Causes of death in relation to stable troponin levels including chronic myocardial injury

Abstract

Background: Many patients presenting with chest pain in the emergency department have stable concentrations of high-sensitivity cardiac troponin T (hs-cTnT) without any acute medical condition. Stable hs-cTnT levels are associated with a high risk of death. This study aimed to investigate causes of death in relation to hs-cTnT concentrations.

Methods: In a cohort of 19,460 patients with chest pain and stable hs-cTnT levels measured 2011-2014, of whom 1528 (7.9%) had chronic myocardial injury, we included all patients who died during follow-up (4.0 ± 1.3 years). Rates of cause-specific death were calculated for hs-cTnT concentrations and adjusted odds ratios (OR) estimated for causes of death at hs-cTnT 5-14 ng/l and >14 ng/l (referent hs-cTnT < 5 ng/l).

Results: The study cohort comprised 1577 patients (8.1%), of whom 684 (43%) had chronic myocardial injury (hs-cTnT > 14 ng/l). Annual cardiovascular and non-cardiovascular death rates increased with increasing hs-cTnT from 0.07% and 0.4% (<5 ng/l) to 17% and 15% (≥50 ng/l), respectively. The ratio of cardiovascular to non-cardiovascular death increased with higher hs-cTnT. Patients with hs-cTnT 5-14 ng/l were 87% more likely to die from cardiovascular causes than those with hs-cTnT < 5 ng/l (adjusted OR: 1.87, 95% CI: 1.24-2.80). The association was similar for patients with chronic myocardial injury.

Conclusions: Hs-cTnT concentrations of 5-14 ng/l and >14 ng/l are associated with an almost twofold risk of cardiovascular death, whereas cardiovascular death almost never occurs in patients with undetectable troponin. Only with hs-cTnT concentrations ≥ 50 ng/l were cardiovascular diseases the predominant cause of death.

Keywords: Cardiac biomarker; Chest pain; Mortality; Prognosis; Troponin.