Abstract P262: Comparison of Contemporary, Highly-sensitive and Supersensitive Troponin Assays as Predictors of Incident Cardiovascular Events - A Prospective Analysis of the Finrisk 1997 Cohort
Introduction: Besides the role in diagnosis of acute cardiac events, troponins seem to be powerful biomarkers in terms of risk stratification in the general population. The objective of our study was to compare the performance of three troponin assays with different sensitivities in cardiovascular disease (CVD) risk prediction in a population-based cohort without a history of CVD events. We hypothesized that troponins may predict future CVD events even in healthy individuals and that the predictive power may depend on the sensitivity of the assay.
Methods: Troponin I concentrations were measured using a contemporary sensitive (Abbott TnI), a highly sensitive (Abbott hsTnI), and a supersensitive assay (Singulex) in participants aged 25-74 years of the FINRISK 1997 cohort, followed up for 14 years. Individuals with a history of major adverse cardiovascular event (MACE, n=470) and pregnant women (n=76) were excluded and 7,899 persons were included in the analysis. Study endpoints were defined as incident myocardial infarction (MI), coronary heart disease (CHD), CVD (including all of the above plus ischemic stroke), incident heart failure (HF) and MACE (including all of the above). We used Cox proportional hazards regression to determine relative risks per one standard deviation increment in troponin, followed by measures of discrimination and reclassification using 10-fold cross-validation to control for overoptimism.
Results: During follow-up, we observed 1,074 incident MACE, which included 277 MI events, 529 CHD events, 770 CVD events, and 505 cases of HF. We observed significantly (p<0.001) increased hazard ratios (HR) for the supersensitive troponin assay for incident MI (HR 1.24 [95% confidence interval (CI) 1.11-1.39]), and CVD (HR 1.15 [CI 1.07-1.24]). For HF and MACE, both highly sensitive and supersensitive troponin showed significantly increased HR (HF: 1.19 [CI 1.1-1.3] and 1.28 [CI 1.18-1.39]; MACE 1.12 [CI 1.05-1.19] and 1.18 [CI 1.11-1.25]), respectively. There was no overall improvement in net reclassification (NRI). Focusing on the clinical NRI, which determines reclassification in individuals with an intermediate risk according to the Framingham risk score, the NRI was significantly improved for HF (NRI 10.2%, p<0.001), and MACE (NRI 5.1%, p<0.001), when using the supersensitive troponin assay.
Conclusions: In our large population-based cohort high-sensitivity troponin assays improved risk prediction for cardiovascular endpoints. The use of a supersensitive troponin assay led to an improvement of the clinical NRI for MACE, HF, and CHD.
- © 2013 by American Heart Association, Inc.