the need for device implantation was infrequent, with a notable need for ICDs in LAD involvement and pacemakers in RCA involvement.