The effects of atrial fibrillation (AF) and its burden on in-hospital mortality in patients with Takotsubo cardiomyopathy (TCM) are unclear. Here, we examined the effect of AF and paroxysmal AF on in-hospital outcomes in patients with TCM.
We used ICD-10 codes to retrospectively identify patients with a primary diagnosis of TCM in the National Inpatient Sample database 2016-2018. We compared in-hospital outcomes in TCM patients with and without AF before and after propensity score matching. The effect of AF burden on outcomes was assessed in patients with paroxysmal AF and no AF.
Of the 4,733 patients with a primary diagnosis of TCM, 650 (13.7%) had AF, and 4,083 (86.3%) did not. Of TCM patients with AF, 368 (56.6%) had paroxysmal AF. In-hospital mortality was higher in patients with AF before (3.4% vs 1.2%, P < 0.001) and after propensity matching (3.4% vs 1.7%, P = 0.021) but did not differ between the paroxysmal AF and the no AF groups ( P = 0.205). In the matched cohorts, both AF and paroxysmal AF groups were associated with a higher rate of cardiogenic shock (AF, P < 0.001; paroxysmal AF, P < 0.001), ventricular arrhythmia (AF, P = 0.002; paroxysmal AF, P = 0.02), acute kidney injury (AF, P = 0.007; paroxysmal AF, P = 0.008), and acute respiratory failure (AF, P < 0.001; paroxysmal AF, P < 0.001) compared with the no AF group.
Although AF was associated with increased in-hospital mortality, paroxysmal AF did not affect in-hospital mortality, suggesting a higher AF burden is associated with worse clinical outcome in patients with TCM.
Takotsubo cardiomyopathy (TCM), or stress-induced cardiomyopathy, is characterized by transient dysfunction of the left ventricle (LV). The etiology is unclear, but TCM is usually associated with sudden physical or emotional stress. Although previously considered benign because the LV systolic dysfunction resolves almost completely in most cases,
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.