Distribution of High-Sensitivity Troponin Taken Without Conventional Clinical Indications in Critical Care Patients and Its Association With Mortality.

OBJECTIVES: To describe the distribution of high-sensitivity troponin in a consecutive cohort of patients in critical care units, regardless of clinical indication, and its association with clinical outcomes. DESIGN: Prospective observational study. SETTING: Single-center teaching hospital. PATIENTS: Consecutive patients admitted to two adult critical care units (general critical care unit and neuroscience critical care unit) over a 6-month period. INTERVENTIONS: All patients had high-sensitivity troponin tests performed at admission and tracked throughout their critical care stay, regardless of whether the supervising team felt there was a clinical indication. The results were not revealed to patients or clinicians unless clinically requested. MEASUREMENTS AND MAIN RESULTS: There were 1,033 patients in the study cohort (general critical care unit 750 and neuroscience critical care unit 283). The median high-sensitivity troponin was 21 ng/L (interquartile range, 7-86 ng/L), with 560 patients (54.2%) above the upper limit of normal as defined by the manufacturer. Admission high-sensitivity troponin concentrations above the upper limit of normal in general critical care unit and neuroscience critical care unit were associated with increasing age, comorbidity, markers of illness severity, and the need for organ support. On adjusted analysis, the high-sensitivity troponin concentration remained an independent predictor of critical care mortality in general critical care unit and neuroscience critical care unit. CONCLUSIONS: High-sensitivity troponin elevation, taken outside the context of conventional clinical indications, was common in the critically ill. Such elevations were associated with increasing age, comorbidity, illness severity, and the need for organ support. Admission high-sensitivity troponin concentration is an independent predictor of critical care mortality and as such may represent a novel prognostic biomarker at admission.

Is high sensitivity troponin, taken regardless of a clinical indication, associated with 1 year mortality in critical care patients?

The aim of this study was to assess whether high sensitivity troponin (hs-cTnI) is associated with 1 year mortality in critical care (CC). One year mortality data were obtained from NHS Digital for a consecutive cohort of patients admitted to general CC unit (GCCU) and neuroscience CC unit (NCCU) who had hs-cTnI tests performed throughout their CC admission, regardless of whether the test was clinically indicated. Cox proportional hazards were used to estimate the risk of 1-year mortality. A landmark analysis was undertaken to assess whether any relationship at 1 year was driven by mortality within the first 30 days. A total of 1033 consecutive patients were included. At 1 year 254 (24.6%) patients had died. The admission log(10)hs-cTnI concentration in the entire cohort (HR 1.35 (95% CI 1.05-1.75) p = 0.009 with a bootstrap of 1000 samples) was independently associated with 1 year mortality. On landmark analysis the association with 1 year mortality was driven by 30 day mortality. These results indicate that admission hs-cTnI concentration is independently associated with 1 year mortality in CC and this relationship may be driven by differences in mortality at 30 days.

Incidence and 1-year outcome of periprocedural myocardial infarction following cardiac surgery: are the Universal Definition and Society for Cardiovascular Angiography and Intervention criteria fit for purpose?

OBJECTIVES: The diagnosis and clinical implications of periprocedural myocardial infarction (PPMI) following coronary artery bypass grafting (CABG) are contentious, especially the importance of PPMI in the interpretation of trial data. METHODS: Consecutive patients admitted to a cardiothoracic critical care unit over a 6-month period following open cardiac surgery had high-sensitivity cardiac troponin I assay performed on admission and every day for 48 h, regardless of whether there was a request by the supervising clinical team. Patients were categorized as PPMI using both the Universal Definition of Myocardial Infarction (UDMI) and Society of Cardiovascular Angiography and Interventions (SCAI) criteria. Multivariable Cox regression analysis was performed to assess whether any relationships between PPMI diagnoses and 1-year mortality were independent. RESULTS: There were 2 groups of consecutive patients: (i) after CABG (n = 245) and (ii) after non-CABG surgery (n = 243). Of the CABG patients, 20.4% met criteria for UDMI PPMI and 87.6% for SCAI PPMI. The diagnosis of UDMI PPMI was independently associated with 1-year mortality on multivariable Cox regression analysis [hazard ratio 4.16 (95% confidence interval 1.28-13.49)]. Of 243 patients who had non-CABG cardiac surgery, 11.4% met criteria for UDMI PPMI and 85.2% for SCAI PPMI but neither were associated with 1-year mortality. CONCLUSIONS: The incidence of SCAI PPMI in a real-world cohort of cardiac surgery patients is so high as to be of limited clinical value. In contrast, a diagnosis of UDMI PPMI post-CABG is independently associated with 1-year mortality, so may have clinical (and research) utility.