Elevated Cardiac Biomarkers in Relatively Healthy U.S. Adults.

Background: Despite the importance of early cardiovascular disease (CVD) intervention, little data exists for evaluating cardiovascular risk in adults without traditional CVD risk factors (e.g., diabetes, hypertension).

Methods: We included 4,544 adults from the 1999-2004 National Health and Nutrition Examination Survey without prevalent diabetes, hypertension, chronic kidney disease, or CVD. We used multi-variable adjusted Cox proportional hazards regression modeling to assess the relationship between logarithmically transformed cardiac biomarkers (high sensitivity cardiac troponin T (hs-cTnT), hs-cTnI (Abbott, Ortho, and Siemens assays), and NT-proBNP) and CVD mortality among a nationally representative cohort of relatively healthy adults.

Results: The mean age was 38.2 years (SD 12.8) and 53.9% were women. 8.7% had elevated levels of hs-cTnT or NT-proBNP above previously established thresholds for subclinical CVD. In multivariable adjusted models, each doubling of hs-cTnT was associated with a 49% increased risk of CVD mortality (Hazard Ratio (HR) 1.49, 95%CI 1.02-2.17, =0.04). Only two of the hs-cTnI assays (Abbott and Ortho) were significantly associated with CVD mortality (Abbott HR 1.48, 95%CI 1.06-2.07, =0.02; Ortho HR 1.47, 95%CI 1.23-1.77, =0.0001). Each doubling of NT-proBNP was associated with a 41% increased risk of CVD mortality (HR 1.38, 95%CI 1.09-1.74, =0.008).

Conclusion: Younger patients who maintain relatively good health may still carry occult CVD risk. Efforts to reduce population-wide CVD should consider novel methods for risk stratification, as standard CVD risk factors may overlook subpopulations at risk.