Heart failure after myocardial infarction in the era of primary percutaneous coronary intervention: Mechanisms, incidence and identification of patients at risk

Bioelectronics hydrogels for implantable cardiac and brain disease medical treatment application

Hydrogel-based bioelectronic systems offer significant benefits for point-of-care diagnosis, treatment of cardiac and cerebral disease, surgical procedures, and other medical applications, ushering in a new era of advancements in medical technology. Progress in hydrogel-based bioelectronics has advanced from basic instrument and sensing capabilities to sophisticated multimodal perceptions and feedback systems. Addressing challenges related to immune responses and inflammation regulation after implantation, physiological dynamic mechanism, biological toxicology as well as device size, power consumption, stability, and signal conversion is crucial for the practical implementation of hydrogel-based bioelectronics in medical implants. Therefore, further exploration of hydrogel-based bioelectronics is imperative, and a comprehensive review is necessary to steer the development of these technologies for use in implantable therapies for cardiac and brain/neural conditions. In this review, a concise overview is provided on the fundamental principles underlying ionic electronic and ionic bioelectronic mechanisms. Additionally, a comprehensive examination is conducted on various bioelectronic materials integrated within hydrogels for applications in implantable medical treatments. The analysis encompasses a detailed discussion on the representative structures and physical attributes of hydrogels. This includes an exploration of their intrinsic properties such as mechanical strength, dynamic capabilities, shape-memory features, stability, stretchability, and water retention characteristics. Moreover, the discussion extends to properties related to interactions with tissues or the environment, such as adhesiveness, responsiveness, and degradability. The intricate relationships between the structure and properties of hydrogels are thoroughly examined, along with an elucidation of how these properties influence their applications in implantable medical treatments. The review also delves into the processing techniques and characterization methods employed for hydrogels. Furthermore, recent breakthroughs in the applications of hydrogels are logically explored, covering aspects such as materials, structure, properties, functions, fabrication procedures, and hybridization with other materials. Finally, the review concludes by outlining the future prospects and challenges associated with hydrogels-based bioelectronics systems.

Assessment of the prognostic performance of TIMI, PAMI, CADILLAC and GRACE scores for short-term major adverse cardiovascular events in patients undergoing emergent percutaneous revascularisation: a prospective observational study

OBJECTIVES

Accurately predicting short-term MACE (major adverse cardiac events) following primary percutaneous coronary intervention (PCI) remains a clinical challenge. This study aims to assess the effectiveness of four established risk scores in predicting short-term MACE after primary PCI.

DESIGN

Prospective observational study.

SETTING

The National Institute of Cardiovascular Diseases, Karachi, Pakistan.

PARTICIPANTS

We enrolled a cohort of consecutive adult patients diagnosed with ST-elevation myocardial infarction undergoing primary PCI over a 6-month period, from 1 January 2022 to 30 June 2022.

OUTCOME MEASURES

All the patients were followed at intervals of 3 months up to 12 months, and MACE events were recorded. Thrombolysis in Myocardial Infarction (TIMI), Primary Angioplasty in Myocardial Infarction (PAMI), Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) and Global Registry of Acute Coronary Events (GRACE) scores were obtained.

RESULTS

A total of 2839 patients (79.3% male, mean age 55.6±11.2 years) were included. Over a median follow-up of 244 days, the composite MACE rate was 18.4% (521). All-cause mortality was 13.5% (384), reinfarction requiring revascularisation was 4.3% (121), heart failure-related rehospitalisation was 2.7% (76), stent thrombosis occurred in 5.6% (160) and cerebrovascular accident events were documented in 1% (28). The area under the curve for TIMI, PAMI, CADILLAC and GRACE scores was 0.682 (95% CI 0.655 to 0.709), 0.688 (95% CI 0.663 to 0.713), 0.686 (95% CI 0.66 to 0.711) and 0.695 (95% CI 0.669 to 0.72), respectively, for the prediction of MACE. On multivariable Cox regression, high-risk categories based on GRACE score were independent predictors of MACE with adjusted HR of 1.88 (95% CI 1.28 to 2.77; p=0.001).

CONCLUSIONS

A significant proportion of patients experienced short-term MACE after primary PCI. While none of the assessed scores demonstrated significant predictive power, the GRACE score exhibited comparatively better predictive ability than the TIMI, PAMI and CADILLAC scores.

A refined, minimally invasive, reproducible ovine ischaemia-reperfusion-infarction model using implantable defibrillators: Methodology and validation

Ischaemic heart disease remains a leading cause of premature mortality and morbidity. Understanding the associated pathophysiological mechanisms of cardiac dysfunction arising from ischaemic heart disease and the identification of sites for new therapeutic interventions requires a preclinical model that reproduces the key clinical characteristics of myocardial ischaemia, reperfusion and infarction. Here, we describe and validate a refined and minimally invasive translationally relevant approach to induce ischaemia, reperfusion and infarction in the sheep. The novelty and refinement in the procedure stems from utilization of implantable cardiac defibrillators prior to coronary engagement, balloon angioplasty to induce infarction, and intra-operative anti-arrhythmic drug protocols to reduce adverse arrhythmic events. The protocol is readily adoptable by researchers with access to standard fluoroscopic instrumentation, and it requires minimally invasive surgery. These refinements lead to a substantial reduction of intra-operative mortality to 6.7% from previously published values ranging between 13% and 43%. The model produces key characteristics associated with the fourth universal definition of myocardial infarction, including ECG changes, elevated cardiac biomarkers and cardiac wall motility defects. In conclusion, the model closely replicates the clinical paradigm of myocardial ischaemia, reperfusion and infarction in a translationally relevant large animal setting, and the applied refinements reduce the incidence of intra-operative mortality typically associated with preclinical myocardial infarction models.

Extracellular Vesicles-in-Hydrogel (EViH) targeting pathophysiology for tissue repair

Regenerative medicine endeavors to restore damaged tissues and organs utilizing biological approaches. Utilizing biomaterials to target and regulate the pathophysiological processes of injured tissues stands as a crucial method in propelling this field forward. The Extracellular Vesicles-in-Hydrogel (EViH) system amalgamates the advantages of extracellular vesicles (EVs) and hydrogels, rendering it a prominent biomaterial in regenerative medicine with substantial potential for clinical translation. This review elucidates the development and benefits of the EViH system in tissue regeneration, emphasizing the interaction and impact of EVs and hydrogels. Furthermore, it succinctly outlines the pathophysiological characteristics of various types of tissue injuries such as wounds, bone and cartilage injuries, cardiovascular diseases, nerve injuries, as well as liver and kidney injuries, underscoring how EViH systems target these processes to address related tissue damage. Lastly, it explores the challenges and prospects in further advancing EViH-based tissue regeneration, aiming to impart a comprehensive understanding of EViH. The objective is to furnish a thorough overview of EViH in enhancing regenerative medicine applications and to inspire researchers to devise innovative tissue engineering materials for regenerative medicine.

Association of Time in Target Range of Resting Heart Rate With Adverse Clinical Outcomes in Patients With Acute Coronary Syndromes After Percutaneous Coronary Intervention

Heart rate (HR) has been proved to be associated with major adverse cardiovascular events (MACE) in Acute coronary syndrome patients. However, the threshold value and clinical significance of time in target of resting heart rate (TTR-HR) remain insufficiently elucidated. Our study aimed to evaluate the independent association between TTR-HR and cardiovascular outcomes in the follow-up study of ACS. A total of 1455 ACS patients who underwent percutaneous coronary intervention (PCI) and were admitted to 22 hospitals between 2019 and 2022 were enrolled and followed up for 12 months. MACE was defined as a composite of cardiac death, nonfatal recurrent myocardial infarction, ischemic-driven revascularization, and ischemic stroke. The association between TTR-HR and cardiovascular outcomes was assessed using Cox regression model. Compared to patients with TTR-HR 0-50% and >50%-75%, patients with TTR-HR > 75%-100% were older and less alcohol user, less likely to use diuretics and anti-diabetic drugs, these patients had less comorbidities of hyperlipidemia, diabetes, heart failure, and cardiac shock. After 12 months follow up, the incidence of MACE and composite endpoint but not mortality was higher in patients with TTR-HR 0-50% and >50%-75% than those with TTR-HR > 75%-100%. After multivariate adjustment, TTR-HR [hazard ratio = 2.11, 95% CI: 1.19-3.74, p = 0.01] was independently associated with composite endpoint. In summary, our study demonstrates that TTR-HR holds significant prognostic value, with TTR-HR > 75%-100% being independently associated with reduced composite endpoint risk in ACS patients following PCI. These findings emphasize the importance of effective heart rate control in ACS patients following PCI.

Sodium-Glucose Cotransporter-2 Inhibitors After Acute Myocardial Infarction: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Cardiovascular disease is on the rise globally, with ischemic heart disease being the leading cause of mortality and morbidity. While sodium-glucose cotransporter 2 inhibitors (SGLT2i) have been shown to improve cardiovascular outcomes in patients with heart failure, evidence is limited in guiding initiation in post-acute myocardial infarction (post-AMI) patients. Hence, this study aimed to appraise the current literature on the effect of SGLT2i on the clinical outcomes of post-AMI patients.

METHODS

A comprehensive search of PubMed, EMBASE, SCOPUS, and ClinicalTrials.gov was conducted up to 1 May 2024. Only randomized controlled trials studying the use of SGLT2i in post-AMI patients were included. We included adult patients aged 18 years old and older diagnosed with AMI and initiated on SGLT2i in the acute post-AMI setting. SGLT2i studies solely in heart failure settings were excluded.

RESULTS

Eight clinical trials were included in the systematic review, comprising 11,436 patients. Compared with placebo, SGLT2i initiation in post-AMI patients significantly reduced total number of heart failure hospitalizations (risk ratio [RR] 0.74, 95% confidence interval [CI] 0.62-0.90) and was associated with a lower N-terminal pro-B-type natriuretic peptide (NT-proBNP) level (- 26.67 pg/ml, 95% CI - 41.74 to - 11.59). There was no difference in all-cause mortality (RR 1.02, 95% CI 0.81-1.28), cardiovascular mortality (RR 1.03, 95% CI 0.83-1.28), change in left ventricular ejection fraction, and glycated hemoglobin (HbA1c), as compared with placebo.

CONCLUSION

SGLT2i use in patients with AMI was associated with a reduction in heart failure hospitalizations and a decrease in NT-proBNP. There were no significant differences in mortality outcomes.

REGISTRATION

PROSPERO identifier number CRD42024540843.

Anti-inflammatory effects of proprotein convertase subtilisin/kexin 9 inhibitor therapy in the early phase of acute myocardial infarction

This study examined the anti-inflammatory and endothelial function-enhancing effects of proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitor therapy in the early phase after acute myocardial infarction (AMI) by assessing changes in tumor necrosis factor-α (TNF-α) levels and the L-arginine/asymmetric-dimethylarginine (ADMA) ratio. This retrospective, single-center cohort study included patients who underwent successful timely primary percutaneous coronary intervention (PCI) for first-onset AMI between September 2017 and March 2018. The PCSK9 inhibitor group comprised patients who received 75 mg alirocumab up to 7 days after AMI, while the standard therapy group comprised patients who did not. We evaluated the change in TNF-α levels and the L-arginine/ADMA ratio at the time of hospital admission and prior to discharge. PCSK9 inhibitor therapy in the early phase after AMI suppressed TNF-α levels (standard therapy group, 1.64 ± 2.14 pg/mL vs. PCSK9 inhibitor group, 0.26 ± 0.33 pg/mL; p = 0.033) and increased the L-arginine/ADMA ratio (standard therapy group, - 13.0 ± 39.7 vs. PCSK9 inhibitor group, 23.2 ± 39.7; p = 0.042). Upon multiple regression analysis adjusted for sex, age, and peak creatine kinase levels, PCSK9 inhibitor therapy was associated with TNF-α suppression (p = 0.025; β = - 0.235, 95% confidence interval [CI], - 0.436 to - 0.033). The L-arginine/ADMA ratio was also analyzed using multiple regression, adjusted for sex, age, peak creatine kinase levels, and smoking, showing a significant improvement in the ratio (p = 0.018; β = 41.913, 95% CI, 10.337-73.491). Moreover, a weak negative correlation was suggested between the change in TNF-α levels and the change in L-arginine/ADMA ratio (r = - 0.393, p = 0.058). PCSK9 inhibitor therapy in the early phase after AMI suppresses TNF-α levels and improves the L-arginine/ADMA ratio, potentially indicating anti-inflammatory and endothelial function-enhancing effects.

Impact of rapid response system in mortality and complications post-orthopedic surgery: a retrospective cohort study

BACKGROUND

Rapid response systems (RRSs) are used in hospitals to identify and treat deteriorating patients. However, RRS implementation and outcomes in orthopedic and surgical patients remain controversial. We aimed to investigate whether the RRS affects mortality and complications after orthopedic surgery.

METHODS

The National Health Insurance Service of South Korea provided the data for this population-based cohort study. Individuals who were admitted to the hospital that implemented RRS were categorized into the RRS group and those admitted to a hospital that did not implement the RRS were categorized into the non-RRS group. In-hospital mortality and postoperative complications were the endpoints.

RESULTS

A total of 931,774 adult patients were included. Among them, 93,293 patients underwent orthopedic surgery in a hospital that implemented RRS and were assigned to the RRS group, whereas 838,481 patients were assigned to the non-RRS group. In multivariable logistic regression analysis, the RRS group was not associated with in-hospital mortality after orthopedic surgery compared with the non-RRS group (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.80, 1.08; P = 0.350). However, the RRS group was associated with a 14% lower postoperative complication rate after orthopedic surgery than the non-RRS group (OR 0.86, 95% CI 0.84, 0.86; P < 0.001).

CONCLUSIONS

The RRS was not associated with in-hospital mortality following orthopedic surgery in South Korea. However, RRS deployment was related to a decreased risk of postoperative complications in patients undergoing orthopedic surgery.

Effect of sodium-glucose co-transporter 2 inhibitors (SGLT2i) on N-terminal pro-B-type natriuretic peptide (NT-proBNP) level and structural changes following myocardial infarction: A systematic review and meta-analysis

BACKGROUND

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are anti-hyperglycemic drugs and have been proven to have cardiovascular protective effects for patients with heart failure regardless of their diabetes status. However, the benefit of SGLT2i following myocardial infarction (MI) remains incompletely established. This review aimed to investigate the impact of SGLT2i on NT-proBNP levels and structural changes post-MI.

METHOD

Medline, ClinicalTrial.gov, Scopus, and Directory of open-access journals were searched to retrieve the relevant articles. Eligible studies were randomized clinical trials that assessed NT-proBNP and cardiac structural changes in patients who received SGLT2i compared to placebo following MI. Two reviewers independently screened articles, extracted data, and assessed study quality.

RESULT

Four studies were included in this review, including patients with and without diabetes. While two studies showed no marked decrease from the baseline in NT-proBNP levels between the SGLT2i group and the control group, two studies reported a substantial reduction. The meta-analysis included three of these studies, with a total of 238 participants. The meta-analysis did not find a statistically significant drop in NT-proBNP levels post-MI in the SGLT2 inhibitors group compared to placebo (pooled SMD = 0.16, 95% CI 0.57-0.26, P 0.45). Furthermore, different echocardiographic parameters were reported in the included trials, yet no meta-analysis could be conducted to assess the influence of SGLT2i on cardiac remodeling post-MI.

CONCLUSION

SGLT2i did not result in a statistically significant reduction of NT-proBNP level subsequent to myocardial infarction. A knowledge gap exists regarding the impact of these agents on cardiac remodeling post-MI. Future high-quality clinical trials are needed to provide more robust evidence.

Vectorcardiography Predicts Heart Failure in Patients Following ST Elevation Myocardial Infarction

BACKGROUND

Modeling outcomes, such as onset of heart failure (HF) or mortality, in patients following ST elevation myocardial infarction (STEMI) is challenging but clinically very useful. The acute insult following a myocardial infarction and chronic degeneration seen in HF involve a similar process where a loss of cardiomyocytes and abnormal remodeling lead to pump failure. This process may alter the strength and direction of the heart's net depolarization signal. We hypothesize that changes over time in unique parameters extracted using vectorcardiography (VCG) have the potential to predict outcomes in patients post-STEMI and could eventually be used as a noninvasive and cost-effective surveillance tool for characterizing the severity and progression of HF to guide evidence-based therapies.

METHODS

We identified 162 patients discharged from Michigan Medicine between 2016 and 2021 with a diagnosis of acute STEMI. For each patient, a single 12-lead ECG > 1 week pre-STEMI and > 1 week post-STEMI were collected. A set of unique VCG parameters were derived by analyzing features of the QRS complex. We used LASSO regression analysis incorporating clinical variables and VCG parameters to create a predictive model for HF, mortality, or the composite at 90, 180, and 365 days post-STEMI.

RESULTS

The VCG model is most predictive for HF onset at 90 days with a robust AUC. Variables from the HF model mitigating or driving risk, at a p < 0.05, were primarily parameters that assess the area swept by the depolarization vector including the 3D integral and convex hull in select spatial octants and quadrants.

Multi-Modality Deep Infarct: Non-invasive identification of infarcted myocardium using composite in-silico-human data learning

Myocardial infarction (MI) continues to be a leading cause of death worldwide. The precise quantification of infarcted tissue is crucial to diagnosis, therapeutic management, and post-MI care. Late gadolinium enhancement-cardiac magnetic resonance (LGE-CMR) is regarded as the gold standard for precise infarct tissue localization in MI patients. A fundamental limitation of LGE-CMR is the invasive intravenous introduction of gadolinium-based contrast agents that present potential high-risk toxicity, particularly for individuals with underlying chronic kidney diseases. Herein, we develop a completely non-invasive methodology that identifies the location and extent of an infarct region in the left ventricle via a machine learning (ML) model using only cardiac strains as inputs. In this transformative approach, we demonstrate the remarkable performance of a multi-fidelity ML model that combines rodent-based in-silico-generated training data (low-fidelity) with very limited patient-specific human data (high-fidelity) in predicting LGE ground truth. Our results offer a new paradigm for developing feasible prognostic tools by augmenting synthetic simulation-based data with very small amounts of in-vivo human data. More broadly, the proposed approach can significantly assist with addressing biomedical challenges in healthcare where human data are limited.

Multi-Modality Deep Infarct: Non-invasive identification of infarcted myocardium using composite in-silico-human data learning

Myocardial infarction (MI) continues to be a leading cause of death worldwide. The precise quantification of infarcted tissue is crucial to diagnosis, therapeutic management, and post-MI care. Late gadolinium enhancement-cardiac magnetic resonance (LGE-CMR) is regarded as the gold standard for precise infarct tissue localization in MI patients. A fundamental limitation of LGE-CMR is the invasive intravenous introduction of gadolinium-based contrast agents that present potential high-risk toxicity, particularly for individuals with underlying chronic kidney diseases. Herein, we develop a completely non-invasive methodology that identifies the location and extent of an infarct region in the left ventricle via a machine learning (ML) model using only cardiac strains as inputs. In this transformative approach, we demonstrate the remarkable performance of a multi-fidelity ML model that combines rodent-based in-silico-generated training data (low-fidelity) with very limited patient-specific human data (high-fidelity) in predicting LGE ground truth. Our results offer a new paradigm for developing feasible prognostic tools by augmenting synthetic simulation-based data with very small amounts of in-vivo human data. More broadly, the proposed approach can significantly assist with addressing biomedical challenges in healthcare where human data are limited.

Effect of sacubitril-valsartan on left ventricular remodeling in patients with acute myocardial infarction after primary percutaneous coronary intervention: a systematic review and meta-analysis

Background

Sacubitril-valsartan has been widely reported for reducing the risk of cardiovascular death and improving left ventricular remodeling in patients with heart failure (HF). However, the effect of sacubitril-valsartan in patients with acute myocardial infarction (AMI) remains controversial. Therefore, we conducted this meta-analysis to investigate whether sacubitril-valsartan could reverse left ventricular remodeling and reduce cardiovascular adverse events in AMI patients after primary percutaneous coronary intervention (PPCI).

Materials and methods

Two researchers independently retrieved the relevant literature from PubMed, Embase, The Cochrane Library, China National Knowledge Infrastructure (CNKI), and the Wanfang database. The retrieval time was limited from inception to 1 June 2023. Randomized controlled trials (RCTs) meeting the inclusion criteria were included and analyzed.

Results

In total, 21 RCTs involving 2442 AMI patients who underwent PPCI for revascularization were included in this meta-analysis. The meta-analysis showed that compared with the angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB), sacubitril-valsartan treatment in AMI patients after PPCI significantly reduced left ventricular end-diastolic dimension (LVEDD) (weighted mean difference (WMD) -3.11, 95%CI: -4.05∼-2.16, p < 0.001), left ventricular end-diastolic volume (LVEDV) (WMD -7.76, 95%CI: -12.24∼-3.27, p = 0.001), left ventricular end-systolic volume (LVESV) (WMD -6.80, 95%CI: -9.45∼-4.15, p < 0.001) and left ventricular end-systolic dimension (LVESD) (WMD -2.53, 95%CI: -5.30-0.24, p < 0.001). Subgroup analysis according to the dose of sacubitril-valsartan yielded a similar result. Meanwhile, PPCI patients using sacubitril-valsartan therapy showed lower risk of major adverse cardiac events (MACE) (OR = 0.36, 95%CI: 0.28-0.46, p < 0.001), myocardial reinfarction (OR = 0.54, 95%CI: 0.30-0.98, p = 0.041) and HF (OR = 0.35, 95%CI: 0.26-0.47, p < 0.001) without increasing the risk of renal insufficiency, hyperkalemia, or symptomatic hypotension. At the same time, the change of LV ejection fraction (LVEF) (WMD 3.91, 95%CI: 3.41-4.41, p < 0.001), 6 min walk test (6MWT) (WMD 43.56, 95%CI: 29.37-57.76, p < 0.001) and NT-proBNP level (WMD -130.27, 95%CI: -159.14∼-101.40, p < 0.001) were statistically significant.

Conclusion

In conclusion, our meta-analysis indicates that compared with ACEI/ARB, sacubitril-valsartan may be superior to reverse left ventricular remodeling, improve cardiac function, and effectively reduce the risk of MACE, myocardial reinfarction, and HF in AMI patients after PPCI during follow-up without increasing the risk of adverse reactions including renal insufficiency, hyperkalemia, and symptomatic hypotension.

Cardiovascular Disease, Depressive Symptoms, and Heart Failure in Mexican American Aged 75 Years and Older During 12 Years of Follow Up

Objective

To examine the relationship of cardiovascular disease (CVD) and high depressive symptoms (HDS) with heart failure (HF) among Mexican American older adults without HF at baseline over 12-years of follow-up.

Methods

A 12-year prospective cohort study of 1,018 Mexicans Americans aged 75 and older from the Hispanic Established Population for the Epidemiologic Study of the Elderly (2004-2016). Measures included socio-demographics, CVD (heart attack or stroke), HDS, smoking status, body mass index, cognitive function, and HF. Participant were grouped into: CVD and HDS (n=11), CVD only (n=122), HDS only (n=44), and no CVD or HDS (n=841). Odds ratio (OR) and 95% Confidence Interval (CI) of HF over time were estimated using the Generalized Estimating Equation.

Results

Participants with CVD and HDS and those with HDS only had greater odds (OR=4.70, 95%CI=1.98-11.2 and OR=3.26, 95%CI=1.82-5.84, respectively) of HF over time, after controlling for all covariates. No significant association was found between CVD only and HF (OR=1.25, 95%CI=0.90-1.76).

Conclusion

Mexican American older adults with HDS only or both HDS and CVD were at high risk of HF. Appropriate management of CVD and depressive symptoms may reduce the onset of HF among this population.

Pressure-Controlled Intermittent Coronary Sinus Occlusion (PiCSO) in Acute Myocardial Infarction: The PiCSO-AMI-I Trial

BACKGROUND

Primary percutaneous coronary intervention (pPCI) has improved clinical outcomes in patients with ST-segment-elevation myocardial infarction. However, as many as 50% of patients still have suboptimal myocardial reperfusion and experience extensive myocardial necrosis. The PiCSO-AMI-I trial (Pressure-Controlled Intermittent Coronary Sinus Occlusion-Acute Myocardial Infarction-I) evaluated whether PiCSO therapy can further reduce myocardial infarct size (IS) in patients undergoing pPCI.

METHODS

Patients with anterior ST-segment-elevation myocardial infarction and Thrombolysis in Myocardial Infarction flow 0-1 were randomized at 16 European centers to PiCSO-assisted pPCI or conventional pPCI. The PiCSO Impulse Catheter (8Fr balloon-tipped catheter) was inserted via femoral venous access after antegrade flow restoration of the culprit vessel and before proceeding with stenting. The primary end point was the difference in IS (expressed as a percentage of left ventricular mass) at 5 days by cardiac magnetic resonance. Secondary end points were the extent of microvascular obstruction and intramyocardial hemorrhage at 5 days and IS at 6 months.

RESULTS

Among 145 randomized patients, 72 received PiCSO-assisted pPCI and 73 conventional pPCI. No differences were observed in IS at 5 days (27.2%±12.4% versus 28.3%±11.45%; P=0.59) and 6 months (19.2%±10.1% versus 18.8%±7.7%; P=0.83), nor were differences between PiCSO-treated and control patients noted in terms of the occurrence of microvascular obstruction (67.2% versus 64.6%; P=0.85) or intramyocardial hemorrhage (55.7% versus 60%; P=0.72). The study was prematurely discontinued by the sponsor with no further clinical follow-up beyond 6 months. However, up to 6 months of PiCSO use appeared safe with no device-related adverse events.

CONCLUSIONS

In this prematurely discontinued randomized trial, PiCSO therapy as an adjunct to pPCI did not reduce IS when compared with conventional pPCI in patients with anterior ST-segment-elevation myocardial infarction. PiCSO use was associated with increased procedural time and contrast but no increase in adverse events up to 6 months.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03625869.

Widely distributable and retainable in-situ gelling material for treating myocardial infarction

Intramyocardial hydrogel injection is a promising therapy to prevent negative remodeling following myocardial infarction (MI). In this study, we report a mechanism for in-situ gel formation without external stimulation, resulting in an injectable and tissue-retainable hydrogel for MI treatment, and investigate its therapeutic outcomes. A liquid-like polymeric solution comprising poly(3-acrylamidophenylboronic acid-co-acrylamide) (BAAm), polyvinyl alcohol (PVA), and sorbitol (S) increases the viscous modulus by reducing the pre-added sorbitol concentration is developed. This solution achieves a sol-gel transition in-vitro in heart tissue by spontaneously diffusing the sorbitol. After intramyocardial injection, the BAAm/PVA/S with lower initial viscous modulus widely spreads in the myocardium and gelate compared to a viscoelastic alginate (ALG) hydrogel and is retained longer than the BAAm/S solution. Serial echocardiogram analyses prove that injecting the BAAm/PVA/S into the hearts of subacute MI rats significantly increases the fraction shortening and ejection shortening and attenuates the expansion of systolic LV diameter for up to 21 d after injection compared to the saline injection as a control, but the ALG injection does not. In addition, histological evaluation shows that only the BAAm/PVA/S decreases the infarct size and increases the wall thickness 21 d after injection. The BAAm/PVA/S intramyocardial injection is better at restraining systolic ventricular dilatation and cardiac failure in the rat MI model than in the control groups. Our findings highlight an effective injectable hydrogel therapy for MI by optimizing injectability-dependent distribution and retention of injected material. STATEMENT OF SIGNIFICANCE: In-situ gelling material is a promising strategy for intramyocardial hydrogel injection therapy for myocardial infarction (MI). Since the sol-gel transition of reported materials is driven by external stimulation such as temperature, pH, or ultraviolet, their application in vivo remains challenging. In this study, we first reported a synthetic in-situ gelling material (BAAm/PVA/S) whose gelation is stimulated by spontaneously reducing pre-added sorbitol after contacting the heart tissue. The BAAm/PVA/S solution spreads evenly, and is retained for at least 21 d in the heart tissue. Our study demonstrated that intramyocardial injection of the BAAm/PVA/S with more extensive distribution and longer retention had better effects on preventing LV dilation and improving cardiac function after MI than that of viscoelastic ALG and saline solution. We expect that these findings provide fundamental information for the optimum design of injectable biomaterials for treating MI.

High serum lactate dehydrogenase as a predictor of cardiac insufficiency at follow-up in elderly patients with acute myocardial infarction

BACKGROUND

Impairment of cardiac function progresses after acute myocardial infarction (AMI). Lactate dehydrogenase (LDH), a marker of cardiac injury and an enzyme in anaerobic glycolysis, is suggested as a risk factor for patient mortality in inflammatory diseases.

METHODS

In this study, 448 older and 445 younger AMI patients were recruited and followed up. The effect of baseline serum LDH on post-infarction cardiac function was assessed at follow-up.

RESULTS

Elderly patients in the high baseline LDH group had a high risk of being diagnosed with cardiac insufficiency during follow-up (adjusted hazard ratio: 3.643, P = 0.007), and the follow-up left ventricular ejection fraction of the quartile subgroup tended to decrease with increasing in baseline serum LDH (adjusted odds ratio: 1.301, P = 0.001) for each 100 U/L increase. The LVDd and LVVd of elderly patients in the high LDH group were not significantly different from those of patients in the normal LDH group at baseline but were further increased in the high LDH group at follow-up. In younger patients, the effect of LDH on post-infarction cardiac structure and function was similar to that in older patients, but unlike older patients, Cox regression analysis showed that LDH was not the predominant influence.

CONCLUSION

Longitudinal changes in cardiac function were independently associated with high baseline serum LDH levels in patients with AMI. Baseline LDH levels are superior to other myocardial injury markers and may be a useful parameter in predicting future cardiac dysfunction after AMI, especially in the elderly.

Intramyocardial Hemorrhage Leads to Higher MACE Rate by Increasing Myocardial Infarction Volume in Patients with STEMI

Background and Aims

Whether IMH can directly cause persistent myocardial necrosis after reperfusion therapy in STEMI patients is still unclear. We conducted a prospective study to compare the cardiovascular parameters in patients with STEMI with and without IMH to explore the potential correlations between IMH and poor outcomes.

Methods and Results

We prospectively enrolled 65 consecutive patients with newly diagnosed STEMI admitted to the CCU of the Second Xiangya Hospital of Central South University between April 2019 and November 2021, all of whom underwent primary PCI. Of these, 38 (58.5%) and 27 (41.5%) patients were in the IMH-absent and IMH-present groups, respectively. At a mean time of 5-7 days after reperfusion therapy, the volume of MI measured using LGE sequence was larger in STEMI patients with IMH than in patients without IMH (34.2 ± 12.7 cm3 vs 21.1 ± 13.1 cm3, P<0.001). HsTNT levels were significantly higher in the IMH-present group than in the IMH-absent [2500.0 (1681.5-4307.0) pg/mL vs 1710.0 (203.0-3363.5) pg/mL, P=0.021] group during hospitalization. The LVEF measured using CMR in the IMH-present group was lower than that in the IMH-absent group (30.7 ± 9.8% vs 42.3 ± 11.0%, P < 0.001). The rate of MACE at 12 months in IMH-present group was significantly higher than in the IMH-absent group (9/27 VS 2/38, P = 0.012).

Conclusion

IMH can lead to further expansion of MI volumes in patients with STEMI, resulting in lower LVEF and higher MACE rate in the post-discharge follow-up.

Angiotensin II Is Involved in MLKL Activation During the Development of Heart Failure Following Myocardial Infarction in Rats

Several reports assume that myocardial necroptotic cell death is induced during the development of chronic heart failure. Although it is well accepted that angiotensin II induces apoptotic cell death of cardiac myocytes, the involvement of angiotensin II in the induction of myocardial necroptosis during the development of heart failure is still unknown. Therefore, we examined the role of angiotensin II in myocardial necroptosis using rat failing hearts following myocardial infarction and cultured cardiomyocytes. We found that administration of azilsartan, an angiotensin II AT1 receptor blocker, or trandolapril, an angiotensin-converting enzyme inhibitor, to rats from the 2nd to the 8th week after myocardial infarction resulted in preservation of cardiac function and attenuation of mixed lineage kinase domain-like (MLKL) activation. Furthermore, the ratio of necroptotic cell death was increased in neonatal rat ventricular cardiomyocytes cultured with conditioned medium from rat cardiac fibroblasts in the presence of angiotensin II. This increase in necroptotic cells was attenuated by pretreatment with azilsartan. Furthermore, activated MLKL was increased in cardiomyocytes cultured in conditioned medium. Pretreatment with azilsartan also prevented the conditioned medium-induced increase in activated MLKL. These results suggest that angiotensin II contributes to the induction of myocardial necroptosis during the development of heart failure.

Development of a thick and functional human adipose-derived stem cell tissue sheet for myocardial infarction repair in rat hearts

BACKGROUND

Heart failure (HF) is a major cause of death worldwide. The most effective treatment for HF is heart transplantation, but its use is limited by the scarcity of donor hearts. Recently, stem cell-based therapy has emerged as a promising approach for treating myocardial infarction. Our research group has been investigating the use of human induced pluripotent stem cell-derived cardiomyocyte patches as a potential therapeutic candidate. We have successfully conducted eight cases of clinical trials and demonstrated the safety and effectiveness of this approach. However, further advancements are necessary to overcome immune rejection and enhance therapeutic efficacy. In this study, we propose a novel and efficient technique for constructing mesenchymal stem cell (MSC) tissue sheets, which can be transplanted effectively for treating myocardial infarction repair.

METHODS

We applied a one-step method to construct the human adipose-derived mesenchymal stem cell (hADSC) tissue sheet on a poly(lactic-co-glycolic acid) fiber scaffold. Histology, immunofluorescence, and paracrine profile assessment were used to determine the organization and function of the hADSC tissue sheet. Echocardiography and pathological analyses of heart sections were performed to evaluate cardiac function, fibrosis area, angiogenesis, and left ventricular remodeling.

RESULTS

In vitro, the hADSC tissue sheet showed great organization, abundant ECM expression, and increased paracrine secretion than single cells. In vivo, the hADSC tissue sheet group demonstrated improved cardiac functional recovery, less ventricular remodeling, decreased fibrosis, and enhanced angiogenesis than the MI group.

CONCLUSIONS

We developed thick and functional hADSC tissue sheets via the one-step strategy. The hADSC tissue sheet showed excellent performance in treating myocardial infarction in the rat model.

Reduced graphene oxide coated alginate scaffolds: potential for cardiac patch application

BACKGROUND

Cardiovascular diseases, particularly myocardial infarction (MI), are the leading cause of death worldwide and a major contributor to disability. Cardiac tissue engineering is a promising approach for preventing functional damage or improving cardiac function after MI. We aimed to introduce a novel electroactive cardiac patch based on reduced graphene oxide-coated alginate scaffolds due to the promising functional behavior of electroactive biomaterials to regulate cell proliferation, biocompatibility, and signal transition.

METHODS

The fabrication of novel electroactive cardiac patches based on alginate (ALG) coated with different concentrations of reduced graphene oxide (rGO) using sodium hydrosulfite is described here. The prepared scaffolds were thoroughly tested for their physicochemical properties and cytocompatibility. ALG-rGO scaffolds were also tested for their antimicrobial and antioxidant properties. Subcutaneous implantation in mice was used to evaluate the scaffolds' ability to induce angiogenesis.

RESULTS

The Young modulus of the scaffolds was increased by increasing the rGO concentration from 92 ± 4.51 kPa for ALG to 431 ± 4.89 kPa for ALG-rGO-4 (ALG coated with 0.3% w/v rGO). The scaffolds' tensile strength trended similarly. The electrical conductivity of coated scaffolds was calculated in the semi-conductive range (~ 10-4 S/m). Furthermore, when compared to ALG scaffolds, human umbilical vein endothelial cells (HUVECs) cultured on ALG-rGO scaffolds demonstrated improved cell viability and adhesion. Upregulation of VEGFR2 expression at both the mRNA and protein levels confirmed that rGO coating significantly boosted the angiogenic capability of ALG against HUVECs. OD620 assay and FE-SEM observation demonstrated the antibacterial properties of electroactive scaffolds against Escherichia coli, Staphylococcus aureus, and Streptococcus pyogenes. We also showed that the prepared samples possessed antioxidant activity using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay and UV-vis spectroscopy. Histological evaluations confirmed the enhanced vascularization properties of coated samples after subcutaneous implantation.

CONCLUSION

Our findings suggest that ALG-rGO is a promising scaffold for accelerating the repair of damaged heart tissue.

Longitudinal Trajectory Modeling to Assess Adherence to Sacubitril/Valsartan among Patients with Heart Failure

Medication adherence in chronic conditions is a long-term process. Modeling longitudinal trajectories using routinely collected prescription data is a promising method for describing adherence patterns and identifying at-risk groups. The study aimed to characterize distinct long-term sacubitril/valsartan adherence trajectories and factors associated with them in patients with heart failure (HF). Subjects with incident HF starting sac/val in 2017-2018 were identified from the Campania Regional Database for Medication Consumption. We estimated patients' continuous medication availability (CMA9; R package AdhereR) during a 12-month period. We selected groups with similar CMA9 trajectories (Calinski-Harabasz criterion; R package kml). We performed multinomial regression analysis, assessing the relationship between demographic and clinical factors and adherence trajectory groups. The cohort included 4455 subjects, 70% male. Group-based trajectory modeling identified four distinct adherence trajectories: high adherence (42.6% of subjects; CMA mean 0.91 ± 0.08), partial drop-off (19.6%; CMA 0.63 ± 0.13), moderate adherence (19.3%; CMA 0.54 ± 0.11), and low adherence (18.4%; CMA 0.17 ± 0.12). Polypharmacy was associated with partial drop-off adherence (OR 1.194, 95%CI 1.175-1.214), while the occurrence of ≥1 HF hospitalization (OR 1.165, 95%CI 1.151-1.179) or other hospitalizations (OR 1.481, 95%CI 1.459-1.503) were associated with low adherence. This study found that tailoring patient education, providing support, and ongoing monitoring can boost adherence within different groups, potentially improving health outcomes.

Factors associated with complications in ST-elevation myocardial infarction: a single-center experience

BACKGROUND

ST-elevation myocardial infarction (STEMI) is a major public health problem. This study aimed to determine the prevalence and identify the determinants of STEMI-related complications in the Cardiology Intensive Care Unit of the Sud Francilien Hospital Center (SFHC).

METHODS

We retrospectively analyzed the data of 315 patients with STEMI aged ≥ 18 years. Logistic regression was used to identify factors independently associated with the occurrence of complications.

RESULTS

Overall, 315 patients aged 61.7 ± 13.4 years, of whom 261 were men, had STEMI during the study period. The hospital frequency of STEMI was 12.7%. Arrhythmias and acute heart failure were the main complications. Age ≥ 75 years (adjusted odds ratio [aOR], 5.18; 95% confidence interval [CI], 3.92-8.75), hypertension (aOR, 3.38; 95% CI, 1.68-5.82), and cigarette smoking (aOR, 3.52; 95% CI, 1.69-7.33) were independent determinants of acute heart failure. Meanwhile, diabetes mellitus (aOR, 1.74; 95% CI, 1.09-3.37), history of atrial fibrillation (aOR, 2.79; 95% CI, 1.66-4.76), history of stroke or transient ischemic attack (aOR, 1.99; 95% CI, 1.31-2.89), and low high-density lipoprotein-cholesterol (HDL-C) levels (aOR, 3.70; 95% CI, 1.08-6.64) were independent determinants of arrhythmias.

CONCLUSION

STEMI is a frequent condition at SFHC and is often complicated by acute heart failure and arrhythmias. Patients aged ≥ 75 years, those with hypertension or diabetes mellitus, smokers, those with a history of atrial fibrillation or stroke, and those with low HDL-C levels require careful monitoring for the early diagnosis and management of these complications.

Monocyte heterogeneity in cardiovascular disease

Monocytes circulate the vasculature at steady state and are recruited to sites of inflammation where they differentiate into macrophages (MФ) to replenish tissue-resident MФ populations and engage in the development of cardiovascular disease (CVD). Monocytes display considerable heterogeneity, currently reflected by a nomenclature based on their expression of cluster of differentiation (CD) 14 and CD16, distinguishing CD14++CD16- classical (cMo), CD14++CD16+ intermediate (intMo) and CD14+CD16++ non-classical (ncMo) monocytes. Several reports point to shifted subset distributions in the context of CVD, with significant association of intMo numbers with atherosclerosis, myocardial infarction, and heart failure. However, clear indications of their causal involvement as well as their predictive value for CVD are lacking. As recent high-parameter cytometry and single-cell RNA sequencing (scRNA-Seq) studies suggest an even higher degree of heterogeneity, better understanding of the functionalities of these subsets is pivotal. Considering their high heterogeneity, surprisingly little is known about functional differences between MФ originating from monocytes belonging to different subsets, and implications thereof for CVD pathogenesis. This paper provides an overview of recent findings on monocyte heterogeneity in the context of homeostasis and disease as well as functional differences between the subsets and their potential to differentiate into MФ, focusing on their role in vessels and the heart. The emerging paradigm of monocyte heterogeneity transcending the current tripartite subset division argues for an updated nomenclature and functional studies to substantiate marker-based subdivision and to clarify subset-specific implications for CVD.

Protocatechuic acid prevents isoproterenol-induced heart failure in mice by downregulating kynurenine-3-monooxygenase

Protocatechuic acid (3,4-dihydroxybenzoic acid) prevents oxidative stress, inflammation and cardiac hypertrophy. This study aimed to investigate the therapeutic effects of protocatechuic acid in an isoproterenol-induced heart failure mouse model and to identify the underlying mechanisms. To establish the heart failure model, C57BL/6NTac mice were given high-dose isoproterenol (80 mg/kg body weight) for 14 days. Echocardiography revealed that protocatechuic acid reversed the isoproterenol-induced downregulation of fractional shortening and ejection fraction. Protocatechuic acid attenuated cardiac hypertrophy as evidenced by the decreased heart-weight-to-body-weight ratio and the expression of Nppb. RNA sequencing analysis identified kynurenine-3-monooxygenase (Kmo) as a potential target of protocatechuic acid. Protocatechuic acid treatment or transfection with short-interfering RNA against Kmo ameliorated transforming growth factor β1-induced upregulation of Kmo, Col1a1, Col1a2 and Fn1 in vivo or in neonatal rat cardiac fibroblasts. Kmo knockdown attenuated the isoproterenol-induced increase in cardiomyocyte size, as well as Nppb and Col1a1 expression in H9c2 cells or primary neonatal rat cardiomyocytes. Moreover, protocatechuic acid attenuated Kmo overexpression-induced increases in Nppb mRNA levels. Protocatechuic acid or Kmo knockdown decreased isoproterenol-induced ROS generation in vivo and in vitro. Thus, protocatechuic acid prevents heart failure by downregulating Kmo. Therefore, protocatechuic acid and Kmo constitute a potential novel therapeutic agent and target, respectively, against heart failure.

Impact of Complete Revascularization on Development of Heart Failure in Patients With Acute Coronary Syndrome and Multivessel Disease: A Subanalysis of the CORALYS Registry

Background The impact of complete revascularization (CR) on the development of heart failure (HF) in patients with acute coronary syndrome and multivessel coronary artery disease undergoing percutaneous coronary intervention remains to be elucidated. Methods and Results Consecutive patients with acute coronary syndrome with multivessel coronary artery disease from the CORALYS (Incidence and Predictors of Heart Failure After Acute Coronary Syndrome) registry were included. Incidence of first hospitalization for HF or cardiovascular death was the primary end point. Patients were stratified according to completeness of coronary revascularization. Of 14 699 patients in the CORALYS registry, 5054 presented with multivessel disease. One thousand four hundred seventy-three (29.2%) underwent CR, while 3581 (70.8%) did not. Over 5 years follow-up, CR was associated with a reduced incidence of the primary end point (adjusted hazard ratio [HR], 0.66 [95% CI, 0.51-0.85]), first HF hospitalization (adjusted HR, 0.67 [95% CI, 0.49-0.90]) along with all-cause death and cardiovascular death alone (adjusted HR, 0.74 [95% CI, 0.56-0.97] and HR, 0.56 [95% CI, 0.38-0.84], respectively). The results were consistent in the propensity-score matching population and in inverse probability treatment weighting analysis. The benefit of CR was consistent across acute coronary syndrome presentations (HR, 0.59 [95% CI, 0.39-0.89] for ST-segment elevation myocardial infarction and HR, 0.71 [95% CI, 0.50-0.99] for non-ST-elevation acute coronary syndrome) and in patients with left ventricular ejection fraction >40% (HR, 0.52 [95% CI, 0.37-0.72]), while no benefit was observed in patients with left ventricular ejection fraction ≤40% (HR, 0.77 [95% CI, 0.37-1.10], P for interaction 0.04). Conclusions CR after acute coronary syndrome reduced the risk of first hospitalization for HF and cardiovascular death, as well as first HF hospitalization, and cardiovascular and overall death both in patients with ST-segment elevation myocardial infarction and non-ST-elevation acute coronary syndrome. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04895176.

Persistent mortality and heart failure burden of anterior ST-segment elevation myocardial infarction following primary percutaneous coronary intervention: real-world evidence from the US Medicare Data Set

OBJECTIVES

We sought to compare the temporal trends in the incidence of death and rehospitalisation for congestive heart failure (CHF) following anterior ST-elevation myocardial infarction (STEMI) in a Medicare cohort of beneficiaries treated with primary percutaneous coronary intervention (PCI) in 2005 (n=1479) with those treated in 2016 through quarter (Q) 2 of 2017 (n=22 432).

DESIGN

This retrospective analysis examined outcomes using both descriptive and regression analysis to control for differences in patient clinical characteristics over time.

PRIMARY OUTCOME MEASURES

The primary outcomes are 1 year and 2 year rates of mortality and re-hospitalisation for CHF.

RESULTS

The 1 year mortality rate was numerically higher in the 2016 cohort at 10.3% (95% CI 9.9 to 10.7) versus 8.9% (CI 7.4 to 10.3; p=0.068). The 2 year mortality rate was significantly higher in the 2016 cohort at 14.5% (CI 13.9 to 15.1) versus 11.4% (CI 9.2 to 13.6; p<0.01). The 1 year rehospitalisation for CHF was lower in the 2016 cohort at 10.6% (CI 10.0 to 11.2) versus 16.7% (CI 14.0 to 19.4; p<0.001), but the 2 year rate was not significantly different at 19.3% (CI 17.7 to 20.9) versus 20.7% (CI 16.4 to 24.9; p=0.55). After adjustment for covariates with two models, the 1 year mortality increased by 2.3% (CI 0.8 to 3.7; p<0.01) and 4.1% (CI 2.6 to 5.6; p<0.001) in the 2016 cohort. The 2 year adjusted mortality also increased by 4.2% (CI 2.0 to 6.4; p<0.001) and 6.5% (CI 4.2 to 8.7; p<0.001) in the 2016 cohort. The risk adjusted trends for rehospitalisation for CHF were similar to the unadjusted findings.

CONCLUSIONS

Despite prior improvements in STEMI outcomes in the reperfusion era related to the broad adoption of timely PCI, there is a persistent high mortality and CHF burden in Medicare beneficiaries with anterior STEMI. New strategies that address reperfusion injury and enhance myocardial salvage are needed.

Simple Complexity: Incorporating Bioinspired Delivery Machinery within Self-Assembled Peptide Biogels

Bioinspired self-assembly is a bottom-up strategy enabling biologically sophisticated nanostructured biogels that can mimic natural tissue. Self-assembling peptides (SAPs), carefully designed, form signal-rich supramolecular nanostructures that intertwine to form a hydrogel material that can be used for a range of cell and tissue engineering scaffolds. Using the tools of nature, they are a versatile framework for the supply and presentation of important biological factors. Recent developments have shown promise for many applications such as therapeutic gene, drug and cell delivery and yet are stable enough for large-scale tissue engineering. This is due to their excellent programmability—features can be incorporated for innate biocompatibility, biodegradability, synthetic feasibility, biological functionality and responsiveness to external stimuli. SAPs can be used independently or combined with other (macro)molecules to recapitulate surprisingly complex biological functions in a simple framework. It is easy to accomplish localized delivery, since they can be injected and can deliver targeted and sustained effects. In this review, we discuss the categories of SAPs, applications for gene and drug delivery, and their inherent design challenges. We highlight selected applications from the literature and make suggestions to advance the field with SAPs as a simple, yet smart delivery platform for emerging BioMedTech applications.

Complement factor D derived from epicardial adipose tissue participates in cardiomyocyte apoptosis after myocardial infarction by mediating PARP-1 activity

BACKGROUND

Acute myocardial infarction (MI) is considered to be the main cause of congestive heart failure. The aim of this study was to provide an in-depth analysis of athophysiological processes and provide key targets for intervention in the occurrence of acute MI.

METHODS

A rat model of MI was established by ligation of left anterior descending branch. Heart tissue, epicardial adipose tissue (EAT) and subcutaneous adipose tissue (SAT) were collected. H9c2 cells were used to explore the mechanism of complement factor D (CFD) regulating cardiomyocyte apoptosis.

RESULTS

Myocardial apoptosis were observed in MI rat, and more EAT was found in the MI group in vivo. The conditioned medium prepared by EAT (EAT-CM) significantly reduced the activity of H9c2 cells. The content of CFD in EAT was significantly increased, and CFD promoted cardiomyocyte apoptosis in vitro and CFD-IN1 (a selective inhibitor of CFD) could revised this effect. CFD induced poly ADP-ribosepolymerase-1 (PARP-1) overactivation. Furthermore, the addition of pan-caspase inhibitor Z-VAD in the SAT-CM + CFD group couldn't affect H9c2 cell apoptosis. CFD induced cell apoptosis via PARP-1 activation and PARP-1 inhibitor 3-Aminobenzamide could revise this effect. The injection of CFD-IN1 in MI rat model confirmed that inhibition of CFD activity alleviated cardiomyocytes apoptosis.

CONCLUSION

Our findings indicate that EAT mediating cardiomyocyte apoptosis after MI through secretion of CFD and activation of PARP-1 activity.

Gasdermin D-mediated pyroptosis in myocardial ischemia and reperfusion injury: Cumulative evidence for future cardioprotective strategies

Cardiomyocyte death is one of the major mechanisms contributing to the development of myocardial infarction (MI) and myocardial ischemia/reperfusion (MI/R) injury. Due to the limited regenerative ability of cardiomyocytes, understanding the mechanisms of cardiomyocyte death is necessary. Pyroptosis, one of the regulated programmed cell death pathways, has recently been shown to play important roles in MI and MI/R injury. Pyroptosis is activated by damage-associated molecular patterns (DAMPs) that are released from damaged myocardial cells and activate the formation of an apoptosis-associated speck-like protein containing a CARD (ASC) interacting with NACHT, LRR, and PYD domains-containing protein 3 (NLRP3), resulting in caspase-1 cleavage which promotes the activation of Gasdermin D (GSDMD). This pathway is known as the canonical pathway. GSDMD has also been shown to be activated in a non-canonical pathway during MI and MI/R injury via caspase-4/5/11. Suppression of GSDMD has been shown to provide cardioprotection against MI and MI/R injury. Although the effects of MI or MI/R injury on pyroptosis have previously been discussed, knowledge concerning the roles of GSDMD in these settings remains limited. In this review, the evidence from in vitro, in vivo, and clinical studies focusing on cardiac GSDMD activation during MI and MI/R injury is comprehensively summarized and discussed. Implications from this review will help pave the way for a new therapeutic target in ischemic heart disease.

The cardiac wound healing response to myocardial infarction

Myocardial infarction (MI) is defined as evidence of myocardial necrosis consistent with prolonged ischemia. In response to MI, the myocardium undergoes a series of wound healing events that initiate inflammation and shift to anti-inflammation before transitioning to tissue repair that culminates in scar formation to replace the region of the necrotic myocardium. The overall response to MI is determined by two major steps, the first of which is the secretion of proteases by infiltrating leukocytes to breakdown extracellular matrix (ECM) components, a necessary step to remove necrotic cardiomyocytes. The second step is the generation of new ECM that comprises the scar; and this step is governed by the cardiac fibroblasts as the major source of new ECM synthesis. The leukocyte component resides in the middle of the two-step process, contributing to both sides as the leukocytes transition from pro-inflammatory to anti-inflammatory and reparative cell phenotypes. The balance between the two steps determines the final quantity and quality of scar formed, which in turn contributes to chronic outcomes following MI, including the progression to heart failure. This review will summarize our current knowledge regarding the cardiac wound healing response to MI, primarily focused on experimental models of MI in mice. This article is categorized under: Cardiovascular Diseases > Molecular and Cellular Physiology Immune System Diseases > Molecular and Cellular Physiology.

Exercise training after myocardial infarction increases survival but does not prevent adverse left ventricle remodeling and dysfunction in high-fat diet fed mice

AIMS

Aerobic exercise is an important component of rehabilitation after cardiovascular injuries including myocardial infarction (MI). In human studies, the beneficial effects of exercise after an MI are blunted in patients who are obese or glucose intolerant. Here, we investigated the effects of exercise on MI-induced cardiac dysfunction and remodeling in mice chronically fed a high-fat diet (HFD).

MAIN METHODS

C57Bl/6 male mice were fed either a standard (Chow; 21% kcal/fat) or HFD (60% kcal/fat) for 36 weeks. After 24 weeks of diet, the HFD mice were randomly subjected to an MI (MI) or a sham surgery (Sham). Following the MI or sham surgery, a subset of mice were subjected to treadmill exercise.

KEY FINDINGS

HFD resulted in obesity and glucose intolerance, and this was not altered by exercise or MI. MI resulted in decreased ejection fraction, increased left ventricle mass, increased end systolic and diastolic diameters, increased cardiac fibrosis, and increased expression of genes involved in cardiac hypertrophy and heart failure in the MI-Sed and MI-Exe mice. Exercise prevented HFD-induced cardiac fibrosis in Sham mice (Sham-Exe) but not in MI-Exe mice. Exercise did, however, reduce post-MI mortality.

SIGNIFICANCE

These data indicate that exercise significantly increased survival after MI in a model of diet-induced obesity independent of effects on cardiac function. These data have important translational ramifications because they demonstrate that environmental interventions, including diet, need to be carefully evaluated and taken into consideration to support the effects of exercise in the cardiac rehabilitation of patients who are obese.

A Critical Evaluation of Patient Pathways and Missed Opportunities in Treatment for Heart Failure

BACKGROUND

Heart failure (HF) is a global problem responsible for significant morbidity and mortality.

METHODS

This review describes the patient pathways and missed opportunities related to treatment for patients with HF.

RESULTS

The contemporary management strategies in HF, including medical therapies, device therapy, transplant, and palliative care. Despite the strong evidence base for therapies that improve prognosis and symptoms, there remains a large number of patients that are not optimally managed. The treatment of patients with HF is highly influenced by those who are caring for them and varies widely across geographical regions. HF patients can be broadly classified into two key groups: those who have known HF, and those who are incidentally found to have reduced left ventricular systolic dysfunction or other cardiac abnormality when an echocardiogram is performed. While all patients are under the care of a general practitioner or family doctor, in other instances, non-cardiologist physicians, cardiologists, and specialist HF nurses-each will have varying levels of expertise in managing HF-are part of the broader team involved in the specialist management of patients with HF.

CONCLUSIONS

There are many potential missed opportunities in HF treatment, which include general opportunities, medications, etiology-specific therapy, device therapy, therapies when initial treatments fail, and palliative care.

Device-Based Approaches Targeting Cardioprotection in Myocardial Infarction: The Expanding Armamentarium of Innovative Strategies

Coronary reperfusion therapy has played a pivotal role for reducing mortality and heart failure after acute myocardial infarction. Although several adjunctive approaches have been studied for reducing infarct size further, both ischemia-reperfusion injury and microvascular obstruction are still major contributors to both early and late clinical events after acute myocardial infarction. The progress in the field of cardioprotection has found several promising proof-of-concept preclinical studies. However, translation from bench to bedside has not been very successful. This comprehensive review discusses the importance of infarct size as a driver of clinical outcomes post-acute myocardial infarction and summarizes recent novel device-based approaches for infarct size reduction. Device-based interventions including mechanical cardiac unloading, myocardial cooling, coronary sinus interventions, supersaturated oxygen therapy, and vagal stimulation are discussed. Many of these approaches can modify ischemic myocardial biology before reperfusion and offer unique opportunities to target ischemia-reperfusion injury.

Carbohydrate antigen 125 combined with N-terminal pro-B-type natriuretic peptide in the prediction of acute heart failure following ST-elevation myocardial infarction

The value of serum carbohydrate antigen 125 (CA125) combined with N-terminal pro-B-type natriuretic peptide (NT-proBNP) in the evaluation of acute heart failure (AHF) after ST-segment elevation myocardial infarction (STEMI) remains unclear. The aim of this study was to evaluate the efficacy of CA125 combined with NT-proBNP in predicting AHF following STEMI. A total of 233 patients with STEMI were evaluated, including 39 patients with Killip II-IV and 194 patients with Killip I. The optimal cutoff point for predicting AHF was determined by receiver operating characteristic (ROC) curve, and the independent predictors of AHF were evaluated by multiple logistic regression. According to the cutoff value, it was divided into three groups: C1 = CA125 < 13.20 and NT-proBNP < 2300 (n = 138); C2 = CA125 ≥ 13.20 or NT-proBNP ≥ 2300 (n = 59); C3 = CA125 ≥ 13.20 and NT-proBNP ≥ 2300 (n = 36). Differences between groups were compared by odds ratio (OR). The levels of CA125 and NT-proBNP in AHF group were higher than those in non-AHF group (19.90 vs 10.00, P < .001; 2980.00 vs 1029.50, P < .001, respectively). The optimal cutoff values of CA125 and NT-proBNP for predicting AHF were 13.20 and 2300, both of which were independent predictors of AHF. The incidence of AHF during hospitalization was highest in C3 (69.44%), middle in C2 (20.34%) and lowest in C1 (1.45%). After adjustment for clinical confounding variables, compared with C1: C2 (OR = 6.41, 95% CI: 1.22-33.84, P = .029), C3 (OR = 19.27, 95% CI: 3.12-118.92, P = .001). Elevated CA125 and NT-proBNP are independent predictors of AHF in STEMI patients, and their combination can improve the recognition efficiency.

Myocardial Viability Testing in the Management of Ischemic Heart Failure

Although major advances have occurred lately in medical therapy, ischemic heart failure remains an important cause of death and disability. Viable myocardium represents a cause of reversible ischemic left ventricular dysfunction. Coronary revascularization may improve left ventricular function and prognosis in patients with viable myocardium. Although patients with impaired left ventricular function and multi-vessel coronary artery disease benefit the most from revascularization, they are at high risk of complications related to revascularization procedure. An important element in selecting the patients for myocardial revascularization is the presence of the viable myocardium. Multiple imaging modalities can assess myocardial viability and predict functional improvement after revascularization, with dobutamine stress echocardiography, nuclear imaging tests and magnetic resonance imaging being the most frequently used. However, the role of myocardial viability testing in the management of patients with ischemic heart failure is still controversial due to the failure of randomized controlled trials of revascularization to reveal clear benefits of viability testing. This review summarizes the current knowledge regarding the concept of viable myocardium, depicts the role and tools for viability testing, discusses the research involving this topic and the controversies related to the utility of myocardial viability testing and provides a patient-centered approach for clinical practice.

Blockade of Wnt Secretion Attenuates Myocardial Ischemia-Reperfusion Injury by Modulating the Inflammatory Response

Wnt (a portmanteau of Wingless and Int-1) signaling in the adult heart is largely quiescent. However, there is accumulating evidence that it gets reactivated during the healing process after myocardial infarction (MI). We here tested the therapeutic potential of the Wnt secretion inhibitor LGK-974 on MI healing. Ischemia/reperfusion (I/R) injury was induced in mice and Wnt signaling was inhibited by oral administration of the porcupine inhibitor LGK-974. The transcriptome was analyzed from infarcted tissue by using RNA sequencing analysis. The inflammatory response after I/R was evaluated by flow cytometry. Heart function was assessed by echocardiography and fibrosis by Masson's trichrome staining. Transcriptome and gene set enrichment analysis revealed a modulation of the inflammatory response upon administration of the Wnt secretion inhibitor LGK-974 following I/R. In addition, LGK-974-treated animals showed an attenuated inflammatory response and improved heart function. In an in vitro model of hypoxic cardiomyocyte and monocyte/macrophage interaction, LGK974 inhibited the activation of Wnt signaling in monocytes/macrophages and reduced their pro-inflammatory phenotype. We here show that Wnt signaling affects inflammatory processes after MI. The Wnt secretion inhibitor LGK-974 appears to be a promising compound for future immunomodulatory approaches to improve cardiac remodeling after MI.

Myocardial perfusion recovery induced by an α-calcitonin gene-related peptide analogue

BACKGROUND

Endogenous calcitonin gene-related peptide (CGRP) induces cardioprotective effects through coronary vasodilation. However, the systemic administration of CGRP induces peripheral vasodilation and positive chronotropic and inotropic effects. This study aims to examine the net effect on coronary perfusion of the systemically administered α-calcitonin gene-related peptide analogue, SAX, in rats during myocardial infarction.

METHODS

Forty Sprague-Dawley rats underwent myocardial infarction. Following left anterior descending artery occlusion, [99mTc]Tc-sestamibi was administered to determine the myocardial perfusion before treatment. Twenty minutes, 24 and 48 h after [99mTc]Tc-sestamibi injection, the rats were treated with either SAX or placebo. Final infarct size was determined three weeks later by [99mTc]Tc-sestamibi SPECT/CT scan.

RESULTS

Thirty-one rats survived the surgery and 20 completed the follow-up SPECT/CT scan (SAX n = 12; Placebo n = 8). At baseline, there was no difference in size of perfusion defect between the groups (P = .88), but at follow-up the SAX group had improved myocardial recovery compared to the placebo group (P = .04), corresponding to a relative perfusion recovery of 55% in SAX-treated rats.

CONCLUSION

The CGRP analogue, SAX, has a cardioprotective effect in this rat model of myocardial infarction, improving myocardial perfusion recovery after chronic occlusion of the coronary artery.

Mechanical response of cardiac microtissues to acute localized injury

After a myocardial infarction (MI), the heart undergoes changes including local remodeling that can lead to regional abnormalities in mechanical and electrical properties, ultimately increasing the risk of arrythmias and heart failure. While these responses have been successfully recapitulated in animal models of MI, local changes in tissue and cell-level mechanics caused by MI remain difficult to study in vivo. Here, we developed an in vitro cardiac microtissue (CMT) injury system which through acute focal injury recapitulates aspects of the regional responses seen following an MI. Using a pulsed laser, cell death was induced in the center of the microtissue causing a loss of calcium signaling and a complete loss of contractile function in the injured region and resulting in a 39% reduction in the CMT's overall force production. After 7 days, the injured area remained void of CMs and showed increased expression of vimentin and fibronectin, two markers for fibrotic remodeling. Interestingly, while the injured region showed minimal recovery, calcium amplitudes in uninjured regions returned to levels comparable to control. Furthermore, overall force production returned to pre-injury levels despite the lack of contractile function in the injured region. Instead, uninjured regions exhibited elevated contractile function, compensating for the loss of function in the injured region, drawing parallels to changes in tissue-level mechanics seen in vivo. Overall, this work presents a new in vitro model to study cardiac tissue remodeling and electromechanical changes after injury.

IL-6 inhibitors effectively reverse post-infarction cardiac injury and ischemic myocardial remodeling via the TGF-β1/Smad3 signaling pathway

Approximately one in four myocardial infarctions occur in older patients. The majority of therapeutic advances are either not appropriate or not tested in elderly patients. The main reasons for deviating from the guidelines are justified concerns regarding the effectiveness of the recommended forms of therapy, fear of adverse drug reactions and ethical concerns. Targeting interleukin 6 (IL-6) for ventricular remodeling after cardiovascular damage is a feasible alternative to standard polypharmaceutics, but the underlying molecular mechanisms are not well understood. Continuous activation of the IL-6-associated cytokine receptor gp130 leads to cardiomyopathic hypertrophy. TGFβ1 is involved in forming fibrosis in various organs, and its overexpression can cause myocardial hypertrophy and fibrosis. Il-6 has been hypothesized to be indirectly involved in cardiac remodeling via the TGFβ1/Smad signaling transduction pathway. In the present study, a rat model of acute myocardial ischemia, IL-6 and IL-6 receptor blockers were injected directly into the necrotic myocardium. Changes in cardiac function, myocardial infarction area, myocardial collagen, necrotic myocardial fibrosis and levels of TGFβ1, IL-6 and MMP2/9 were quantified in myocardial tissue fibrosis by ELISA. The present study demonstrated that IL-6 stimulated myocardial fibrosis through the TGFβ1-Smad-MM2/9 signaling transduction pathway. Overall, this provided a solid foundation for understanding the relationship between IL-6 and ventricular remodeling.

Celastrol: A Promising Agent Fighting against Cardiovascular Diseases

Cardiovascular diseases (CVD) are leading causes of morbidity and mortality worldwide; therefore, seeking effective therapeutics to reduce the global burden of CVD has become increasingly urgent. Celastrol, a bioactive compound isolated from the roots of the plant Tripterygium wilfordii (TW), has been attracting increasing research attention in recent years, as it exerts cardiovascular treatment benefits targeting both CVD and their associated risk factors. Substantial evidence has revealed a protective role of celastrol against a broad spectrum of CVD including obesity, diabetes, atherosclerosis, cerebrovascular injury, calcific aortic valve disease and heart failure through complicated and interlinked mechanisms such as direct protection against cardiomyocyte hypertrophy and death, and indirect action on oxidation and inflammation. This review will mainly summarize the beneficial effects of celastrol against CVD, largely based on in vitro and in vivo preclinical studies, and the potential underlying mechanisms. We will also briefly discuss celastrol’s pharmacokinetic limitations, which hamper its further clinical applications, and prospective future directions.

Prognostic implications for patients after myocardial infarction: an integrative literature review and in-depth interviews with patients and experts

Background

As patients with myocardial infarction (MI) survive for a long time after acute treatment, it is necessary to pay attention to the prevention of poor prognosis such as heart failure (HF). To identify the influencing factors of adverse clinical outcomes through a review of prospective cohort studies of post-MI patients, and to draw prognostic implications through in-depth interviews with post-MI patients who progressed to HF and clinical experts.

Methods

A mixed-method design was used that combined a scoping review of 21 prospective cohort studies, in-depth interviews with Korean post-MI patients with HF, and focus group interviews with cardiologists and nurses.

Results

A literature review showed that old age, diabetes, high Killip class, low left ventricular ejection fraction, recurrent MI, comorbidity of chronic disease and current smoking, and low socioeconomic status were identified as influencing factors of poor prognosis. Through interviews with post-MI patients, these influencing factors identified in the literature as well as a lack of disease awareness and lack of self-care were confirmed. Experts emphasized the importance of maintaining a healthy lifestyle after acute treatment with the recognition that it is a chronic disease that must go together for a lifetime.

Conclusion

This study confirmed the factors influencing poor prognosis after MI and the educational needs of post-MI patients with transition to HF. Healthcare providers should continue to monitor the risk group, which is expected to have a poor prognosis, along with education emphasizing the importance of self-care such as medication and lifestyle modification.

Epidemiology of heart failure hospitalization in patients with stable atherothrombotic disease: Insights from the TRA 2°P-TIMI 50 trial

BACKGROUND

Heart failure (HF) is a growing public health problem and ischemic heart disease is an important risk factor. Understanding the epidemiology of HF in patients with atherosclerosis may help identify subgroups at greater risk who have the potential to derive greater benefit from preventive strategies.

METHODS AND RESULTS

The TRA 2°P-TIMI 50 trial randomized 26,449 patients with stable atherosclerosis to the antiplatelet agent vorapaxar versus placebo. Hospitalization for HF (HHF) endpoints were adjudicated from serious adverse events by blinded structured review using established definitions. HHF incidence was estimated using Kaplan-Meier analysis. Independent predictors of HHF risk were identified using multivariable logistic regression. The effect of vorapaxar on HHF risk was explored using Cox regression. The estimated incidence of HHF at 3 years was 1.6%. Independent predictors of HHF included prior HF (adjusted odds ratio [adj-OR]: 8.31; 95% confidence interval [CI]: 6.56-10.54), age (adj-OR [per 10 years]: 1.67; 95% CI: 1.47-1.89), type 2 diabetes mellitus (T2DM; adj-OR: 2.55; 95% CI: 2.01-3.24), polyvascular disease (two-territory disease, adj-OR: 1.89; 95% CI: 1.46-2.44; three-territory disease, adj-OR: 2.68; 95% CI: 1.94-3.70), chronic kidney disease (CKD; adj-OR: 1.65; 95% CI: 1.30-2.11), body mass index (BMI; adj-OR [per 5 kg/m² ]: 1.15; 95% CI: 1.03-1.27), prior myocardial infarction (MI) (adj-OR: 1.35; 95% CI: 1.03-1.78), and hypertension (adj-OR: 1.44; 95% CI: 1.02-2.04). Patients who experienced HHF during follow-up had higher rates of subsequent rehospitalization and death. Vorapaxar did not modify the risk of HHF.

CONCLUSIONS

In patients with stable atherosclerosis, prior HF, age, T2DM, polyvascular disease, CKD, BMI, prior MI, and hypertension are important predictors of HHF risk.

Time trends of coronary procedures, guideline-based drugs and all-cause mortality following acute coronary syndrome in patients with bipolar disorder

AIM

This study analyzed time trends in the use of coronary procedures, guideline-based drugs, and 1-year all-cause and presumed cardiovascular mortality (CV) following acute coronary syndrome (ACS) in patients with and without bipolar disorder (BD).

METHOD

Using Danish registries 497 patients with ACS and BD in the period 1996-2016 were matched 1:2 on age, sex and year of ACS to patients without preexisting psychiatric disease.

RESULTS

Patients with BD and ACS received fewer coronary angiography (CAG) compared to psychiatric healthy controls (PHC). However, the difference between the populations decreased over time. For percutaneous coronary intervention (PCI) and coronary artery bypass (CABG) no differences in trend over time were found. In general patients with BD redeemed fewer prescriptions of guideline-based tertiary prophylactic drugs compared to PHCs. The difference remains constant over time for all drugs except for acetylsalicylic acid, lipid-lowering drugs and beta blockers, where the difference decreased. The 1-year all-cause mortality gap and the presumed CV mortality gap remained unchanged.

CONCLUSION

Despite improvements in treatment disparities regarding CAG, acetylsalicylic acid, lipid-lowering drugs and beta-blockers, the treatment gap remained unchanged concerning PCI and CABG. Likewise, patients with BD experienced a lower rate of the remaining redeemed prescriptions. The overall crude mortality risk ratio for patients with BD experiencing ACS remained unchanged over the study period compared to PHC.

Sacubitril/valsartan in Heart Failure and Beyond-From Molecular Mechanisms to Clinical Relevance

As the ultimate pathophysiological event, heart failure (HF) may arise from various cardiovascular (CV) conditions, including sustained pressure/volume overload of the left ventricle, myocardial infarction or ischemia, and cardiomyopathies. Sacubitril/valsartan (S/V; formerly termed as LCZ696), a first-in-class angiotensin receptor/neprilysin inhibitor, brought a significant shift in the management of HF with reduced ejection fraction by modulating both renin-angiotensin-aldosterone system (angiotensin II type I receptor blockage by valsartan) and natriuretic peptide system (neprilysin inhibition by sacubitril) pathways. Besides, the efficacy of S/V has been also investigated in the setting of other CV pathologies which are during their pathophysiological course and progression deeply interrelated with HF. However, its mechanism of action is not entirely clarified, suggesting other off-target benefits contributing to its cardioprotection. In this review article our goal was to highlight up-to-date clinical and experimental evidence on S/V cardioprotective effects, as well as most discussed molecular mechanisms achieved by this dual-acting compound. Although S/V was extensively investigated in HF patients, additional large studies are needed to elucidate its effects in the setting of other CV conditions. Furthermore, with its antiinflamatory potential, this agent should be investigated in animal models of inflammatory heart diseases, such as myocarditis, while it may possibly improve cardiac dysfunction as well as inflammatory response in this pathophysiological setting. Also, discovering other signalling pathways affected by S/V should be of particular interest for basic researches, while it can provide additional understanding of its cardioprotective mechanisms.

An Explainable Transformer-Based Deep Learning Model for the Prediction of Incident Heart Failure

Predicting the incidence of complex chronic conditions such as heart failure is challenging. Deep learning models applied to rich electronic health records may improve prediction but remain unexplainable hampering their wider use in medical practice. We aimed to develop a deep-learning framework for accurate and yet explainable prediction of 6-month incident heart failure (HF). Using 100,071 patients from longitudinal linked electronic health records across the U.K., we applied a novel Transformer-based risk model using all community and hospital diagnoses and medications contextualized within the age and calendar year for each patient's clinical encounter. Feature importance was investigated with an ablation analysis to compare model performance when alternatively removing features and by comparing the variability of temporal representations. A post-hoc perturbation technique was conducted to propagate the changes in the input to the outcome for feature contribution analyses. Our model achieved 0.93 area under the receiver operator curve and 0.69 area under the precision-recall curve on internal 5-fold cross validation and outperformed existing deep learning models. Ablation analysis indicated medication is important for predicting HF risk, calendar year is more important than chronological age, which was further reinforced by temporal variability analysis. Contribution analyses identified risk factors that are closely related to HF. Many of them were consistent with existing knowledge from clinical and epidemiological research but several new associations were revealed which had not been considered in expert-driven risk prediction models. In conclusion, the results highlight that our deep learning model, in addition high predictive performance, can inform data-driven risk factor identification.

Myocardial Viability – An Important Decision Making Factor in the Treatment Protocol for Patients with Ischemic Heart Disease

Ischemic heart disease (IHD) affects > 110 million individuals worldwide and represents an important contributor to the rise in the prevalence of heart failure and the associated mortality and morbidity. Despite modern therapies, up to one-third of patients with acute myocardial infarction would develop heart failure. IHD is a pathologic condition of the myocardium resulting from the imbalance in a given moment between its oxygen demands and the actual perfusion. Acute and chronic forms of the disease may potentially lead to extensive and permanent damage of the cardiac muscle. From a clinical point of view, determination of the still viable extent of myocardium is crucial for the therapeutic protocol – since ischemia is the underlying cause, then revascularization should provide for a better prognosis. Different methods for evaluation of myocardial viability have been described – each one presenting some advantages over the others, being, in the same time, inferior in some respects. The review offers a relatively comprehensive overview of methods available for determining myocardial viability.

High-Spatiotemporal-Resolution Visualization of Myocardial Strains Through Vector Doppler Estimation: A Small-Animal Study

High-frequency ultrasound (HFUS) imaging is extensively used for cardiac diseases in small animals due to its high spatial resolution. However, there is a lack of a system that can provide a 2-D high-spatiotemporal dynamic visualization of mouse myocardial strains. In this article, a dynamic HFUS (40 MHz) high-resolution strain imaging was developed through the vector Doppler imaging. Following in vitro tests using a rubber balloon phantom, in vivo experiments were performed on wild-type (WT) and myocardial infarction (MI) mice. High-resolution dynamic images of myocardial strains were obtained in the longitudinal, radial, and circumferential directions at a frame rate of 1 kHz. Global peak strain values for WT mice were -19.3% ± 1.3% (longitudinal), 31.4% ± 1.7% (radial in the long axis), -19.9% ±.8% (circumferential), and 34.4% ± 1.9% (radial in the short axis); those for the MI mice were -16.1% ±.9% (longitudinal), 26.8% ± 2.9% (radial in the long axis), -15.2% ± 2.7% (circumferential), and 21.6% ± 4.8% (radial in the short axis). These results indicate that the strains for MI mice are significantly lower than those for WT mice. Regional longitudinal strain curves in the epicardial, midcardial, and endocardial layers were measured and the peak strain values for WT mice were -22.% and -16.8% in the endocardial and epicardial layers, respectively. However, no significant difference in the layer-based values was noted for the MI mice. Regional analysis results revealed obvious myocardial strain variation in the apical anterior region in the MI mice. The experimental results demonstrate that the proposed dynamic cardiac strain imaging can be useful in high-performance imaging of small-animal cardiac diseases.