High-sensitivity cardiac troponin-T concentrations and their prognostic implications in patients with paroxysmal supraventricular tachycardia.

Aims: To examine whether elevated high-sensitivity troponin-T (hs-TnT) concentrations in patients with paroxysmal supraventricular tachycardia (PSVT) without known cardiovascular disease (CVD) are associated with an increased risk of death.

Methods: Patients with de novo PSVT and ≥ 1 measured hs-TnT level from 2013 to 2020 during hospitalization without known CVD were retrospectively identified in the Danish nationwide registries. Elevated hs-TnT was defined as ≥14 ng/l. The primary outcome was all-cause mortality assessed at 0-30 days and 31-365 days, using multivariable Cox regression with average treatment effect, rendering standardized absolute and relative risks. The secondary outcome was a composite endpoint of myocardial infarction, coronary revascularization, stroke, or heart failure-related contact.

Results: A total of 1203 patients were included, with 792 (65.8 %) patients having elevated hs-TnT levels. The standardized mortality risk within 30 days was significantly higher in patients with elevated hs-TnT compared with those with normal concentrations [2.38 %, 95 % confidence interval (CI): 1.38 to 3.37 versus <0.01 %, 95 % CI: <0.01 to <0.01; 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 (p = 0.31). The risk of the composite secondary outcome did not significantly differ between the groups.

Conclusion: In patients with de novo PSVT and without known CVD, elevated hs-TnT concentrations were associated with increased short-term mortality. Long-term mortality was not significantly affected by elevated hs-TnT, likely due to study limitations, and requires further investigation.