Elevated hs-cTnT levels could indicate subclinical cardiac disease
medwireNews: Minor increases in high-sensitivity cardiac troponin T (hs-cTnT) levels may represent an early biochemical signature of subclinical heart disease, researchers report.
hs-cTnT measurements could therefore “be potentially used to target therapy to prevent or delay left ventricular remodeling and progression to heart failure symptoms and death,” say the study authors.
Christopher deFilippi (Inova Heart and Vascular Institute, Falls Church, Virginia, USA) and colleagues analyzed the association between hs-cTnT levels and markers of subclinical cardiovascular disease (CVD) among people aged 45–84 years who participated in the Multi-Ethnic Study of Atherosclerosis.
They found that replacement fibrosis, characterized by late gadolinium enhancement (LGE), was present in 6.3% of 1753 participants who did not have interim CVD events over 10 years of follow-up.
Participants were split into five groups based on hs-cTnT concentration at baseline; those with levels below the limit of detection (<3 ng/mL) and four additional categories of equal participant numbers (3.0–4.25, 4.26–5.87, 5.88–8.80, and ≥8.81 ng/L).
After adjustment for factors including demographics, CVD risk factors, and biochemical markers, participants in the highest category were almost 2.5 times more likely to have LGE scar than those with undetectable hs-cTnT levels (odds ratio=2.41).
Furthermore, participants in the highest hs-cTnT category were 1.5 times more likely to have an increase in left ventricular (LV) mass of more than 12% compared with those with undetectable hs-cTnT levels after adjustment for baseline LV mass, demographics, and CVD risk factors. A greater proportion of participants in the highest hs-cTnT group experienced an LV end-diastolic volume increase of more than 8%, but this association was not significant in adjusted analyses.
By contrast, there was no association between baseline hs-cTnT levels and LV ejection fraction, suggesting that “biochemical evidence of subclinical myocardial injury is a greater marker for increasing LV mass and LV dilatation than for declining systolic function,” write deFilippi and colleagues in Circulation.
The team identified “strong associations” between hs-cTnT levels and incident heart failure, coronary heart disease events, and cardiovascular death, and these associations remained after adjusting for measurements of LV structure and function.
“Accounting for these measures in a multivariate model for outcomes supports the hypothesis that hs-cTnT levels provides a unique biochemical signature that is independent of even the most precise measures of cardiac structure,” explain the authors.
They caution that follow-up cardiac magnetic resonance data were not available for approximately 40% of participants, and those who completed the study were older and less healthy than those who did not.
Nevertheless, they conclude that “clinical studies of lifestyle changes or pharmacologic therapy may consider using hs-cTnT levels in middle age and older adults to identify those most likely to benefit from specific therapy to prevent remodeling and fibrosis.”
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