Cardiomyocyte Injury Following Acute Ischemic Stroke: Protocol for a Prospective Observational Cohort Study

Cordyceps: Alleviating ischemic cardiovascular and cerebrovascular injury - A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Cordyceps has a long medicinal history as a nourishing herb in traditional Chinese medicine (TCM). Ischemic cardio-cerebrovascular diseases (CCVDs), including cerebral ischemic/reperfusion injury (CI/RI) and myocardial ischemic/reperfusion injury (MI/RI), are major contributors to mortality and disability in humans. Numerous studies have indicated that Cordyceps or its artificial substitutes have significant bioactivity on ischemic CCVDs, however, there is a lack of relevant reviews.

AIM OF THE STUDY

This review was conducted to investigate the chemical elements, pharmacological effects, clinical application and drug safety of Cordycepson ischemic CCVDs.

MATERIALS AND METHODS

A comprehensive search was conducted on the Web of Science, PubMed, Chinese National Knowledge Infrastructure (CNKI), and Wanfang databases using the keywords "Cordyceps", "Cerebral ischemic/reperfusion injury", and "Myocardial ischemic/reperfusion injury" or their synonyms. The retrieved literature was then categorized and summarized.

RESULTS

The study findings indicated that Cordyceps and its bioactive components, including adenosine, cordycepin, mannitol, polysaccharide, and protein, have the potential to protect against CI/RI and MI/RI by improving blood perfusion, mitigating damage from reactive oxygen species, suppressing inflammation, preventing cellular apoptosis, and promoting tissue regeneration. Individually, Cordyceps could reduce neuronal excitatory toxicity and blood-brain barrier damage caused by cerebral ischemia. It can also significantly improve cardiac energy metabolism disorders and inhibit calcium overload caused by myocardial ischemia. Additionally, Cordyceps exerts a significant preventive or curative influence on the factors responsible for heart/brain ischemia, including hypertension, thrombosis, atherosclerosis, and arrhythmia.

CONCLUSION

This study demonstrates Cordyceps' prospective efficacy and safety in the prevention or treatment of CI/RI and MI/RI, providing novel insights for managing ischemic CCVDs.

Stroke-heart syndrome: current progress and future outlook

Stroke can lead to cardiac complications such as arrhythmia, myocardial injury, and cardiac dysfunction, collectively termed stroke-heart syndrome (SHS). These cardiac alterations typically peak within 72 h of stroke onset and can have long-term effects on cardiac function. Post-stroke cardiac complications seriously affect prognosis and are the second most frequent cause of death in patients with stroke. Although traditional vascular risk factors contribute to SHS, other potential mechanisms indirectly induced by stroke have also been recognized. Accumulating clinical and experimental evidence has emphasized the role of central autonomic network disorders and inflammation as key pathophysiological mechanisms of SHS. Therefore, an assessment of post-stroke cardiac dysautonomia is necessary. Currently, the development of treatment strategies for SHS is a vital but challenging task. Identifying potential key mediators and signaling pathways of SHS is essential for developing therapeutic targets. Therapies targeting pathophysiological mechanisms may be promising. Remote ischemic conditioning exerts protective effects through humoral, nerve, and immune-inflammatory regulatory mechanisms, potentially preventing the development of SHS. In the future, well-designed trials are required to verify its clinical efficacy. This comprehensive review provides valuable insights for future research.

Sex Differences in Outcomes of Acute Myocardial Injury After Stroke

BACKGROUND

Sex differences in presentation, treatment, and prognosis of cardiovascular disorders are well recognized. Although an association between acute myocardial injury and mortality after ischemic stroke has been demonstrated, it is unclear whether prevalence and outcome of poststroke acute myocardial injury differ between women and men.

METHODS AND RESULTS

We prospectively screened consecutive patients with acute ischemic stroke and serial high-sensitivity cardiac troponin T measurements admitted to our center. Acute myocardial injury was defined as at least 1 high-sensitivity cardiac troponin T value above the upper reference limit (14 ng/L) with a rise/fall of >20%. Rates of acute myocardial injury were also calculated using sex-specific high-sensitivity cardiac troponin T cutoffs (women upper reference limit, 9 ng/L; men upper reference limit, 16 ng/L). Logistic regression analyses were performed to evaluate the association between acute myocardial injury and outcomes. Of 1067 patients included, 494 were women (46%). Women were older, had a higher rate of known atrial fibrillation, were more likely to be functionally dependent before admission, had higher stroke severity, and more often had cardioembolic strokes (all P values <0.05). The crude prevalence of acute myocardial injury differed by sex (29% women versus 23% men, P=0.024). Statistically significant associations between acute myocardial injury and outcomes were observed in women (7-day in-hospital mortality: adjusted odds ratio [aOR], 3.2 [95% CI, 1.07-9.3]; in-hospital mortality: aOR, 3.3 [95% CI, 1.4-7.6]; modified Rankin Scale score at discharge: aOR, 1.6 [95% CI, 1.1-2.4]) but not in men. The implementation of sex-specific cutoffs did not increase the prognostic value of acute myocardial injury for unfavorable outcomes.

CONCLUSIONS

The prevalence of acute myocardial injury after ischemic stroke and its association with mortality and greater disability might be sex-dependent.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03892226.

Myocardial injury in patients with acute ischemic stroke detected by cardiovascular magnetic resonance imaging

BACKGROUND

Patients with acute ischemic stroke (AIS) are at high risk of adverse cardiovascular events. Until now, the burden of myocardial injury derived from cardiovascular magnetic resonance imaging (CMR) has not been established in this population.

METHODS

Patients with AIS underwent CMR at 3 Tesla within 120 h after the index stroke as part of a prospective, single-center study. Patients with persistent atrial fibrillation were excluded. Morphology and function of both cardiac chambers and atria were assessed applying SSFP cine. Myocardial tissue differentiation was based on native and contrast-enhanced imaging including late gadolinium enhancement (LGE) after 0.15 mmol/kg gadobutrol for focal fibrosis and parametric T2- and T1-mapping for diffuse findings. To detect myocardial deformation global longitudinal (GLS), circumferential (GCS) and radial (GRS) strain was measured applying feature tracking. Cardiac troponin was measured using a high-sensitivity assay (99th percentile upper reference limit 14 ng/L). T2 mapping values were compared with 20 healthy volunteers.

RESULTS

CMR with contrast media was successfully performed in 92 of 115 patients (mean age 74 years, 40% female, known myocardial infarction 6%). Focal myocardial fibrosis (LGE) was detected in 31 of 92 patients (34%) of whom 23/31 (74%) showed an ischemic pattern. Patients with LGE were more likely to have diabetes, prior myocardial infarction, prior ischemic stroke, and to have elevated troponin levels compared to those without. Presence of LGE was accompanied by diffuse fibrosis (increased T1 native values) even in remote cardiac areas as well as reduced global radial, circumferential and longitudinal strain values. In 14/31 (45%) of all patients with LGE increased T2-mapping values were detectable.

CONCLUSIONS

More than one-third of patients with AIS have evidence of focal myocardial fibrosis on CMR. Nearly half of these changes may have acute or subacute onset. These findings are accompanied by diffuse myocardial changes and reduced myocardial deformation. Further studies, ideally with serial CMR measurements during follow-up, are required to establish the impact of these findings on long-term prognosis after AIS.

Data lake-driven analytics identify nocturnal non-dipping of heart rate as predictor of unfavorable stroke outcome at discharge

BACKGROUND

Post-stroke heart rate (HR) and heart rate variability (HRV) changes have been proposed as outcome predictors after stroke. We used data lake-enabled continuous electrocardiograms to assess post-stroke HR and HRV, and to determine the utility of HR and HRV to improve machine learning-based predictions of stroke outcome.

METHODS

In this observational cohort study, we included stroke patients admitted to two stroke units in Berlin, Germany, between October 2020 and December 2021 with final diagnosis of acute ischemic stroke or acute intracranial hemorrhage and collected continuous ECG data through data warehousing. We created circadian profiles of several continuously recorded ECG parameters including HR and HRV parameters. The pre-defined primary outcome was short-term unfavorable functional outcome after stroke indicated through modified Rankin Scale (mRS) score of > 2.

RESULTS

We included 625 stroke patients, 287 stroke patients remained after matching for age and National Institute of Health Stroke Scale (NIHSS; mean age 74.5 years, 45.6% female, 88.9% ischemic, median NIHSS 5). Both higher HR and nocturnal non-dipping of HR were associated with unfavorable functional outcome (p < 0.01). The examined HRV parameters were not associated with the outcome of interest. Nocturnal non-dipping of HR ranked highly in feature importance of various machine learning models.

CONCLUSIONS

Our data suggest that a lack of circadian HR modulation, specifically nocturnal non-dipping, is associated with short-term unfavorable functional outcome after stroke, and that including HR into machine learning-based prediction models may lead to improved stroke outcome prediction.

Introduction of a cascaded segmentation pipeline for parametric T1 mapping in cardiovascular magnetic resonance to improve segmentation performance

The manual and often time-consuming segmentation of the myocardium in cardiovascular magnetic resonance is increasingly automated using convolutional neural networks (CNNs). This study proposes a cascaded segmentation (CASEG) approach to improve automatic image segmentation quality. First, an object detection algorithm predicts a bounding box (BB) for the left ventricular myocardium whose 1.5 times enlargement defines the region of interest (ROI). Then, the ROI image section is fed into a U-Net based segmentation. Two CASEG variants were evaluated: one using the ROI cropped image solely (cropU) and the other using a 2-channel-image additionally containing the original BB image section (crinU). Both were compared to a classical U-Net segmentation (refU). All networks share the same hyperparameters and were tested on basal and midventricular slices of native and contrast enhanced (CE) MOLLI T1 maps. Dice Similarity Coefficient improved significantly (p < 0.05) in cropU and crinU compared to refU (81.06%, 81.22%, 72.79% for native and 80.70%, 79.18%, 71.41% for CE data), while no significant improvement (p < 0.05) was achieved in the mean absolute error of the T1 time (11.94 ms, 12.45 ms, 14.22 ms for native and 5.32 ms, 6.07 ms, 5.89 ms for CE data). In conclusion, CASEG provides an improved geometric concordance but needs further improvement in the quantitative outcome.

Cardiac Troponins for the Clinical Management of Patients with Claudication and without Cardiac Symptoms

Many patients with peripheral arterial disease (PAD) exhibit undiagnosed obstructive coronary artery disease. We aim to identify the patients with lifestyle limiting claudication due to PAD and without cardiac symptoms, requiring coronary revascularization based on high-sensitive troponin T (hsTnT) values. We assessed hsTnT in consecutive patients referred for elective endovascular treatment due to claudication [Rutherford categories (RC) 2 & 3] between January 2018 and December 2021. Diagnostic work-up by non-invasive imaging and, if required, cardiac catheterization was performed according to clinical data, ECG findings and baseline hsTnT. The occurrence of cardiac death, myocardial infarction or urgent revascularization during follow-up was the primary endpoint. Of 346 patients, 14 (4.0%) exhibited elevated hsTnT ≥ 14 ng/L, including 7 (2.0%) with acute myocardial injury by serial hsTnT sampling. Coronary revascularization by percutaneous coronary intervention was necessary in 6 of 332 (1.5%) patients with normal versus nine of 14 (64.3%) patients with elevated hsTnT (p < 0.001). During 2.4 ± 1.4 years of follow-up, 20 of 286 (7.0%) patients with normal versus four of 13 (30.8%) with elevated hsTnT at baseline reached the composite primary endpoint (p = 0.03 by log-rank test). In conclusion, elevated troponins in cardiac asymptomatic patients with claudication modify subsequent cardiac management and may increase the need for closer surveillance and more aggressive conservative management in polyvascular disease.

Frequency, associated variables, and outcomes of acute myocardial injury according to the fourth Universal Definition of Myocardial Infarction in patients with acute ischemic stroke

BACKGROUND

Myocardial injury as indicated by elevation of cardiac troponin levels is common after acute ischemic stroke (AIS) and linked to poor outcomes. Previous studies rarely reported on serial hs-cTn measurements to distinguish whether myocardial injury is acute or chronic. Thus, little is known about frequency, associated variables, and outcome of acute myocardial injury in AIS.

METHODS AND PATIENTS

In this single-centered observational cohort study, from 01/2019 to 12/2020, consecutive patients with neuroimaging-confirmed AIS <48 h after symptom onset, and serial troponin measurements within the first 2 days after admission (Roche Elecsys®, hs-cardiac troponin T) were prospectively registered. Acute myocardial injury was defined according to the fourth Universal Definition of Myocardial Infarction (troponin above the upper reference limit and rise/fall>20%). Outcomes of interest were in-hospital mortality and unfavorable functional status at discharge (modified Rankin Scale >1).

RESULTS

Out of 1067 analyzed patients, 25.3% had acute myocardial injury, 40.4% had chronic myocardial injury and 34.3% had no myocardial injury. Older age, higher stroke severity, thrombolytic treatment, and impaired kidney function were independently associated with acute myocardial injury. In-hospital mortality was higher in patients with acute myocardial injury than in those without (13% vs 3%, adjusted OR, 2.9% [95% CI, 1.6-5.5]). Compared with no myocardial injury, both acute and chronic myocardial injury were associated with unfavorable functional status at discharge (adjusted OR, 1.6 [95% CI, 1.1-2.5] and OR, 1.7 [95% CI, 1.2-2.4], respectively).

CONCLUSIONS

A quarter of patients with AIS have evidence of acute myocardial injury according to the fourth Universal Definition of Myocardial Infarction. The strong association with in-hospital mortality highlights the need for clinical awareness and future studies on underlying mechanisms.

TRoponin of Unknown origin in STroke evaluated by multi-component cardiac Magnetic resonance Imaging – The TRUST-MI study

Aims

Increased high-sensitive cardiac troponin I (hs-cTnI) levels are common in patients with acute ischemic stroke. However, only a minority demonstrates culprit lesions on coronary angiography, suggesting other mechanisms, e.g., inflammation, as underlying cause of myocardial damage. Late Gadolinium Enhancement (LGE)-cardiac magnetic resonance (CMR) with mapping techniques [T1, T2, extracellular volume (ECV)] allow the detection of both focal and diffuse myocardial abnormalities. We investigated the prevalence of culprit lesions by coronary angiography and myocardial tissue abnormalities by a comprehensive CMR protocol in troponin-positive stroke patients.

Methods and results

Patients with troponin-positive acute ischemic stroke and no history of coronary artery disease were prospectively enrolled. Coronary angiography and CMR (LGE, T1 + T2 mapping, ECV) were performed within the first days of the acute stroke. Twenty-five troponin-positive patients (mean age 62 years, 44% females) were included. 2 patients (8%) had culprit lesions on coronary angiography and underwent percutaneous coronary intervention. 13 patients (52%) demonstrated LGE: (i) n = 4 ischemic, (ii) n = 4 non-ischemic, and (iii) n = 5 ischemic AND non-ischemic. In the 12 LGE-negative patients, mapping revealed diffuse myocardial damage in additional 9 (75%) patients, with a high prevalence of increased T2 values.

Conclusions

Our data show a low prevalence of culprit lesions in troponin-positive stroke patients. However, &gt; 50% of the patients demonstrated myocardial scars (ischemic + non-ischemic) by LGE-CMR. Mapping revealed additional myocardial abnormalities (mostly inflammatory) in the majority of LGE-negative patients. Therefore, a comprehensive CMR protocol gives important insights in the etiology of troponin which might have implications for the further work-up of troponin-positive stroke patients.

Stroke-Heart Syndrome: Recent Advances and Challenges

After ischemic stroke, there is a significant burden of cardiovascular complications, both in the acute and chronic phase. Severe adverse cardiac events occur in 10% to 20% of patients within the first few days after stroke and comprise a continuum of cardiac changes ranging from acute myocardial injury and coronary syndromes to heart failure or arrhythmia. Recently, the term stroke–heart syndrome was introduced to provide an integrated conceptual framework that summarizes neurocardiogenic mechanisms that lead to these cardiac events after stroke. New findings from experimental and clinical studies have further refined our understanding of the clinical manifestations, pathophysiology, and potential long‐term consequences of the stroke–heart syndrome. Local cerebral and systemic mediators, which mainly involve autonomic dysfunction and increased inflammation, may lead to altered cardiomyocyte metabolism, dysregulation of (tissue‐resident) leukocyte populations, and (micro‐) vascular changes. However, at the individual patient level, it remains challenging to differentiate between comorbid cardiovascular conditions and stroke‐induced heart injury. Therefore, further research activities led by joint teams of basic and clinical researchers with backgrounds in both cardiology and neurology are needed to identify the most relevant therapeutic targets that can be tested in clinical trials.

Coronary angiography in acute ischemic stroke patients: frequency and determinants of pathological findings in a multicenter cohort study

Background

Myocardial injury as indicated by cardiac troponin elevation is associated with poor prognosis in acute stroke patients. Coronary angiography (CAG) is the diagnostic gold-standard to rule-out underlying obstructive coronary artery disease (CAD) in these patients. However, weighing risks and benefits of coronary angiography (CAG) against each other is particularly challenging, because stroke patients undergoing CAG may have a higher risk for secondary intracranial bleeding. Current guidelines remain vague. Thus, the aim of this study was to analyze frequency of pathological findings of CAG and associated clinical factors.

Methods

We analyzed indications and frequency of CAG performed in acute ischemic stroke patients in clinical routine in two European tertiary care hospitals from 2011 to 2018. All data were obtained retrospectively. Multiple logistic regression analyses were performed to identify variables associated with absence of obstructive coronary artery disease defined as presence of at least one coronary vessel stenosis ≥ 50%.

Results

A total of 139 AIS patients underwent CAG. Frequent indications for CAG were suspected acute coronary syndrome (N = 114) or scheduled cardiac surgery (N = 25). Acute coronary stenting was applied in 51/139 patients. Among patients with suspected acute coronary syndrome, no obstructive CAD was found in 27/114 patients. Absence of obstructive CAD was associated with insular cortex lesions, no clinical symptoms for ACS, less than three cardiovascular risk factors, younger age and normal wall motion.

Conclusion

Several variables suggest absence of CAD in AIS patients and may help in clinical decision making in stroke patients with myocardial injury.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-022-11001-5.

Myocardial injury in acute ischemic stroke

Since antiquity, the interaction of brain and heart has inspired physicians and philosophers. Today, our knowledge has vastly improved, but the exact way of their interaction still holds many secrets to reveal. The interaction between brain and heart merits particular attention in the aftermath of a sudden injury to the brain-like acute ischemic stroke (AIS). This narrative review gives an overview of current knowledge on frequency, prognosis, and potential pathophysiological mechanisms of myocardial injury following AIS.