In-hospital outcomes of anterior versus non-anterior st elevation myocardial infarction complicated with complete atrioventricular block

Abstract Background Complete atrioventricular block (CAVB) is an infrequent complication of acute ST-elevation myocardial infarction (STEMI), and information on its outcomes is scarce. We aimed to address the characteristics and in-hospital outcomes of patients with anterior versus non-anterior STEMI complicated with CAVB in a contemporary, nationwide, all-comer registry, in the U.S. Methods Using the National Inpatient Sample (NIS) database, we identified patients who were hospitalized with STEMI, complicated with CAVB between 2016- 2019. Patients with any cardiac implantable electronic device (CIED) in-situ were excluded. Baseline characteristics, in-hospital procedures and outcomes including time to temporary or permanent pacemaker (PPM)/implantable cardioverter defibrillator (ICD) implantation, length of stay and mortality were collected. Results A total of 17470 patients, were hospitalized with a primary diagnosis of STEMI and concomitant diagnosis of CAVB, 2755(15.8%) with Anterior and 14715(84.2%) with non-anterior STEMI. Non-anterior STEMI patients included more women, had higher prevalence of hypertension, dyslipidemia, smoking history and chronic pulmonary disease, while anterior STEMI patients had higher prevalence of chronic kidney disease and ischemic cardiomyopathy. Anterior STEMI patient had significantly higher rate of in hospital death [955 (35%) vs 2220 (15%), p<0.001], CPR, VT/VF, cardiac arrest, acute heart failure, respiratory failure, mechanical ventilation >96 hours and acute kidney injury. In both groups 40% received temporary pacemaker, but mean time to implantation was longer in anterior STEMI patients [1.1±3.3 vs 0.3±1.2 days, p<0.001]. Rate of any permanent CIED implantation was also significantly higher in the anterior STEMI patients with longer time to PPM implantation, [3.3±3.5 vs 2.8±2.8 days, p<0.001]. Use of mechanical circulatory support devices was significantly higher in anterior STEMI patients. Conclusion In STEMI patients complicated with CAVB, in-hospital outcomes of anterior STEMI were worse comparing to non-anterior STEMI, with significantly higher rates of in-hospital death, in-hospital complications and CIED implantations.