Cardiac troponin T levels associated with HF, CV mortality in older patients

deFilippi CR. JAMA. 2010;doi:10.1001/jama.2010.1708.

Cardiac troponin T levels at baseline, as well as subsequent changes to levels, may predict patients at an increased risk for incident HF and CV mortality, data from a study published in the Journal of the American Medical Association involving a cohort of older patients revealed.

“Elderly individuals comprise the largest subgroup of patients hospitalized for HF, accounting for 80% of the more than 1.1 million US admissions per year,” the researchers said in their study. “Blood-based biomarkers, including CRP, natriuretic peptides and troponins, have been advocated as adjuncts to clinical risk factors to identify community-dwelling older patients at high risk for adverse CV outcomes, but studies examining the additive prognostic value of these markers have reported inconsistent results.”

This led the Maryland- and Texas-based researchers to conduct a longitudinal nationwide cohort study of 4,221 community-dwelling adults of at least 65 years of age without prior HF. They measured cardiac troponin T (cTnT) levels with a highly sensitive assay (Elecsys 2010, Roche Diagnostics) at baseline and repeated between 2 to 3 years later in 2,918 patients.

Levels of cTnT of at least 3 pg/mL were detected in 2,794 patients (66.2%). During a median follow-up of 11.8 years, researchers reported new-onset HF in 1,279 patients and 1,103 CV deaths. Highest cTnT concentrations (>12.94 pg/mL) when compared with undetectable concentrations produced an incident rate per 100 person-years of 6.4 (95% CI, 5.8-7.2; adjusted HR=2.48; 95% CI, 2.04-3.00) for HF and 4.8 (95% CI, 4.3-5.4; adjusted HR=2.91; 95% CI, 2.37-3.58) for CV death.

Further analysis revealed that in patients with initially detectable cTnT, a subsequent increase of more than 50% (n=393, 22%) was associated with a greater risk for HF (adjusted HR=1.61; 95% CI, 1.32-1.97) and CV death (adjusted HR=1.65; 95% CI, 1.35-2.03), whereas a decrease of more than 50% (n=247, 14%) was associated with a lower risk for HF (adjusted HR=0.73; 95% CI, 0.54-0.97) and CV death (adjusted HR=0.71; 95% CI, 0.52-0.97) vs. individuals with a 50% or less change.

Among the study’s limitations were the possibility that the increase in use of medications such as statins over the long follow-up time blunted the predictive value of cTnT, as well as the possibility of unmeasured and residual confounding to have influenced the results.

“Detectable cTnT levels as measured by a highly sensitive assay were present in the majority of community-dwelling older adults in this cohort, and higher concentrations — within a normal range established for a younger general population — reflect a greater burden of CV risk factors and imaging evidence of cardiac disease,” the researchers concluded. “Independent of these comorbidities, cTnT concentrations were associated with risk of new-onset HF and CV death.”

Furthermore, they said, longitudinal changes in cTnT concentrations were common in this cohort and correspond with a dynamic change in risk over time.

Follow CardiologyToday.com on Twitter.