Abstract 8460: High-Sensitivity Cardiac Troponin T and the Risk of Incident Atrial Fibrillation: The Atherosclerosis Risk in Communities (ARIC) Study
Introduction: Structural changes in the heart, such as increased left atrial size and decreased ejection fraction, are known risk factors for atrial fibrillation (AF). An association between cardiac troponin T (hs-cTnT), a marker of myocardial cell damage measured with a high sensitivity assay, and the risk of AF could have implications for AF risk stratification.
Objective: To estimate the association between hs-cTnT and the risk of incident AF in the Atherosclerosis Risk in Communities (ARIC) Study, a prospective cohort of middle-aged adults from 4 U.S. communities.
Methods: Study was restricted to 10,596 participants free of AF at the fourth clinic visit (1996-98). AF was defined using ICD codes from hospitalizations and death certificates. Cox proportional hazards models were used to estimate the association between hs-cTnT and the risk of AF adjusting for potential confounders (Table). Net reclassification index (NRI) was used to examine its discriminative ability for 10-year AF risk (<5%, 5-15%, and >15%).
Results: We observed 920 incident AF cases over 109,607 person-years. The AF rate was lowest among participants with undetectable hs-cTnT levels and greatest among those with hs-cTnT > 0.014 µg/L (Table). After adjustment for potential confounders, a 1 standard deviation difference in ln(hs-cTnT) was associated with a hazard ratio of 1.21 (95% CI = 1.13, 1.30). Addition of hs-cTnT to known AF predictors did not increase the area under the curve appreciably (without hs-cTnT: 0.755, 95% CI = 0.740, 0.771; with hs-cTnT: 0.759, 95% CI = 0.743, 0.774). Among those who developed AF, 3.2% had their risk increased by the inclusion hs-cTnT and 3.9% had their risk decreased (p=0.50). Among those who did not develop AF, 2.7% had their risk increased and 3.4% had their risk decreased (p=0.0001). There was no net improvement in risk stratification (NRI=0.36%, p=0.72).
Conclusions: Hs-cTnT level is associated with an increased rate of AF but did not improve risk stratification.
- © 2011 by American Heart Association, Inc.