AIMS: Atrial fibrillation (AF) is becoming increasingly common. Traditional cardiovascular risk factors (CVRF) do not explain all AF cases. Blood-based biomarkers reflecting cardiac injury such as high-sensitivity troponin I (hsTnI) may help close this gap.
METHODS: We investigated the predictive ability of hsTnI for incident AF in 45,298 participants (median age 51.4 years, 45.0% men) across European community cohorts in comparison to CVRF and established biomarkers (C-reactive protein, N-terminal pro B-type natriuretic peptide).
RESULTS: During a median follow-up of 7.7 years, 1,734 (3.8%) participants developed AF. Those in the highest hsTnI quarter (≥ 4.2 ng/L) had a 3.91-fold (95% confidence interval (CI) 3.30, 4.63, P<0.01) risk for developing AF compared to the lowest quarter (<1.4 ng/L). In multivariable-adjusted Cox proportional hazards models a statistically significant association was seen between hsTnI and AF (hazard ratio (HR) per 1 standard deviation (SD) increase in log10(hsTnI) 1.08, 95% CI 1.01, 1.16, P=0.03). Inclusion of hsTnI did improve model discrimination (C-index CVRF 0.811 vs. C-index CVRF and hsTnI 0.813, P<0.01). Higher hsTnI concentrations were associated with heart failure (HR per SD 1.37, 95% CI 1.12, 1.68, P<0.01) and overall mortality (HR per SD 1.24, 95% CI 1.09, 1.41, P<0.01).
CONCLUSION: hsTnI as a biomarker of myocardial injury does not improve prediction of AF incidence beyond classical CVRF and NT-proBNP. However, it is associated with the AF-related disease heart failure and mortality likely reflecting underlying subclinical cardiovascular impairment.