Abstract
OBJECTIVES: This study sought to determine whether the combined trajectories of cardiac biomarkers identify those older adults with initial low levels who have an increased risk for structural heart disease, incident heart failure (HF), and cardiovascular (CV) death. BACKGROUND: Initial low levels of high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) identify older adults at lower risk for CV events. METHODS: We performed an observational study among older adults without prevalent HF in the CHS (Cardiovascular Health Study). NT-proBNP and hs-cTnT were measured at baseline and after 2 to 3 years. In those with low baseline levels, a significant increase was defined as cardiac troponin T (cTnT) >50% and NT-proBNP >25% increase to >190 pg/ml. Left ventricular ejection fraction and left ventricular mass were measured by echocardiography at baseline and 5 years. Cox regression was used to estimate the association of change in biomarkers with HF and CV mortality. RESULTS: Among 2,008 participants with initially low biomarker concentrations, significant increases occurred in 14.8% for cTnT only, 13.2% for NT-proBNP only, and 6.1% for both. After 10 years, cumulative HF incidence was 50.4% versus 12.2% among those with both biomarkers versus neither biomarker increased. The adjusted relative risk comparing those with increases in both biomarkers versus neither biomarker was 3.56 for incident HF (95% confidence interval: 2.56 to 4.97) and 2.98 for CV mortality (95% confidence interval: 2.98 to 4.26). Among 1,340 participants with serial echocardiography, the frequency of new abnormal left ventricular ejection fraction was 11.8% versus 4% for those with increases in both biomarkers versus neither biomarker (p = 0.007). CONCLUSIONS: Among older adults without HF with initially low cTnT and NT-proBNP, the long-term trajectory of both biomarkers predicts systolic dysfunction, incident HF, and CV death.