Abstract 16558: the Burden of Arrhythmia in Cardiac Amyloidosis Hospitalizations: Perspective from a Nationwide Study

Introduction: Cardiac amyloidosis (CA) is a significantly underdiagnosed cause of infiltrative and restrictive cardiomyopathy, which leads to rapidly progressive heart failure associated with poor outcomes. Hypothesis: There is a paucity of data on the incidence and outcomes of arrhythmia among CA hospitalizations. Methods: Nationwide Inpatient Sample from 2016 to 2017 was used for the present analysis. CA hospitalizations with concurrent arrhythmia were identified by using appropriate ICD-10 CM codes, and it was compared with CA hospitalizations without arrhythmia. The primary outcome was all-cause in-hospital mortality, and secondary outcomes were the length of stay and total hospital cost. The adjusted odds ratio was calculated by multivariable regression analysis after adjusting for baseline characteristics and comorbidities. Results: A total of 5030 hospitalizations with CA were identified, of which 1570 had associated arrhythmia. CA hospitalizations with arrhythmia had higher mortality compared to without arrhythmia (150 (10.82%) vs. 215 (6.21%), P=0.012) (Table 1). Length of stay (9.74 days vs. 8.20 days, P=0.02) and total cost of hospitalization (avg. $ 112840 vs. $88638, P=0.02) were significantly higher in CA hospitalizations with concomitant arrhythmia (Table 1). Among arrhythmia, atrial fibrillation was the most common (89.38%) (Figure 1). Adjusted odds of in-hospital mortality due to any arrhythmia (aOR (adjusted odds ratio) = 1.83, CI (confidence interval) = 1.14 - 2.92, P=0.012) or atrial fibrillation (aOR= 1.73, CI= 1.075-2.277, P= 0.02) were significantly higher in CA hospitalization (Table 2). Conclusions: CA hospitalizations with arrhythmia had a higher adjusted odds of in-hospital mortality as compared to without arrhythmia. Additionally, CA hospitalization with arrhythmia had a longer length of stay, and cost of care. Among all arrhythmia, atrial fibrillation was the most common.