PO-03-204 BURDEN OF ARRHYTHMIAS AND CLINICAL OUTCOMES IN PATIENTS HOSPITALIZED WITH ACUTE MYOCARDITIS ACCORDING TO LARGE DATASET

Abstract

Acute myocarditis is known to cause diverse disorders of heart rhythm which can be difficult to diagnose and further investigate. Moreover, prevalence of arrhythmias and their clinical impact is not well studied in this population. This article aims to investigate the burden, basic characteristics, and clinical outcomes of the most prevalent arrhythmias arising in acute myocarditis (AM). We queried the National Inpatient Sample between 2017-2020 for adult patients who were hospitalized with AM. The primary outcome was inpatient mortality. The secondary outcomes were cardiogenic shock, cardiac arrest, invasive mechanical ventilation, length of stay (LOS) and total hospital cost. Multivariable logistic, linear and Poisson regression analyses were used to estimate clinical outcomes. p-value < 0.05 was significant. There were 14,325 hospitalizations with AM, of which 2,784 (19.7%) had arrhythmia. Mean age was 45.3 yrs, 60.8% were Caucasian, 61.8% were male. The most prevalent arrhythmia was ventricular tachycardia (VT) 1,289 (8.9%), followed by paroxysmal atrial fibrillation (AFib) 604 (4.2%), 3rd degree AV block (AVB) 414 (2.8%), ventricular fibrillation 135 (0.9%), and permanent AFib 119 (0.8%). Subgroup with arrhythmia vs without arrhythmia had HTN 10.3% vs 16.8%; PH 10.3% vs 6.1%; HF 69.7% vs 37.9%; CKD 16.1% vs 9.2%; COPD 12.7% vs 7.6%, respectively. During hospitalization, these subgroups had following complication rates: ACS 27.2% vs 23.7%; AKI 41.3% vs 20.8%; stroke 4.3% vs 1.4%, respectively. Also, subgroup with arrhythmia was associated with higher ICD (7.5% vs 0.3%), PPM (2.7% vs 0.5%), and LVAD (7.9% vs 1.5%) insertion rate. Finally, subgroups with the most frequent arrhythmias (VT, AFib, 3rd degree AVB) demonstrated worse primary and secondary outcomes compared to non-arrhythmic patients (Table 1). Patients hospitalized with AM have significant burden of arrhythmia (almost 20%), mainly VT, AFib, and AVB. Arrhythmic population has prevalent PH, HF, CKD, and COPD. Hospital complications and requirements for device support are also higher in AM patients with arrhythmia resulting into worse mortality, clinical outcomes, and higher resource utilization. When managing patients with AM, early identification and treatment of heart rhythm disorders would improve results. Further research aiming on pathogenesis and long-term outcomes is needed.