Diagnostic and prognostic performance of a novel high-sensitivity cardiac troponin T assay compared to a contemporary sensitive cardiac troponin I assay in patients with acute coronary syndrome

Acute Kidney Injury and High-Sensitivity Cardiac Troponin T Levels in the Emergency Department

Importance

The clinical implications of high-sensitivity cardiac troponin T (hs-cTnT) measurements in patients with acute kidney injury (AKI) in the emergency department (ED) are largely unknown.

Objectives

To investigate associations between serum creatinine (SCr) concentrations and hs-cTnT kinetics, as well as the clinical accuracy of hs-cTnT for myocardial infarction (MI) in patients with AKI.

Design, Setting, and Participants

This retrospective cohort study included 15 111 patient visits to 7 EDs in Sweden from December 9, 2010, to August 31, 2017, by patients 18 years or older fulfilling AKI criteria with 2 or more SCr measurements and 1 or more hs-cTnT measurement. Statistical analysis was performed from October 2, 2022, to September 28, 2023.

Exposure

Dynamic change in SCr during the ED visits.

Main Outcomes and Measures

Linear mixed-effects models were used to estimate the log-linear regression of kinetic change in hs-cTnT. Logistic regression models were applied to calculate odds ratios (ORs) for change in hs-cTnT indicating acute myocardial injury (Δhs-cTnT >20% and elevated hs-cTnT >14 ng/L) in association with change in SCr, and to assess the diagnostic performance of hs-cTnT for MI in patients with chest pain.

Results

There was a total of 15 211 visits by 13 638 patients (median age, 74 years [IQR, 64-83 years]; 8709 men [57%]), of whom 1174 (8%) had an MI. Overall, 11 353 of patients at 14 037 visits without an MI diagnosis (81%) had myocardial injury, and 4396 patients at 14 037 visits (31%) had acute myocardial injury. The change in hs-cTnT among patients without MI was 1.8-fold higher in the highest vs the lowest change in SCr quartile (64.7% [95% CI, 58.4%-71.5%] vs 36.3% [95% CI, 32.4%-40.7%]; exponentiated β coefficient, 1.78 [95% CI, 1.62-1.96]). Patients in the former group were twice as likely to have acute myocardial injury (39% [1378 of 3516 visits] vs 23% [817 of 3507 visits]; adjusted OR, 2.32 [95% CI, 2.08-2.59]). Using a 0 hours hs-cTnT cutoff value of 52 ng/L or higher assigned 627 of 2388 patients (26%) with chest pain to a high-risk group in whom the specificity and positive predictive value for MI was low (78.5% [95% CI, 76.7%-80.2&] and 27.6% [95% CI, 24.1%-31.3%], respectively).

Conclusions and Relevance

This cohort study of patients in the ED suggests that dynamic change in SCr among patients with AKI was associated with hs-cTnT concentrations indicative of acute myocardial injury. These observations were accompanied by poor performance of recommended hs-cTnT-based algorithms for MI risk stratification.

Long-term prognosis of low high-sensitivity cardiac troponin T in the emergency department compared with the general population

BACKGROUND

Long-term prognosis associated with low-high-sensitivity cardiac troponin T (hs-cTnT) concentrations in patients with chest pain is unknown. We investigated these prognostic implications compared with the general population.

METHODS

All first visits to seven emergency departments (ED)s in Sweden were included from 9 December 2010 to 31 August, 2017 by patients presenting with chest pain and at least one hs-cTnT measured. Patients with myocardial injury (any hs-cTnT >14 ng/L), including patients with myocardial infarction (MI) were excluded. Standardised mortality ratios (SMRs) and standardised incidence ratios (SIRs) were calculated as the ratio of the number of observed to expected events. The expected number was computed by multiplying the 1-year calendar period-specific, age-specific and sex-specific follow-up time in the cohort with the corresponding incidence in the general population. HRs were calculated for all-cause mortality and major adverse cardiovascular events (MACE), defined as acute MI, heart failure hospitalisation, cerebrovascular stroke or cardiovascular death, between patients with undetectable (<5 ng/L) and low (5-14 ng/L) hs-cTnT.

RESULTS

A total of 1 11 916 patients were included, of whom 69 090 (62%) and 42 826 (38%) had peak hs-cTnT concentrations of <5 and 5-14 ng/L. Patients with undetectable peak hs-cTnT had a lower mortality risk compared with the general Swedish population (SMR 0.83, 95% CI 0.79 to 0.87), with lower risks observed in all patients ≥65 years of age, but a slightly higher risk of being diagnosed with a future MI (SIR 1.39, 95% CI 1.32 to 1.47). The adjusted risk of a first MACE associated with low versus undetectable peak hs-cTnT was 1.6-fold (HR 1.61, 95% CI 1.53 to 1.70).

CONCLUSION

Patients with chest pain and undetectable hs-cTnT have an overall lower risk of death compared with the general population, with risks being highly age dependent. Detectable hs-cTnT concentrations are still associated with increased long-term cardiovascular risks.

Association of Troponin T measurements with long-term outcomes in patients with coronary artery disease participating in a secondary prevention trial

BACKGROUND AND AIMS

Identification of high-risk patients in secondary cardiovascular prevention may be challenging, although risk stratification tools are available. Cardiac troponins might have predictive value in identification of high-risk patients. The aim of this study was to investigate the association between cardiac Troponin T (cTnT) levels following a coronary event and long-term outcomes.

METHODS

This study was carried out as a subanalysis from a randomized controlled trial conducted at Sørlandet Hospital, Norway, where patients hospitalized with myocardial infarction (MI) or scheduled percutaneous coronary intervention (PCI)/coronary artery bypass grafting (CABG) were included between 2007 and 2017. Participants were followed-up for up to 10 years after the index event through out-patient consultations. cTnT was assessed at each consultation as well as information regarding new cardiovascular events or death.

RESULTS

A total of 1278 patients (18-80 years) with complete measurements of cTnT were included. cTnT was elevated (≥ 14 ng/L) one year after the primary event in 241 (19%) of participants. Median follow-up was 5.7 [SD 2.7] years. Cox regression analyses showed reduced survival (adjusted HR 0.37, 95% CI 0.19-0.72; p = 0.003) and composite endpoint-free survival (adjusted HR 0.73, 95% CI 0.55-0.98; p = 0.04) in participants with elevated cTnT versus participants with low cTnT after adjustment for risk factors at inclusion and randomization assignment.

CONCLUSIONS

Assessment of cTnT after coronary heart events may help identify patients at high risk of poor outcomes and might contribute to more focused secondary preventive treatment.

TRIAL REGISTRATION

The study is registered in ClinicalTrials.gov (NCT00679237).

Using historical cardiac troponins to identify patients at a high risk of myocardial infarction

OBJECTIVE

Many patients who present with chest pain have previous measurements of high-sensitivity cardiac troponin T (hs-cTnT). The clinical usefulness of incorporating these measurements in identifying patients who are at a high risk of myocardial infarction (MI) is unknown. We investigated if the relative change between a historical hs-cTnT and the admission hs-cTnT could improve early identification of patients with a high risk of MI.

METHODS

We included all patients presenting with chest pain to seven different emergency departments (EDs) in Sweden from December 2009 to December 2016, who had at least one hs-cTnT measurement at the presentation and at least one available prior measurement. We used logistic regression to investigate the diagnostic performance of using various combinations of current and historical hs-cTnT measurements in diagnosing MI within 30 days.

RESULTS

A total of 27 809 visits were included, among whom 2686 (9.7%) had an MI within 30 days. A cut-off value for historical hs-cTnT-adjusted admission hs-cTnT with similar specificity (91.2%) as an admission hs-cTnT of ≥52 ng/L identified 4% more MIs (43% vs 39%) and had a higher positive predictive value, 42.6% (95% CI, 41.0% to 44.3%) vs 38.9% (95% CI 37.4% to 40.4%), as well as a higher positive likelihood ratio, 6.95 (95% CI 6.69 to 7.22) vs 5.95 (95% CI 5.73 to 6.18). Among patients with an admission hs-cTnT of <52 ng/L who were classified as high-risk patients when incorporating past hs-cTnT measurements, 28% suffered an MI.

CONCLUSIONS

Historical hs-cTnT levels can be used with admission hs-cTnT to improve early risk stratification of MI in the ED.

Unstable Angina Pectoris With Myocardial Injury Versus Myocardial Infarction in the Era of High-Sensitivity Cardiac Troponin

It is unknown whether outcomes in patients with unstable angina pectoris (UAP) and myocardial injury are different from outcomes in patients with non-ST-segment myocardial infarction (NSTEMI) with low peak concentrations of high-sensitivity cardiac troponin T (hs-cTnT). This study aimed to compare the prognosis in patients with UAP and evidence of myocardial injury, with prognosis in patients with NSTEMI and different peak hs-cTnT concentrations. All visits to 7 different emergency departments in Sweden from December 9, 2009 to December 31, 2016 were identified (n = 5,225,075). We included all hospitalized patients with hs-cTnT >14 ng/L and a diagnosis of UAP or NSTEMI, with ≥2 hours-cTnT measurements. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated for all-cause mortality and cardiovascular events, in patients with NSTEMI categorized according to peak hs-cTnT concentrations, compared with patients with UAP. Altogether, 11,944 patients were included, of whom 1,253 (10%) received a diagnosis of UAP. During a median follow-up of 3.0 years (interquartile [IQR] 1.6 to 4.7), 3,297 patients died. There was no difference comparing patients with NSTEMI with peak hs-cTnT of 15 to 49 ng/L to patients with UAP, with regards to long-term cardiovascular mortality (HR 1.15; 95% CI, 0.85 to 1.56), but the risk of recurrent myocardial infarction was higher in patients with NSTEMI (HR, 1.61; 95% CI, 1.29 to 2.00), and the risk of heart failure hospitalization slightly lower (HR 0.80, 95% CI, 0.64 to 0.99). In conclusion, patients with UAP and myocardial injury have a similar risk of death after discharge, but a lower risk of recurrent myocardial infarction and a marginally higher risk of heart failure, compared with patients with NSTEMI with moderately elevated hs-cTnT levels.

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

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.

Chronic Myocardial Injury and Risk for Stroke

BACKGROUND

Chronic myocardial injury, defined as persistent troponin levels >99th percentile values when measured with high-sensitivity assays (hs-cTn), is common. The association between chronic myocardial injury and stroke is unknown. This study aimed to investigate the association between chronic myocardial injury and stroke.

METHODS

From 2011 to 2014, we included patients with chest pain and high-sensitivity cardiac troponin T levels measured concurrently but without acute conditions associated with elevated high-sensitivity cardiac troponin T levels. Cox regression was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for stroke in patients with stable high-sensitivity cardiac troponin T levels of 5-9, 10-14, 15-29, 30-49, and ≥50 ng/L, using <5 ng/L as reference group. Categories >14 ng/L were defined as chronic myocardial injury.

RESULTS

A total of 19,460 patients were included, among whom 1528 (7.9%) had chronic myocardial injury. During a mean follow-up of 2.1 years, there were 244 (1.2%) strokes. With increasing high-sensitivity cardiac troponin T levels yearly stroke rates increased from 0.24% to 4.0%. Adjusted hazard ratios with 95% confidence intervals for stroke were 1.83 (1.27-2.64) in patients with high-sensitivity cardiac troponin T levels of 5-9 ng/L, increasing to 1.95 (1.21-3.14), 3.38 (1.80-6.35), and 4.32 (1.89-9.91) in patients with high-sensitivity cardiac troponin T levels of 15-29, 30-49, and ≥50 ng/L, respectively.

CONCLUSIONS

Patients with chronic myocardial injury have up to a 4-fold increased risk of stroke compared with patients with high-sensitivity cardiac troponin T levels <5 ng/L. Our findings indicate that patients with any detectable high-sensitivity cardiac troponin T level, in particular those with chronic myocardial injury, have an increased risk of stroke and require further attention.

Risk prediction in stable cardiovascular disease using a high-sensitivity cardiac troponin T single biomarker strategy compared to the ESC-SCORE

Objective

To evaluate the prognostic performance of high-sensitivity cardiac troponin T (hs-cTnT) compared with the ESC-SCORE.

Methods

We included low-risk outpatients with stable cardiovascular (CV) disease categorised into need for non-secondary and secondary prevention. The prognostication of hs-cTnT at index visit was compared with the European Society of Cardiology-Systematic COronary Risk Evaluation (ESC-SCORE) with respect to all-cause mortality (ACM) and two composite endpoints (ACM, acute myocardial infarction (AMI) and stroke and ACM, AMI, stroke and rehospitalisation for acute coronary syndrome (ACS) and decompensated heart failure (DHF)).

Results

Within a median follow-up of 796 days, a total of 16 deaths, 32 composite endpoints of ACM, AMI and stroke and 83 composite endpoints of ACM, AMI, stroke, rehospitalisation for ACS and DHF were observed among 693 stable low-risk outpatients. Using C-statistics, measurement of hs-cTnT alone outperformed the ESC-SCORE for the prediction of ACM in the entire study population (Δarea under the curve (AUC) 0.221, p=0.0039) and both prevention groups (non-secondary: ΔAUC 0.164, p=0.0208; secondary: ΔAUC 0.264, p=0.0134). For the prediction of all other secondary endpoints, hs-cTnT was at least as effective as the ESC-SCORE, both in secondary and non-secondary prevention. Using continuous and categorical net reclassification improvement and integrated discrimination improvement, hs-cTnT significantly improved reclassification regarding all endpoints in the entire population and in the secondary prevention cohort. In non-secondary prevention, hs-cTnT improved reclassification only for ACM. The results were confirmed in an independent external cohort on 2046 patients.

Conclusions

Hs-cTnT is superior to the multivariable ESC-SCORE for the prediction of ACM and a composite endpoint in stable outpatients with and without relevant CV disease.

Trial registration number

NCT01954303; Pre-results.

Low-level troponin elevations following a reduced troponin I cutoff: Increased resource utilization without improved outcomes

OBJECTIVE

The study sought to evaluate changes in mortality and resource utilization in patients with low level troponin elevations following a reduction in the cutoff for normal troponin I (TnI) from 0.5 ng/mL to the 99th percentile (0.06 ng/mL).

METHODS

This was an interrupted time series comparing emergency department (ED) patients with possible acute coronary syndrome (ACS) and TnI values 0.06-0.5 ng/mL before and after an institutional decrease in the TnI cutoff. The primary outcome was overall mortality at 90 days. Secondary outcomes included rates of rehospitalization, subsequent ACS, and coronary intervention within 90 days, as well as rates of anticoagulation, cardiology consultation, cardiac testing, and coronary intervention during the index visit. Outcomes for the pre-cutoff change group (control) and post-cutoff change group (post) were compared using tests of proportions and odds ratios.

RESULTS

The study included a total of 1058 subjects with 529 in each cohort. No significant differences in 90 day outcomes were observed between groups, including mortality (13.2% post vs 14.1% control, OR 0.93 [95% CI: 0.65-1.34], p = 0.705). During the index visit, the post-group demonstrated higher rates of cardiology consultation (55.4% vs 41.2%, OR 1.77 [1.39-2.26], p < 0.0001) and cardiac stress testing (16.4% vs 10.6%, OR 1.66 [1.16-2.38], p = 0.006), but no significant differences in coronary intervention or short-term mortality were observed.

CONCLUSION

A reduction in the TnI cutoff to the 99th percentile did not change mortality or rates of coronary intervention in ED patients with low level troponin elevations, but significantly increased the use of cardiology resources.

Validation of the (Troponin-only) Manchester ACS decision aid with a contemporary cardiac troponin I assay

OBJECTIVES

The Manchester Acute Coronary Syndromes (MACS) decision aid can 'rules in' and 'rule out' acute coronary syndromes (ACS) by combining a patient's symptoms with the results of a single blood test taken at the time of arrival in the Emergency Department (ED). The original model (MACS) included two biomarkers: high sensitivity cardiac troponin T (hs-cTnT) and heart-type fatty acid binding protein (h-FABP). A refined model without h-FABP was found to have comparable sensitivity but greater specificity. We sought to validate MACS and T-MACS using the contemporary Siemens Advia Centaur cardiac troponin I assay to increase usability in practice.

METHODS

This is a secondary analysis from prospective diagnostic cohort study at Stepping Hill Hospital, United Kingdom. Patients presenting with chest pain of suspected cardiac nature warranting rule out for ACS were included. All patients underwent hs-cTnT testing at least 12h after peak symptoms. The primary outcome was a diagnosis of ACS, defined as either prevalent acute myocardial infarction (AMI) or incident major adverse cardiac events (death, AMI or coronary revascularization) within 30days.

RESULTS

Of 405 included patients, 76 (18.8%) had ACS. MACS and T-MACS had similar C-statistics (0.94 for each, p=0.36) and sensitivity (difference 1.3%, 95% CI -1.3 to 3.9%, p=1.00) but T-MACS had significantly greater specificity (difference 16.7%, 95% CI 14.6-18.9%, p<0.0001). T-MACS and MACS would have allowed 36.3% and 22.5% patients to be immediately discharged respectively. Of patients classified as 'very low risk', none had ACS when MACS was used compared to one (0.7%) with T-MACS.

CONCLUSION

Both MACS and T-MACS effectively ruled out ACS even with a contemporary troponin I assay and could be used to reduce unnecessary hospital admissions.

The cardiotoxicity of cetuximab as single therapy in Chinese chemotherapy-refractory metastatic colorectal cancer patients

The cardiac safety of cetuximab, particularly as single approach, has not been investigated extensively. This trial was designed to evaluate the cardiac safety of cetuximab as salvage monotherapy in Chinese chemotherapy-refractory metastatic colorectal cancer (mCRC) patients.Cetuximab was administrated at an initial dose of 400 mg/mon day 1 (week 1), followed by a maintenance dose of 250 mg/m on day 1 of each 7-day cycle. Electrocardiograph (ECG), routine laboratory tests, and troponin I (TNI) Ultra were performed at baseline, during, and after the cetuximab therapy. The incidence of abnormal ECGs, elevated TNI Ultra, cardiac events, and noncardiac events were recorded and analyzed.TNI Ultra+ was found in 20 patients (32.3%) during the cetuximab therapy.TNI Ultra+ occurred more frequently in patients with more than 3 organs affected and accepted fourth or above lines of chemotherapy. The most frequent abnormal ECG was ST depression in 24 (38.7%) patients. The elevated TNI Ultra and abnormal ECGs could recover after the cetuximab therapy. The most of cardiac adverse events were mild and transient and the noncardiac adverse events were also consistent with the known safety profile for cetuximab.Cetuximab showed its cardiac safety as a single agent for chemotherapy-refractory mCRC patients. And TNI Ultra and ECG could be sensitive and convenient approaches for the surveillance of adverse events.

Prognostic Value of Undetectable hs Troponin T in Suspected Acute Coronary Syndrome

BACKGROUND

The search for improved strategies for safe and early discharge of patients with suspected acute coronary syndrome in emergency departments is ongoing. This Biomarkers in Cardiology (BIC)-8 biomarker substudy evaluated the usefulness of high-sensitivity troponin T (hsTnT) below or above the limit of detection (LoD) in low-to-intermediate-risk patients with suspected acute coronary syndrome in the emergency department.

METHODS

Patients were categorized into hsTnT ≥ the 99th percentile, between the 99th percentile and LoD, or undetectable hsTnT (<LoD). HsTnT and copeptin were measured at admission, using a copeptin cut-off of 10 pmol/L. The primary endpoint was death and myocardial infarction within 90 days after admission.

RESULTS

Of 882 patients with all biomarker results, 577 (65.4%) had detectable hsTnT levels (≥LoD). Among the 305 patients (34.6%) with undetectable hsTnT, no myocardial infarctions or deaths occurred within 90 days. In patients with detectable hsTnT at admission (≥LoD but ≤99th percentile), the combined endpoint occurred in 1.5% (6/410) of the copeptin-negative patients and in 6.3% (6/96) of copeptin-positive patients within 90 days (hazard ratio 4.39; 95% confidence interval, 1.42-13.61; P = .01). In patients with an initially elevated hsTnT (≥14 ng/L), 9.7% (3/31) of the copeptin-negative patients and 15.4% (4/26) of the copeptin-positive patients experienced the combined endpoint (hazard ratio 1.61; 95% confidence interval, 0.36-7.17; P = .536).

CONCLUSIONS

In low-to-intermediate-risk patients with suspected acute coronary syndrome, undetectable hsTnT values at admission allow a safe discharge without occurrence of death or myocardial infarction within 90 days.

Safety of percutaneous coronary intervention in patients with acute ischemic stroke/transient ischemic attack and acute coronary syndrome

BACKGROUND

Cardiac events in patients with acute stroke are frequent. Urgent PCI in myocardial infarction is crucial to improve outcome. However, the situation is complex as intracranial hemorrhage is a frequent complication of stroke but antithrombotic medication is indispensable during and after PCI. Therefore in this study, we aimed to investigate the safety of percutaneous coronary intervention (PCI) in patients hospitalized with acute ischemic stroke and concomitant acute coronary syndrome (ACS).

METHODS AND RESULTS

In a single-center, case-series study we investigated 80 patients hospitalized with acute stroke/transient ischemic attack (TIA) and concomitant ACS undergoing coronary angiography. Patients with subsequent PCI were compared to patients with medical treatment alone. The primary end point was the composite of death, recurrent MI, coronary re-intervention, recurrent stroke or bleeding during 1-year follow-up. The secondary end point consisted of the components of the primary end point. Age, gender and cardiovascular risk factors did not differ between groups. However, severity of initial stroke and coronary artery disease was higher in the PCI group. Accordingly, antiplatelet medication with aspirin and clopidogrel was prescribed more frequently in the PCI group. Nevertheless, during 1-year follow-up, the primary end point did not differ between groups [38 vs. 50 %, odds ratio (OR) 1.7, CI 0.69-4.07, P = 0.23]. Intracranial hemorrhage was even numerically lower in patients undergoing PCI (5 vs. 3 %, OR 0.4, CI 0.04-5.6, P = 0.46).

CONCLUSIONS

The primary and secondary end points were not enhanced in patients undergoing PCI. Therefore PCI is safe in patients with stroke/TIA and concomitant ACS.

Efficacy of enteral ticagrelor in hypothermic patients after out-of-hospital cardiac arrest

Introduction

Delivery of crushed ticagrelor via a nasogastric tube is a widely spread off-label use in unconscious patients following out-of-hospital cardiac arrest (OHCA). Notwithstanding the importance of a potent dual antiplatelet therapy in these patients, the efficacy of crushed ticagrelor after OHCA has not been established yet.

Methods

In a prospective, single-center, observational trial, 38 consecutive MI patients after OHCA were included. 27 patients (71.1 %) underwent mild induced hypothermia. The primary outcome was platelet inhibition at 24h measured by impedance aggregometry.

Results

There was sufficient platelet inhibition in most patients after OHCA. In all hypothermic patients, there was an adequate platelet inhibition by ticagrelor at 24 h (p < 0.001). 15 patients (39.5 %) had significant gastroesophageal reflux and one patient with significant reflux had inadequate platelet inhibition at 24 h. There were no stent thrombosis or recurrent atherothrombotic events in these patients.

Conclusion

Administration of crushed ticagrelor via a nasogastric tube reliably inhibited platelet function in vitro and in vivo regardless of the presence of hypothermia in MI patients. Thus, platelet inhibition can be reliably achieved in MI patients during neuroprotective hypothermia following OHCA.

Implications of Introducing High-Sensitivity Cardiac Troponin T Into Clinical Practice: Data From the SWEDEHEART Registry

BACKGROUND

Cardiac troponin is the preferred biomarker for diagnosing myocardial infarction (MI).

OBJECTIVES

The aim of this study was to examine the implications of introducing high-sensitivity cardiac troponin T (hs-cTnT) into clinical practice and to define at what hs-cTnT level risk starts to increase.

METHODS

We analyzed data from 48,594 patients admitted because of symptoms suggesting an acute coronary syndrome and who were entered into a large national registry. Patients were divided into Group 1, those with hs-cTnT<6 ng/l; Group 2, those with hs-cTnT 6 to 13 ng/l; Group 3, those with hs-cTnT 14 to 49 ng/l (i.e., a group in which most patients would have had a negative cardiac troponin T with older assays); and Group 4, those with hs-cTnT≥50 ng/l.

RESULTS

There were 5,790 (11.9%), 6,491 (13.4%), 10,476 (21.6%), and 25,837 (53.2%) patients in Groups 1, 2, 3, and 4, respectively. In Groups 1 to 4, the proportions with MI were 2.2%, 2.6%, 18.2%, and 81.2%. There was a stepwise increase in the proportion of patients with significant coronary stenoses, left ventricular systolic dysfunction, and death during follow-up. When dividing patients into 20 groups according to hs-cTnT level, the adjusted mortality started to increase at an hs-cTnT level of 14 ng/l.

CONCLUSIONS

Introducing hs-cTnT into clinical practice has led to the recognition of a large proportion of patients with minor cardiac troponin increases (14 to 49 ng/l), the majority of whom do not have MI. Although a heterogeneous group, these patients remain at high risk, and the adjusted mortality rate started to increase at the level of the 99th percentile in healthy controls.

Rapid exclusion of acute myocardial infarction in patients with undetectable troponin using a sensitive troponin I assay

Objective

With a high-sensitivity troponin assay, it may be possible to exclude acute myocardial infarction with a single blood test on arrival in the emergency department by using a novel ‘rule out’ cut-off set at the limit of detection of the assay. We aimed to determine whether this can also be achieved using a contemporary sensitive troponin assay that does not meet ‘high-sensitivity’ criteria.

Methods

In a prospective diagnostic cohort study, we included patients presenting to the emergency department with suspected cardiac chest pain. For this secondary analysis, serum samples drawn on arrival were tested using a contemporary sensitive troponin I assay (s-cTnI; Siemens Ultra ADVIA Centaur, 99th percentile 40 ng/L, limit of detection 6 ng/L). Acute myocardial infarction was adjudicated by two independent investigators based on reference standard troponin testing ≥12 h after symptom onset.

Results

Of 414 participants, 70 (16.9%) had acute myocardial infarction and 205 (49.5%) had initial s-cTnI concentrations below the limit of detection. Using the limit of detection as a ‘rule out’ cut-off gave a sensitivity of 94.3% (95% CI 86.0–98.4%) for acute myocardial infarction. If only patients with s-cTnI below the limit of detection and no electrocardiogram ischaemia were considered to have acute myocardial infarction ‘ruled out’ (41.8% of the cohort, n = 174), sensitivity would rise to 97.1% (90.1–99.7%) and negative predictive value to 98.8% (95.9–99.9%).

Conclusions

Acute myocardial infarction cannot be excluded in patients with s-cTnI concentrations below the limit of detection using the contemporary sensitive assay evaluated. Future work with this assay should focus on serial sampling over 1–3 h and combination with clinical information and/or additional biomarkers.

Highly Sensitive Troponin and Critical Illness Insurance: Have the Goalposts Moved Again?

An elevated cardiac troponin is a sine qua non for the clinical diagnosis of myocardial infarction. The sensitivity of troponin assays has improved repeatedly since troponin entered clinical use in the late 1990s. Its most recent iteration, "highly sensitive" troponin will shortly enter clinical use in North America. It is able to detect amounts of troponin 10 times smaller than the current assay. As a result, more myocardial infarctions will be diagnosed. This may have an impact on the number of critical illness claims for heart attack.

"Troponin elevation in coronary ischemia and necrosis"

Detection of a rise and/or fall of cardiac troponin (cTn) is the cornerstone in the diagnosis of myocardial infarction (MI). For the acute risk, it is hypothesized that cTn mirrors activated coagulation and platelet reactivity and indicates the presence of a ruptured plaque, which may help to identify patients at high risk who benefit particularly from aggressive pharmacological treatment and early invasive strategy. High-sensitivity assays using the 99th percentile as the threshold for positivity can achieve sensitivity at presentation of 90 % or more, and performance further improves with subsequent measurements within 3 to 6 h. By 3 h, negative predictive values of almost 100 % have been reported. However, use of assays with higher sensitivity lead ultimately to a loss of clinical specificity. Thus, other conditions than MI, such as stroke, pulmonary embolism, sepsis, acute perimyocarditis, Takotsubo, acute heart failure and tachycardia also can go with elevated troponin levels. The detection of brief rise and subsequent fall of troponin concentration in marathon runners, and even in healthy subjects, after a standardized exercise test has cast doubts on the hypothesis that troponin is released only upon irreversible damage. This kind of troponin leakage may originate from a cytosolic compartment of the cells and not from the necrosis of thin filaments.

Troponins in heart failure

The signs and symptoms of heart failure are frequently unspecific and correlate poorly with objective indices of cardiac function. Objective assessment of cardiac function by echocardiography or other imaging modalities also correlate poorly with symptomatic status and functional capacity. Accordingly, there is a need for circulating biomarkers that can provide incremental diagnostic and prognostic information to the existing armamentarium of tests. The introduction of more sensitive assays that allow determination of very low circulating concentrations of the myofibrillar proteins cardiac troponin I and T has not only resulted in improved diagnostic accuracy in the setting of acute coronary syndromes. The high sensitivity assays have also shown that cardiac troponins are frequently found chronically circulating in a variety of acute and chronic, cardiac and non-cardiac disease conditions, including acute heart failure and chronic symptomatic and asymptomatic left ventricular dysfunction. Cardiac troponin I and T provide may provide clinically useful prognostic information both concerning the future risk of developing heart failure in asymptomatic subjects and the risk of fatal events and hospital admissions in those with already established heart failure This review summarizes current literature on the clinical performance and utility of cardiac troponin measurements as diagnostic and prognostic tools in patients with symptomatic heart failure, as well as in those with asymptomatic left ventricular dysfunction, and clinical phenotypes at high risk for developing heart failure, including stable coronary artery disease, left ventricular hypertrophy, and aortic stenosis.

Prognostic performance of high-sensitivity cardiac troponin T kinetic changes adjusted for elevated admission values and the GRACE score in an unselected emergency department population

PURPOSE

The aim of this study was to test the prognostic performance of rising and falling kinetic changes of high-sensitivity cardiac troponin T (hs-cTnT) and the GRACE score.

METHODS

Rising and falling hs-cTnT changes in an unselected emergency department population were compared.

RESULTS

635 patients with a hs-cTnT >99th percentile admission value were enrolled. Of these, 572 patients qualified for evaluation with rising patterns (n=254, 44.4%), falling patterns (n=224, 39.2%), or falling patterns following an initial rise (n=94, 16.4%). During 407days of follow-up, we observed 74 deaths, 17 recurrent AMI, and 79 subjects with a composite of death/AMI. Admission values >14ng/L were associated with a higher rate of adverse outcomes (OR, 95%CI:death:12.6, 1.8-92.1, p=0.01, death/AMI:6.7, 1.6-27.9, p=0.01). Neither rising nor falling changes increased the AUC of baseline values (AUC: rising 0.562 vs. 0.561, p=ns, falling: 0.533 vs. 0.575, p=ns). A GRACE score ≥140 points indicated a higher risk of death (OR, 95%CI: 3.14, 1.84-5.36), AMI (OR, 95%CI: 1.56, 0.59-4.17), or death/AMI (OR, 95%CI: 2.49, 1.51-4.11). Hs-cTnT changes did not improve the prognostic performance of a GRACE score ≥140 points (AUC, 95%CI: death: 0.635, 0.570-0.701 vs. 0.560, 0.470-0.649 p=ns, AMI: 0.555, 0.418-0.693 vs. 0.603, 0.424-0.782, p=ns, death/AMI: 0.610, 0.545-0.676 vs. 0.538, 0.454-0.622, p=ns). Coronary angiography was performed earlier in patients with rising than with falling kinetics (median, IQR [hours]:13.7, 5.5-28.0 vs. 20.8, 6.3-59.0, p=0.01).

CONCLUSION

Neither rising nor falling hs-cTnT changes improve the prognostic performance of elevated hs-cTnT admission values or the GRACE score. However, rising values are more likely associated with the decision for earlier invasive strategy.

Hotline update of clinical trials and registries presented at the American College of Cardiology Congress 2014

This article provides information and commentaries on trials which were presented at the Hotline and Clinical Trial Update Sessions during the Late Breaking Clinical Trial Sessions at the 63rd annual meeting of the American College of Cardiology in Washington, USA, from 29th to 31st March 2014. This article gives an overview on a number of novel clinical trials in the field of cardiovascular medicine, which were presented. Comprehensive summaries have been generated from the oral presentation and the webcasts of the American College of Cardiology, similar to as previously reported and should provide the readers with the most comprehensive information of relevant publications. The discussed studies are US CoreValve, Choice, Symplcity-HTN-3, GRS, ZEUS, GIPS-III, HEAT-PPCI, COPR-2, MSC-HF, POISE-2, SIRS. The data were presented by leading experts in the field.

Association of high-sensitivity assayed troponin I with cardiovascular phenotypes in the general population: the population-based Gutenberg health study

BACKGROUND

Aim of the study was to analyze the correlation of high-sensitivity assayed troponin I with cardiac and vascular structure and function in a large population-based cohort.

METHODS

In a sample of 4,139 subjects (2,099 men, 2,040 women, age 35-74 years) from the population-based Gutenberg Health Study, troponin I was measured with a high-sensitivity assay that had a limit of detection of 1.9 pg/mL.

RESULTS

In the study cohort, 3,405 subjects had detectable troponin I concentrations [82.3% overall, 89.9% men (N = 1,888), 74.4% women (N = 1,517)]. All analyses were adjusted for age. The strongest correlate between detectable troponin I and measures of cardiac phenotypes was observed for left ventricular mass (p < 0.001) and left ventricular end-diastolic diameter (p < 0.001) for both, women and men. Left ventricular ejection fraction was inversely correlated with troponin I (p value <0.001 in men and 0.0013 in women), also measures of diastolic dysfunction as represented by Tei index and E/E' correlated with detectable troponin I concentrations (p < 0.001 for both gender). With respect to vascular structure and function, troponin I correlated with mean intima-media thickness of the carotid artery (p < 0.001 in men and p = 0.013 in women) but showed only borderline correlation with measures of vascular function represented by flow-mediated dilation (p = 0.05 in women and p = 0.018 in men) and arterial stiffness.

CONCLUSIONS

Troponin I assessed by a high-sensitivity assay correlated with measures of left ventricular hypertrophy and systolic and diastolic function, whereas its correlation with vascular phenotypes was only of weak magnitude.

Quantitative point-of-care troponin T measurement for diagnosis and prognosis in patients with a suspected acute myocardial infarction

Improvement of prehospital triage is essential to ensure rapid management of patients with acute myocardial infarction (AMI). This study evaluates the feasibility of prehospital quantitative point-of-care cardiac troponin T (POC-cTnT) analysis, its ability to identify patients with AMI, and its capacity to predict mortality. The study was performed in the Central Denmark Region from May 2010 to May 2011. As a supplement to electrocardiography, a prehospital POC-cTnT measurement was performed by a paramedic in patients with suspected AMI. AMI was diagnosed according to the universal definition of myocardial infarction using the ninety-ninth percentile upper reference level as diagnostic cut point. The paramedics performed POC-cTnT measurements in 985 subjects with a symptom duration of 70 minutes (95% CI, 35 to 180); of whom, 200 (20%) had an AMI. The prehospital sample was obtained 88 minutes (range, 58 to 131) before the sample made on admission to the hospital. The sensitivity for detection of patients with an AMI was 39% (95% CI, 32% to 46%) and the diagnostic accuracy of the POC-cTnT values was 0.67 (95% CI, 0.64 to 0.71). Adjusted survival analysis showed a strong significant association between elevated prehospital POC-cTnT level above the detection level of 50 ng/L and mortality in patients with a suspected AMI irrespective of whether an AMI was diagnosed. In conclusion, large-scale quantitative prehospital POC-cTnT testing by paramedics is feasible. An elevated prehospital POC-cTnT value contains diagnostic information and is highly predictive of mortality in patients with a suspected AMI.

Short-term outcome of patients with ST-segment elevation myocardial infarction (STEMI) treated with an everolimus-eluting bioresorbable vascular scaffold

OBJECTIVES

To evaluate safety and efficacy of the everolimus-eluting bioresorbable scaffold (BVS) in patients with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

According to the current guidelines, drug-eluting stents are the treatment of choice in patients with STEMI. BVS represents a new technology capable to restore the native vessel vasomotion and potentially avoiding long-term limitations such as stent thrombosis.

METHODS

From October 2012 to May 2013, patients with evidence of STEMI eligible for BVS implantation were included in this study. Exclusion criteria were not defined.

RESULTS

A total of 25 patients, respectively 31 lesions, were treated. Procedural success was achieved in 97%. Two major adverse cardiac events occurred during hospitalization and follow-up: one patient with cardiogenic shock at the index procedure subsequently died. One patient suffered from instable angina with need for interventional revascularization of a previously untreated vessel. One target vessel failure as a consequence of an intra-procedural dissection was seen. However, no target lesion failure was noted. During 132.7 ± 68.7 days of follow-up none of the patients died.

CONCLUSION

Our findings suggest that implantation of BVS in STEMI patients is feasible in this small cohort of highly selected patients. Further evaluation in randomized-controlled trials is needed.

High-sensitivity cardiac troponins: no more 'negatives'

According to recently published expert guidelines, cardiac troponins are the only accepted biomarkers to define acute myocardial infarction. New high sensitivity cardiac troponin assays provide exciting opportunities for early rule-out and rule-in strategies and for identifying high-risk patients early in their presentation to guide early treatment and intervention. This review briefly discusses the history of troponin testing, before going on to cover clinical uses of the new highly sensitive assays in the early assessment of acute myocardial infection. Common clinical pitfalls with the use of these assays are discussed, as is the use of highly sensitive troponins more widely as prognostic markers. Likely future developments in this area are discussed.

High-sensitivity cardiac troponin T compared with standard troponin T testing on emergency department admission: how much does it add in everyday clinical practice?

Background

We compared high‐sensitivity cardiac troponin T (hs‐cTnT) and standard cTnT for acute myocardial infarction (AMI) diagnosis in everyday clinical practice of an emergency department (ED).

Methods and Results

cTnT was measured in 2384 consecutive patients (60±21 years, 52% female) on ED admission. Readmissions to the ED (n=720) and mortality (n=101) were followed for an average period of 239±49 days. There were 53 AMIs (delay, 1 to 96 hours; median, 3 hours), 440 chest pain patients, 286 dyspnea patients, 785 acute or chronic cardiac diseases, and 540 neurological diseases, with the remaining having various internal diseases. The diagnostic performances of hs‐ and standard cTnT were comparable for AMI diagnosis (area under receiver operating characteristics curves [ROC AUC], 0.91±0.02 versus 0.90±0.03; P=0.31). Using the 99th‐percentile cutoff, the sensitivities and specificities for AMI in the whole population were 91% and 74% for hs‐cTnT and 89% and 80% for standard cTnT. hs‐cTnT detected significantly more patients with cardiac diseases (ROC AUC, 0.77±0.01 versus 0.67±0.01; P<0.001). hs‐cTnT and standard cTnT were significant predictors of ED readmissions but not of mortality, but both were not independent predictors of ED readmissions or the combined end point of readmission or mortality in binary logistic regression analysis.

Conclusions

In unselected ED patients the diagnostic performances of hs‐cTnT and standard cTnT for AMI diagnosis did not differ significantly. hs‐cTnT detected significantly more cardiac diseases. hs‐cTnT and standard cTnT were not independent predictors of ED readmissions and mortality from all causes.

Prognostic value of TNF-related apoptosis inducing ligand (TRAIL) in acute coronary syndrome patients

BACKGROUND

Apoptosis plays an important role in the development of heart failure. The aim of the prospectively designed study was to assess whether the concentration of apoptotic markers apoptosis-stimulating fragment (Fas, CD95/APO-1) and tumor necrosis factor-related apoptosis inducing ligand (TRAIL) can predict prognosis in patients with acute coronary syndromes.

METHODS

The concentrations of soluble Fas and TRAIL were determined in 295 patients with acute coronary syndromes. The status of all patients was evaluated at 6 months. The primary goal was a composite end-point of death and hospitalization for heart failure. The secondary end-points were re-MI, death alone and stroke alone.

RESULTS

During the median follow-up of 6 months, 26 patients experienced the composite end-point. Using multivariate logistic regression, the concentration of TRAIL was the strongest significant and independent predictor of composite end-point (OR 0.11 (95% CI 0.03-0.45), p = 0.002). Low concentration was associated with poor prognosis of patients. Other significant predictors of composite end-point were serum creatinine (OR 7.7 (95% CI 1.1-54.5, p = 0.041) and complete revascularization (OR 0.19 (95% CI 0.05-0.78, p = 0.02). Independent significant predictors of death in the multivariate analysis were the concentration of TRAIL (OR 0.053 (95% CI 0.004-0.744), p = 0.029), older age (OR 1.20 (95% CI 1.02-1.41, p = 0.026) and serum creatinine (OR 15.1 (95% CI 1.56-145.2), p = 0.0193). Re-MI or stroke could not be predicted by any combination of obtained parameters.

CONCLUSIONS

Low concentrations of soluble TRAIL represent a strong predictor of a poor prognosis in patients with acute coronary syndrome. The predictive value of TRAIL concentration is independent of age, ejection fraction, index peak troponin level, concentration of BNP or serum creatinine.