Measurement of high-sensitivity troponin T in noncardiac medical intensive care unit patients. Correlation to mortality and length of stay

Management and outcomes with 5-year mortality of patients with mildly elevated high-sensitivity troponin T levels not meeting criteria for myocardial infarction

OBJECTIVES

To examine management and outcomes of patients presenting to EDs with symptoms suggestive of acute coronary syndrome, who have mild non-dynamically elevated high-sensitivity troponin T (HsTnT) levels, not meeting the fourth universal definition of myocardial infarction (MI) criteria (observation group).

METHODS

Consecutive patients presenting to the ED with symptoms suggestive of acute coronary syndrome at Liverpool Hospital, Sydney, Australia, those having ≥2 HsTnT levels after initial assessment were adjudicated according to the fourth universal definition of MI, as MI ruled-in, MI ruled-out, or myocardial injury in whom MI is neither ruled-in nor ruled-out (>1 level ≥15 ng/L, called observation group); follow-up was 5 years.

RESULTS

Of 2738 patients, 547 were in the observation group, of whom 62% were admitted to hospital, 52% to cardiac services, whereas 97% of MI ruled-in patients and 21% of MI ruled-out patients were admitted; P < 0.001. Non-invasive testing occurred in 42% of observation group patients (36% had echo-cardiography), and 16% had coronary angiography. Of observation group patients, MI rates were 1.5% during hospitalisation and 4% during the following year, similar to that in those with MI ruled-in, among those with MI ruled-out, the MI rate was 0.2%. The 1-year death rate was 13% among observation group patients and 11% MI ruled-in patients (P = 0.624), whereas at 5 years among observation group patients, type 1 MI and type 2 MI were 48%, 26% and 58%, respectively (P = 0.001).

CONCLUSION

Very few unselected consecutive patients attending ED, with minor stable HsTnT elevation, had MI, although most had chronic myocardial injury. Late mortality rates among observation group patients were higher than those with confirmed type 1 MI but lower than those with type 2 MI.

Association of high-sensitivity cardiac troponin T with all-cause and cardiovascular mortality in older adults with low lean mass: A 14.6-year longitudinal study

BACKGROUND

Current evidence on the association between high-sensitivity cardiac troponin T (hs-cTnT) levels and mortality in elderly sarcopenic patients is limited. This study aimed to investigate the association of serum hs-cTnT concentrations with all-cause and cardiovascular mortality in older adults with low lean mass (LLM) and without baseline cardiovascular disease.

METHODS

This prospective cohort study included 369 older adults (representing 3.2 million people) from the National Health and Nutrition Examination Survey 1999-2004. Individuals were linked to national death records until 31 December 2019. The weighted Kaplan-Meier analysis, Cox proportional hazards models, restricted cubic spline models, stratified analysis, interaction analysis, and sensitivity analysis were performed to examine the association between hs-cTnT levels and mortality in older adults with LLM.

RESULTS

During 4697 person-years of follow-up (median duration, 14.6 years), 228 (65.6%) deaths were documented, including 56 (15.8%) deaths from cardiovascular disease. Individuals with a hs-cTnT level of ≥14 ng/L had 2.1- and 4.4-fold higher risks of all-cause and cardiovascular mortality, respectively. Compared with the lowest quartile, the fourth quartile of hs-cTnT levels was significantly associated with 3.1- and 6.4-fold higher risks of all-cause and cardiovascular mortality, respectively. Each one standard deviation increase in natural log-transformed hs-cTnT levels significantly and linearly increased the risks of all-cause and cardiovascular mortality by 39% and 61%, respectively. Stratified and sensitivity analyses confirmed the robustness of the association.

CONCLUSIONS

In this nationally representative cohort of US older adults with LLM, higher serum hs-cTnT concentrations were significantly associated with increased risks of all-cause and cardiovascular mortality.

Characterization of Myocardial Injury With High-Sensitivity Troponin

BACKGROUND

High-sensitivity troponin I, cardiac form (hs-cTnI) accelerates the assessment of acute coronary syndrome. Little has been documented about its performance, how it relates to different types of myocardial injury, and its impact on morbidity and mortality. This study sought to expand understanding of hs-cTnI by characterizing types of myocardial injury, the impact of comorbidities, and 30-day outcomes.

METHODS

The study retrospectively evaluated 1,975 patients with hs-cTnI levels obtained in the emergency department or inpatient setting from June to September 2020. Troponin was considered elevated if it was higher than the 99th percentile for either sex. Charts were reviewed to determine the presence of myocardial injury. Troponin elevation was adjusted for demographics, comorbidities, and kidney dysfunction. Thirty-day mortality and readmission rates were calculated.

RESULTS

Of 1,975 patients, 468 (24%) had elevated hs-cTnI, and 330 (17%) had at least 1 type of myocardial injury, type 2 myocardial infarction being the most frequent. Sensitivity and specificity using the 99th percentile as a cutoff were 99% and 92%, respectively. The average maximum hs-cTnI level was significantly higher for type 1 myocardial infarction (P < .001). Being male, Black, non-Hispanic, and a hospital inpatient were all associated with higher initial and peak hs-cTnI levels (P < .001). Elevated hs-cTnI level, age, heart disease, kidney dysfunction, and inpatient status were predictive of 30-day mortality on multivariate analysis.

CONCLUSION

Elevated hs-cTnI levels in emergency department and inpatient settings occurs most commonly because of type 2 myocardial infarction. Maximum hs-cTnI level is associated with the patient's particular type of myocardial injury, certain demographics, and cardiovascular comorbidities, and it may be a predictor of 30-day outcomes.

Associations between elevated high-sensitive cardiac troponin t and outcomes in patients with acute abdominal pain

PURPOSE

The purpose of this study was to determine outcomes in patients presenting to emergency department (ED) with acute abdominal pain and suspected occult myocardial injury [OMI (high-sensitive cardiac troponin T, hs-cTnT level > 14 ng/L)] without clinical signs of myocardial ischaemia. We hypothesized that OMI is a common entity associated with poor outcomes.

METHODS

After institutional research ethics committee approval, a retrospective review was performed on patients subjected to extended use of hs-cTnT measurements during two months period in patients admitted to ED with a chief complaint of abdominal pain, aged 30 years or older and triaged to red, orange, or yellow categories. Primary outcomes were 30-day, six-month, and one-year mortality, respectively. Adjusted mortality rates were compared using the Cox proportional hazard regression model.

RESULTS

Overall, 1000 consecutive patients were screened. A total of 375 patients were subjected to hs-cTnT measurement and 156 of them (41.6%) experienced OMI. None of the patients had acute myocardial infarction diagnosed in the ED. Patients with OMI had a significantly higher 30-day, six-month and one-year mortality compared to the normal hs-cTnT level group [12.8% (20/156) vs. 3.7% (8/219), p = 0.001, 34.0% (53/156) vs. 6.9% (15/219), p < 0.001 and 39.1% (61/156) vs. 9.1 (20/219), p < 0.001, respectively]. OMI was an independent risk factor for mortality at every time point analyzed.

CONCLUSION

Our investigation noted OMI in older patients with co-morbidities and in higher triage category presenting with abdominal pain to ED, respectively. OMI is an independent risk factor for poor outcomes that warrants appropriate screening and management strategy. Our results support the use of hs-cTnT as a prognostication tool in this subgroup of ED patients.

Type 2 MI and Myocardial Injury in the Era of High-sensitivity Troponin

Troponin has been the cornerstone of the definition of MI since its introduction to clinical practice. High-sensitivity troponin has allowed clinicians to detect degrees of myocardial damage at orders of magnitude smaller than previously and is challenging the definitions of MI, with implications for patient management and prognosis. Detection and diagnosis are no doubt enhanced by the greater sensitivity afforded by these markers, but perhaps at the expense of specificity and clarity. This review focuses on the definitions, pathophysiology, prognosis, prevention and management of type 2 MI and myocardial injury. The five types of MI were first defined in 2007 and were recently updated in 2018 in the fourth universal definition of MI. The authors explore how this pathophysiological classification is used in clinical practice, and discuss some of the unanswered questions in this era of availability of high-sensitivity troponin.

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.

Elevation of High-sensitive Troponin T Predicts Mortality After Open Pancreaticoduodenectomy

BACKGROUND

Open pancreaticoduodenectomy has a high complication and measurable mortality rate. Recent reports (based across multiple surgical disciplines) demonstrate that elevated postoperative high sensitivity troponin T (hsTnT) predicts adverse outcomes in non-cardiac surgery. The aim of this study was to evaluate postoperative hsTnT as a prognostic marker of mortality, major adverse cardiovascular events (MACE), post-operative non-cardiac complications and length of stay (including intensive care stay) in open pancreaticoduodenectomy.

METHODS

A retrospective review of open pancreaticoduodenectomy patients was undertaken from 01/10/2017-31/03/2019. Receiver operating characteristic (ROC) curves were calculated to identify ideal cut-off values for hsTnT. Univariate and multivariate analyses were performed to scrutinize the relationship between mean hsTnT and 30-day, 90-day mortality, MACE, post-operative non-cardiac complications and length of stay.

RESULTS

One hundred and nine patients were identified. ROC curves demonstrated a strong correlation between elevated mean hsTnT and 30-day, 90-day mortality and MACE (AUC = 0.937, AUC = 0.852, AUC = 0.779, respectively). Multivariate analysis showed mean hsTnT > 21 ng/l was significantly associated with 90-day mortality (OR 43.928, p = 0.004) and MACE (OR 8.177, p = 0.048).

CONCLUSIONS

HsTnT is predictive of mortality and MACE in the context of open pancreaticoduodenectomy. Association between hsTnT and prolonged critical care stay was less significant. Non-cardiac complications and length of stay show no significant association with hsTnT.

Length of hospital stay among oldest-old patients in acute geriatric ward

PURPOSE

To examine risk factors for prolonged hospital length of stay (LOS) in the oldest-old inpatients aged ≥ 90.

METHODS

This retrospective cross-sectional study was performed in acute Geriatrics Department at Kaplan Medical Center. The target population was the oldest-old inpatients aged ≥ 90 hospitalized with acute illness. In total 1536 admissions of 987 patients admitted between January 2007 and December 2010 from the emergency room were included in the study. We retrieved from the electronic hospital records the following data: demographics, admission diagnosis, comorbidities, laboratory tests, drugs, functional and cognitive status, Charlson Comorbidity Index (CCI) score and age-adjusted CCI score.

RESULTS

The risk factors for a prolonged LOS were tube-feeding, consumption of ≥ 5 drugs, non-independent functional status, diagnosis of urinary tract infection (UTI), pneumonia and malignancy on admission, and comorbidities of congestive heart failure (CHF) and hypoalbuminemia. Multiple linear regression analysis found that UTI, hypoalbuminemia, elevated troponin, pneumonia, number of drugs, malignancy, CHF and number of comorbidities explain a higher risk for a longer LOS.

CONCLUSION

Hospital LOS in the oldest-old patients in acute geriatric ward was associated with admission diagnosis and comorbidities. Awareness of the risk factors for a longer LOS might contribute to reducing hospitalization stay and its related negative consequences. Accurate prediction of prolonged LOS in this age group of patients may be more challenging and require variables that were not included in our study. Future research is warranted.

Is the true clinical value of high-sensitivity troponins as a biomarker of risk? The concept that detection of high-sensitivity troponin 'never means nothing'

INTRODUCTION

High-sensitivity troponin (hs-cTn) assays are central to the diagnosis of myocardial infarction (MI). Their increased sensitivity has facilitated rapid pathways for the exclusion of MI. However, hs-cTn is now more readily detectable in patients without symptoms typical of MI, in whom a degree of myocardial injury is assumed. Recently, the practice of using the 99^th centile of hs-cTn as a working 'upper reference limit' has been challenged. There is increasing evidence that hs-cTn may provide useful prognostic information, regardless of any suspicion of MI, and as such these assays may have potential as a general biomarker for mortality. This raises the concept that detection of hs-cTn 'never means nothing.'

AREAS COVERED

In this review, we will evaluate the evidence for the use of hs-cTn assays outside their common clinical indication to rule out or diagnose acute MI.

EXPERT OPINION

The data presented suggest that hs-cTn testing may in the future have a generalized role as a biomarker of mortality risk and may be used less as a test for ruling in acute MI, but will remain a frontline test to exclude that diagnosis in ED. Further, the data suggest that the detection of hs-cTn 'never means nothing.'

High sensitivity troponin measurement in critical care: Flattering to deceive or 'never means nothing'?

INTRODUCTION

Troponin elevation is central to the diagnosis of acute type 1 myocardial infarction. It is, however, elevated in a range of other conditions, including type 2 myocardial infarction, and this setting is increasingly associated with adverse clinical outcomes. Patients within intensive care frequently have at least one organ failure together with a range of co-morbidities. Interpretation of troponin assay results in this population is challenging. This clinical uncertainty is compounded by the introduction of ever more sensitive troponin assays.

AREAS COVERED

The aims of this review are to (a) describe the currently available literature about the use of troponin assays in intensive care, (b) analyse the challenges presented by the introduction of increasingly sensitive troponin assays and (c) assess whether the role of troponin assays in intensive care may change in the future, dependent upon recent and ongoing research suggesting that they are predictive of outcome regardless of the underlying cause: the 'never means nothing' hypothesis.

High-sensitivity troponin T is an important independent predictor in addition to the Simplified Acute Physiology Score for short-term ICU mortality, particularly in patients with sepsis

PURPOSE

Elevated cardiac troponin levels have been shown to be associated with a poor prognosis under some intensive care conditions. This study investigated whether inclusion of high-sensitivity troponin T (hsTnT) increased the prognostic accuracy of the Simplified Acute Physiology Score (SAPS 3) for general intensive care unit (ICU) patients, cardiac arrest patients, or patients with a non-cardiac arrest diagnosis.

MATERIALS AND METHODS

We performed a single-center cohort study of ICU patients with an hsTnT measurement on ICU admission at a tertiary university hospital between February 2010 and June 2017.

RESULTS

Of 4185 first-time admissions, 856 patients (20.5%) had hsTnT evaluated at ICU admission. Factoring in ICU admission hsTnT values increased the ability of SAPS 3 to accurately predict 30-day mortality (odds ratio 1.27, 95% confidence interval: 1.15-1.41, p < 0.001). Elevated hsTnT levels were not independently associated with 30-day mortality in cardiac arrest patients. In sepsis patients, hsTnT evaluation in addition to SAPS 3 evaluation improved the area under the receiver operating characteristic curve by >10%.

CONCLUSION

Addition of hsTnT evaluation to SAPS 3 enhances the predictive capability of this model in relation to mortality. In sepsis, the hsTnT level may be an important prognostic marker.

Comparison of prognostic values of high-sensitivity cardiac troponin T and N-terminal prohormone brain natriuretic peptide to assess mortality in elderly inpatients

BACKGROUND

Studies have shown that increases in low-level high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal prohormone brain natriuretic peptide (NT-proBNP) in the elderly population lead to high risk of adverse clinical outcomes, such as mortality. In this study, associations between the two biomarkers and long-term mortality in elderly patients hospitalized for medical conditions other than acute cardiovascular events were investigated. A comparison of the predictive value of hs-cTnT and NT-proBNP for all-cause mortality was conducted.

METHODS

A cohort of 715 elderly inpatients free of acute cardiovascular events was initially recruited. Based on tertiles of baseline hs-cTnT and NT-proBNP levels, the elderly were arranged into low, middle, and high groups. The mortality of each group was observed and the predictive values of hs-cTnT and NT-proBNP compared. Additionally, all-cause mortality was analyzed for hs-cTnT and NT-proBNP combined.

RESULTS

There were 135 (18.9%) all-cause mortality cases identified during follow-up (median 47 months). The upper tertile of hs-cTnT was significantly associated with an increased risk of mortality (HR 3.29, 95% CI 1.85-5.85), even after adjustment for potential confounders. However, there were no significant differences observed in mortality rates among the three NT-proBNP groups after adjustment for potential confounders (HR 1.77, 95% CI 0.83-3.17). Compared to NT-proBNP, hs-cTnT was a better predictor of mortality, as area under curves for hs-cTnT and NT-proBNP at 60 months were 0.712 (95% CI 0.616-0.809) and 0.585 (95% CI 0.483-0.6871), respectively. Also, the combination of the two cardiac biomarkers did not render a better predictive value for mortality than hs-cTnT alone.

CONCLUSION

Unlike hs-cTnT, baseline NT-proBNP levels failed to show an independent association with all-cause mortality in hospitalized elderly without acute cardiovascular events. hs-cTnT provided significant prognostic value for mortality in the study cohort.

Cathepsin B and S as markers for cardiovascular risk and all-cause mortality in patients with stable coronary heart disease during 10 years: a CLARICOR trial sub-study

BACKGROUND AND AIMS

The lysosomal cysteine proteases cathepsin B and S have been implicated in the atherosclerotic process. The present paper investigates the association between serum levels of cathepsin B and S and cardiovascular events and mortality in patients with stable coronary heart disease.

METHODS

The CLARICOR trial is a randomised, placebo-controlled trial investigating the effect of clarithromycin versus placebo in patients with stable coronary heart disease. The outcome was time to either a cardiovascular event or all-cause mortality. The placebo group was used as discovery sample and the clarithromycin group as replication sample: n = 1998, n = 1979; mean age (years) 65, 65; 31%, 30% women; follow-up for 10 years; number of composite outcomes n = 1204, n = 1220; respectively. We used a pre-defined multivariable Cox regression model adjusting for inflammation, established cardiovascular risk factors, kidney function, and use of cardiovascular drugs.

RESULTS

Cathepsin B was associated with an increased risk of the composite outcome in both samples after multivariable adjustment (discovery: multivariable ratio (HR) per standard deviation increase 1.12, 95% confidence interval (CI) 1.05-1.19, p < 0.001, replication; HR 1.14, 95% CI 1.07-1.21, p < 0.001). There was no significant association between cathepsin S and the composite outcome in either the discovery or replication sample after multivariable adjustment (p>0.45). Secondary analyses suggest that cathepsin B was predominantly associated with mortality rather than specific cardiovascular events.

CONCLUSIONS

Cathepsin B, but not serum cathepsin S, was associated with an increased risk of cardiovascular events in patients with stable coronary heart disease. The clinical implications of our findings remain to be established.

Relationship between high-sensitivity cardiac troponin T and the prognosis of elderly inpatients with non-acute coronary syndromes

Objective

Low-level high-sensitivity cardiac troponin T (hs-cTnT) increases in elderly population. In this study, the relationship between hs-cTnT level and all-cause death of elderly inpatients with non-acute coronary syndrome (non-ACS) after discharge from the hospital was investigated.

Materials and methods

Non-ACS patients aged >65 years admitted in the General Practice Wards and Department of Geriatrics of Fuxing Hospital Affiliated to Capital Medical University were enrolled in the study. The patients were grouped according to the tertiles of hs-cTnT levels. Biochemical markers, hs-cTnT, and amino-terminal pro-brain natriuretic peptide were measured. The median follow-up period was 47 months, and all-cause deaths of the patients were observed.

Results

A total of 722 patients, including 473 males and 249 females, aged 65-98 (82.43±5.98) years were enrolled in the study. The level of hs-cTnT was found to be higher in males, and increased with age and comorbidities (P<0.01). Compared with low-level group, NT-proBNP level of patients in high-level group was higher, while hemoglobin (Hb), estimated glomerular filtration rate (eGFR), and left ventricular ejection fraction (LVEF) levels were lower (P<0.001). The mortality rate increased significantly with increased hs-cTnT levels (P<0.001). The total number of deaths was 136 (18.8%), and of these, 108 (79.4%) were noncardiac deaths. Risk of all-cause deaths in the highest hs-cTnT level group was 7.3 times higher than that of the lowest hs-cTnT level group (95% CI: 4.29-12.51, P<0.001). After adjusting for gender, age, comorbidities, NT-proBNP, Hb, eGFR, and LVEF, hs-cTnT level still affected the patient's survival time (HR: 3.01, 95% CI: 1.67-5.43, P<0.001).

Conclusion

These findings suggest that low-level hs-cTnT was increased in elderly inpatients without ACS. They further highlight that baseline hs-cTnT level was associated with increased risk of all-cause deaths among patients after their discharge, and most deaths were from non-cardiovascular diseases.

N-terminal pro-brain natriuretic peptide and high-sensitivity troponin T exhibit additive prognostic value for the outcome of critically ill patients

BACKGROUND

Patients treated at medical intensive care units suffer from various pathologies and often present with elevated troponin T (TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. Both markers may reflect different forms of cardiac involvement in critical illness. Therefore, the aim of our study was to examine the synergistic prognostic potential of NT-proBNP and high-sensitivity TnT (hs)TnT in unselected critically ill patients.

METHODS

We included all consecutive patients admitted to our intensive care unit within one year, excluding those suffering from acute myocardial infarction or undergoing cardiac surgery and measured NT-proBNP and TnT plasma levels on the day of admission and 72 hours thereafter.

RESULTS

Of the included 148 patients, 52% were male, mean age was of 64.2 ± 16.8 years and 30-day mortality was 33.2%. Non-survivors showed significantly higher NT-proBNP and TnT plasma levels as compared with survivors (p<0.01). An elevation of both markers exhibited an additive effect on mortality, as those with both NT-proBNP and TnT levels above the median had a 30-day mortality rate of 51.0%, while those with both markers below the median had a 16.7% mortality rate (hazard ratio 3.7). These findings were independent of demographic and clinical parameters (p<0.05).

CONCLUSIONS

Our findings regarding the individual predictive properties of NT-proBNP and TnT are in line with literature. However, we were able to highlight that they exhibit additive prognostic potential which exceeds their individual value. This might be attributed to a difference in underlying pathomechanisms and an assessment of synergistic risk factors.

High sensitivity troponins in contemporary cardiology practice: are we turning a corner?

INTRODUCTION

Troponin is considered to be the gold standard biomarker for ruling out MI. There has been a drive to improve the diagnostic speed, and as such the high sensitivity cardiac troponin (hs-cTn) assays have been introduced into clinical practice and are now part of international guidelines. Their novel value in clinical practice more generally is becoming apparent. Areas covered: In this review we will evaluate the evidence for the use of hs-cTn assays in clinical practice, the issues with the assay and how the hs-cTn can be utilized in the future as a biomarker of cardiovascular risk. Expert commentary: The use of the hs-cTn assays as a 'rule out' test for MI is compelling, as a 'rule in' there are significant issues relating the specificity of the assay for MI. The future of the assay may lie in population screening and risk modeling.

Influence of case definition on incidence and outcome of acute coronary syndromes

OBJECTIVE

Acute coronary syndromes (ACS) are common, but their incidence and outcome might depend greatly on how data are collected. We compared case ascertainment rates for ACS and myocardial infarction (MI) in a single institution using several different strategies.

METHODS

The Hull and East Yorkshire Hospitals serve a population of ∼560 000. Patients admitted with ACS to cardiology or general medical wards were identified prospectively by trained nurses during 2005. Patients with a death or discharge code of MI were also identified by the hospital information department and, independently, from Myocardial Infarction National Audit Project (MINAP) records. The hospital laboratory identified all patients with an elevated serum troponin-T (TnT) by contemporary criteria (>0.03 µg/L in 2005).

RESULTS

The prospective survey identified 1731 admissions (1439 patients) with ACS, including 764 admissions (704 patients) with MIs. The hospital information department reported only 552 admissions (544 patients) with MI and only 206 admissions (203 patients) were reported to the MINAP. Using all 3 strategies, 934 admissions (873 patients) for MI were identified, for which TnT was >1 µg/L in 443, 0.04-1.0 µg/L in 435, ≤0.03 µg/L in 19 and not recorded in 37. A further 823 patients had TnT >0.03 µg/L, but did not have ACS ascertained by any survey method. Of the 873 patients with MI, 146 (16.7%) died during admission and 218 (25.0%) by 1 year, but ranging from 9% for patients enrolled in the MINAP to 27% for those identified by the hospital information department.

CONCLUSIONS

MINAP and hospital statistics grossly underestimated the incidence of MI managed by our hospital. The 1-year mortality was highly dependent on the method of ascertainment.

ST2 Predicts Mortality and Length of Stay in a Critically Ill Noncardiac Intensive Care Unit Population

OBJECTIVES

The biomarker suppression of tumorigenicity 2 (ST2) is a well-established clinical biomarker of cardiac strain and is frequently elevated in a variety of cardiac conditions. Here, we sought to evaluate the prognostic value of ST2 in critically ill medical intensive care unit (MICU) patients without primary cardiac illness.

METHODS

We measured ST2 and high-sensitivity troponin T (hsTnT) on plasma specimens collected on 441 patients following admission to a noncardiac MICU and evaluated the prognostic power of ST2 both alone and in multivariate models.

RESULTS

Of these critically ill patients, 96% exhibited ST2 concentrations above the reference interval. ST2 concentrations were highly predictive of intensive care unit and hospital length of stay, as well as in-hospital mortality, with high concentrations predicting a poor prognosis. Rates of in-hospital mortality were more than four times higher in patients with ST2 concentrations in the highest compared with the lowest quartile. In multivariate analysis, ST2 remained an important predictor of death after adjustment for age, hsTnT, and common diagnoses.

CONCLUSIONS

ST2 is increased and predictive of prognosis in critically ill patients without primary cardiac disease, suggesting that critically ill patients may often have unrecognized cardiac injury. Clinical decision support algorithms incorporating ST2 and hsTnT results may be useful in patient risk stratification.

Clinical implications of high-sensitivity cardiac troponin measurements in hospitalized medical patients

Background

The increased use of high sensitivity cardiac troponins (hs-cTn), have made the diagnosis of non-ST elevation myocardial infarction (MI) challenging, especially in complex medical patients, in whom the clinical presentation of MI is nonspecific and multiple comorbidities as well as non-ischemic acute conditions may account for elevated hs-cTn levels. The aim of this study was to assess the frequency of both elevated hs-cTn levels and dynamic changes in hospitalized patients.

Methods and Findings

We conducted a retrospective study identifying all patients hospitalized in the Internal Medicine Division of Rabin Medical Center, Israel between January 2011 to December 2011, for whom at least one hs-cTn T (hs-cTnT) measurement was obtained. Collected data included patient demographics, acute and chronic diagnosis, hs-cTnT and creatinine levels and date of death. Hs-cTnT levels were obtained in 5,696 admissions and was above the 99th percentile (> = 13 ng/L) in 61.6% of the measurements. A relative change of 50% or higher was observed in 24% of the admissions. Among those with elevated hs-cTnT levels, acute coronary syndromes (ACS) accounted for only 6.1% of acute diagnoses. Maximal hs-cTnT levels above 100 ng/L but not dynamic changes discriminated between ACS and non-ACS conditions (positive and negative predictive values of 12% and 96% respectively). The frequency of elevated hs-cTnT levels was age-dependent and over 75% of patients aged >70 years-old had levels above the 99th percentile. Multivariate analysis identified hs-cTnT levels higher than the 99th percentile, as an independent, strong predictor for 30-day mortality (OR 4.58 [2.8, 7.49], p<0.0001).

Conclusions

Elevated hs-cTnT levels together with dynamic changes are frequent findings among hospitalized patients and in most cases, are not related to the ACS diagnosis. These findings highlight the diagnostic challenge of ACS in this complex population. Further studies are needed in order to optimize the use of hs-cTnT measurements in hospitalized patients.