Risk of death and thrombosis in patients admitted to the emergency department with supraventricular tachycardias

Background: Few data are available on the clinical course of patients with supraventricular tachycardia (SVT).

Objective: The purpose of this study was to assess the 1-year risk of adverse events in patients with SVT.

Methods: This was a retrospective observational study conducted within TriNetX. On the basis of the International Classification of Diseases, Tenth Revision, Clinical Modification codes recorded at the emergency department admission, patients not taking oral anticoagulation were categorized into SVT, atrial fibrillation (AF), atrial flutter, or control (CTRL) groups. The primary outcome was the 1-year risk of a composite of all-cause death or thromboembolism. Cox regression analysis was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) after 1:1 propensity score matching. Sensitivity analyses were performed in clinically relevant subgroups. Incident AF and new oral anticoagulation prescriptions were reported during the study period.

Results: We identified 23,524 patients with SVT (mean age 54.6±19.3 years; 14,000 [59.5%] women), 5413 with atrial flutter (66.9±15.7 years; 1907 [35.2%] women), 157,715 with AF (72.5±14.0 years, 68,813 [43.6%] women), and 150,807 CTRLs (43.0±17.4 years; 88,540 [58.7%] women). After propensity score matching, the risk of composite outcome in patients with SVT was higher than that in CTRLs (HR 2.89; 95% CI 2.65-3.17) but lower than that in patients with atrial flutter (HR 0.87; 95% CI 0.79-0.97) and those with AF (HR 0.69; 95% CI 0.65-0.73). The risk of adverse events in patients with SVT was more pronounced during the first 30 days in males, those aged ≥65 years, or those with multimorbidity. Patients with SVT had an increased risk of incident AF than did CTRLs.

Conclusion: The increased risk of adverse events in patients with SVT appears to be most pronounced in the short term and partly associated with the increased likelihood of incident AF.