Highly sensitive assay detected cardiac troponin T levels in structural heart disease

de Lemos J. JAMA. 2010;304:2503-2512.

Issue: January 2011

Researchers of a population-based cohort study have reported that a highly sensitive assay identified cardiac troponin T levels, which was associated with structural heart disease and subsequent mortality.

“Detectable levels of cardiac troponin T (cTnT) are strongly associated with structural heart disease and increased risk of death and adverse CV events; however, cTnT is rarely detectable in the general population using standard assays,” the researchers wrote.

This led them to test a highly sensitive assay (Elecsys 2010, Roche Diagnostics) to determine whether cTnT levels measured with the new assay associate with structural heart disease and subsequent mortality. The study included 3,546 participants aged 30 to 65 years who enrolled in the multi-ethnic, population-based Dallas Heart Study.

After measuring the cardiac structure and function and mortality for a median follow-up of 6.4 years, researchers detected cTnT levels of at least 0.003 ng/mL in 25% (95% CI, 22.7-27.4) of the population with the highly sensitive assay vs. 0.7% (95% CI, 0.3-1.1) of the population with a standard assay.

Furthermore, 151 deaths were reported, with 62 resulting from CVD. Unadjusted all-cause mortality increased from 1.9% (95% CI, 1.5-2.6) to 28.4% (95% CI, 21-37.8) across higher cTnT categories (P<.001). After adjusting for traditional risk factors, including CRP and chronic kidney disease, cTnT was still independently associated with all-cause mortality (highest category adjusted HR=2.8; 95% CI, 1.4-5.2).

This led the researchers to conclude that higher cTnT levels, which are less than the detection range of currently available assays, may be considered a marker of “end organ” CV damage from a variety of risk factors and pathological cardiac and vascular processes.

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