Stable high-sensitivity cardiac troponin T levels and the association with frailty and prognosis in patients with chest pain

Background: Chronic myocardial injury is defined by stable high-sensitivity cardiac troponin (hs-cTn) levels above the 99th percentile value, which may be a sign of a biologically aged heart. This study investigated the association between frailty and chronic myocardial injury. Methods: In a cohort of patients with chest pain and stable hs-cTnT levels measured 2011-2014, we included all patients who were assessed by two scoring systems measuring frailty. Adjusted odds ratios (ORs) were calculated to estimate the risk of frailty at different hs-cTnT levels (referent: hs-cTnT ≤ 14 ng/l). Cox regression was used to estimate risks of death and cardiovascular events in relation to frailty status and hs-cTnT levels (referent: non-frail and hs-cTnT ≤ 14 ng/l). Results: A total of 979 patients were included, of whom 269 (27%) had chronic myocardial injury. The risk of being frail was almost four times higher in patients with chronic myocardial injury, compared with patients in the reference group (hs-cTnT ≥ 30 ng/l: OR: 3.69, 95% CI: 2.02-6.76). During a follow-up of 4.3 years, 275 (28%) patients died. Mortality risks increased with increasing hs-cTnT levels and degree of frailty, being increased four-fold in frail patients with hs-cTnT levels ≥ 30 ng/l (HR: 4.07, 95% CI: 2.42-6.86). Conclusions: Stable hs-cTnT levels are associated with the degree of frailty, and frailty measurements could help to identify patients with stable hs-cTnT levels who are at a high risk of death. The findings support the hypothesis that chronic myocardial injury could be a marker of a biologically aged heart.