Elevated troponin level with negative outcome was found in ischemic stroke

Predictive value of serum initial brain natriuretic peptide and troponin on functional prognosis in noncardiogenic patients with anterior and posterior circulation cerebral infarction

BACKGROUND

Brain natriuretic peptide (BNP) and troponin have a close relationship with cardiogenic cerebral embolism (CCE), but their relationship with noncardiogenic patients with anterior circulation ischemia (ACI) and posterior circulation ischemia (PCI) is not clear.

OBJECTIVE

To explore the predictive value of serum initial BNP and troponin on the functional prognosis of patients with noncardiogenic ACI and PCI.

METHODS

Consecutive patients with first-episode cerebral infarction within 12 hours of symptom onset were enrolled in the present 1-year prospective cohort study. Serum levels of BNP and troponin were collected within 12 hours of onset. Infarction location was classified as ACI and PCI by magnetic resonance imaging (MRI). According to the modified Rankin Scale (mRS) score at 90 days after onset, ACI and PCI cases were respectively divided into a good prognosis group (mRS score between 0 and 2) and a poor prognosis group (mRS score between 3 and 6). The general state of health and results of laboratory examinations and other auxiliary examinations of all patients were recorded. Single-factor analysis and multivariate logistic regression analysis were used to assess the relationship between serum levels of BNP, troponin, and functional outcome.

RESULTS

The multivariate logistic regression found that higher levels of initial BNP (odds ratio [OR] = 1.024; 95% confidence interval [CI]: 1.006-1.041; p = 0.007) and C-reactive protein (CRP) (OR = 1.184; 95%CI: 1.024-1.369; p = 0.022) were independent predictors of poor functional prognosis of noncardiogenic PCI at 90 days after onset after adjusting for age, gender, ethnicity, history of hypertension and of diabetes.

CONCLUSIONS

The levels of initial BNP and CRP were related to poor functional outcomes in noncardiogenic PCI patients at 3 months, independent of troponin.

Hemodynamics in acute stroke: Cerebral and cardiac complications

Hemodynamics is the study of blood flow, where parameters have been defined to quantify blood flow and the relationship with systemic circulatory changes. Understanding these perfusion parameters, the relationship between different blood flow variables and the implications for ischemic injury are outlined in the ensuing discussion. This chapter focuses on the hemodynamic changes that occur in ischemic stroke, and their contribution to ischemic stroke pathophysiology. We discuss the interaction between cardiovascular response and hemodynamic changes in stroke. Studying hemodynamic changes has a key role in stroke prevention, therapeutic implications and prognostic importance in acute ischemic stroke: preexisting hemodynamic and autoregulatory impairments predict the occurrence of stroke. Hemodynamic failure predisposes to the formation of thromboemboli and accelerates infarction due to impairing compensatory mechanisms. In ischemic stroke involving occlusion of a large vessel, persistent collateral circulation leads to preservation of ischemic penumbra and therefore justifying endovascular thrombectomy. Following thrombectomy, impaired autoregulation may lead to reperfusion injury and hemorrhage.

Elevated troponin levels are associated with early neurological worsening in ischemic stroke with atrial fibrillation

Serum cardiac troponin I (cTnI) is often elevated in patients with ischemic stroke, and is associated with their prognosis. Since cTnI is also closely related to atrial fibrillation (AF), cTnI may be a sensitive prognostic indicator in patients with AF-related stroke. This study aimed to evaluate the association between serum cTnI and early neurological deterioration (END) in patients with AF-related stroke. We included consecutive AF-related stroke patients between 2013 and 2015. END was defined as an increase ≥ 2 in the total NIHSS score or ≥ 1 in the motor NIHSS score within the first 72 h of admission. A total of 1,133 patients with AF-related stroke were evaluated. In multivariable analysis, cTnI [adjusted odds ratio (aOR) = 1.16, 95% confidence interval (CI) 1.00–1.34; P = 0.047] remained significant after adjusting for confounders. Initial NIHSS score (aOR = 1.03, 95% CI 1.00–1.06; P = 0.043) was also positively associated with END; meanwhile, the use of anticoagulants was negatively associated in both vitamin K antagonists (aOR = 0.35, 95% CI 0.23–0.54; P < 0.001) and new oral anticoagulants (aOR = 0.41, 95% CI 0.19–0.89; P = 0.024). In conclusion, higher serum cTnI was associated with END in patients with AF-related stroke.

Troponin T Predicts Cardioembolic Aetiology and Clinical Outcome in Undetermined Ischaemic Stroke in Hyperacute Phase

BACKGROUND

Elevated high-sensitivity cardiac troponin T (hs-cTnT) levels have been related to clinical outcome in stroke patients. However, the role of hs-cTnT and its potential as a biomarker in ischaemic stroke (IS) has not been well established. This study aims to determine whether basal hs-cTnT determination in the hyperacute phase of undetermined IS and transient ischaemic attack (TIA) can predict the cardioembolic aetiology and clinical outcome.

METHODS

We prospectively studied 110 consecutive patients with undetermined acute IS and TIA. hs-cTnT levels were determined at hospital arrival. Large vessel stenosis/occlusion and previously known aetiologies at admission were exclusion criteria for this study. All patients were subjected to a complete aetiological evaluation. A 12-month follow-up was performed in all patients. The subtype of IS was evaluated following the SSS-TOAST criteria. We established two groups at admission: cardioembolic aetiology (group A) and noncardioembolic aetiologies (group B).

RESULTS

The number of patients in each group was similar (group A: 52, 47.27%; group B, 58, 52.73%). Patients in group A had elevated hs-cTnT more frequently (61.54% versus 17.24%; P < .001). Group A patients had significantly higher mortality at 3 months (14.29% versus 1.82%, P = .025). In the multivariate analysis, elevated hs-cTnT was the only independent predictor of cardioembolic aetiology (odds ratio: 14.821; 95% confidence interval: 3.717-59.102, P < .001).

CONCLUSION

Baseline hs-cTnT assessment in undetermined strokes and TIA during the hyperacute phase is independently associated with cardioembolic aetiology.

Is Troponin really a reliable marker in patients with acute ischemic stroke?

BACKGROUND AND PURPOSE

Cardiac troponin I (cTnI) is a reliable marker to diagnose acute myocardial infarction, but the pathophysiological explanation for the increase in cTnI levels in patients with acute ischemic stroke (IS) remains unknown. To overcome this question, we aimed to compare serum cTnI levels in acute coronary syndrome (ACS) concomitant with and without stroke. By doing like this, we thought that we could demonstrate the effect of stroke on TrpI level.

METHODS

Serum cTnI levels of 41 patients having ACS with acute IS during hospitalization were compared with 97 control patients having only ACS. Cranial CT was performed to evaluate the lesions. The severity of IS was evaluated objectively by national institutes of health stroke scale.

RESULTS

cTnI levels were found to be similar in both groups. Presence of diabetes mellitus, coronary artery disease and previous myocardial infarction were more frequent in patients with acute IS. The cTnI levels in the patients with the cranial lesion in the anterior circulation was higher (p = 0.039). Presence of acute IS, cTnI level higher than 20 ng/mL and left ventricular ejection fraction < 40% were found to be independent risk factors for mortality (p < 0.05).

CONCLUSIONS

We found that abnormal troponin levels were more likely to be due to cardiac causes than cerebral ones in this first study evaluating the cTnI levels in patients with ACS concomitant with acute IS. The severity of IS, lesion location in the anterior circulation and higher troponin levels were associated with mortality.

Ethnicity-Specific Changes in Cardiac Troponin T in Response to Acute Mental Stress and Ethnicity-Specific Cutpoints for the R Wave of the aVL Lead

Acute mental stressor-induced cardiac stress responses might contribute to excessive myocardial strain and resultant cardiovascular episode risk. We assessed ethnicity-specific acute cardiac stress (by measuring cardiac troponin T (cTnT) and N-terminal prohormone of brain natriuretic peptide) related to hemodynamic activity. The prospective Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study was conducted during 2007-2008 in South Africa. In the cross-sectional phase of the SABPA study, 388 black and white participants underwent a 1-minute acute mental stressor, during which blood pressure was continuously measured. Fasting blood samples for cardiac stress markers were obtained before and 10 minutes after stress (% change). Resting 10-lead electrocardiogram measured the R wave of the aVL lead (RaVL). Black participants exhibited greater cardiac stress responses (P < 0.001), diastolic blood pressure, total peripheral resistance, and stroke volume compared with white participants, who displayed decreases in cardiac stress and increases in cardiac output. Prestress and stressor cTnT cutpoints of 4.2 pg/mL predicted 24-hour, daytime, and nighttime diastolic hypertension in black participants (P < 0.001). These cTnT cutpoints were associated with an ethnicity-specific RaVL cutpoint of 0.28 mV (odds ratio = 3.49, 95% confidence interval: 2.18, 5.83; P = 0.021). Acute mental stress elicited an α-adrenergic activation pattern and cardiac stress hyperreactivity only in black participants. Mental stress might increase the black population's risk for ischemic episodes and heart disease.

Insula stroke: the weird and the worrisome

Infarction of the insula is a common scenario with large tissue-volume strokes in the middle cerebral artery territory. Considered to be part of the central autonomic network, infarction of this region is associated with autonomic disturbances, in particular cardiovascular dysregulation. Risk of aspiration following stroke is also associated with involvement of the insula, consistent with its purported participation in complex functions of the mouth and pharynx. Strokes restricted to the insula are rare and present with a broad range of symptoms that offer a window of insight into the diverse functionality of the insular cortex. Chemosensory, autonomic, vestibular, auditory, somatosensory, language and oropharyngeal functional deficits are all recognised, among others. Long-term sequelae are unknown but profound symptoms, such as hemiparesis, are usually transient. Understanding the patterns of dysfunction highlighted provides the basis for future strategies to optimise stroke management on the discovery of insula involvement.

Circulating Troponin I Level in Patients with Acute Ischemic Stroke

PURPOSE OF REVIEW

Cardiac troponin levels in the blood are an important biomarker of acute coronary events, but may also be elevated in the context of acute ischemic stroke without an obvious concurrent myocardial insult. The objective of this study and systematic review is to determine how high the circulating troponin I level can rise due to ischemic stroke.

RECENT FINDINGS

Anonymized medical records from Vanderbilt University Medical Center were reviewed identifying 151,972 unique acute ischemic stroke events, of which 1226 met criteria for inclusion in this study. Included patients had at least one measurement of troponin I level documented during the hospital visit when an acute ischemic stroke was diagnosed and were free of known cardiac/coronary disease, renal impairment, sepsis, or other confounders. In this group, 20.6% had a circulating troponin I level elevated over the reference range, but 99% were below 2.13 ng/mL. This is significantly lower than the distribution observed in a cohort of 89,423 unique cases of acute coronary syndrome (p < 2.2^-16). A systematic review of published literature further supported the conclusion that troponin I level may increase due to an acute ischemic stroke, but rarely rises above 2 ng/mL. Because of the shared risk factors between stroke and coronary artery disease, clinicians caring for patients with acute ischemic stroke should always have a high index of suspicion for comorbid cardiac and cardiovascular disease. In general, troponin I levels greater than 2 ng/mL should not be attributed to an acute ischemic stroke, but should prompt a thorough evaluation for coronary artery disease.

A Review of Neurogenic Stunned Myocardium

Neurologic stunned myocardium (NSM) is a phenomenon where neurologic events give rise to cardiac abnormalities. Neurologic events like stroke and seizures cause sympathetic storm and autonomic dysregulation that result in myocardial injury. The clinical presentation can involve troponin elevation, left ventricular dysfunction, and ECG changes. These findings are similar to Takotsubo cardiomyopathy and acute coronary syndrome. It is difficult to distinguish NSM from acute coronary syndrome based on clinical presentation alone. Because of this difficulty, a patient with NSM who is at high risk for coronary heart disease may undergo cardiac catheterization to rule out coronary artery disease. The objective of this review of literature is to enhance physician's awareness of NSM and its features to help tailor management according to the patient's clinical profile.

Acute Simian Varicella Virus Infection Causes Robust and Sustained Changes in Gene Expression in the Sensory Ganglia

Primary infection with varicella-zoster virus (VZV), a neurotropic alphaherpesvirus, results in varicella. VZV establishes latency in the sensory ganglia and can reactivate later in life to cause herpes zoster. The relationship between VZV and its host during acute infection in the sensory ganglia is not well understood due to limited access to clinical specimens. Intrabronchial inoculation of rhesus macaques with simian varicella virus (SVV) recapitulates the hallmarks of VZV infection in humans. We leveraged this animal model to characterize the host-pathogen interactions in the ganglia during both acute and latent infection by measuring both viral and host transcriptomes on days postinfection (dpi) 3, 7, 10, 14, and 100. SVV DNA and transcripts were detected in sensory ganglia 3 dpi, before the appearance of rash. CD4 and CD8 T cells were also detected in the sensory ganglia 3 dpi. Moreover, lung-resident T cells isolated from the same animals 3 dpi also harbored SVV DNA and transcripts, suggesting that T cells may be responsible for trafficking SVV to the ganglia. Transcriptome sequencing (RNA-Seq) analysis showed that cessation of viral transcription 7 dpi coincides with a robust antiviral innate immune response in the ganglia. Interestingly, a significant number of genes that play a critical role in nervous system development and function remained downregulated into latency. These studies provide novel insights into host-pathogen interactions in the sensory ganglia during acute varicella and demonstrate that SVV infection results in profound and sustained changes in neuronal gene expression.

IMPORTANCE

Many aspects of VZV infection of sensory ganglia remain poorly understood, due to limited access to human specimens and the fact that VZV is strictly a human virus. Infection of rhesus macaques with simian varicella virus (SVV), a homolog of VZV, provides a robust model of the human disease. Using this model, we show that SVV reaches the ganglia early after infection, most likely by T cells, and that the induction of a robust innate immune response correlates with cessation of virus transcription. We also report significant changes in the expression of genes that play an important role in neuronal function. Importantly, these changes persist long after viral replication ceases. Given the homology between SVV and VZV, and the genetic and physiological similarities between rhesus macaques and humans, our results provide novel insight into the interactions between VZV and its human host and explain some of the neurological consequences of VZV infection.

Elevated troponin T after acute ischemic stroke: Association with severity and location of infarction

BACKGROUND

Serum troponin elevation, characteristic of ischemic myocardial injury, has been observed in some acute ischemic stroke (AIS) patients. Its cause and significance are still controversial. The purpose of this study is to find determinants of troponin elevation and its relationship with stroke severity and location.

METHODS

Between January 2013 and August 2013, 114 consecutive AIS patients confirmed by diffusion-weighted magnetic resonance imaging were recruited in this study. Serum troponin T level was measured as part of routine laboratory testing on admission. Ten lead standard electrocardiogram (ECG) was performed and stoke severity was assessed based on National Institutes of Health Stroke Scale (NIHSS).

RESULTS

Troponin T was elevated in 20 (17.6%) of 114 patients. Patients with elevated troponin were more likely to have higher age, higher serum creatinine and ischemic ECG changes. Troponin levels were higher in patients with more severe stroke measured by NIHSS [7.96 (6.49-9.78) vs. 13.59 (10.28-18.00)]. There was no association between troponin and locations of stroke and atrial fibrillation. There were 6 (5%) patients with elevated troponin in the presence of normal creatinine and ECG.

CONCLUSION

Stroke severity, not its location, was associated with higher troponin levels. Abnormal troponin levels are more likely, but not exclusively, to be due to cardiac and renal causes than cerebral ones.

Values of troponin T and myoglobin predictive of non-cardiac ischemia in rats

OBJECTIVES

Biochemical markers are important for the timely diagnosis and follow-up of ischemic events. Most of the markers have been previously studied in the context of cardiac ischemia. However, research on markers of non-cardiac events has been insufficient. Therefore, we investigated the relationship between troponin and myoglobin which are commonly used markers of cardiac ischemia, in non-cardiac ischemia.

MATERIALS AND METHODS

Forty-eight rats were equally divided into six groups. Group I was the control group. Group II was the sham group and received a simple laparotomy. The superior mesenteric artery was clamped in groups III and IV in order to create mesenteric ischemia. The left femoral artery was clamped in groups V and VI in order to create peripheral ischemia. Intracardiac blood samples were taken from all groups (during the 3(rd) hour of ischemia in groups III and V and the 6(th) hour of ischemia in group IV and VI) and troponin T and myoglobin levels were measured.

RESULTS

Troponin and myoglobin levels were statistically similar in groups I and II. Moreover, increments were detected for troponin and myoglobin in ischemia groups according to group I and II. Furthermore, higher troponin Tlevels were detected after three hours of mesenteric ischemia and higher myoglobin values were observed after six hours of mesenteric ischemia (P<0.05).

CONCLUSION

Troponin T and myoglobin are not specific for non-cardiac ischemia, and they may be useful for detecting other ischemic events.