6-year change in high sensitivity cardiac troponin T and the risk of atrial fibrillation in the Atherosclerosis Risk in Communities cohort

Background: Circulating high sensitivity cardiac troponin T (hs-cTnT) is associated with incidence of atrial fibrillation (AF), but the association of changes in hs-cTnT over time on incident AF has not been explored. Hypothesis: Six-year increase in circulating hs-cTnT will be associated with increased risk of AF and will contribute to improved prediction of incident AF. Methods: We conducted a prospective cohort analysis of 8431 participants from the Atherosclerosis Risk in Communities (ARIC) study. hs-cTnT change was categorized at visit 2 and 4 as undetectable (<5 ng/L), detectable (≥5 ng/L, <14 ng/L), or elevated (≥14 ng/L). We used Cox regression to examine the association between the combination of hs-cTnT categories at two visits and incident AF. We also assessed the impact of adding absolute hs-cTnT change on risk discrimination for AF by C-statistics and net reclassification improvement (NRI). Results: Over a mean follow-up of 16.5 years, 1629 incident AF cases were diagnosed. Among participants with undetectable hs-cTnT at visit 2, the multivariable HR of AF was 1.28 (95% CI 1.12–1.48) among those with detectable or elevated hs-cTnT at visit 4 compared to those in which hs-cTnT remained undetectable. Among those with detectable hs-cTnT at visit 2, compared to those who remained in the detectable hs-cTnT group, reduction to undetectable at visit 4 was associated with lower risk of AF (HR 0.74, 95% CI 0.59–0.94), while increment to elevated was associated with higher AF risk (HR 1.30, 95% CI 1.01–1.68). Adding hs-cTnT change to our main model with baseline hs-cTnT did not result in significant improvement in the C-statistic or substantial NRI. Conclusion: Six-year increase in circulating hs-cTnT was associated with elevated risk of incident AF.