High-sensitivity Troponin I Measurement in a Large Contemporary Cohort: Implications for Clinical Care.

Background: Contemporary methods of cardiovascular risk stratification are frequently inaccurate. Biomarkers such as high-sensitivity troponin I (hsTnI) have the potential to improve risk stratification. However, uncertainties exist regarding factors that determine hsTnI concentration. Our aim was to investigate the prevalence of elevated hsTnI in a large, contemporary Canadian cohort and describe the effect of comorbidities on hsTnI concentration.

Methods: We report a large dataset of 41,602 visits in which hsTnI was measured routinely in ambulatory outpatients. hsTnI was remeasured in 28% of patients, with a mean time between measurements of 387 days (IQR 364-441). Low-, medium-, and high-risk categories were created based on hsTnI cutoffs for each sex. Laboratory data, blood pressure, and anthropomorphic measures were extracted from the electronic medical record Results: Remeasurement of hsTnI did not change risk category in 92.7% of cases. Male sex, higher HDL-C, higher Hgb A1c, decreasing eGFR, and increasing systolic blood pressure were significant predictors of increased hsTnI. High non-HDL-C and the use of statins were associated with lower hsTnI. The inverse relationship between hsTnI and non-HDL-C was partially corrected when the confounding effect of statin therapy was considered. Model fit was poor (adjusted R-Squared = 0.0091).

Conclusion: Traditional cardiovascular risk factors were predictors of serum hsTnI levels, however a significant amount of the variance in hsTnI cannot be explained by these factors alone. This suggests that hsTnI adds additional information that is not provided by traditional risk stratification methods and supports ongoing study of hsTnI as a biomarker for cardiovascular risk stratification.