Abstract
BACKGROUND: Few data are available on the risk of death and thromboembolism in patients with supraventricular tachycardia (SVT). PURPOSE: To assess the risk of adverse events in SVT patients admitted to the emergency department (ED). METHODS: Retrospective study utilizing a global federated health research network (TriNetX). Based on the ICD codes recorded at the ED admission, patients were categorized in: SVT (I41.1), atrial fibrillation (AF, I48.0,1,2,91), atrial flutter (I48.3,4,92), and a control group with palpitations (R00.2) without arrhythmias (CTRL). Primary outcome was the 1-year risk of a composite of all-cause death and thromboembolism (ischemic stroke, transient ischemic attack, and peripheral arterial embolism). Secondary outcomes were the 1-year risk of each component of the composite outcome. Cox-regression analysis was used to produce hazard ratios (HRs) and 95% confidence intervals (CI) after 1:1 propensity score matching (PSM). The exploratory analysis was performed to assess the risk of first episode of thromboembolism. Other sensitivity analyses were performed to validate the results of the main analysis in patients ≥65 years, with multimorbidity, and not on oral anticoagulation (OAC). RESULTS: We identified 37,793 SVT patients (58.5±19.2 years, 55.8% females), 239,490 AF patients (70±19.2 years, 47.3% females), 20,674 atrial flutter patients (68.6±15.1, 15.1% females), and 89,152 CTRL (43.5±17.8 years, 60.1% females). Before PSM, in SVT patients the mean age and the prevalence of cardiovascular risk factors was lower than AF and atrial flutter patients but higher than CTRL. After PSM, no difference was found among the three groups. After PSM, the risk of composite outcome in SVT patients was higher compared to CTRL (HR 2.80, 95%CI 2.61-3.00), similar to atrial flutter patients (HR 0.98, 95%CI 0.94-1.03), and a lower compared to AF patients (HR 0.85, 95%CI 0.82-0.88) (Figure 1). These results were consistent also for the secondary outcomes, for the risk of the first thromboembolic event (Figure 2), and in all the sensitivity analyses. CONCLUSION: SVT patients have a risk of death and thromboembolism comparable to those with atrial flutter, but lower than AF. Further studies are needed to evaluate the possible beneficial effect of OAC in this clinical context. [Figure: see text] [Figure: see text]