High-sensitivity cardiac troponin-T concentrations and their prognostic implications in paroxysmal supraventricular tachycardia: A nationwide study

Abstract

Abstract Introduction Paroxysmal supraventricular tachycardia (PSVT) may mimic symptoms and electrocardiographic findings compatible with acute coronary syndromes. As a result, cardiac troponin concentrations are frequently measured upon presentation. Although PSVT may increase troponin concentrations, the expected magnitude and prognostic clinical value of high-sensitivity troponin (hs-TnT) concentrations remain uncertain. Purpose The purpose of this study was to examine whether elevated hs-TnT concentrations in PSVT patients were associated with a higher risk of death from any cause. Methods We used Danish nationwide registry data from January 2013 through December 2019. PSVT was defined as all supraventricular tachycardias except atrial fibrillation and atrial flutter. The inclusion criteria were de novo PSVT and at least one measured hs-TnT level during hospitalization. Exclusion criteria were a history of cardiovascular disease (coronary artery disease, atrial fibrillation or flutter, or heart failure) or absence of hemoglobin or creatinine measurement within one day of the hs-TnT measurement. Elevated hs-TnT was defined as a value of ≥14 ng/l (the conventional 99th percentile upper reference limit). The primary outcome was death from any cause evaluated at 0-30 and 31-365 days, using multivariable Cox regression with average treatment effect, rendering standardized absolute and relative risks. Results A total of 1029 patients were included. Median age was 58 years (25th to 75th percentile: 45-71), and 45% were male. Elevated hs-TnT level was observed in 674 (65.5%) patients, who also had a higher prevalence of cardiovascular comorbidities. The median hs-TnT level was 16 ng/l (25th to 75th percentile: 10-35). The standardized mortality risk at 30 days was significantly higher in patients with elevated hs-TnT compared with patients with normal hs-TnT concentrations (2.38% [95% confidence interval (CI): 1.38 to 3.37] versus <0.01% [95% CI: <0.01 to <0.01]) (Figure 1). The relative risk was 58722906 (95% CI: 23126570 to 94319242), p = 0.001. At 31-365 days, the standardized risk of death was 1.51% (95% CI: 0 to 3.28) in individuals with a normal hs-TnT and 4.23% (95% CI: 2.81 to 5.66) in those with an elevated hs-TnT (Figure 2), resulting in a relative risk of 2.81 (95% CI: 0 to 6.32), p = 0.31. Conclusion In patients without prior cardiovascular disease, an elevated hs-TnT concentration during the first episode of PSVT was only associated with an increased early mortality risk. Long-term mortality was not affected by elevated hs-TnT.Figure 1Figure 2