The non-cardiac use and significance of cardiac troponins

Extracellular Non-Coding RNAs in Cardiovascular Diseases

Cardiovascular diseases (CVDs) remain the world's leading cause of death despite the best available healthcare and therapy. Emerging as a key mediator of intercellular and inter-organ communication in CVD pathogenesis, extracellular vesicles (EVs) are a heterogeneous group of membrane-enclosed nano-sized vesicles released by virtually all cells, of which their RNA cargo, especially non-coding RNAs (ncRNA), has been increasingly recognized as a promising diagnostic and therapeutic target. Recent evidence shows that ncRNAs, such as small ncRNAs, circular RNAs, and long ncRNAs, can be selectively sorted into EVs or other non-vesicular carriers and modulate various biological processes in recipient cells. In this review, we summarize recent advances in the literature regarding the origin, extracellular carrier, and functional mechanisms of extracellular ncRNAs with a focus on small ncRNAs, circular RNAs, and long ncRNAs. The pathophysiological roles of extracellular ncRNAs in various CVDs, including atherosclerosis, ischemic heart diseases, hypertension, cardiac hypertrophy, and heart failure, are extensively discussed. We also provide an update on recent developments and challenges in using extracellular ncRNAs as biomarkers or therapeutical targets in these CVDs.

Of mitochondrion and COVID-19

COVID-19, a pandemic disease caused by a viral infection, is associated with a high mortality rate. Most of the signs and symptoms, e.g. cytokine storm, electrolytes imbalances, thromboembolism, etc., are related to mitochondrial dysfunction. Therefore, targeting mitochondrion will represent a more rational treatment of COVID-19. The current work outlines how COVID-19's signs and symptoms are related to the mitochondrion. Proper understanding of the underlying causes might enhance the opportunity to treat COVID-19.

Impact of more conservative European Society of Cardiology guidelines on the management of patients with acute chest pain

OBJECTIVE

Early diagnosis or rule-out of acute coronary syndrome (ACS) is a key competence of emergency medicine. Changes in the NSTE-ACS guidelines of the European Society of Cardiology (ESC) in 2015 and 2020 both warranted a henceforth more conservative approach regarding high-sensitivity troponin t (hsTnt) testing. We aimed to assess the impact of more conservative guidelines on the frequency of early rule-out and prolonged observation with repeated hsTnt testing at a high-volume tertiary care emergency department.

PATIENTS AND METHODS

We conducted a pre- and post-changeover analysis 3 months before and 3 months after transition from less (hsTnt cut-off 30 ng/L, 3-hour rule-out) to more conservative (hsTnt cut-off 14 ng/L, 1-hour rule-out) guidelines in 2015, comparing proportions of patients requiring repeated testing.

RESULTS

We included 5442 cases of symptoms suspicious of acute cardiac origin (3451 before, 1991 after, 2370 (44%) female, age 55 (SD 19) years). The proportion of patients fulfilling early-rule out criteria decreased from 68% (2348 patients) before to 60% (1195 patients) with the 2015 guidelines (P < .01). Those requiring repeated testing significantly (P < .01) increased from 22% (743 patients) to 25% (494 patients). Positive results in repeated testing significantly (P = .02) decreased from 43% (320 patients) to 37% (181 patients). Invasive diagnostics were performed in 91 patients (2.6%) before and in 75 patients (3.8%) after (P = .02) the guideline revision.

CONCLUSION

The implementation of the more conservative 2015 ESC guidelines led to a minor rise in prolonged observations because of an increase in negative repeated testing and to an increase in invasive procedures.

Comparison of urokinase and reteplase thrombolytic treatment in patients with high-risk pulmonary embolism

Thrombolytic treatment is recommended for patients with high-risk pulmonary embolism. The present study compared thrombolytic therapy with urokinase and reteplase. A total of 37 patients presenting with acute high-risk pulmonary embolism at the Intensive Care Unit of Weinan Central Hospital of Shaanxi Province (Weinan, China) between June 2013 and January 2017 were retrospectively analyzed. According to their treatment, these subjects were assigned to the reteplase group (n=16) or the urokinase group (n=21). Systolic blood pressure (SBP), heart rate (HR) and respiratory rate (RR) were recorded prior to, and at 2, 4, 24 and 48 h after thrombolytic therapy. Complications, including bleeding, were closely monitored. Changes in blood gas analysis, troponin-T (TNT), pro-B-type natriuretic peptide (pro-BNP) and D-dimer (D-D) were observed. In the reteplase and urokinase group, 11 and 13 cases exhibited marked improvement, treatment was rated as effective in 4 and 6 cases, and 1 and 2 mortalities occurred, resulting in an overall effective rate of 93.8 and 90.5%, respectively (P>0.05). In the reteplase group, one patient was unsuccessfully resuscitated and died. In the urokinase group, one patient died of gastric hemorrhage after 22 h of thrombolysis, while another patient died of brain failure resuscitation. The treatment improved the SBP in each of the two groups (P<0.05), and this outcome was similar between these two groups (P>0.05). HR and RR were similar prior to and after thrombolytic therapy (P>0.05). In contrast to the urokinase group, TNT was significantly decreased after thrombolyis compared with the baseline in the reteplase group. Complications in the reteplase group were higher, but in contrast to the urokinase group, no life-threatening bleeding occurred. Although reteplase is as effective as urokinase in treating high-risk pulmonary embolism, reteplase may reduce myocardial damage.

Predictive value of positive high-sensitivity troponin T in intubated traumatic brain injury patients

OBJECTIVEThe clinical relevance of high-sensitivity troponin T (HsTnT) in trauma patients is not well explored. In this study, the authors aimed to study the predictive value of serum HsTnT in intubated patients who had sustained traumatic brain injury (TBI).METHODSA retrospective analysis was conducted for all intubated TBI patients between 2010 and 2014 at a national level 1 trauma center. Data were analyzed and compared based on the HsTnT status on admission (group 1, negative results; and group 2, positive results). Receiver operating characteristic curves were used to determine sensitivity, specificity, and cutoff level of HsTnT to predict mortality. Time to earlier discharge from hospital or death was modeled using Cox proportional hazard models to describe the relationship between HsTnT and in-hospital mortality.RESULTSOf the 826 intubated TBI patients, 490 underwent HsTnT testing; 65.7% had positive HsTnT results. Patients in group 2 had a higher Injury Severity Score (p = 0.001) and head Abbreviated Injury Scale (AIS) score (p = 0.004) than those in group 1. In addition, group 2 patients were more likely to have lower Glasgow Coma Scale scores (p = 0.001) and more likely to experience intraventricular hemorrhage, brain edema, pneumonia, and sepsis (p = 0.001). HsTnT values positively correlated with head AIS score (r = 0.19, p = 0.001) and varied by the type of lesion and time to death. Ventilator days and length of hospital stay were more prolonged in group 2 patients (p = 0.001). Area under the curve (AUC) analysis showed that HsTnT ≥ 26.5 ng/L predicted all-cause mortality (AUC 0.75, 95% CI 0.699-0.801) with 80% sensitivity. Positive HsTnT was an independent predictor of mortality in multivariate models (adjusted OR 3.10, 95% CI 1.308-7.351) even after excluding chest injury (adjusted OR 4.18, 95% CI 1.320-13.231).CONCLUSIONSPositive HsTnT results are associated with poor outcomes in intubated patients with TBI. In this subset of patients, measuring serum HsTnT on admission is a useful tool for early risk stratification and expedited care; however, further prospective studies are warranted.

Brain-Heart Interactions in Traumatic Brain Injury

The cardiovascular manifestations associated with nontraumatic head disorders are commonly known. Similar manifestations have been reported in patients with traumatic brain injury (TBI); however, the underlying mechanisms and impact on the patient's clinical outcomes are not well explored. The neurocardiac axis theory and neurogenic stunned myocardium phenomenon could partly explain the brain-heart link and interactions and can thus pave the way to a better understanding and management of TBI. Several observational retrospective studies have shown a promising role for beta-adrenergic blockers in patients with TBI in reducing the overall TBI-related mortality. However, several questions remain to be answered in clinical randomized-controlled trials, including population selection, beta blocker type, dosage, timing, and duration of therapy, while maintaining the optimal mean arterial pressure and cerebral perfusion pressure in patients with TBI.

Cardiac troponin for predicting all-cause mortality in patients with acute ischemic stroke: a meta-analysis

Cardiac troponins are specific biomarkers of cardiac injury. However, the prognostic usefulness of cardiac troponin in patients with acute ischemic stroke is still controversial. The objective of this meta-analysis was to investigate the association of cardiac troponin elevation with all-cause mortality in patients with acute ischemic stroke. PubMed and Embase databases were searched for relevant studies up to April 31, 2017. All observational studies reporting an association of baseline cardiac troponin-T (cTnT) or troponin-I (cTnI) elevation with all-cause mortality risk in patients with acute ischemic stroke were included. Pooled adjusted risk ratio (RR) and corresponding 95% confidence interval (CI) were obtained using a random effect model. Twelve studies involving 7905 acute ischemic stroke patients met our inclusion criteria. From the overall pooled analysis, patients with elevated cardiac troponin were significantly associated with increased risk of all-cause mortality (RR: 2.53; 95% CI: 1.83-3.50). The prognostic value of cardiac troponin elevation on all-cause mortality risk was stronger (RR: 3.54; 95% CI: 2.09-5.98) during in-hospital stay. Further stratified analysis showed elevated cTnT (RR: 2.36; 95% CI: 1.47-3.77) and cTnI (RR: 2.79; 95% CI: 1.68-4.64) level conferred the similar prognostic value of all-cause mortality. Acute ischemic stroke patients with elevated cTnT or cTnI at baseline independently predicted an increased risk of all-cause mortality. Determination of cardiac troponin on admission may aid in the early death risk stratification in these patients.

Elevation of troponin I in acute ischemic stroke

Background. Cardiac morbidities account for 20% of deaths after ischemic stroke and is the second commonest cause of death in acute stroke population. Elevation of cardiac troponin has been regarded as a prognostic biomarker of poor outcome in patients with acute stroke.

Methods. This retrospective study enrolled 871 patients with acute ischemic stroke from August 2010 to March 2015. Data included vital signs, laboratory parameters collected in the emergency department, and clinical features during hospitalization. National Institutes of Health Stroke Scale (NIHSS), Barthel index, and modified Rankin Scale (mRS) were used to assess stroke severity and outcome.

Results. Elevated troponin I (TnI) > 0.01 µg/L was observed in 146 (16.8%) patients. Comparing to patients with normal TnI, patients with elevated TnI were older (median age 77.6 years vs. 73.8 years), had higher median heart rates (80 bpm vs. 78 bpm), higher median white blood cells (8.40 vs. 7.50 1,000/m³) and creatinine levels (1.40 mg/dL vs. 1.10 mg/dL), lower median hemoglobin (13.0 g/dL vs. 13.7 g/dL) and hematocrit (39% vs. 40%) levels, higher median NIHSS scores on admission (11 vs. 4) and at discharge (8 vs. 3), higher median mRS scores (4 vs3) but lower Barthel index scores (20 vs. 75) at discharge (p < 0.001). Multivariate analysis revealed that age ≥ 76 years (OR 2.25, CI [1.59–3.18]), heart rate ≥ 82 bpm (OR 1.47, CI [1.05–2.05]), evidence of clinical deterioration (OR 9.45, CI [4.27–20.94]), NIHSS score ≥ 12 on admission (OR 19.52, CI [9.59–39.73]), and abnormal TnI (OR 1.98, CI [1.18–3.33]) were associated with poor outcome. Significant factors for in-hospital mortality included male gender (OR 3.69, CI [1.45–9.44]), evidence of clinical deterioration (OR 10.78, CI [4.59–25.33]), NIHSS score ≥ 12 on admission (OR 8.08, CI [3.04–21.48]), and elevated TnI level (OR 5.59, CI [2.36–13.27]). C-statistics revealed that abnormal TnI improved the predictive power of both poor outcome and in-hospital mortality. Addition of TnI > 0.01 ug/L or TnI > 0.1 ug/L to the model-fitting significantly improved c-statistics for in-hospital mortality from 0.887 to 0.926 (p = 0.019) and 0.927 (p = 0.028), respectively.

Discussion. Elevation of TnI during acute stroke is a strong independent predictor for both poor outcome and in-hospital mortality. Careful investigation of possible concomitant cardiac disorders is warranted for patients with abnormal troponin levels.

Troponin T in Patients with Traumatic Chest Injuries with and without Cardiac Involvement: Insights from an Observational Study

BACKGROUND

Serum troponin T (TnT) is a common marker of myocardial injury. However, its implication in the absence of clinical evidence of cardiac reason is not well established.

AIMS

The aim of this study was to identify the implications of positive TnT in traumatic chest injury (TCI) patients regardless of the cardiac involvement.

MATERIALS AND METHODS

We conducted a retrospective analysis of all TCI patients admitted to level 1 trauma center between 2008 and 2011. Patients who underwent TnT testing were divided into two groups: Group 1 (positive TnT) and Group 2 (negative TnT). The two groups were analyzed and compared, and multivariate regression analyses were performed to identify predictors of TnT positivity and mortality.

RESULTS

Out of 993 blunt TCI patients, 19.3% had positive TnT (Group 1). On comparison to Group 2, patients in Group 1 were 5 years younger and more likely to have head, cardiac, hepatic, splenic, and pelvic injuries, in addition to lung contusion. Positive TnT was associated with higher Injury Severity Score (ISS) (P = 0.001), higher chest Abbreviated Injury Score (AIS) (P = 0.001), and longer hospital stay (P = 0.03). In addition, Group 1 patients were more likely to undergo chest tube insertion, exploratory laparotomy, mechanical ventilation, and tracheostomy. Twenty patients had cardiac involvement, and of them 14 had positive TnT. Among 973 patients who showed no evidence of cardiac involvement, 178 had positive TnT (18.3%). There were 104 deaths (60% in Group 1). On multivariate regression analysis, the predictors of hospital mortality were positive TnT, head injury, and high ISS, whereas, the predictors of TnT positivity were cardiac, hepatic, and pelvic injuries; higher ISS; and age.

CONCLUSIONS

Positive TnT in blunt TCI patients is a common challenge, particularly in polytrauma cases. Patients with positive TnT tend to have the worst outcome even in the absence of clinical evidence of acute cardiac involvement. Positive TnT is also a reflection of the severity of chest or extrathoracic injuries; however, further prospective studies are warranted.

Incidentally Raised Cardiac Troponin I Has a Worse Prognosis in Older Patients Compared to Those with Normal Cardiac Troponin I and Patients with Acute Coronary Syndrome: A Cohort Study

BACKGROUND

Incidentally elevated cardiac troponin I (cTnI) levels are common in acutely unwell older patients. However, little is known about how this impacts on the prognosis of these patients.

OBJECTIVE

We aimed to investigate whether incidentally elevated cTnI levels (group 1) are associated with poorer outcome when compared to age- and sex-matched patients without an elevated cTnI level (group 2), and to patients diagnosed with acute coronary syndrome (group 3).

PATIENTS AND METHODS

This prospective, matched cohort study placed patients ≥75 years old who were admitted to a University teaching hospital into groups 1-3, based on the cTnI levels and underlying diagnosis. Outcomes were compared between the groups using mixed-effects regression models and adjusted for renal function and C-reactive protein. All-cause mortality at discharge, at 1 month and 3 months, alongside the length of hospital stay (LOS), were recorded.

RESULTS

In total, 315 patients were included, with 105 patients in each of the 3 groups. The mean age was 84.8 ± 5.5 years, with 41.9% males. All patients were followed up for 3 months. The percent all-cause mortality at discharge and the LOS for groups 1, 2 and 3 were 12.4, 3.8 and 8.6% and 11.2, 8.5 and 7.7 days, respectively. Group 1 had significantly increased mortality at 3 months [odds ratio (OR) 2.80, 95% confidence interval (CI) 1.12-6.96; p = 0.040] and LOS (OR 1.39, 95% CI 1.08-1.79; p = 0.008) compared to group 2 and did not differ significantly when compared to 3-month mortality (OR 2.39, 95% CI 0.91-6.29; p = 0.079) or LOS (OR 1.26, 95% CI 0.96-1.66; p = 0.097) in group 3.

CONCLUSION

There is a significant association between an incidental rise in cTnI level with mortality and LOS in older patients. Further research is required to evaluate whether a more systematic management of these patients would improve the prognosis.

Cardiac Extracellular Vesicles in Normal and Infarcted Heart

Heart is a complex assembly of many cell types constituting myocardium, endocardium and epicardium that intensively communicate to each other in order to maintain the proper cardiac function. There are many types of intercellular intracardiac signals, with a prominent role of extracellular vesicles (EVs), such as exosomes and microvesicles, for long-distant delivering of complex messages. Cardiomyocytes release EVs, whose content could significantly vary depending on the stimulus. In stress, such as hypoxia, inflammation or injury, cardiomyocytes increase secretion of EVs. In hypoxic conditions, cardiac EVs are enriched with angiogenic and prosurvival factors. In acute myocardial infarction (AMI), damaged cardiac muscle cells produce EVs with increased content of angiogenic, anti-apoptotic, mitogenic and growth factors in order to induce repair and healing of the infarcted myocardium. Exosomal microRNAs play a central role in cardiac regeneration. In AMI, circulating cardiac EVs abundantly contain cardiac-specific miRNAs that serve as indicators of cardiac damage and have a big diagnostic potential as AMI biomarkers. Cardioprotective and regenerative properties of exosomes derived from cardiac and non-cardiac stem/progenitor cells are very helpful to be used in cell-free cardiotherapy and regeneration of post-infarct myocardium.