Association of atrial fibrillation burden with in-hospital outcomes in patients with Takotsubo cardiomyopathy

increasing evidence now suggests TCM may have a worse prognosis. Recent data have shown that short-term mortality ranges from 1%-8%, and long-term mortality may possibly exceed that of patients with ST-elevation myocardial infarction. Furthermore, the presence of underlying risk factors such as chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), ^, older age, physical stress, and drug use contribute to in-hospital mortality. The most common arrhythmia—atrial fibrillation (AF)—affects 1.7-6.7 million people in the United States, and its prevalence is almost doubled in patients older than 50 years. ^, Patients with AF have a 5-fold increased risk of stroke, along with higher in-hospital mortality. Previous studies have shown that the prevalence of AF in TCM patients ranges from 6%–25%. ^{, ,} In the few studies that have examined the effect of AF on in-hospital mortality in TCM patients, the results have varied; some have shown that TCM patients with AF have a significantly high in-hospital mortality, ^, whereas others suggest that AF does not contribute to higher in-hospital mortality in TCM patients. ^{, ,} In most studies, AF has been defined in a binary manner, as present or not present. ^{, , , , ,} However, the burden of AF, defined as the quantity and amount of a patient’s AF, may also affect clinical outcomes. Classic AF is divided by AF burden into paroxysmal, persistent, or permanent types. Emerging evidence has shown that an increased AF burden leads to a higher risk of stroke and higher mortality rate. In this study, we conducted a propensity analysis using the most updated National Inpatient Sample (NIS) database to examine the effect of AF on in-hospital mortality in TCM patients. Furthermore, to assess specifically the effect of AF burden, we did a subgroup analysis on TCM patients with paroxysmal AF and TCM patients without AF.