High-sensitivity cardiac troponin concentrations during convalescence can be used to predict long-term cardiovascular [CV] death after acute coronary syndrome (ACS), and it may be possible to improve targeting of therapeutic interventions by monitoring troponin throughout follow-up, according to study results published in Heart.
This multicenter, prospective, observational cohort study of patients with ACS (N=2140) was used to investigate the long-term prognostic capabilities of serial convalescent high-sensitivity cardiac troponin I concentrations. After excluding patients with recurrent myocardial infarctions occurring after the index event, concentrations were measured at 1, 4, and 12 months after the index event in 1776 patients (mean age, 66.4±12 years; 72% men) with additional review for ≥2 years.
At 4 months, patients were stratified by troponin concentration into 3 groups using the 99th percentile (>16 ng/L for women and >34 ng/L for men) and median concentration of patients within the reference range. Cardiovascular death after the 4-month visit was the primary outcome.
Four-month troponin concentrations were measurable in 1759 (99%) of 1776 patients and were ≤5 ng/L (median) and >99th percentile in 44.8% (795) and 9.3% (166), respectively. Median troponin concentrations declined at every visit over the first year, with values of 8.2 ng/L (1 month), 6.1 ng/L (4 months), and 4.8 ng/L (12 months).
During follow-up, there were 375 deaths, 202 of which were secondary to CV causes. In unadjusted models, 4-month troponin concentrations were significantly associated with CV death (hazard ratio (HR) 1.5; 95% CI, 1.42-1.59 per doubling).
After adjustments were made for global registry of acute coronary events score, troponin persisted as an independent predictor of CV death (HR 1.36; 95% CI, 1.26-1.47 per doubling), with the highest risk observed in patients whose concentrations increased at 12 months. Patients with convalescent troponin concentrations over the 99th percentile had an increased risk for CV death compared with patients ≤5 ng/L (HR 4.87; 95% CI, 2.96-7.99).
Study limitations included variation in biomarkers between study centers, a lack of direct comparison between peak high-sensitivity troponin concentration and the high-sensitivity follow-up assay, and variation in reported troponin concentration among analyzers.
Study investigators concluded that “the measurement of high-sensitivity cardiac troponin in the convalescent phase following [ACS] identifies an important group of patients at high risk for recurrent cardiac events and death. Recognition of this increased risk may allow better targeting of secondary prevention therapies and could improve the clinical impact of future therapeutic trials in patients with [ACS].”
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Adamson PD, McAllister D, Pilbrow A, et al. Convalescent troponin and cardiovascular death following acute coronary syndrome [published online July 23, 2019]. Heart. doi:10.1136/heartjnl-2019-315084