Early-Onset Complete Atrioventricular Block - Prevalence, Etiology and Utilization of Cardiac Implantable Electronic Devices

BackgroundInformation regarding the prevalence and etiologies of complete atrioventricular block (CAVB) in younger patients is scarce. We aimed to investigate the potential causes for non-iatrogenic CAVB, the prevalence of CAVB without an identified etiology, the utilization of guidelines-recommended advanced imaging modalities in adults presenting with an early-onset CAVB of unidentified etiology, as well as to identify the predictors for cardiac implantable electronic device (CIED) insertion. MethodsUsing the National Inpatient Sample (NIS) database, we identified patients aged 18-60 hospitalized with non-iatrogenic CAVB in the US between 2015 (last quarter)-2019. Baseline demographics, clinical characteristics, potential etiologies for CAVB, advanced imaging utilization as well as outcomes including the need for temporary cardiac pacing (TCP) and CIED implantation were analyzed. Multivariable logistic regression models were used to identify predictors of CIED implantation. ResultsAn estimated total of 14,495 patients aged 18-60 with non-iatrogenic CAVB were identified. The mean age was 51 years, 60% were males and 3,050 (21%) had documentation of a prior conduction disorder. Eleven percent of the patients had a diagnosis of syncope and 6% suffered from a cardiac arrest. Two third of the patients (9,735, 67%) had no identified etiology for CAVB, of whom 8,205 (84%) were implanted with a permanent pacemaker (PPM), 180 patients (2%) with an implantable cardioverter-defibrillator (ICD), and 295 patients (3%) with a cardiac resynchronization therapy device. Only 40 patients (0.3%) underwent advanced imaging during their hospitalization. In multivariate analyses, older age [adjusted OR 1.046 (1.04-1.05), p<0.001] and the need for TCP [adjusted OR 1.543 (1.29-1.84), p<0.001], emerged as predictors for PPM implantation. Cardiac arrest [adjusted OR 2.786 (1.69-4.58), p<0.001] and younger age [adjusted OR 0.98 (0.96-0.99), p=0.02], were associated with ICD implantation. 185 patients (1.3%) died during their hospitalization. ConclusionThe majority of patients, hospitalized in the US for non-iatrogenic early-onset CAVB, had no identified etiology for their conduction disease. Despite the current US and European guidelines recommendation, advanced imaging prior to CIED implantation was under-utilized in this patient population.