Clinical Interpretation of Elevated Concentrations of Cardiac Troponin T, but Not Troponin I, in Nursing Home Residents

Objective: Cardiac troponins T (cTnT) and I (cTnI) are the preferred biomarkers to detect myocardial damage. The present study explores the value of measuring cardiac troponins (cTn) in nursing home residents, by investigating its relation to heart failure and 1-year mortality using 1 cTnT and 2 cTnI assays that are widely used in clinical practice. Design: All participants under went extensive clinical examinations and echocardiographic assessment for the diagnosis of heart failure. cTn was measured using high-sensitive (hs)-cTnT (Roche), hs-cTnI (Abbott), and sensitive cTnI (Beckman) assays. The glomerular filtration rate was estimated (eGFR) using serum creatinine and cystatin C concentrations. Data on all-cause mortality were collected at 1-year follow-up. Participants and Setting: Participants were 495 long-term nursing home residents, older than 65 years, of 5 Dutch nursing home organizations. Results: Median (IQR) concentrations were 20.6 (17.8-30.6), 6.8 (4.1-12.5), and 4.0 (2.0-8.0) ng/L for hs-cTnT, hs-cTnI, and cTnI, respectively. In total, 79% had elevated hs-cTnT concentrations, whereas only 9% and 5% of hs-cTnI and cTnI concentrations were elevated. Most important and independent determinants for higher hs-cTnT and hs-cTnI concentrations were heart failure and renal dysfunction. Whereas both heart failure (odds ratio [OR] 3.4) and eGFR lower than 60 mL/min/1.73 m(2) (OR 3.6) were equal contributors to higher hs-cTnT concentrations (all P <. 001), hs-cTnI and cTnI were less associated with renal dysfunction (OR of, respectively, 1.9 and 2.1; P < .01) in comparison with heart failure (OR 4.3 and 4.7, respectively, P < .001). Furthermore, residents with higher hs-cTnT or hs-cTnI concentrations (fourth quartile) had respectively 4 versus 2 times more risk of 1-year mortality compared with lower concentrations. Conclusion: Regardless of their cardiac health, hs-cTnT but not hs-cTnI concentrations were elevated in almost all aged nursing home residents, questioning the use of the current diagnostic cutoff in elderly with high comorbidity. Nonetheless, measuring cardiac troponins, especially hs-cTnT, had a promising role in assessing future risk of mortality. (C) 2015 AMDA - The Society for Post-Acute and Long-Term Care Medicine.