Stress biomarker changes following a series of repeated static and dynamic apneas in non-divers

PURPOSE

This study examined the magnitude of physiological strain imposed by repeated maximal static and dynamic apneas through assessing a panel of stress-related biomarkers.

METHODS

Eleven healthy men performed on three separate occasions (≥72-h apart): a series of five repeated maximal (i) static (STA) or (ii) dynamic apneas (DYN) or (iii) a static eupneic protocol (CTL). Venous blood samples were drawn at 30, 90, and 180-min after each protocol to determine ischaemia modified albumin (IMA), neuron-specific enolase (NSE), myoglobin, and high sensitivity cardiac troponin T (hscTnT) concentrations.

RESULTS

IMA was elevated after the apnoeic interventions (STA,+86%;DYN,+332%,p ≤ 0.047) but not CTL (p = 0.385). Myoglobin was higher than baseline (23.6 ± 3.9 ng/mL) 30-min post DYN (+70%,38.8 ± 13.3 ng/mL,p = 0.030). A greater myoglobin release was recorded in DYN compared with STA and CTL (p ≤ 0.035). No changes were observed in NSE (p = 0.207) or hscTnT (p = 0.274).

CONCLUSIONS

Five repeated maximal DYN led to a greater muscle injury compared with STA but neither elicited myocardial injury or neuronal-parenchymal damage.

Implementation of high sensitivity troponin into routine clinical practice - results of the extended CARdiac MArkers guideline uptake in Europe group (CARMAGUE) survey

BACKGROUND

Measurement of cardiac troponin (cTn) by a high sensitivity method is now the recommended strategy for the detection of myocardial injury. An international survey was undertaken to assess how this has been implemented.

METHODS

A questionnaire based around 14 domains on cardiac biomarkers was distributed electronically with the aid of professional societies accessed by a web link within the invitation. Results were returned electronically then extracted into a relational database for analysis.

RESULTS

Responses were obtained from 663 laboratories across 76 countries ranging from 1 to 69 largest country. The majority of responses (79.6%) came from the European area. Responses were grouped into broad geographic areas for analysis. Most responses came from hospitals providing a local and regional service of which the majority provided angioplasty. cTn measurement was the dominant biomarker. The majority of laboratories include creatine kinase (CK) in their cardiac profile and approximately 50% also offer the MB isoenzyme of CK. The majority of laboratories (91.9%) measure cTn by a high sensitivity method. Sex specific reference ranges were typically implemented for cardiac troponin I but not for cardiac troponin T. The preferred unit of measurement was nanograms/L. A structured decision-making pathway utilising high sensitivity cTn measurement was used by 83.3% of laboratories who responded. Single sample rule out is common but the majority used serial sampling strategy based on measurement on admission and three hours.

CONCLUSIONS

Measurement of cTn by a high sensitivity method is now well established internationally, the use of rapid diagnostic protocols lags behind.

Comparison of the clinical chemistry score to other biomarker algorithms for rapid rule-out of acute myocardial infarction and risk stratification in patients with suspected acute coronary syndrome

BACKGROUND

The clinical chemistry score (CCS) comprising high-sensitivity cardiac troponins (hs-cTn), glucose and estimated glomerular filtration rate has been previously validated with superior accuracy for detection and risk stratification of acute myocardial infarction (AMI) compared to hs-cTn alone.

METHODS

The CCS was compared to other biomarker-based algorithms for rapid rule-out and prognostication of AMI including the hs-cTnT limit-of-blank (LOB, <3 ng/L) or limit-of-detection (LOD, <5 ng/L) and a dual marker strategy (DMS) (copeptin <10 pmol/L and hs-cTnT ≤14 ng/L) in 1506 emergency department (ED) patients with symptoms suggestive of acute coronary syndrome. Negative predictive values (NPV) and sensitivities for AMI rule-out, and 12-month combined endpoint rates encompassing mortality, myocardial re-infarction, as well as stroke were assessed.

RESULTS

NPVs of 100% (95% CI: 98.3-100%) were observed for CCS = 0, hs-cTnT LoB and hs-cTnT LoD with rule-out efficacies of 11.1%, 7.6% and 18.3% as well as specificities of 13.0% (95% CI: 9.9-16.6%), 8.8% (95% CI: 7.3-10.5%) and 21.4% (95% CI: 19.2-23.8%), respectively. A CCS ≤ 1 achieved a rule-out in 32.2% of all patients with a NPV of 99.6% (95% CI: 98.4-99.9%) and specificity of 37.4% (95% CI: 34.2-40.5%) compared to a rule-out efficacy of 51.2%, NPV of 99.0 (95% CI: 98.0-99.5) and specificity of 59.7% (95% CI: 57.0-62.4%) for the DMS. Rates of the combined end-point of death/AMI within 30 days ranged between 0.0% and 0.7% for all fast-rule-out protocols.

CONCLUSIONS

The CCS ensures reliable AMI rule-out with low short and long-term outcome rates for a specific ED patient subset. However, compared to a single or dual biomarker strategy, the CCS displays reduced efficacy and specificity, limiting its clinical utility.

Auxiliary roles of nardilysin in the early diagnosis of acute coronary syndrome: a prospective cohort study, the Nardi-ACS study

Acute coronary syndrome (ACS) includes myocardial infarction (MI) and unstable angina (UA). MI is defined by elevated necrosis markers, preferably high-sensitivity cardiac troponins (hs-cTn). However, it takes hours for cTn to become elevated after coronary occlusion; therefore, difficulties are associated with diagnosing early post-onset MI or UA. The aim of this prospective cohort study was to examine the diagnostic ability of serum nardilysin (NRDC) for the early detection of ACS. This study consisted of two sequential cohorts, the Phase I cohort, 435 patients presenting to the emergency room (ER) with chest pain, and the Phase II cohort, 486 patients with chest pain who underwent coronary angiography. The final diagnosis was ACS in 155 out of 435 patients (35.6%) in the phase I and 418 out of 486 (86.0%) in the phase II cohort. Among 680 patients who presented within 24 h of onset, 466 patients (68.5%) were diagnosed with ACS. Serum NRDC levels were significantly higher in patients with ACS than in those without ACS. The sensitivity of NRDC in patients who presented within 6 h after the onset was higher than that of hsTnI, and the AUC of NRDC within 1 h of the onset was higher than that of hsTnI (0.718 versus 0.633). Among hsTnI-negative patients (300 of 680 patients: 44.1%), 136 of whom (45.3%) were diagnosed with ACS, the sensitivity and the NPV of NRDC were 73.5 and 65.7%, respectively. When measured in combination with hsTnI, NRDC plays auxiliary roles in the early diagnosis of ACS.

Distribution and prognostic value of high-sensitivity cardiac troponin T and I across glycemic status: a population-based study

BACKGROUND

Whether distributions and prognostic values of high-sensitivity cardiac troponin (hs-cTn) T and I are different across normoglycemic, prediabetic, and diabetic populations is unknown.

METHODS

10127 adult participants from the National Health and Nutrition Examination Survey 1999-2004 with determined glycemic status and measurement of at least one of hs-cTn assays were included, from whom healthy participants and presumably healthy diabetic and prediabetic participants were selected to investigate pure impacts of glycemic status on distributions of hs-cTn. The nonparametric method and bootstrapping were used to derive the 99th upper reference limits of hs-cTn and 95% CI. Participants with available follow-up and hs-cTn concentrations of all 4 assays were included in prognostic analyses. Associations of hs-cTn with all-cause and cardiac-specific mortality were modeled by Cox proportional hazard regression under the complex survey design. The incremental value of hs-cTn to an established risk score in predicting cardiac-specific mortality was assessed by the 10-year area under time-dependent receiver operating characteristic curve (AUC) using the Fine-Grey competing risk model.

RESULTS

Among 9714 participants included in prognostic analyses, 5946 (61.2%) were normoglycemic, 2172 (22.4%) prediabetic, and 1596 (16.4%) diabetic. Hyperglycemic populations were older than the normoglycemic population but sex and race/ethnicity were similar. During the median follow-up of 16.8 years, hs-cTnT and hs-cTnI were independently associated with all-cause and cardiac-specific mortality across glycemic status. In the diabetic population, adjusted hazard ratios per 1-standard deviation increase of log-transformed hs-cTnT and hs-cTnI (Abbott) concentrations were 1.77 (95% CI 1.48-2.12; P < .001) and 1.83 (95% CI 1.33-2.53; P < .001), respectively, regarding cardiac-specific mortality. In the diabetic but not the normoglycemic population, adding either hs-cTnT (difference in AUC: 0.062; 95% CI 0.038-0.086; P < 0.001) or hs-cTnI (Abbott) (difference in AUC: 0.071; 95% CI 0.046-0.097; P < 0.001) would significantly increase the discriminative ability of the risk score; AUC of the score combined with hs-cTnT would be further improved by incorporating hs-cTnI (0.018; 95%CI 0.006-0.029; P = 0.002). The 99th percentile of hs-cTnT of the presumably healthy diabetic population was higher than the healthy population and had no overlap in 95% CIs, however, for hs-cTnI 99th percentiles of the two populations were very close and 95% CIs extensively overlapped.

CONCLUSIONS

Hs-cTnT and hs-cTnI demonstrated consistent prognostic associations across glycemic status but incremental predictive values in hyperglycemic populations only. The susceptibility of hs-cTnT 99th percentiles to diabetes plus the additive value of hs-cTnI to hs-cTnT in diabetic cardiovascular risk stratification suggested hs-cTnI and hs-cTnT may be differentially associated with glycemic status, but further research is needed to illustrate the interaction between hyperglycemia and hs-cTn.

Antibody-functionalized gold nanoclusters/gold nanoparticle platform for the fluorescence turn-on detection of cardiac troponin I

A selective fluorescence turn-on immunosensor for the specific detection of cardiac troponin I (cTnI), the potent biomarker for myocardial infarction diagnosis, was developed with a nano couple comprised of protein-stabilized gold nanocluster and gold nanoparticle. The red fluorescence of cTnI-specific antibody tagged bovine serum albumin stabilized gold nanoclusters was quenched with gold nanoparticles (AuNP) via the intensive interaction between amine and hydroxyl functionalities of BSA and AuNP. Through this, the adsorption of gold nanoclusters at the surface of AuNP, resulting in a core-satellite assembly, was assumed to quench the fluorescence emission. While in the presence of cTnI antigen, this gets disturbed due to the formation of immunocomplex between cTnI antigen and antibody, which restricts the close interaction between gold clusters and nanoparticles, thereby restoring quenched fluorescence. The enhancement in fluorescence signal is directly related to the concentration of cTnI, and this facilitates the selective detection of cTnI in the linear concentration range 0.7 to 10 ng/mL without any interference from other potentially interfering co-existing biomolecules. An appreciable limit of detection of 0.51 ng/mL and a limit of quantification of 0.917 ng/mL for cTnI is comparable to that of the previous report.

European Association of Cardio-Thoracic Surgery (EACTS) expert consensus statement on perioperative myocardial infarction after cardiac surgery

Cardiac surgery may lead to myocardial damage and release of cardiac biomarkers through various mechanisms such as cardiac manipulation, systemic inflammation, myocardial hypoxia, cardioplegic arrest and ischaemia caused by coronary or graft occlusion. Defining perioperative myocardial infarction (PMI) after cardiac surgery presents challenges, and the association between the current PMI definitions and postoperative outcomes remains uncertain. To address these challenges, the European Association of Cardio-Thoracic Surgery (EACTS) facilitated collaboration among a multidisciplinary group to evaluate the existing evidence on the mechanisms, diagnosis and prognostic implications of PMI after cardiac surgery. The review found that the postoperative troponin value thresholds associated with an increased risk of mortality are markedly higher than those proposed by all the current definitions of PMI. Additionally, it was found that large postoperative increases in cardiac biomarkers are prognostically relevant even in absence of additional supportive signs of ischaemia. A new algorithm for PMI detection after cardiac surgery was also proposed, and a consensus was reached within the group that establishing a prognostically relevant definition of PMI is critically needed in the cardiovascular field and that PMI should be included in the primary composite outcome of coronary intervention trials.

Sex-related differences in non-ischemic myocardial injury in the emergency department: A real-world perspective

BACKGROUND

Myocardial injury is associated with adverse outcomes. No data are reported about sex differences in incidence and factors associated with myocardial injury in an emergency department (ED) setting from a real-world perspective. We aimed to assess whether sex plays a major role in the diagnosis of myocardial injury in the ED.

METHODS

In this subanalysis of a retrospective study, patients presenting at the ED with at least one high-sensitivity cardiac troponin T (hs-cTnT) value and without acute coronary syndromes diagnosis were compared.

RESULTS

31,383 patients were admitted to the ED, 4660 had one hs-cTnT value, and 3937 were enrolled: 1943 females (49.4%) and 1994 males (50.6%). The diagnosis of myocardial injury was higher among men (36.8% vs. 32.9%, p < 0.01). Male sex was independently associated with myocardial injury. An older age, an elevated NT-proB-type Natriuretic Peptide and a lower estimated glomerular filtrate rate were independently associated with myocardial injury in both sexes.

CONCLUSIONS

In the ED, from a real-world perspective, myocardial injury occurred more frequently in males, and it was associated with older age and the presence of cardiac, lung, and kidney disease but not higher hs-cTnT values.

The liver-heart axis in patients with severe obesity: The association between liver fibrosis and chronic myocardial injury may be explained by shared risk factors of cardiovascular disease

BACKGROUND

Severe obesity is associated with increased risk of non-alcoholic fatty liver disease and cardiovascular disease. We hypothesized that liver fibrosis as quantified by the Enhanced Liver Fibrosis (ELF) test would be predictive of myocardial injury and fibrosis, expressed by higher concentrations of cardiac troponin T and I measured by high-sensitivity assays (hs-cTnT and hs-cTnI, respectively).

MATERIAL AND METHODS

We performed cross-sectional analyses of baseline data from 136 patients (mean age 45 years, 38 % male) with severe obesity participating in the non-randomized clinical trial Prevention of Coronary Heart Disease in Morbidly Obese Patients (ClinicalTrials.gov NCT00626964). Associations between ELF scores, hs-cTnT, and hs-cTnI concentrations were assessed using linear regression analysis.

RESULTS

ELF scores were associated with hs-cTnT in the unadjusted model (B 0.381, 95 % Confidence Interval [CI] 0.247, 0.514), but the association was attenuated upon adjustment for potential confounders (B -0.031, 95 % CI -0.155, 0.093). Similarly, for hs-cTnI, an observed association with ELF scores in the unadjusted model was attenuated upon adjustment for potential confounders ((B 0.432, 95 % CI 0.179, 0.685) and (B 0.069, 95 % CI -0.230, 0.367), respectively). Age, sex, hypertension, and estimated glomerular filtration rate were amongst the shared predictors of ELF score, hs-cTnT, and hs-cTnI that provided the univariable models with the highest R-squared and lowest Akaike Information Criterion values.

CONCLUSIONS

Contrary to our hypothesis, ELF score did not predict myocardial injury and fibrosis, but we rather demonstrated an association between liver fibrosis and myocardial injury and fibrosis may be explained by shared risk factors of cardiovascular disease.

Clinical Value of Troponin Levels to Cardiac Function and Prognosis in Patients with Fulminant Myocarditis

Troponin (Tn) is a biomarker related to myocardial necrosis and is elevated in patients with myocarditis. This study aimed to investigate the association between cardiac Tn levels and the course of cardiac function, and prognosis in patients with fulminant myocarditis (FM) receiving percutaneous mechanical circulatory support (MCS).We used data from a multicenter retrospective registry, CHANGE PUMP 2, which included 216 patients with FM who required MCS. Among them, 141 patients whose Tn levels were available were analyzed. The patients were divided into low and high Tn groups according to the median values of TnT and TnI.The median age was 54 years, and 59.6% were male. The TnT and TnI on day 1 (at MCS initiation) were 3.8 (1.4-10.0) and 21.4 (8.4-68.8) ng/mL. While the left ventricular ejection fraction (LVEF) was similar on day 1 (25.0% versus 24.5%), the low Tn group showed better LVEF improvement on day 7 than the high Tn group (45.0% versus 25.3%, P < 0.001). LVEF at 1 year after admission was higher in the low Tn group (65.0% versus 59.7%, P = 0.039). The low Tn group had a better 90-day composite endpoint in death, durable left ventricular assist device implantation, and heart transplantation compared to the high Tn group (hazard ratio 0.47, 95% CI 0.23-0.95).Tn levels were associated with short- and long-term cardiac recovery and adverse outcomes in patients with FM receiving MCS due to cardiogenic shock.

Prognostic value of high-sensitivity cardiac troponin in non-cardiac surgical patients in intensive care units

Type II myocardial injury following surgical procedures is associated with adverse outcomes. The prognostic value of high-sensitivity cardiac troponin (hs-cTn) due to type II myocardial injury in surgical patients admitted to intensive care unit (ICU) remains unclear. The aim of this study was to assess prognostic value of hs-cTn in type II acute myocardial injury in non-cardiac surgical patients requiring post-operative ICU admission. Retrospective analysis of patients admitted to two level III ICUs following surgery and had hs-cTn measured on the day of ICU admission. Patients who had type I acute myocardial infarction (AMI) during their admission were excluded from the study. The primary outcome was hospital mortality. Secondary outcomes included ICU mortality, ICU length of stay (LOS) and hospital LOS. A total of 420 patients were included. On univariable analysis, higher hs-cTn was associated with increased hospital mortality (14.6% vs 6.3%, p = 0.008), ICU LOS (41.1 h, vs 25 h, p = 0.004) and hospital LOS (253 h vs 193 h, p = 0.02). On multivariable analysis, hs-cTn was not independently associated with increased risk of hospital mortality. However, in patients who had elective surgery, hs-cTn was associated with increased risk (OR 1.048; 95% CI 1.004-1.094; p = 0.031) of hospital mortality with area under the receiver operating characteristic curve of 0.753 (95% CI 0.598-0.908). In elective surgical patients, hs-cTn was associated with increased risk of mortality. Larger multicentre studies are required to confirm this association that may assist in risk stratification of elective surgical patients requiring ICU admission.

Analytical assays and bootstrap resampling method to validate performance of the Roche Elecsys STAT highly sensitive troponin T assay and its application for the 'rule-out' part of ESC guidelines for NTSTEMI

BACKGROUND

The European Society of Cardiology (ESC) guidelines recommend a dynamic (0-1h) cardiac troponin (cTn) determination for non-ST elevation myocardial infarction diagnosis. For patients with low cTn levels, a discharge from emergency can be considered. Nevertheless, cTn cutoffs for discharge are lower than the limits of quantification proposed by laboratory reagent suppliers.

AIM

Validate cTn assay on the Elecsys STAT kit.

MATERIALS AND METHODS

Precision, trueness, repeatability and within-laboratory variability were calculated from internal quality control and plasma pooled at 5.78 and 10.73 ng/L. Accuracy was calculated from external quality control. Uncertainty of measurement was calculated from (i) the uncertainty of the standard and control values and (ii) by precision from pooled plasma. Distribution of precision results from pooled plasma has been evaluated by bootstrap simulations. Dilution linearity tests with patient plasma were performed to evaluate the method for values near 5 ng/L.

RESULTS

Precision and trueness ranged from 1.35 to 4.45% and from 0.14 to -3.74%, respectively. Accuracy results ranged from 101.40 to 104.90%. Within laboratory variability was 2.91%. Uncertainty ranged from 3.66% to 19.90% for higher (2188) to lower values (5.78 ng/L). Bootstrap simulations allowed utilization of precision data from pooled plasma to evaluate cTn assay. The method was linear from 4.48 to 39.80 ng/L. A linear regression model best described the data.

CONCLUSION

Elecsys STAT method provides accurate cTn results, including patients with cTn results categorizing them as 'rule-out' in the ESC guidelines.

Postoperative elevated cardiac troponin levels predict all-cause mortality and major adverse cardiovascular events following noncardiac surgery: A dose-response meta-analysis of prospective studies

STUDY OBJECTIVE

To perform a dose-response meta-analysis for the association between postoperative myocardial injury (PMI) in noncardiac surgery and the risk of all-cause mortality or major adverse cardiovascular event (MACE).

DESIGN

Dose-response meta-analysis of prospective studies with weighted (WL) or generalized (GL) linear and restricted cubic spline (RCS) regression.

SETTING

Teaching hospitals.

PATIENTS

Adult patients undergoing noncardiac surgery.

INTERVENTIONS

No.

MEASUREMENTS

The primary outcome was all-cause mortality. The secondary outcome was MACE.

MAIN RESULTS

29 studies (53,518 patients) were included. The overall incidence of PMI was 26.0% (95% CI 21.0% to 32.0%). Compared to those without PMI, patients with PMI had an increased risk of all-cause mortality at short- (<12 months) (cardiac troponin[cTn]I: unadj OR 1.71,95%CI 1.22 to 2.41, P < 0.001; cTnT: unadj OR 2.33,95%CI 2.07 to 2.63, P < 0.001), and long-term (≥ 12 months) (cTnI: unadj OR 1.80, 95%CI 1.63 to 1.99; cTnT: unadj OR 1.47,95%CI 1.33 to 1.62) (All P < 0.001) follow-up. For MACE, the group with elevated values was associated with an increased risk (cTnI: unadj OR 1.98, 95% CI 1.13 to 3.47, P = 0.018; cTnT: unadj OR 2.29, 95% CI 1.88 to 2.79, P < 0.001). Dose-response analysis showed positive associations between PMI (per 1× upper reference limit[URL] increment) and all-cause mortality both at short- (unadj OR) (WL, OR 1.09, 95% CI 1.09 to 1.10; GL, OR 1.06, 95% CI 1.06 to 1.07; RCS in the range of 1-2× URL, OR = 2.43, 95%CI 2.25 to 2.62) and long-term follow-up (unadj HR) (WL, OR 1.16, 95% CI 1.14 to 1.17; GL, OR 1.15, 95% CI 1.13 to 1.16; RCS in the range of 1-2.75× URL, OR = 1.23, 95%CI 1.13 to 1.33), and MACE at longest follow-up (unadj OR) (WL: OR 1.53, 95% CI 1.49 to 1.57; GL: OR 1.46, 95% CI 1.42 to 1.50; RCS in the range of 1-2 x URL, OR = 3.10, 95%CI 2.51 to 3.81) (All P < 0.001). For mild cTn increase below URL, the risk of mortality increased with every increment of 0.25xURL (WL, OR 1.03, 95% CI 1.02 to 1.03; GL, OR 1.05, 95% CI 1.03 to 1.07; RCS in the range of 0-0.5 URL, OR = 9.41, 95% CI 7.41 to 11.95) (All P < 0.001).

CONCLUSIONS

This study shows positive WL or GL and RCS dose-response relationships between PMI and all-cause mortality at short (< 12 mons)- and long-term (≥ 12 mons) follow-up, and MACE at longest follow-up. For mild cTn increase below URL, the risk of mortality also increases even with every increment of 0.25× URL.

Chest pain in cardiac amyloidosis: occurrence, causes and prognostic significance

BACKGROUND

Chest pain is experienced by patients with cardiac amyloidosis (CA), but a systematic investigation of its frequency, underlying etiologies and clinical significance is lacking.

METHODS

Clinical, echocardiographic, laboratory characteristics, available coronary arteries imaging and endomyocardial biopsy (EMB) findings of 174 patients with CA (n = 104 with transthyretin, ATTR; n = 70 with light chains, AL) were analyzed.

RESULTS

Chest pain was reported in 66 (38%) CA patients. Compared to those without, patients with chest pain had more frequently a history of coronary artery disease (CAD) (27% vs 15%, p = 0.048) and heart failure (HF) symptoms (62% vs 43%, p = 0.015), higher high sensitivity troponin I (hs-cTnI, 101 vs 65 ng/L, p = 0.032) and higher brain natriuretic peptide (597 vs 407 ng/L, p = 0.024). Among CA patients with chest pain undergoing coronary arteries imaging (n = 37), obstructive CAD was detected in 14 (38%), 13 of whom with ATTR-CA. Of these 37 patients, EMB was available in 10 and vascular/perivascular amyloid deposition was detected in 4/5 (80%) of AL-CA patients and 1/5 ATTR-CA. Among patients with suspected acute coronary syndrome (n = 22), obstructive CAD was detected in 9/17 (53%) ATTR-CA and 0/5 AL-CA; hs-cTnI levels were similar between those with and without obstructive CAD. During a follow-up of 17 (8-34) months, chest pain was a significant predictor of HF hospitalization (HR1.86, 95% CI 1.02-3.39, p = 0.042), even after adjustment for CA subtype and CAD.

CONCLUSION

Chest pain is a common symptom in patients with CA, reflects a more advanced cardiac impairment and predicts future HF hospitalization. The etiology of chest pain seems to differ, with obstructive CAD more frequent in ATTR-CA whilst amyloid vascular/perivascular involvement more common in AL-CA.

Screening and evaluation of TBX20 and CITED2 mutations in children with congenital cardiac septal defects: Correlation with cardiac troponin T and caspase-3

Congenital cardiac septal defect (CCSD) is the main type of congenital heart disease and owns a very high mortality rate among newborns. CCSD is controlled by specific transcription factors, including T-box transcription factor 20 (TBX20) and Cbp/P300 interacting transactivator with Glu/Asp rich carboxy-terminal domain 2 (CITED2) which are key molecular actors in heart development. Here, we screened for mutations in TBX20 and CITED2 genes in Egyptian children with CCSD and assessed their association with CCSD susceptibility and with cardiac troponin T (cTnT) and the apoptotic marker caspase-3 as biochemical markers for CCSD. Thirty unrelated newborns and children affected with CCSD and 30 matched healthy controls with no personal history of cardiac diseases were recruited. Selection criteria were children (<18 years) with any age diagnosed with CCSD using ECHO. Mutational analysis and genotyping were done using PCR-Sanger DNA sequencing technique. Serum cTnT and caspase-3 were analyzed using ELISA. Sequencing analysis identified 2 TBX20 variants (c.766T>C and c.39T>C) in the CCSD and control groups and 2 CITED2 variants (c.12T>C and c.9C>T) in one CCSD patient, while were absent in controls. In silico analysis identified TBX20 c.766T>C (rs3999941) as a missense (F256L) pathogenic variant and the other three variants as synonymous and benign. Compared with controls, TBX20 c.766T>C TC genotype and minor C allele were candidate high-risk factors for CCSD. Besides, serum cTnT and caspase-3 were dramatically elevated in CCSD children compared to controls. TBX20 c.766T>C TC genotype was associated with high cTnT in CCSD children. Conclusively, we advocate TBX20 c.766T>C variant as a potential genetic marker for CCSD which might associate with high cTnT levels. CITED2 genetic variants might have rare incidence among Egyptian CCSD children. Serum cTnT and caspase-3 are useful markers for ascertaining CCSD in children. These data could be exploited in prenatal genetic counseling, pre-implantation genotyping, and therapy of CCSD.

Natriuretic Peptides and Cardiac Troponins: Markers of Disease Progression and Risk in Light Chain Cardiac Amyloidosis

PURPOSE OF REVIEW

Light chain (AL) amyloidosis can cause an infiltrative cardiomyopathy that can result in symptomatic heart failure. The vague, nonspecific onset of signs and symptoms may lead to a delay in diagnosis and treatment leading to poor outcomes. Cardiac biomarkers, such as troponins and natriuretic peptides, play a pivotal role in diagnosis, determining prognosis, and assessing treatment response in patients with AL amyloidosis. Because of the evolving landscape for both diagnosis and treatment of AL cardiac amyloidosis, we review the critical role these and other biomarkers play in the clinical management of this disease.

RECENT FINDINGS

A number of conventional cardiac and noncardiac serum biomarkers are commonly used in AL cardiac amyloidosis and may be surrogates for cardiac involvement and inform prognosis. These include typical heart failure biomarkers such as levels of circulating natriuretic peptides as well as cardiac troponins. Other noncardiac biomarkers frequently measured in AL cardiac amyloidosis included difference between the involved and uninvolved free light chains (dFLC) and markers of endothelial cell activation and damage such as von Willebrand factor antigen and matrix metalloproteinases. AL amyloidosis can lead to cardiac involvement which has been associated with poor outcomes, especially if not identified and treated early. Natriuretic peptides and cardiac troponins are cornerstones for the diagnosis and management of AL cardiac amyloidosis. Their levels may represent cardiac stress, injury, and possibly degree of cardiac involvement, and they play a key role in AL amyloidosis disease staging.

Sex-specific differences in myocardial injury incidence after COVID-19 mRNA-1273 booster vaccination

AIMS

To explore the incidence and potential mechanisms of oligosymptomatic myocardial injury following COVID-19 mRNA booster vaccination.

METHODS AND RESULTS

Hospital employees scheduled to undergo mRNA-1273 booster vaccination were assessed for mRNA-1273 vaccination-associated myocardial injury, defined as acute dynamic increase in high-sensitivity cardiac troponin T (hs-cTnT) concentration above the sex-specific upper limit of normal on day 3 (48-96 h) after vaccination without evidence of an alternative cause. To explore possible mechanisms, antibodies against interleukin-1 receptor antagonist (IL-1RA), the SARS-CoV-2-nucleoprotein (NP) and -spike (S1) proteins and an array of 14 inflammatory cytokines were quantified. Among 777 participants (median age 37 years, 69.5% women), 40 participants (5.1%; 95% confidence interval [CI] 3.7-7.0%) had elevated hs-cTnT concentration on day 3 and mRNA-1273 vaccine-associated myocardial injury was adjudicated in 22 participants (2.8% [95% CI 1.7-4.3%]). Twenty cases occurred in women (3.7% [95% CI 2.3-5.7%]), two in men (0.8% [95% CI 0.1-3.0%]). Hs-cTnT elevations were mild and only temporary. No patient had electrocardiographic changes, and none developed major adverse cardiac events within 30 days (0% [95% CI 0-0.4%]). In the overall booster cohort, hs-cTnT concentrations (day 3; median 5, interquartile range [IQR] 4-6 ng/L) were significantly higher compared to matched controls (n = 777, median 3 [IQR 3-5] ng/L, p < 0.001). Cases had comparable systemic reactogenicity, concentrations of anti-IL-1RA, anti-NP, anti-S1, and markers quantifying systemic inflammation, but lower concentrations of interferon (IFN)-λ1 (IL-29) and granulocyte-macrophage colony-stimulating factor (GM-CSF) versus persons without vaccine-associated myocardial injury.

CONCLUSION

mRNA-1273 vaccine-associated myocardial injury was more common than previously thought, being mild and transient, and more frequent in women versus men. The possible protective role of IFN-λ1 (IL-29) and GM-CSF warrant further studies.

Exercise-induced myocardial T1 increase and right ventricular dysfunction in recreational cyclists: a CMR study

PURPOSE

Although cardiac troponin I (cTnI) increase following strenuous exercise has been observed, the development of exercise-induced myocardial edema remains unclear. Cardiac magnetic resonance (CMR) native T1/T2 mapping is sensitive to the pathological increase of myocardial water content. Therefore, we evaluated exercise-induced acute myocardial changes in recreational cyclists by incorporating biomarkers, echocardiography and CMR.

METHODS

Nineteen male recreational participants (age: 48 ± 5 years) cycled the 'L'étape du tour de France" (EDT) 2021' (175 km, 3600 altimeters). One week before the race, a maximal graded cycling test was conducted to determine individual heart rate (HR) training zones. One day before and 3-6 h post-exercise 3 T CMR and echocardiography were performed to assess myocardial native T1/T2 relaxation times and cardiac function, and blood samples were collected. All participants were asked to cycle 2 h around their anaerobic gas exchange threshold (HR zone 4).

RESULTS

Eighteen participants completed the EDT stage in 537 ± 58 min, including 154 ± 61 min of cycling time in HR zone 4. Post-race right ventricular (RV) dysfunction with reduced strain and increased volumes (p < 0.05) and borderline significant left ventricular global longitudinal strain reduction (p = 0.05) were observed. Post-exercise cTnI (0.75 ± 5.1 ng/l to 69.9 ± 41.6 ng/l; p < 0.001) and T1 relaxation times (1133 ± 48 ms to 1182 ± 46 ms, p < 0.001) increased significantly with no significant change in T2 (p = 0.474). cTnI release correlated with increase in T1 relaxation time (p = 0.002; r = 0.703), post-race RV dysfunction (p < 0.05; r = 0.562) and longer cycling in HR zone 4 (p < 0.05; r = 0.607).

CONCLUSION

Strenuous exercise causes early post-race cTnI increase, increased T1 relaxation time and RV dysfunction in recreational cyclists, which showed interdependent correlation. The long-term clinical significance of these changes needs further investigation.

TRIAL REGISTRATION NUMBERS AND DATE

NCT04940650 06/18/2021. NCT05138003 06/18/2021.

Kinetics of cardiac troponin and other biomarkers in patients with ST elevation myocardial infarction

Objective

To examine changes in concentration, time-to-peak and the ensuing half-life of cardiac biomarkers in patients with myocardial infarction.

Methods

Blood sampling was performed every third hour within 24 h after percutaneous coronary intervention (PCI) on a cohort of patients with ST elevation myocardial infarction. Cardiac troponin (cTn) was measured by the Dimension Vista, Vitros, Atellica, and Alinity high-sensitivity (hs) cTnI assays, and the Elecsys hs-cTnT assay. Further, creatine kinase (CK), myoglobin, creatine kinase MB (CKMB) and other biomarkers were analyzed.

Results

A total of 36 patients completed blood sampling (median age 60 years, IQR 56.4-66.5 years; seven women, 19.4%). Hs-cTnI measured by the Vitros assay was the first hs-cTn to peak at 9.1 h (95%-CI 6.2-10.1) after PCI and 11.7 h (95%-CI 10.4-14.8) after symptoms onset. There were no notable differences between hs-cTn assays in regard to time-to-peak. Also, Vitros hs-cTnI reached the highest median ratio of concentration to upper reference level of nearly 2,000. The median half-life from peak concentration ranged from 7.6 h for myoglobin (CI 6.8-8.6) to 17.8 h for CK (CI 6.8-8.6). For hs-cTn assays the median T½ ranged from 12.4 h for the Vista hs-cTnI assay (95%-CI 11.0-14.1 h) to 17.3 h for the Elecsys hs-cTnT (95%-CI 14.9-20.8 h).

Conclusions

This study updates knowledge on the kinetics of cardiac biomarkers in current clinical use. There was no notable difference in trajectories, time-to-peak or half-life between hs-cTn assays.

Predictive and prognostic value of different cardiac troponin assays: a nationwide register-based cohort study

AIMS

Guidelines do not differentiate between the available assays of cardiac troponin (cTn). We compared the prognostic and predictive ability of cTn assays.

METHODS AND RESULTS

This was a nationwide cohort study of patients with acute coronary syndrome (ACS) and ≥ 2 cTn measurements of one of four assays: Roche high-sensitivity cTnT (hs-cTnT), Abbott high sensitivity cTnI (hs-cTnI), Siemens Vista cTnI, and Siemens cTnI Ultra. Data were collected from Danish registries from 2009-18. Peak cTn concentration normalized to the 99th percentile was used. Outcomes were myocardial infarction (MI) during admission, one-year all-cause-, cardiovascular-, and non-cardiovascular mortality. Receiver operating characteristics and logistic regression calculating odds ratios (OR) were used. A total of 90 705 patients were included, of which 20 550 (23%) had MI. Siemens Vista cTnI was the strongest predictor of MI, Area under the curve (auc) 0.93 (95% CI 0.93-0.93). In 1 year 9012 (9.9%) of patients had died. An inverted U-shape relationship was observed between concentration of cTn and all-cause mortality. Hs-cTnT OR 21.3 (95% CI 18.4-24.8) at 2-5 times the 99th percentile and 12.1 (95% CI 10.3-14.1) for concentrations >100 times the 99th percentile. The inverted U-shape relationship was only present for non-cardiovascular mortality. The strongest predictor of cardiovascular mortality was hs-cTnT, OR 11.3 (95% CI 6.4-21.8) at 1-2 times the 99th percentile and 88.8 (95% CI 53.2-163.0) for concentrations >100 times the 99th percentile.

CONCLUSION

Siemens Vista cTnI was the strongest predictor of MI and hs-cTnT was the strongest predictor of mortality. An inverted U-shape relationship was observed between cTn concentration and non-cardiovascular mortality.

Rifampicin efficacy against doxorubicin-induced cardiotoxicity in mice

BACKGROUND

The toxic effect of doxorubicin on the heart limits its clinical usage in cancer therapy. This work intended to investigate, for the first time, the efficacy of rifampicin administration against doxorubicin-induction of cardiotoxicity in mice. Forty adult male albino mice were distributed into four sets: Control, Doxorubicin, Doxorubicin + Rifampicin 0.107, and Doxorubicin + Rifampicin 0.214, with n = 10 for each. Heart histopathology and biochemical assays for heart function tests [creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), cardiac troponin I (cTnI), atrial natriuretic peptide (ANP), and vascular endothelial growth factor (VEGF)], oxidative stress [malondialdehyde (MDA) and superoxide dismutase (SOD)], and minerals [phosphorus, sodium, potassium, and calcium] were done.

RESULTS

Doxorubicin-induced cardiotoxicity using a total dose of 15 mg/kg was confirmed histologically. Cardiomyocytes showed congestion, necrosis, edema, and inflammatory cell infiltration. Biochemically, elevations in LDH, CK, and AST activities, p < 0.001, as well as increases in cTnI and ANP levels, p < 0.001, increased oxidative stress (MDA, p < 0.001), high minerals (Na, K, p < 0.001, P, p < 0.01, and Ca, p < 0.05), with reduced VEGF concentration, p < 0.001, and low antioxidant (SOD, p < 0.001) were observed in the Doxorubicin group compared to control. Co-treatment with rifampicin significantly (p < 0.001) reduced the increased oxidative stress, high Na and K, increased LDH, CK, AST, cTnI, and ANP, and elevated the low SOD toward the normal ranges. Our histological data supported our biochemical data; rifampicin dose 0.214 mg/kg showed better improvements than dose 0107.

CONCLUSIONS

Our results demonstrated that rifampicin could help protect the body against doxorubicin-induced cardiotoxicity through its antioxidative effect.

Troponin in early presenters to rule out myocardial infarction

AIMS

Whether a single cardiac troponin measurement can safely rule out myocardial infarction in patients presenting within a few hours of symptom onset is uncertain. The study aim was to assess the performance of troponin in early presenters.

METHODS AND RESULTS

In patients with possible myocardial infarction, the diagnostic performance of a single measurement of high-sensitivity cardiac troponin I at presentation was evaluated and externally validated in those tested ≤3, 4-12, and >12 h from symptom onset. The limit-of-detection (2 ng/L), rule-out (5 ng/L), and sex-specific 99th centile (16 ng/L in women; 34 ng/L in men) thresholds were compared. In 41 103 consecutive patients [60 (17) years, 46% women], 12 595 (31%) presented within 3 h, and 3728 (9%) had myocardial infarction. In those presenting ≤3 h, a threshold of 2 ng/L had greater sensitivity and negative predictive value [99.4% (95% confidence interval 99.2%-99.5%) and 99.7% (99.6%-99.8%)] compared with 5 ng/L [96.5% (96.2%-96.8%) and 99.3% (99.1%-99.4%)]. In those presenting ≥3 h, the sensitivity and negative predictive value were similar for both thresholds. The sensitivity of the 99th centile was low in early and late presenters at 71.4% (70.6%-72.2%) and 92.5% (92.0%-93.0%), respectively. Findings were consistent in an external validation cohort of 7088 patients.

CONCLUSION

In early presenters, a single measurement of high-sensitivity cardiac troponin I below the limit of detection may facilitate the safe rule out of myocardial infarction. The 99th centile should not be used to rule out myocardial infarction at presentation even in those presenting later following symptom onset.

Different expression and prognostic value of troponin in ischemic cardiomyopathy and non-ischemic dilated cardiomyopathy

BACKGROUND

Early risk stratification of patients with ischemic cardiomyopathy (ICM) and non-ischemic dilated cardiomyopathy (NIDCM) may be beneficial for therapies.

METHODS

We retrospectively enrolled all patients admitted for acute heart failure (HF) between January 2019 and December 2021 in Zhongshan Hospital Fudan University, dividing them according to etiology (ICM or NIDCM). Cardiac troponin T (TNT) concentration was compared between two groups. Risk factors for positive TNT and in-hospital all-cause mortality were investigated with regression analysis.

RESULTS

A total of 1525 HF patients were enrolled, including 571 ICM and 954 NIDCM. The TNT positive patients were not different between the two groups (41.3% in ICM group vs. 37.8% in NIDCM group, P = 0.215). However, the TNT value in ICM group were significantly higher than that in NIDCM group (0.025 (0.015-0.053) vs. 0.020 (0.014-0.041), P = 0.001). NT-proBNP was independently associated with TNT in both ICM and NIDCM group. Although the in-hospital all-cause mortality did not show much difference between the two groups (1.1% vs. 1.9%, P = 0.204), the NIDCM diagnosis was associated with reduced risk of mortality after multiple adjustments (OR 0.169, 95% CI 0.040-0.718, P = 0.016). Other independent risk factors included the level of NT-proBNP (OR 8.260, 95% CI 3.168-21.533, P < 0.001), TNT (OR 8.118, 95% CI 3.205-20.562, P < 0.001), and anemia (OR 0.954, 95% CI 0.931-0.978, P < 0.001). The predictive value of TNT and NT-proBNP for all-cause mortality was similar. However, the best cutoff values of TNT for mortality were different between ICM and NIDCM groups, which were 0.113 ng/mL and 0.048 ng/mL, respectively.

CONCLUSION

The TNT level was higher in ICM patient than that in NIDCM patients. TNT was an independent risk factor for in-hospital all-cause mortality for both ICM and NIDCM patients, although the best cutoff value was higher in ICM patients.

Trajectories of cardiac troponin in the decades before cardiovascular death: a longitudinal cohort study

BACKGROUND

High-sensitivity cardiac troponin testing is a promising tool for cardiovascular risk prediction, but whether serial testing can dynamically predict risk is uncertain. We evaluated the trajectory of cardiac troponin I in the years prior to a cardiovascular event in the general population, and determine whether serial measurements could track risk within individuals.

METHODS

In the Whitehall II cohort, high-sensitivity cardiac troponin I concentrations were measured on three occasions over a 15-year period. Time trajectories of troponin were constructed in those who died from cardiovascular disease compared to those who survived or died from other causes during follow up and these were externally validated in the HUNT Study. A joint model that adjusts for cardiovascular risk factors was used to estimate risk of cardiovascular death using serial troponin measurements.

RESULTS

In 7,293 individuals (mean 58 ± 7 years, 29.4% women) cardiovascular and non-cardiovascular death occurred in 281 (3.9%) and 914 (12.5%) individuals (median follow-up 21.4 years), respectively. Troponin concentrations increased in those dying from cardiovascular disease with a steeper trajectory compared to those surviving or dying from other causes in Whitehall and HUNT (Pinteraction < 0.05 for both). The joint model demonstrated an independent association between temporal evolution of troponin and risk of cardiovascular death (HR per doubling, 1.45, 95% CI,1.33-1.75).

CONCLUSIONS

Cardiac troponin I concentrations increased in those dying from cardiovascular disease compared to those surviving or dying from other causes over the preceding decades. Serial cardiac troponin testing in the general population has potential to track future cardiovascular risk.

Prognostic value of cardiac troponin in elderly patients with paroxysmal supraventricular tachycardia: A multicenter study

BACKGROUND

An elevated level of cardiac troponin I (cTnI) frequently accompanies an episode of supraventricular tachycardia (SVT). However, the predictive value of cTnI in elderly SVT patients has not been examined.

METHODS

We collected the electronic medical records of elderly SVT patients (over 65 years old) who visited four Taiwanese emergency departments over a 2-year period. The patients who underwent cTnI testing were included in the cohort and further categorized based on their cTnI results (positive or negative). The study's primary outcomes were the 5-year risks of major adverse cardiovascular events (MACE) and SVT recurrence.

RESULTS

One hundred and twenty-four patients met the inclusion criteria. Of these patients, 39 (31.5%) had a positive cTnI result, and 85 (68.5%) had a negative cTnI result. Patients with a positive cTnI result were older (p = 0.029) and had a longer hospital stay (p = 0.023) than those with a negative cTnI result. Multivariate analysis showed that age > 75 years (OR = 2.41; 95% CI 1.07-5.45; p = 0.034) was an independent predictor for cTnI elevation. In the survival analysis, no difference in the incidence of five-year MACE (p = 0.656) was observed between the cTnI-positive and cTnI-negative groups. Multivariate analysis revealed that a history of coronary artery disease was the only significant independent risk factor for MACE (HR = 4.30; 95% 95% CI 1.41-13.05; p = 0.010). For SVT recurrence, the multivariate analysis revealed that previous SVT (HR = 3.37; 95% CI 1.53-7.39; p = 0.002), smoking history (HR = 2.32; 95% CI 1.03-5.24; p = 0.043), and RFA treatment (HR = 0.20; 95% CI 0.06-0.65; p = 0.008) were significant independent predictors.

CONCLUSIONS

An increased cardiac troponin level may not effectively indicate the risk of MACE in elderly SVT patients. Physicians might want to be cautious when interpreting troponin test results for this specific patient group.

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).

Retrospective analysis of intra-patient laboratory variation demonstrates that the BD Vacutainer® Barricor™ blood collection tube reduces troponin variation

OBJECTIVE

The BD Vacutainer® Barricor™ plasma blood collection tube uses a mechanical separator during centrifugation to separate plasma from the cellular elements of blood. Compared to use of plasma separator tubes (PST™) with gel, Barricor™ produces a cleaner sample with less residual cellular content. We sought to determine if Barricor™ reduces pre-analytical error compared to PST™.

DESIGN & METHODS

We used a model previously published that utilizes serial differences between intra-patient measurements transformed into a Taylor series of variation vs time with the y-intercept equal to the sum of short-term analytic variation, preanalytic variation and biologic variation. The intra-patient variation of chloride, sodium, potassium, and troponin-T (hs-TnT) obtained from the Emergency Department of a large tertiary care center sampled with PST™ (May 2015-April 2018, n = 59,762 specimens) or Barricor™ (May 2018-May 2021, n = 61,512 specimens) was evaluated. All specimens were analyzed on either Roche Modular or Cobas® instruments. For each analyte, pairs of intra-patient results were tabulated and separated by 1 h intervals. The average between-pair variations were then regressed against time. We also determined the number of intra-patient outliers using the reference change value for each analyte.

RESULTS

The Barricor™ hs-TnT y-intercept (-0.0132) was significantly lower than the PST™ intercept (0.9109; p = 0.022). This was also true for chloride (y-intercept = 1.0067 in Barricor™ and 1.3431 in PST™, p = 0.037). The percentage of hs-TnT outliers was significantly lower in Barricor™ (8.32 %) vs PST™ (12.2 %; p < 0.001).

CONCLUSION

The analytical and biological variations are assumed to be steady over the study periods; we ascribe the difference in the y-intercept to the preanalytical effect of the Barricor™ tube reducing platelets and other cellular debris.

Use and Prognostic Implications of Cardiac Troponin in COVID-19

Myocardial injury is common in patients with COVID-19 and is associated with an adverse prognosis. Cardiac troponin (cTn) is used to detect myocardial injury and assist with risk stratification in this population. SARS-CoV-2 infection can play a role in the pathogenesis of acute myocardial injury due to both direct and indirect damage to the cardiovascular system. Despite the initial concerns about an increased incidence of acute myocardial infarction (MI), most cTn increases are related to chronic myocardial injury due to comorbidities and/or acute nonischemic myocardial injury. This review will discuss the latest findings on this topic.

Sex differences in myocardial injury after non-cardiac surgery and postoperative mortality

BACKGROUND

Myocardial injury after non-cardiac surgery (MINS) has recently been accepted as a predictor of mortality. However, sex differences in the incidence of MINS and survival thereafter are not fully understood. This study aimed to compare the incidence of MINS and mortality among male and female patients.

METHODS

This single-center study was conducted using the database of a large tertiary referral hospital. Consecutive patients with cardiac troponin (cTn) detected within 30 days after non-cardiac surgery performed between January 2010 and June 2019 were grouped according to sex. The incidence of MINS and mortality of patients with MINS were compared between men and women.

RESULTS

Of the 33,311 patients, 18,546 (55.7%) were men and 14,765 (44.3%) were women. In a multivariable analysis, women showed a significantly lower incidence of MINS than did men (17.9% vs. 14.2%; odds ratio, 0.76; 95% confidence interval [CI], 0.71-0.81; P < 0.001). In patients with MINS, the propensity-score-matched analysis showed that 30-day mortality did not differ according to sex, but mortality in females was significantly lower than that in males during the overall follow-up (33.0% vs. 25.7%; hazard ratio, 0.75; 95% CI, 0.66-0.84; P < 0.001).

CONCLUSION

The incidence of MINS was lower in women than in men. In patients with MINS, female sex may be associated with a survival benefit. Further studies are needed to confirm these findings.

Methods for analyzing positive cardiac troponin assay interference

OBJECTIVES

The cardiac damage biomarkers cardiac troponin T (cTnT) and troponin I (cTnI) are used to identify patients with myocardial infarction (MI). To make the correct clinical decisions it is important to identify false positive results due to troponin assay interference. Often interferences are caused by high-molecular weight immunocomplexes called macrotroponin that may result in false troponin elevations because of delayed troponin clearance, or heterophilic antibodies that crosslink troponin assay antibodies and generate troponin-independent signals.

DESIGN & METHODS

We describe and compare four methods for cTnI assay interference analysis using a protein G spin column method, gel filtration chromatography and two versions of a sucrose gradient ultracentrifugation for cTnI assay interference analysis on five patients with confirmed cTnI interference and one MI patient without cTnI interference from our troponin interference referral center.

RESULTS

The protein G spin column method had a high between run variability but was still able to identify all five patients with cTnI interference. The sucrose gradient ultracentrifugation methods and the gel filtration method had simlar performancec and correctly identified the immunocomplexes that caused the cTnI interference.

CONCLUSIONS

Our experience is that these methods are sufficient to safely confirm or exclude positive cTnI assay interference.

Evaluations of coronary microvascular dysfunction in a patient with thrombotic microangiopathy and cardiac troponin elevation: a case report

Background

Thrombotic microangiopathy (TMA) syndromes include thrombotic thrombocytopenic purpura (TTP) and haemolytic uremic syndrome, and contribute to myocardial infarction and multiple organ failure. Although coronary microvascular dysfunction (CMD) is the key for understanding the pathophysiology of cardiac involvement in TMA, there is limited knowledge on the recovery from CMD in patients with TMA.

Case summary

An 80-year-old woman was brought to the emergency department due to worsening back pain, dyspnoea on exertion, jaundice, and fever. Although she had typical TTP symptoms and elevated cardiac troponin level, ADAMTS13 activity was preserved (34%), leading to the diagnosis of TMA with myocardial infarction. She underwent plasma exchange and was administered aspirin and prednisolone. Magnetic resonance imaging revealed iliopsoas abscess, which is a possible aetiologic factor of sepsis-related TTP. She had impaired coronary flow reserve (CFR) with angiographically non-obstructive epicardial coronary arteries. Improved CFR was observed on follow-up, suggesting existence of transient CMD caused by TMA. After treatment of the iliopsoas abscess with antibiotics for 3 months, she was discharged without any adverse complications.

Discussion

Coronary microvascular dysfunction is an underlying mechanism of myocardial infarction, with or without epicardial obstructive coronary artery stenosis. TMA is characterized by pathological lesions caused by endothelial cell damage in small terminal arteries and capillaries, with complete or partial occlusion caused by platelet and hyaline thrombi. CMD and its recovery are keys for understanding the natural history of cardiac involvement in TMA. In vivo evaluations of CMD can provide mechanistic insights into the cardiac involvement in TMA.

Differences between cardiac Troponin I versus T according to the duration of myocardial ischemia

BACKGROUND

Cardiac troponin T (cTnT) and troponin I (cTnI) are expressed as an obligate 1:1 complex in the myocardium. However, blood levels of cTnI often rise much higher than cTnT in myocardial infarction (MI), whereas cTnT is often higher in patients with stable conditions such as atrial fibrillation. Here we examine hs-cTnI and hs-cTnT after different durations of experimental cardiac ischemia.

METHODS

hs-cTnI, hs-cTnT, and the hs-cTnT/hs-cTnI ratio were measured in plasma samples from rats before and at 30 and 120 minutes after 5, 10, 15, and 30 minutes of myocardial ischemia. The animals were killed after 120 minutes of reperfusion, and the infarct volume and volume at risk were measured. hs-cTnI, hs-cTnT, and the hs-cTnT/hs-cTnI ratio were also measured in plasma samples collected from patients with ST-elevation myocardial infarction.

RESULTS

hs-cTnT and hs-cTnI increased over ten-fold in all rats subjected to ischemia. The increase of hs-cTnI and hs-cTnT after 30 minutes was similar, resulting in a hs-cTnI/hs-cTnT ratio around 1. The hs-cTnI/hs-cTnT ratio was also around 1 in blood samples collected at 120 minutes in rats subjected to 5 or 10 minutes of ischemia where no localized necrosis was observed. In contrast, the hs-cTnI/hs-cTnT ratio at 2 hours was 3.6-5.5 after longer ischemia that induced cardiac necrosis. The large hs-cTnI/hs-cTnT ratio was confirmed in patients with anterior STEMI.

CONCLUSION

Both hs-cTnI and hs-cTnT increased similarly after brief periods of ischemia that did not cause overt necrosis, whereas the hs-cTnI/hs-cTnT ratio tended to increase following longer ischemia that induced substantial necrosis. A low hs-cTnI/hs-cTnT ratio around 1 may signify non-necrotic cTn release.

High-Sensitivity Cardiac Troponin T and Cognitive Decline in Older Adults: Results of the Berlin Aging Study II

INTRODUCTION

There is evidence of an association between markers of cardiac injury and cognition in patients with cardiovascular disease. We hypothesized that levels of high-sensitivity cardiac troponin T (hs-cTnT) are associated with cognitive performance and cognitive decline in a population of predominantly healthy older adults.

METHODS

We included 1,226 predominantly healthy adults ≥60 years from the Berlin Aging Study II. Participants were recruited from the general population of the Berlin metropolitan area from 2009 to 2014. At baseline, participants underwent measurement of hs-cTnT and cognitive testing using the extended Consortium to Establish a Registry for Alzheimer's Disease (CERAD-Plus) battery. In addition, the Digit Symbol Substitution Test (DSST) was performed at baseline and at follow-up (7.3 ± 1.4 years after the baseline visit). The CERAD test results were summarized into four cognitive domains (processing speed, executive function, visuo-construction, and memory). After summing-up the respective raw scores, we calculated standardized z scores. We performed unadjusted and adjusted linear regression models to assess links between hs-cTnT and cognitive domains. We used linear mixed models to analyze associations between hs-cTnT and cognitive decline according to changes in DSST scores over time.

RESULTS

The mean age of study participants at baseline was 68.5 (±3.6) years, 49% were female, and median hs-cTnT levels were 6 ng/L (IQR 4-8 ng/L). We detected no significant association between hs-cTnT and different cognitive domains at baseline after adjustment for age, sex, education, and cardiovascular risk factors. Hs-cTnT was associated with cognitive decline, which remained statistically significant after full adjustment (adjusted beta-coefficient -0.82 (-1.28 to -0.36), p = 0.001). After stratification for sex, the association with hs-cTnT remained statistically significant in men but not in women.

CONCLUSION

Higher hs-cTnT levels in older men are associated with cognitive decline measured with the DSST.

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.

Copeptin with high-sensitivity cardiac troponin to rule out non-ST-elevation myocardial infarction early on: A systematic review and meta-analysis

High-sensitivity cardiac troponin (hs-cTn) with copeptin in rapidly ruling out non-ST-elevation myocardial infarction (NSTEMI) remains controversial. We aimed to evaluate the diagnostic accuracy of this combination compared to hs-cTn alone. A literature search of electronic databases was performed from inception to 26 March 2022. Primary studies that evaluated the diagnostic accuracy of hs-cTn with and without copeptin in patients with NSTEMI were eligible. The reference standard consisted of all available medical results, including a significant rise or fall of cTn with at least one value above the 99th percentile of the reference population. The QUality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used to assess the quality of the included studies. Thirteen studies involving 8,966 patients, 1,405 of whom were diagnosed with NSTEMI (prevalence, 15.67 %), were included. Combining copeptin with hs-cTn (99th percentile of the healthy population as the threshold) at admission improved the sensitivity from 0.89 to 0.96 (95 % confidence interval [CI] 0.84-0.93 vs 0.93-0.98); the specificity reduced from 0.79 to 0.56 (95 % CI 0.71-0.86 vs 0.51-0.60). In five studies with 6,073 participants (900 NSTEMI), the hs-cTn alone (with 'very low' or limit of detection [LoD] threshold) had higher diagnostic sensitivity than the dual-marker strategy (0.98 vs 0.96). Combining copeptin with hs-cTn (99th percentile of the population as the threshold) at admission improved sensitivity in NSTEMI identification at the expense of specificity. However, with the LoD threshold for hs-cTn, copeptin had no additional value, deterring the widespread use of copeptin if the hs-cTn assay is clinically available.

Cardiac troponin release following coronary artery bypass grafting: mechanisms and clinical implications

The use of biomarkers is undisputed in the diagnosis of primary myocardial infarction (MI), but their value for identifying MI is less well studied in the postoperative phase following coronary artery bypass grafting (CABG). To identify patients with periprocedural MI (PMI), several conflicting definitions of PMI have been proposed, relying either on cardiac troponin (cTn) or the MB isoenzyme of creatine kinase, with or without supporting evidence of ischaemia. However, CABG inherently induces the release of cardiac biomarkers, as reflected by significant cTn concentrations in patients with uncomplicated postoperative courses. Still, the underlying (patho)physiological release mechanisms of cTn are incompletely understood, complicating adequate interpretation of postoperative increases in cTn concentrations. Therefore, the aim of the current review is to present these potential underlying mechanisms of cTn release in general, and following CABG in particular (Graphical Abstract). Based on these mechanisms, dissimilarities in the release of cTnI and cTnT are discussed, with potentially important implications for clinical practice. Consequently, currently proposed cTn biomarker cut-offs by the prevailing definitions of PMI might warrant re-assessment, with differentiation in cut-offs for the separate available assays and surgical strategies. To resolve these issues, future prospective studies are warranted to determine the prognostic influence of biomarker release in general and PMI in particular.

Diagnosis of acute myocardial infarction: highlighting cardiac troponins as vital biomarkers

The molecular marker, cardiac troponin (cTn) is a complex protein that is attached to tropomyosin on the actin filament. It is an essential biomolecule in terms of the calcium-mediated regulation of the contractile apparatus in myofibrils, the release of which is an indication of the dysfunction of cardiomyocytes and hence the initiation of ischemic phenomena in the heart tissue. Fast and accurate analysis of cTn may help the diagnosis and management of acute myocardial infarction (AMI), for which electrochemical biosensors and microfluidics devices can be of great benefit. This editorial aims to highlight the importance of cTn as vital biomarkers in AMI diagnosis.

Clinical implications of cardiac troponin-I in patients with hypertensive crisis visiting the emergency department

OBJECTIVES

Cardiac troponin-I (cTnI) is a representative marker of myocardial injury. Elevation of cTnI is frequently observed in patients with hypertensive crisis, but few studies have examined its prognostic significance in hypertensive crisis. We aimed to determine whether cTnI could predict all-cause mortality in patients with hypertensive crisis visiting the emergency department (ED).

METHODS

This observational study included patients aged ≥18 years who visited an ED between 2016 and 2019 for hypertensive crisis, defined as systolic blood pressure (BP) ≥180 mmHg and/or diastolic BP ≥110 mmHg. Among 6467 patients, 3938 who underwent a cTnI assay were analysed.

RESULTS

Among the 3938 patients, 596 (15.1%) had cTnI levels above the 99th percentile upper reference limit (elevated cTnI >40 ng/L) and 600 (15.2%) had cTnI levels between the detection limit (≥10 ng/L) and the 99th percentile upper reference limit (detectable cTnI). The 3-year all-cause mortality in the elevated, detectable and undetectable cTnI groups were 41.6%, 36.5% and 12.8%, respectively. After adjusting for confounding variables, elevated cTnI patients (adjusted hazard ratio [HR], 2.01; 95% confidence interval [CI], 1.61-2.52) and detectable cTnI patients (adjusted HR, 1.64; 95% CI, 1.32-2.04) showed a significantly higher risk of 3-year all-cause mortality than did patients with undetectable cTnI.

CONCLUSIONS

In patients with hypertensive crisis, elevated cTnI levels provide useful prognostic information and permit the early identification of patients with an increased risk of death. Moreover, putatively normal but detectable cTnI levels also significantly correlated with a higher risk of all-cause mortality. Intensive treatment and follow-up strategies are needed for patients with hypertensive crisis with elevated and detectable cTnI levels.Key messagesCardiac troponin-I level was an independent prognostic factor for all-cause mortality in patients with hypertensive crisis.Detectable but normal range cardiac troponin-I, which was considered clinically insignificant, also had a prognostic impact on all-cause mortality comparable to elevated cardiac troponin-I levels.

Short-term exposure to traffic-related air pollution and STEMI events: Insights into STEMI onset and related cardiac impairment

AIMS

Evidence on the impacts of traffic-related air pollution (TRAP) on ST-segment elevation myocardial infarction (STEMI) events is limited. We aimed to assess the acute effects of TRAP exposure on the clinical onset of STEMI and related cardiac impairments.

METHODS AND RESULTS

We recruited patients who were admitted for STEMI and underwent primary percutaneous coronary intervention at Peking University Third Hospital between 2014 and 2020. Indicators relevant to cardiac impairments were measured. Concomitantly, hourly concentrations of traffic pollutants were monitored throughout the study period, including fine particulate matter, black carbon (BC), particles in size ranges of 5-560 nm, oxides of nitrogen (NO_X), nitrogen dioxide, and carbon monoxide. The mean (SD) age of participants was 62.4 (12.5) years. Daily average (range) concentrations of ambient BC and NO_X were 3.9 (0.1-25.0) μg/m³ and 90.8 (16.6-371.7) μg/m³. Significant increases in STEMI risks of 5.9% (95% CI: 0.1, 12.0) to 21.9% (95% CI: 6.0, 40.2) were associated with interquartile range increases in exposure to TRAP within a few hours. These changes were accompanied by significant elevations in cardiac troponin T levels of 6.9% (95% CI: 0.2, 14.1) to 41.7% (95% CI: 21.2, 65.6), as well as reductions in left ventricular ejection fraction of 1.5% (95% CI: 0.1, 2.9) to 3.7% (95% CI: 0.8, 6.4). Furthermore, the associations were attenuated in participants living in areas with higher residential greenness levels.

CONCLUSIONS

Our findings extend current understanding that short-term exposure to higher levels of traffic pollution was associated with increased STEMI risks and exacerbated cardiac impairments, and provide evidence on traffic pollution control priority for protecting vulnerable populations who are at greater risks of cardiovascular events.

Diagnostic performance of a rapid, novel, whole blood, point of care high-sensitivity cardiac troponin I assay for myocardial infarction

BACKGROUND

We evaluated the diagnostic performance of a whole blood, point of care (POC) high-sensitivity cardiac troponin I (hs-cTnI) assay for myocardial infarction (MI) compared to central laboratory assays.

METHODS

Consecutive patients presenting to the emergency department with symptoms of ischemia were studied. Serial hs-cTnI testing was based on clinical indication at presentation. Parallel measurements were made using fresh whole blood on Siemens Atellica VTLi POC assay, EDTA plasma on Abbott ARCHITECT i2000 used in practice, and heparin plasma on Siemens Atellica. MI was determined according to the Fourth Universal Definition of MI using 99th percentiles. Sensitivities and negative predictive values (NPV) were calculated using 99th percentile URLs.

RESULTS

1089 Patients, 418 females and 671 males, were enrolled. There were 91 (8.4%) MIs. At baseline (0 h), POC hs-cTnI assay had a sensitivity of 65.7% (95% CI 47.8-80.9) for females and 67.9% (54.0-79.7) for males and NPV of 96.4% (93.9-98.1) for females and 96.7% (94.9-98.0) for males. At 2 h, sensitivity improved to 82.9% (66.4-93.4) for females and 80.4% (67.6-89.8) for males, while NPV improved to 98.2% (96.1-99.3) and 97.9% (96.3-99.0), respectively. For central laboratory assays, comparable diagnostics were observed at 2 h: females - sensitivity 94.3% (80.8-99.3) for ARCHITECT and 79.4% (62.1-91.3) for Atellica, and NPV 99.3% (97.6-99.9) and 98.0% (95.8-99.2), respectively; males - sensitivity 87.5% (75.9-94.8) for ARCHITECT and 80.4% (67.6-89.8) for Atellica, NPVs of 98.7% (97.3-99.5) and 97.9% (96.3-99.0), respectively.

CONCLUSIONS

The POC, whole blood Atellica VTLi hs-cTnI assay demonstrated comparable diagnostic accuracy for MI to central laboratory assays using 99th percentiles.

Fiber-integrated WGM optofluidic chip enhanced by microwave photonic analyzer for cardiac biomarker detection with ultra-high resolution

Cardiac troponin I (cTnI) plays an important role in emergency diagnosis of cardiovascular diseases, which exists predominately in the form of cardiac troponin I-C (cTnI-C) complex. We proposed a fiber-integrated optofluidic chip immunosensor with time-delay-dispersion based microwave photonic analyzer (MPA) for cTnI-C detection. The whispering gallery mode (WGM) fiber probe was fabricated by embedding a polydopamine functionalized hollow glass microsphere (HGMS) into the etched capillary-fiber structure, and the WGMs could be excited through the efficient coupling between the thin-wall capillary and the HGMS. The reflective WGM optofluidic chip functioned as a wavelength tuner to construct fiber ring laser cavity, whose laser output wavelength was cTnI-C concentration-dependent. The tiny wavelength variation of sensing laser was converted into a radio-frequency (RF) response, which was retrieved by measuring the change of RF-domain free spectrum range (FSR) in time-delay-dispersion based MPA, and the quantitative detection of cTnI-C complex can be achieved with high resolution. Experimental results show that this immunosensor had a limit of detection (LOD) of 0.59 ng/mL, and a detection resolution of 1.2 fg/mL. The relative resolving power was 10²-10⁴-fold higher than that of others optical fiber cTnI biosensors. The proposed fiber-integrated optofluidic chip provides an innovative lab-on-chip diagnostic tool for myocardial damage.

Prognostic Value of Serum Cardiac Troponin in Acute Ischemic Stroke: An Updated Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Cardiac troponin (cTn) is a specific biomarker of cardiac injury and elevation of cTn is related to increased mortality. However, prognostic value of cTn in patients with acute ischemic stroke (AIS) still remains to be elucidated. The aim of this review is to explore the strength of association between elevated cTn and mortality after AIS onset.

METHODS

PubMed, EMBASE, and Cochrane Library were searched from inception to July 12, 2021 without language restriction. All studies reporting the association between cTn on admission and mortality in AIS patients have been included in this review. Meta-analysis was performed for overall and pre-specified subgroup risk ratios (RR) were obtained using a random effect model. Study quality was assessed for each included study.

RESULTS

There were 20 studies included in this meta-analysis with 9779 AIS patients met the inclusion criteria. There was significant association between elevated cTn and mortality in patients with AIS (RR 3.87; 95% CI 3.24-4.63). The association was consistent across the pre-specified subgroup analyses by type of troponin (cTnT or cTnI), assay of troponin (conventional or high-sensitivity), region (Asian or Non-Asian), definite exclusion of ACS/AMI patients or not (yes or not mentioned), adjusted AF, HF and impaired renal function or not (yes or no).

CONCLUSIONS

AIS patients with elevated cTn at baseline has an increased risk of mortality. Early and routine evaluation of cTn may contribute to timely detection of comorbid cardiac injury and prevent unfavorable outcomes in patients with AIS.

PROSPERO REGISTRATION NUMBER

CRD42020160912.

Type 2 myocardial infarction: a diagnostic and therapeutic challenge in contemporary cardiology

In the expanding world of cardiovascular diseases, rapidly reaching pandemic proportions, the main focus is still on coronary atherosclerosis and its clinical consequences. However, at least in the Western world, middle-aged male patients with acute myocardial infarction are no more the rule. Due to a higher life expectancy and major medical advances, physicians are to treat older and frailer individuals, usually with multiple comorbidities. In this context, myocardial ischaemia and infarction frequently result from an imbalance between myocardial oxygen supply and demand-i.e., type 2 myocardial infarction (T2MI), according to the current universal definition-rather than coronary atherothrombosis. Moreover, the increasing use of high-sensitivity cardiac troponin assays has led to a heightened detection of T2MI-often causing relatively little myocardial injury-, which seems to have doubled its numbers in recent years. Nevertheless, owing to its multifaceted pathophysiology and clinical presentation, T2MI is still underdiagnosed. Perhaps more importantly, T2MI is also victim of undertreatment, as drugs that constitute the cornerstone of therapy in most cardiovascular diseases are much more unlikely to be prescribed in T2MI than in coronary atherothrombosis. In this paper, we review the recent literature on the classification, pathophysiology, epidemiology, and management of T2MI, trying to summarise the state-of-the-art knowledge about this increasingly important pathologic condition. Finally, based on the current scientific evidence, we also propose an algorithm that may be easily utilised in clinical practice, in order to improve T2MI diagnosis and risk stratification.

The ratio of cardiac troponin T to troponin I may indicate non-necrotic troponin release among COVID-19 patients

BACKGROUND

Although cardiac troponin T (cTnT) and troponin I(cTnI) are expressed to similar amount in cardiac tissue, cTnI often reach ten-times higher peak levels compared to cTnT in patients with myocardial necrosis such as in acute myocardial infarction (MI). In contrast, similar levels of cTnT and cTnI are observed in other situations such as stable atrial fibrillation and after strenuous exercise.

OBJECTIVE

Examine cTnT and cTnI levels in relation to COVID-19 disease and MI.

METHODS

Clinical and laboratory data from the local hospital from an observational cohort study of 27 patients admitted with COVID-19 and 15 patients with myocardial infarction (MI) that were analyzed with paired cTnT and cTnI measurement during hospital care.

RESULTS

Levels of cTnI were lower than cTnT in COVID-19 patients (TnI/TnT ratio 0.3, IQR: 0.1-0.6). In contrast, levels of cTnI were 11 times higher compared to cTnT in 15 patients with MI (TnI/TnT ratio 11, IQR: 7-14). The peak cTnI/cTnT ratio among the patients with MI following successful percutaneous intervention were 14 (TnI/TnT ratio 14, IQR: 12-23). The 5 COVID-19 patient samples collected under possible necrotic events had a cTnI/cTnT ratio of 5,5 (IQR: 1,9-8,3).

CONCLUSIONS

In patients with COVID-19, cTnT is often elevated to higher levels than cTnI in sharp contrast to patients with MI, indicating that the release of cardiac troponin has a different cause in COVID-19 patients.

Diagnostic accuracy of a high-sensitivity troponin I assay and external validation of 0/3 h rule out strategies

AIMS

The timely diagnosis and exclusion of acute coronary syndromes in the Emergency Department (ED) remains a challenge. This study aims to evaluate the diagnostic accuracy of a high-sensitivity cardiac troponin I assay (Siemens TNIH) on serial sampling for ED patients as standalone test and in rule-out algorithms as recommendations remain assay specific.

METHODS AND RESULTS

This secondary analysis from a prospective diagnostic accuracy study at 14 centres included ED patients presenting with chest pain of suspected cardiac nature. Serum drawn on arrival and 3 h later was batchtested for TNIH. The target condition was an adjudicated diagnosis of acute myocardial infarction (AMI). We evaluated the diagnostic accuracy of absolute and relative delta criteria and four rule-out strategies. Of 802 included patients, 13.8% had AMI. Absolute delta criteria had superior accuracy to relative criteria (C-statistic 0.94 vs. 0.76, P < 0.001). However, no delta criteria achieved >95.5% sensitivity for AMI when used alone. Ruling out AMI with TNIH below the 99th percentile at 0 and 3 h had 88.3% (95% confidence interval 80.8-93.6%) sensitivity. The adapted European Society of Cardiology (ESC) 0/2 h algorithm had higher sensitivity (98.2%) than both High-STEACS (93.7%, P = 0.03) and the ESC 0/3 h algorithm (79.3%, P < 0.001). These pathways ruled out 63%, 74%, and 88% patients, respectively.

CONCLUSION

With serial sampling over 3 h, the Siemens TNIH assay should be used with a validated algorithm incorporating bespoke cut-offs and absolute delta criteria. In our analysis, the adapted ESC 0/2 h algorithm had greatest sensitivity. 'Ruling out' AMI using the 99th percentile of the assay cannot be recommended.

High-Sensitivity Troponin T Testing for Pediatric Patients in the Emergency Department

Debate exists on the usefulness of high-sensitivity cardiac troponin (hs-cTn) testing in pediatric patients due to the perceived low incidence of myocardial injury and lack of data concerning its efficacy. We evaluated the contribution of an increased hs-cTnT above the 99th percentile upper-reference limit (URL) to clinical diagnoses made in pediatric patients presenting to the emergency department (ED). Retrospective cohort study including patients aged 0-18 years presenting to the ED from 2018 to 2020 where hs-cTnT was measured. Sex-specific 99th percentile URLs of 15 and 10 ng/L for males and females, respectively, were used, with concentrations above these thresholds considered indicative of myocardial injury. Overall, 356 patients were identified in whom hs-cTnT concentrations were measured during ED clinical evaluation. Hs-cTnT was increased above the 99th percentile on presentation in 36 patients (10.1%). Twelve patients (3.4%) had a clinical cardiac diagnosis made. Hs-cTnT was increased in 6 of these (50.0%). Serial hs-cTnT from 106 patients with an initial hs-cTnT < 99th percentile was subsequently elevated in 5 (4.6%); none of whom had a final clinical cardiac diagnosis. Hs-cTnT has high specificity, but low sensitivity when used as a screening tool for myocardial injury when the gold standard is mostly clinical assessment. In present practice, however, they do not appear to track well with clinical diagnoses. Further studies are needed to more clearly define the role of hs-cTnT in this patient population.

Rare survival of high-tension electrocution shock in a crossbred Jersey cattle: a complete profile on critical care monitoring

Background

Accidental electrocution was more common in animals and death was mostly due to shock and cardiac arrest. Survival of animals or humans could be possible if victims receive immediate medical support.

Case description

A 3-year-old crossbred Jersey heifer was presented to the Emergency and Critical Care Medicine Referral Clinic of the Veterinary College and Research Institute, Orathanadu, with a history of accidental electrocution by broken high-tension overhead power transmission line during grazing in the paddy fields. The animal was dull and depressed, dark red, and some areas were charred in appearance on the dorsum and limbs. The animal showed difficulty walking due to the electrocution burn injury and was poorly responding to the surroundings. Clinical examination revealed subnormal temperature, polypnea, pale mucous membranes, ruminal atony, and arrhythmias on auscultation.

Findings/treatment and outcome

On point of care (PoC) hematology testing, leukocytosis, neutrophilia, and microcytosis were observed. PoC electrolyte analysis revealed hypocalcemia (ionized calcium 0.89 mmol/L), mild hypochloremia, and severe hypokalemia (2.81 mmol/L). PoC biochemistry revealed hypoglycemia (41 mg/dl). PoC elevated levels of serum cardiac troponin (0.33 ng/dl) indicated cardiac damage. Aspartate aminotransferase (1794 U/L), CK-MB (699 U/L) and LDH (6.7 U/L) were also elevated. On PoC urinalysis, proteinuria, myoglobinuria, and glucosuria were observed. Evident clinical recovery, wound healing, and improvement in animal activities were observed.

Conclusion

High-voltage electrocution injury is a serious type of accident with the potential risk of multi-organ damage and death. Early diagnosis of electrocution and immediate management enhances the expectancy of complete recovery.

Ultra-highly sensitive cardiac troponin I: Age and sex differences in healthy individuals

Background

Associations between elevated circulating cardiac troponin I (cTnI) levels and adverse cardiac outcomes were established prior to the ability to measure extremely low levels of cTnI. Immunoassays that achieve precise ultra-highly sensitive quantification of cTnI (u-hs-cTnI) will allow accurate measurement in healthy subjects. We aimed to evaluate the distribution of u-hs-cTnI values measured by (Simoa HD-1 Analyzer, Quanterix Corporation, Lexington, MA) in healthy subjects and characterize relations to sex and age.

Methods

Two independent, healthy cohorts (total of 200 women, 200 men) aged 18-86 years were analyzed in duplicate using the u-hs-cTnI Immunoassay. The u-hs-cTnI 99th percentiles were calculated as the upper limits considering a robust estimation against outliers with 90% confidence intervals. The Quanterix immunoassay analytical performance was established and compared to an existing clinical assay (ARCHITECT STAT High Sensitivity Troponin I, Abbott Laboratories, Wiesbaden, Germany).

Results

The lower limit of detection of the u-hs-cTnI assay was calculated to be 0.005 ng/L; we accurately quantified u-hs-cTnI in 95% of healthy individuals. The Quanterix immunoassay within overlapping concentrations correlated with the Abbott assay (R2 = 0.932). The calculated combined 99th percentile was 7.94 ng/L (90% Confidence Interval [CI], 5.47-10.52). Women had lower mean u-hs-cTnI concentrations than men under the age of 40 years. The sex-specific 99th percentile for female vs. male individuals was 4.89 ng/L (90%CI, 3.71-6.25) and 10.49 ng/L (90%CI, 5.19-15.06), respectively.

Conclusion

The Quanterix immunoassay provides precise quantification in 95% of healthy individuals. Women under the age of 40 years have significantly lower levels of u-hs-cTnI than men.

Analytical and Clinical Considerations in Implementing the Roche Elecsys Troponin T Gen 5 STAT Assay

OBJECTIVES

To evaluate the analytical and clinical performance characteristics of the fifth-generation troponin T reagent.

METHODS

Troponin T was measured in 2,332 paired serum and plasma samples from emergency department and hospital patients using the fourth- and fifth-generation reagents. Testing was repeated after recentrifugation to determine the frequency of analytical outliers and percentage of patients with elevated values for each assay. We conducted separate experiments to determine the effects of biotin and hemolysis interference, as well as measure interinstrument variability, for fifth-generation troponin T.

RESULTS

Analytic outliers occurred more frequently using the fifth-generation reagent (3.4%) compared with the fourth-generation reagent (1.0%). The frequency of elevated troponin T above the 99th percentile upper reference limit was 26% for the fourth-generation reagent and 52% for the fifth-generation reagent. Clinically significant assay interference by biotin was observed at 20 ng/mL, but hemolysis interference was not observed until an H index of 150. Instrument-to-instrument variability between e411 and e601/602 instrument platforms is predicted to confound clinical interpretation of troponin changes.

CONCLUSIONS

Analytical outliers and instrument-to-instrument variability are the two analytical variables most likely to confound interpretation of changes in fifth-generation troponin T results over time.