Association between peak troponin level and prognosis among patients admitted to intensive cardiovascular care unit

Introduction: High-sensitivity cardiac troponin (hs-cTn) is a key biomarker for myocardial injury, yet its prognostic value in intensive cardiovascular care units (ICCU) remains poorly understood. We aimed to assess the association between peak hs-cTn levels and prognosis in ICCU patients.

Methods: All patients admitted to a tertiary care center ICCU between July 2019 - July 2023 were prospectively enrolled. Patients were divided into five groups according to their peak hs-cTnI levels: A) hs-cTnI <100 ng/L; B) hs-cTnI of 100-1000 ng/L; C) hs-cTnI of 1000-10,000 ng/L; D) hs-cTnI of 10,000-100,000 ng/L and E) hs-cTnI ≥100,000 ng/L. The primary outcome was all-cause mortality at one year.

Results: A total of 4149 patients (1273 females [30.7 %]) with a median age of 69 (IQR 58-79) were included. Group E was highly specific for myocardial infarction (97.4 %) and especially for ST segment elevation myocardial infarction (STEMI) (87.5 %). Patients in group E were 56 % more likely to die at 1-year in an adjusted Cox model (95 % CI 1.09-2.23, p = 0.014) as compared with group A. Subgroup analyses revealed that among STEMI patients, higher peak hs-cTnI levels were not associated with higher mortality rate (HR 1.04, 95 % CI 0.4-2.72, p = 0.9), in contrast to patients with NSTEMI (HR 7.62, 95 % CI 1.97-29.6, p = 0.003).

Conclusions: Peak hs-cTnI levels ≥100,000 ng/L were linked to higher one-year mortality, largely indicative of large myocardial infarctions. Notably, the association between elevated hs-cTnI levels and mortality differed between STEMI and NSTEMI patients, warranting further investigation.