Objectives High-sensitivity cardiac troponin testing is used in the diagnosis of acute coronary syndromes but its role during convalescence is unknown. We investigated the long-term prognostic significance of serial convalescent high-sensitivity cardiac troponin concentrations following acute coronary syndrome.
Methods In a prospective multicentre observational cohort study of 2140 patients with acute coronary syndrome, cardiac troponin I concentrations were measured in 1776 patients at 4 and 12 months following the index event. Patients were stratified into three groups according to the troponin concentration at 4 months using the 99th centile (women>16 ng/L, men>34 ng/L) and median concentration of those within the reference range. The primary outcome was cardiovascular death.
Results Troponin concentrations at 4 months were measurable in 99.0% (1759/1776) of patients (67±12 years, 72% male), and were ≤5 ng/L (median) and >99th centile in 44.8% (795) and 9.3% (166), respectively. There were 202 (11.4%) cardiovascular deaths after a median of 4.8 years. After adjusting for the Global Registry of Acute Coronary Events score, troponin remained an independent predictor of cardiovascular death (HR 1.4, 95% CI 1.3 to 1.5 per doubling) with the highest risk observed in those with increasing concentrations at 12 months. Patients with 4-month troponin concentrations >99th centile were at increased risk of cardiovascular death compared with those ≤5 ng/L (29.5% (49/166) vs 4.3% (34/795); adjusted HR 4.9, 95% CI 3.8 to 23.7).
Conclusions Convalescent cardiac troponin concentrations predict long-term cardiovascular death following acute coronary syndrome. Recognising this risk by monitoring troponin may improve targeting of therapeutic interventions.
Trial registration number ACTRN12605000431628;Results.
- acute coronary syndromes
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Contributors PDA and DM undertook all data analysis. PDA drafted the initial manuscript. KP, JWP, CP, AP, NLM, DEN, AMR and AS provided additional advice and review of data analysis including the statistical analysis plan and data interpretation. AMR, RND, RWT and CE were involved in trial design, funding and conduct of the study. All authors contributed to manuscript revision.
Funding The Coronary Disease Cohort Study was funded by the Health Research Council of New Zealand; National Heart Foundation of New Zealand; New Zealand Lotteries Grant Board and Foundation for Research, Science and Technology. This work was supported by New Zealand Health Research Council (Programme Grants 02/152, 08/070, 11/1070); New Zealand National Heart Foundation; New Zealand Lotteries Grant Board and the Foundation for Research, Science and Technology.
Competing interests NLM has received consultancy, research grants and speaker fees from manufacturers of cardiac troponin testing including Abbott Diagnostics, Roche and Singulex. AMR has received consultancy, research grants and speaker fees from manufacturers of cardiac troponin testing including Abbott Diagnostics and Roche Diagnostics. AS has received consultancy from Abbott Diagnostics. PDA, DM, AP, JWP, KP, DEN, CE, CP, RWT and RND report no other potential conflict of interest relevant to this article.
Provenance and peer review Not commissioned; externally peer reviewed.
Patient consent for publication Not required.
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