Validation of the slaughterhouse porcine heart model for ex-situ heart perfusion studies

INTRODUCTION

To validate slaughterhouse hearts for ex-situ heart perfusion studies, we compared cold oxygenated machine perfusion in less expensive porcine slaughterhouse hearts (N = 7) to porcine hearts that are harvested following the golden standard in laboratory animals (N = 6).

METHODS

All hearts received modified St Thomas 2 crystalloid cardioplegia prior to 4 hours of cold oxygenated machine perfusion. Hearts were perfused with homemade modified Steen heart solution with a perfusion pressure of 20-25 mmHg to achieve a coronary flow between 100-200 mL/min. Reperfusion and testing was performed for 4 hours on a normothermic, oxygenated diluted whole blood loaded heart model. Survival was defined by a cardiac output above 3 L with a mean aortic pressure above 60 mmHg.

RESULTS

Both groups showed 100% functional survival, with laboratory hearts displaying superior cardiac function. Both groups showed similar decline in function over time.

CONCLUSION

We conclude that the slaughterhouse heart can be used as an alternative to laboratory hearts and provides a cost-effective method for future ex-situ heart perfusion studies.

Stress hyperglycemia and poor outcomes in patients with ST-elevation myocardial infarction: a systematic review and meta-analysis

Background

Hyperglycemia, characterized by elevated blood glucose levels, is frequently observed in patients with acute coronary syndrome, including ST-elevation myocardial infarction (STEMI). There are conflicting sources regarding the relationship between hyperglycemia and outcomes in STEMI patients. We aimed to compile evidence to assess the association between hyperglycemia and adverse outcomes.

Methods

We conducted a comprehensive search for articles on PubMed and Embase using search strategies which yielded 4,061 articles. After full-text screening, 66 articles were included for systematic review, and 62 articles were further selected for meta-analysis.

Results

The 66 included articles spanned the years 2005-2023. Of these, 45 articles reported admission blood glucose, 13 articles used HbA1c, and 7 articles studied fasting blood glucose. Most studies defined STEMI with primary PCI as their inclusion criteria. Mortality was the most often outcome reported related to hyperglycemia. Overall, 55 (83.3%) studies were at low risk of bias. Both admission and fasting blood glucose were significantly related to short- and long-term mortality after STEMI, with a pooled risk ratio (RR) of 3.02 (95%CI: 2.65-3.45) and 4.47 (95% CI: 2.54-7.87), respectively. HbA1c showed substantial association with long-term mortality (HR 1.69, 95% CI: 1.31-2.18)) with a pooled RR of 1.58 (95% CI 1.26-1.97). In subsequent analyses, admission hyperglycemia was associated with an increased risk of reinfarction (pooled RR 1.69, 95% CI 1.31-2.17), heart failure (pooled RR 1.56, 95% CI: 1.37-1.77), cardiogenic shock (pooled RR 3.68, 95% CI 2.65-5.11), repeat PCI or stent thrombosis (pooled RR 1.99, 95% CI 1.21-3.28), and composite major adverse cardiac and cerebrovascular events (MACCE) (pooled RR 1.99, 95% CI: 1.54-2.58).

Conclusions

Our study demonstrated that hyperglycemia has a strong association with poor outcomes after STEMI. Admission and fasting blood glucose are predictors for short-term outcomes, while HbA1c is more appropriate for predicting longer-term outcomes in STEMI patients.

Systematic Review Registration

PROSPERO 2021 (CRD42021292985).

In-hospital mortality of patients with acute coronary syndrome (ACS) after implementation of national health insurance (NHI) in Indonesia

BACKGROUND

The National Health Insurance (NHI) was implemented in Indonesia in 2014, and cardiovascular diseases are one of the diseases that have overburdened the healthcare system. However, data concerning the relationship between NHI and cardiovascular healthcare in Indonesia are scarce. We aimed to describe changes in cardiovascular healthcare after the implementation of the NHI while determining whether the implementation of the NHI is related to the in-hospital mortality of patients with acute coronary syndrome (ACS).

METHODS

This is a retrospective comparative study of two cohorts in which we compared the data of 364 patients with ACS from 2013 to 2014 (Cohort 1), before and early after NHI implementation, with those of 1142 patients with ACS from 2018 to 2020 (Cohort 2), four years after NHI initiation, at a tertiary cardiac center in Makassar, Indonesia. We analyzed the differences between both cohorts using chi-square test and Mann-Whitney U test. To determine the association between NHI and in-hospital mortality, we conducted multivariable logistic regression analysis.

RESULTS

We observed an increase in NHI users (20.1% to 95.6%, p < 0.001) accompanied by a more than threefold increase in patients with ACS admitted to the hospital in Cohort 2 (from 364 to 1142, p < 0.001). More patients with ACS received invasive treatment in Cohort 2, with both thrombolysis and percutaneous coronary intervention (PCI) rates increasing more than twofold (9.2% to 19.2%; p < 0.001). There was a 50.8% decrease in overall in-hospital mortality between Cohort 1 and Cohort 2 (p < 0.001).

CONCLUSIONS

This study indicated the potential beneficial effect of universal health coverage (UHC) in improving cardiovascular healthcare by providing more accessible treatment. It can provide evidence to urge the Indonesian government and other low- and middle-income nations dealing with cardiovascular health challenges to adopt and prioritize UHC.

Detection of acute coronary occlusion with a novel mobile electrocardiogram device: a pilot study

Aims

Many portable electrocardiogram (ECG) devices have been developed to monitor patients at home, but the majority of these devices are single lead and only intended for rhythm disorders. We developed the miniECG, a smartphone-sized portable device with four dry electrodes capable of recording a high-quality multi-lead ECG by placing the device on the chest. The aim of our study was to investigate the ability of the miniECG to detect occlusive myocardial infarction (OMI) in patients with chest pain.

Methods and results

Patients presenting with acute chest pain at the emergency department of the University Medical Center Utrecht or Meander Medical Center, between May 2021 and February 2022, were included in the study. The clinical 12-lead ECG and the miniECG before coronary intervention were recorded. The recordings were evaluated by cardiologists and compared the outcome of the coronary angiography, if performed. A total of 369 patients were measured with the miniECG, 46 of whom had OMI. The miniECG detected OMI with a sensitivity and specificity of 65 and 92%, compared with 83 and 90% for the 12-lead ECG. Sensitivity of the miniECG was similar for different culprit vessels.

Conclusion

The miniECG can record a multi-lead ECG and rule-in ST-segment deviation in patients with occluded or near-occluded coronary arteries from different culprit vessels without many false alarms. Further research is required to add automated analysis to the recordings and to show feasibility to use the miniECG by patients at home.

ECG-only explainable deep learning algorithm predicts the risk for malignant ventricular arrhythmia in phospholamban cardiomyopathy

BACKGROUND

Phospholamban (PLN) p.(Arg14del) variant carriers are at risk for development of malignant ventricular arrhythmia (MVA). Accurate risk stratification allows timely implantation of intracardiac defibrillators and is currently performed with a multimodality prediction model.

OBJECTIVE

This study aimed to investigate whether an explainable deep learning-based approach allows risk prediction with only electrocardiogram (ECG) data.

METHODS

A total of 679 PLN p.(Arg14del) carriers without MVA at baseline were identified. A deep learning-based variational auto-encoder, trained on 1.1 million ECGs, was used to convert the 12-lead baseline ECG into its FactorECG, a compressed version of the ECG that summarizes it into 32 explainable factors. Prediction models were developed by Cox regression.

RESULTS

The deep learning-based ECG-only approach was able to predict MVA with a C statistic of 0.79 (95% CI, 0.76-0.83), comparable to the current prediction model (C statistic, 0.83 [95% CI, 0.79-0.88]; P = .054) and outperforming a model based on conventional ECG parameters (low-voltage ECG and negative T waves; C statistic, 0.65 [95% CI, 0.58-0.73]; P < .001). Clinical simulations showed that a 2-step approach, with ECG-only screening followed by a full workup, resulted in 60% less additional diagnostics while outperforming the multimodal prediction model in all patients. A visualization tool was created to provide interactive visualizations (https://pln.ecgx.ai).

CONCLUSION

Our deep learning-based algorithm based on ECG data only accurately predicts the occurrence of MVA in PLN p.(Arg14del) carriers, enabling more efficient stratification of patients who need additional diagnostic testing and follow-up.

Predictors of major adverse cardiac events among patients with chest pain and low HEART score in the emergency department

AIM

For patients who present to the emergency departments (ED) with undifferentiated chest pain, the risk of major adverse cardiac events (MACE) may be underestimated in low-HEART score patients. We aimed to identify characteristics of patients who were classified as low risk by HEART score but subsequently developed MACE at 6 weeks.

METHODS

We studied a multiethnic cohort of patients who presented with chest pain arousing suspicion of acute coronary syndrome to EDs in the Netherlands and Singapore. Patients were risk-stratified using HEART score and followed up for MACE at 6 weeks. Risk factors of developing MACE despite low HEART scores (scores 0-3) were identified using logistic and Cox regression models.

RESULTS

Among 1376 (39.8%) patients with low HEART scores, 63 (4.6%) developed MACE at 6 weeks. More males (53/806, 6.6%) than females (10/570, 2.8%) with low HEART score developed MACE. There was no difference in outcomes between ethnic groups. Among low-HEART score patients with 2 points for history, 21% developed MACE. Among low-HEART score patients with 1 point for troponin, 50% developed MACE, while 100% of those with 2 points for troponin developed MACE. After adjusting for HEART score and potential confounders, male sex was independently associated with increased odds (OR 4.12, 95%CI 2.14-8.78) and hazards (HR 3.93, 95%CI 1.98-7.79) of developing MACE despite low HEART score.

CONCLUSION

Male sex, highly suspicious history and elevated troponin were disproportionately associated with MACE. These characteristics should prompt clinicians to consider further investigation before discharge.

Hemofiltration Improves Blood Perfusate Conditions Leading to Improved Ex Situ Heart Perfusion

The aim was to optimize the perfusate composition by including a hemofiltrator to the PhysioHeartplatform for ex situ heart perfusion of porcine slaughterhouse hearts. Fourteen hearts were harvested from Dutch Landrace pigs and slaughtered for human consumption. All hearts were preserved for 4 hours using static cold storage before reperfusion for 4 hours on the PhysioHeart platform. Seven hearts were assigned to the hemofiltration group, where a hemofiltrator was added to the perfusion circuit, while the control group did not receive hemofiltration. In the hemofiltration group, the perfusion fluid was filtrated for 1 hour with a flow of 1 L/hour before reperfusion. After mounting the heart, hemofiltration was maintained at 1 L/hour, and cardiac function and blood samples were analyzed at multiple time points. Preserved cardiac function was defined as a cardiac output >3.0 L/min with a mean aortic pressure >60 mm Hg and a left atrial pressure <15 mm Hg. Hemofiltration resulted in a significantly reduced potassium concentration at all time points ( p < 0.001), while sodium levels remained at baseline values ( p < 0.004). Furthermore, creatinine and ammonia levels decreased over time. Functional assessment demonstrated a reduced left atrial pressure ( p < 0.04) and a reduction of the required dobutamine dose to support myocardial function ( p < 0.003) in the hemofiltration group. Preserved cardiac function did not differ between groups. Hemofiltration results in an improved biochemical composition of the whole blood perfusate and preserves cardiac function better during normothermic perfusion based on a reduced left atrial pressure (LAP) and dobutamine requirement to support function.

Automatic triage of twelve-lead electrocardiograms using deep convolutional neural networks: a first implementation study

Aims

Expert knowledge to correctly interpret electrocardiograms (ECGs) is not always readily available. An artificial intelligence (AI)-based triage algorithm (DELTAnet), able to support physicians in ECG prioritization, could help reduce current logistic burden of overreading ECGs and improve time to treatment for acute and life-threatening disorders. However, the effect of clinical implementation of such AI algorithms is rarely investigated.

Methods and results

Adult patients at non-cardiology departments who underwent ECG testing as a part of routine clinical care were included in this prospective cohort study. DELTAnet was used to classify 12-lead ECGs into one of the following triage classes: normal, abnormal not acute, subacute, and acute. Performance was compared with triage classes based on the final clinical diagnosis. Moreover, the associations between predicted classes and clinical outcomes were investigated. A total of 1061 patients and ECGs were included. Performance was good with a mean concordance statistic of 0.96 (95% confidence interval 0.95-0.97) when comparing DELTAnet with the clinical triage classes. Moreover, zero ECGs that required a change in policy or referral to the cardiologist were missed and there was a limited number of cases predicted as acute that did not require follow-up (2.6%).

Conclusion

This study is the first to prospectively investigate the impact of clinical implementation of an ECG-based AI triage algorithm. It shows that DELTAnet is efficacious and safe to be used in clinical practice for triage of 12-lead ECGs in non-cardiology hospital departments.

Deep neural network-based clustering of deformation curves reveals novel disease features in PLN pathogenic variant carriers

Echocardiographic deformation curves provide detailed information on myocardial function. Deep neural networks (DNNs) may enable automated detection of disease features in deformation curves, and improve the clinical assessment of these curves. We aimed to investigate whether an explainable DNN-based pipeline can be used to detect and visualize disease features in echocardiographic deformation curves of phospholamban (PLN) p.Arg14del variant carriers. A DNN was trained to discriminate PLN variant carriers (n = 278) from control subjects (n = 621) using raw deformation curves obtained by 2D-speckle tracking in the longitudinal axis. A visualization technique was used to identify the parts of these curves that were used by the DNN for classification. The PLN variant carriers were clustered according to the output of the visualization technique. The DNN showed excellent discriminatory performance (C-statistic 0.93 [95% CI 0.87-0.97]). We identified four clusters with PLN-associated disease features in the deformation curves. Two clusters showed previously described features: apical post-systolic shortening and reduced systolic strain. The two other clusters revealed novel features, both reflecting delayed relaxation. Additionally, a fifth cluster was identified containing variant carriers without disease features in the deformation curves, who were classified as controls by the DNN. This latter cluster had a very benign disease course regarding development of ventricular arrhythmias. Applying an explainable DNN-based pipeline to myocardial deformation curves enables automated detection and visualization of disease features. In PLN variant carriers, we discovered novel disease features which may improve individual risk stratification. Applying this approach to other diseases will further expand our knowledge on disease-specific deformation patterns. Overview of the deep neural network-based pipeline for feature detection in myocardial deformation curves. Firstly, phospholamban (PLN) p.Arg14del variant carriers and controls were selected and a deep neural network (DNN) was trained to detect the PLN variant carriers. Subsequently, a clustering-based approach was performed on the attention maps of the DNN, which revealed 4 distinct phenotypes of PLN variant carriers with different prognoses. Moreover, a cluster without features and a benign prognosis was detected.

Gene therapy during ex situ heart perfusion: a new frontier in cardiac regenerative medicine?

Ex situ organ preservation by machine perfusion can improve preservation of organs for transplantation. Furthermore, machine perfusion opens up the possibilities for selective immunomodulation, creation of tolerance to ischemia-reperfusion injury and/or correction of a pathogenic genetic defect. The application of gene modifying therapies to treat heart diseases caused by pathogenic mutations during ex situ heart perfusion seems promising, especially given the limitations related to delivery of vectors that were encountered during clinical trials using in vivo cardiac gene therapy. By isolating the heart in a metabolically and immunologically favorable environment and preventing off-target effects and dilution, it is possible to directly control factors that enhance the success rate of cardiac gene therapy. A literature search of PubMed and Embase databases was performed to identify all relevant studies regarding gene therapy during ex situ heart perfusion, aiming to highlight important lessons learned and discuss future clinical prospects of this promising approach.

Generation and characterization of novel human induced pluripotent stem cell (iPSC) lines originating from five asymptomatic individuals carrying the PLN-R14del pathogenic variant and a non-carrier relative

The rare genetic alteration PLN-c.(40_42delAGA), leading to the deletion of arginine 14 (p.R14del) in phospholamban, is associated with dilated and arrhythmogenic cardiomyopathies occurring in early-adulthood. However, some carriers remain asymptomatic with normal lifespans. Here, we report human induced pluripotent stem cell (iPSC) lines generated from peripheral blood mononuclear cells (PBMCs) of five PLN-R14del carriers, who were asymptomatic at the time of blood collection, and one non-carrier family member. Each line exhibited typical iPSC morphology, pluripotency markers, and tri-lineage differentiation. These cell lines provide a valuable model to investigate the mechanisms underlying the onset, progression, and patient-specific resistance to PLN-R14del-induced cardiomyopathy.

Global Left Ventricular Myocardial Work Efficiency in Patients With Severe Rheumatic Mitral Stenosis and Preserved Left Ventricular Ejection Fraction

BACKGROUND

Assessment of left ventricular (LV) function plays a pivotal role in the management of patients with valvular heart disease, including those caused by rheumatic heart disease. Noninvasive LV pressure-strain loop analysis is emerging as a new echocardiographic method to evaluate global LV systolic function, integrating longitudinal strain by speckle-tracking analysis and noninvasively measured blood pressure to estimate myocardial work. The aim of this study was to characterize global LV myocardial work efficiency in patients with severe rheumatic mitral stenosis (MS) with preserved ejection fraction (EF).

METHODS

We retrospectively included adult patients with severe rheumatic MS with preserved EF (> 50%) and sinus rhythm. Healthy individuals without structural heart disease were included as a control group. Global LV myocardial work efficiency was estimated with a proprietary algorithm from speckle-tracking strain analyses, as well as noninvasive blood pressure measurements.

RESULTS

A total of 45 individuals with isolated severe rheumatic MS with sinus rhythm and 45 healthy individuals were included. In healthy individuals without structural heart disease, the mean global LV myocardial work efficiency was 96% (standard deviation [SD], 2), Compared with healthy individuals, median global LV myocardial work efficiency was significantly worse in MS patients (89%; SD, 4; p < 0.001) although the LVEF was similar.

CONCLUSIONS

Individuals with isolated severe rheumatic MS and preserved EF, had global LV myocardial work efficiencies lower than normal controls.

Evaluating the Arteriotomy Size of a New Sutureless Coronary Anastomosis Using a Finite Volume Approach

OBJECTIVES

The ELANA® Heart Bypass creates a standardized sutureless anastomosis. Hereby, we investigate the influence of arteriotomy and graft size on coronary hemodynamics.

METHODS

A computational fluid dynamics (CFD) model was developed. Arteriotomy size (standard 1.43 mm2; varied 0.94 - 3.6 mm2) and graft diameter (standard 2.5 mm; varied 1.5 - 5.0 mm) were independent parameters. Outcome parameters were coronary pressure and flow, and fractional flow reserve (FFR).

RESULTS

The current size ELANA (arteriotomy 1.43 mm2) presented an estimated FFR 0.65 (39 mL/min). Enlarging arteriotomy increased FFR, coronary pressure, and flow. All reached a maximum once the arteriotomy (2.80 mm2) surpassed the coronary cross-sectional area (2.69 mm2, i.e. 1.85 mm diameter), presenting an estimated FFR 0.75 (46 mL/min). Increasing graft diameter was positively related to FFR, coronary pressure, and flow.

CONCLUSION

The ratio between the required minimal coronary diameter for application and the ELANA arteriotomy size effectuates a pressure drop that could be clinically relevant. Additional research and eventual lengthening of the anastomosis is advised.

Cold Oxygenated Machine Perfusion Improves Functional Survival of Slaughterhouse Porcine Hearts

The aim of our study was to explore the effect of cold oxygenated machine perfusion in slaughterhouse porcine hearts on functional myocardial survival compared to static cold storage (SCS). Seventeen hearts were harvested from Dutch Landrace Hybrid pigs, which were sacrificed for human consumption and randomly assigned to the 4 hours SCS group (N = 10) or the 4 hours cold oxygenated machine perfusion group (N = 7). Hearts were perfused with a homemade Heart Solution with a perfusion pressure of 20-25 mm Hg to achieve a coronary flow between 100 and 200 ml/minute. After 4 hours of preservation, all hearts were functionally assessed during 4 hours on a normothermic, oxygenated diluted whole blood (1:2) loaded heart model. Survival was defined by a cardiac output above 3 L with a mean aortic pressure above 60 mm Hg. Survival was significantly better in the cold oxygenated machine perfusion group, where 100% of the hearts reached the 4 hours end-point, as compared with 30% in the SCS group ( p = 0.006). Interestingly, warm ischemic time was inversely related to survival in the SCS group with a correlation coefficient of -0.754 ( p = 0.012). Cold oxygenated machine perfusion improves survival of the slaughterhouse porcine heart.

Comparison of Four-Dimensional Flow MRI, Two-Dimensional Phase-Contrast MRI and Echocardiography in Transposition of the Great Arteries

Pulmonary artery (PA) stenosis is a common complication after the arterial switch operation (ASO) for transposition of the great arteries (TGA). Four-dimensional flow (4D flow) CMR provides the ability to quantify flow within an entire volume instead of a single plane. The aim of this study was to compare PA maximum velocities and stroke volumes between 4D flow CMR, two-dimensional phase-contrast (2D PCMR) and echocardiography. A prospective study including TGA patients after ASO was performed between December 2018 and October 2020. All patients underwent echocardiography and CMR, including 2D PCMR and 4D flow CMR. Maximum velocities and stroke volumes were measured in the main, right, and left PA (MPA, LPA, and RPA, respectively). A total of 39 patients aged 20 ± 8 years were included. Maximum velocities in the MPA, LPA, and RPA measured by 4D flow CMR were significantly higher compared to 2D PCMR (p < 0.001 for all). PA assessment by echocardiography was not possible in the majority of patients. 4D flow CMR maximum velocity measurements were consistently higher than those by 2D PCMR with a mean difference of 65 cm/s for the MPA, and 77 cm/s for both the RPA and LPA. Stroke volumes showed good agreement between 4D flow CMR and 2D PCMR. Maximum velocities in the PAs after ASO for TGA are consistently lower by 2D PCMR, while echocardiography only allows for PA assessment in a minority of cases. Stroke volumes showed good agreement between 4D flow CMR and 2D PCMR.

Electrocardiogram Devices for Home Use: Technological and Clinical Scoping Review

BACKGROUND

Electrocardiograms (ECGs) are used by physicians to record, monitor, and diagnose the electrical activity of the heart. Recent technological advances have allowed ECG devices to move out of the clinic and into the home environment. There is a great variety of mobile ECG devices with the capabilities to be used in home environments.

OBJECTIVE

This scoping review aimed to provide a comprehensive overview of the current landscape of mobile ECG devices, including the technology used, intended clinical use, and available clinical evidence.

METHODS

We conducted a scoping review to identify studies concerning mobile ECG devices in the electronic database PubMed. Secondarily, an internet search was performed to identify other ECG devices available in the market. We summarized the devices' technical information and usability characteristics based on manufacturer data such as datasheets and user manuals. For each device, we searched for clinical evidence on the capabilities to record heart disorders by performing individual searches in PubMed and ClinicalTrials.gov, as well as the Food and Drug Administration (FDA) 510(k) Premarket Notification and De Novo databases.

RESULTS

From the PubMed database and internet search, we identified 58 ECG devices with available manufacturer information. Technical characteristics such as shape, number of electrodes, and signal processing influence the capabilities of the devices to record cardiac disorders. Of the 58 devices, only 26 (45%) had clinical evidence available regarding their ability to detect heart disorders such as rhythm disorders, more specifically atrial fibrillation.

CONCLUSIONS

ECG devices available in the market are mainly intended to be used for the detection of arrhythmias. No devices are intended to be used for the detection of other cardiac disorders. Technical and design characteristics influence the intended use of the devices and use environments. For mobile ECG devices to be intended to detect other cardiac disorders, challenges regarding signal processing and sensor characteristics should be solved to increase their detection capabilities. Devices recently released include the use of other sensors on ECG devices to increase their detection capabilities.

[Cardiomyopathy due to a mutation in the phospholamban gene: a high-impact genetic abnormality]

A mutation in the Phospholamban gene where the Arginine at position 14 (PLN-R14Del) is missing is causing a severe cardiomyopathy often leading to cardiac transplantation in the Netherlands. We estimated that approximately 25% of all transplanted patients carry this mutation. The origin is dated somewhere around the year 1300 in the north of country. Currently we have identified 1600 carriers with the identical mutation. We are in the process of developing and applying gene therapy to come to a specific treatment for the 700 carriers with symptoms we see today.

Sex-stratified differences in early antithrombotic treatment response in patients presenting with ST-segment elevation myocardial infarction

BACKGROUND

The mechanisms underlying the increased risk of bleeding that female patients with ST-segment Elevation Myocardial Infarction (STEMI) exhibit, remains unclear. The present report assessed sex-related differences in response to pre-hospital dual antiplatelet therapy (DAPT) initiation in patients with STEMI.

METHODS

The COMPARE CRUSH trial randomized patients presenting with STEMI to receive a pre-hospital loading dose of crushed or integral prasugrel tablets in the ambulance. In this substudy, we compared platelet reactivity levels and the occurrence of high platelet reactivity (HPR; defined as platelet reactivity ≥208) between sexes at 4 prespecified time points after DAPT initiation, and evaluated post-PCI bleeding between groups.

RESULTS

Out of 633 STEMI patients, 147 (23%) were female. Females compared with males presented with significantly higher levels of platelet reactivity and higher HPR rates at baseline (232 [IQR, 209-256] vs 195 [IQR, 171-220], P < .01, and 76% vs 41%, OR 4.58 [95%CI, 2.52-8.32], P < .01, respectively). Moreover, female sex was identified as the sole independent predictor of HPR at baseline (OR 5.67 [95%CI, 2.56-12.53], P < .01). Following DAPT initiation, levels of platelet reactivity and the incidence of HPR were similar between sexes. Post-PCI bleeding occurred more frequently in females compared with males (10% vs 2%, OR 6.02 [95%CI, 2.61-11.87], P < .01). Female sex was an independent predictor of post-PCI bleeding (OR 3.25 [95%CI, 1.09-9.72], P = .04).

CONCLUSIONS

In this contemporary STEMI cohort, female STEMI patients remain at risk of bleeding complications after primary PCI. However, this is not explained by sex-specific differences in the pharmacodynamic response to pre-hospital DAPT initiation.

Sex-Related Bleeding Risk in Acute Coronary Syndrome Patients Receiving Dual Antiplatelet Therapy with Aspirin and a P2Y12 Inhibitor

OBJECTIVE

The aim of this work was to study sex differences in major bleeding risk in relation to dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS).

METHODS AND RESULTS

The Rijnmond Collective Cardiology Research registry was designed to evaluate the application and outcomes of DAPT after ACS/PCI in the Rijnmond region in the Netherlands. Overall, 1,172 women (median age 67.5 years) and 3,087 men (median age 62.2 years) with ACS/PCI were enrolled between August 2011 and June 2013. Based on a tailored regional DAPT guideline aiming at bleeding risk minimization, 52.6% women and 66.9% men received prasugrel as first-choice P2Y12 inhibitor, in addition to aspirin. Women more frequently had contraindications for the use of prasugrel (and therefore received clopidogrel) than men (47.9 vs. 26.9%, p < 0.001). Femoral access was more common in women than in men (47.6 vs. 38.1%, p < 0.001). Women had higher incidence of major bleeding at 1 year than men (2.6 vs. 1.6%, p = 0.018). After adjustment for established bleeding risk factors, female sex was associated with over two-fold higher risk of major bleeding (adjusted hazard ratio 2.33; 95% confidence interval 1.26-4.32). This difference was apparent at discharge and appeared to be caused by access site bleedings (0.9 vs. 0.1%, p < 0.001). No sex differences were found in non-access site-related major bleeding up to 1 year.

CONCLUSION

Women with ACS/PCI receiving DAPT had higher major bleeding risk caused by an excess in access site bleeds, mainly in relation to the femoral approach.

Generation, High-Throughput Screening, and Biobanking of Human-Induced Pluripotent Stem Cell-Derived Cardiac Spheroids

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are of paramount importance for human cardiac disease modeling and therapeutics. We recently published a cost-effective strategy for the massive expansion of hiPSC-CMs in two dimensions (2D). Two major limitations are cell immaturity and a lack of three-dimensional (3D) arrangement and scalability in high-throughput screening (HTS) platforms. To overcome these limitations, the expanded cardiomyocytes form an ideal cell source for the generation of 3D cardiac cell culture and tissue engineering techniques. The latter holds great potential in the cardiovascular field, providing more advanced and physiologically relevant HTS. Here, we describe an HTS-compatible workflow with easy scalability for the generation, maintenance, and optical analysis of cardiac spheroids (CSs) in a 96-well-format. These small CSs are essential to fill the gap present in current in vitro disease models and/or generation for 3D tissue engineering platforms. The CSs present a highly structured morphology, size, and cellular composition. Furthermore, hiPSC-CMs cultured as CSs display increased maturation and several functional features of the human heart, such as spontaneous calcium handling and contractile activity. By automatization of the complete workflow, from the generation of CSs to functional analysis, we increase intra- and inter-batch reproducibility as demonstrated by high-throughput (HT) imaging and calcium handling analysis. The described protocol allows modeling of cardiac diseases and assessing drug/therapeutic effects at the single-cell level within a complex 3D cell environment in a fully automated HTS workflow. In addition, the study describes a straightforward procedure for long-term preservation and biobanking of whole-spheroids, thereby providing researchers the opportunity to create next-generation functional tissue storage. HTS combined with long-term storage will substantially contribute to translational research in a wide range of areas, including drug discovery and testing, regenerative medicine, and the development of personalized therapies.

Infection prevention and control in Indonesian hospitals: identification of strengths, gaps, and challenges

BACKGROUND

Infection prevention and control (IPC) in hospitals is key to safe patient care. There is currently no data regarding the implementation of IPC in hospitals in Indonesia. The aim of this study was to assess the existing IPC level in a nationwide survey, using the World Health Organization (WHO) IPC assessment framework tool (IPCAF), and to identify strengths, gaps, and challenges.

METHODS

A cross-sectional study was conducted from July to November 2021. Of all general hospitals in Indonesia, 20% (N = 475) were selected using stratified random sampling based on class (A, B, C and D; class D with a maximum of 50 beds and class A with ≥ 250 beds) and region. The IPCAF was translated into Indonesian and tested in four hospitals. Questions were added regarding challenges in the implementation of IPC. Quantitative IPCAF scores are reported as median (minimum-maximum). IPC levels were calculated according to WHO tools.

RESULTS

In total, 355 hospitals (74.7%) participated in this study. The overall median IPCAF score was 620.0 (535.0-687.5). The level of IPC was mostly assessed as advanced (56.9% of hospitals), followed by intermediate (35.8%), basic (7.0%) and inadequate (0.3%). In the eastern region of the country, the majority of hospitals scored intermediate level. Of the eight core components, the one with the highest score was IPC guidelines. Almost all hospitals had guidelines on the most important topics, including hand hygiene. Core components with the lowest score were surveillance of healthcare-associated infections (HAIs), education and training, and multimodal strategies. Although > 90% of hospitals indicated that surveillance of HAIs was performed, 57.2% reported no availability of adequate microbiology laboratory capacity to support HAIs surveillance. The most frequently reported challenges in the implementation of IPC were communication with the management of the hospitals, followed by the unavailability of antimicrobial susceptibility testing results and insufficient staffing of full-time IPC nurses.

CONCLUSION

The IPC level in the majority of Indonesian hospitals was assessed as advanced, but there was no even distribution over the country. The IPCAF in combination with interviews identified several priority areas for interventions to improve IPC in Indonesian hospitals.

Assessment of aortic and cerebral haemodynamics and vascular brain injury with 3 and 7 T magnetic resonance imaging in patients with aortic coarctation

Aims

Coarctation of the aorta (CoA) is characterized by a central arteriopathy resulting in increased arterial stiffness. The condition is associated with an increased risk of stroke. We aimed to assess the aortic and cerebral haemodynamics and the presence of vascular brain injury in patients with previous surgical CoA repair.

Methods and results

Twenty-seven patients with CoA (median age 22 years, range 12-72) and 25 age- and sex-matched controls (median age 24 years, range 12-64) underwent 3 T (heart, aorta, and brain) and 7 T (brain) magnetic resonance imaging scans. Haemodynamic parameters were measured using two-dimensional phase-contrast images of the ascending and descending aorta, internal carotid artery (ICA), basilar artery (BA), middle cerebral artery (MCA), and perforating arteries. Vascular brain injury was assessed by rating white matter hyperintensities, cortical microinfarcts, lacunes, and microbleeds. Pulse wave velocities in the aortic arch and descending aorta were increased and ascending aortic distensibility was decreased in patients with CoA vs. controls. Patients with CoA showed a higher mean flow velocity in the right ICA, left ICA, and BA and a reduced distensibility in the right ICA, BA, and left MCA. Haemodynamic parameters in the perforating arteries, total cerebral blood flow, intracranial volumes, and vascular brain injury were similar between the groups.

Conclusion

Patients with CoA show an increased flow velocity and reduced distensibility in the aorta and proximal cerebral arteries, which suggests the presence of a generalized arteriopathy that extends into the cerebral arterial tree. No substantial vascular brain injury was observed in this relatively young CoA population, although the study was inadequately powered regarding this endpoint.

Phospholamban R14del disease: The past, the present and the future

Arrhythmogenic cardiomyopathy affects significant number of patients worldwide and is characterized by life-threatening ventricular arrhythmias and sudden cardiac death. Mutations in multiple genes with diverse functions have been reported to date including phospholamban (PLN), a key regulator of sarcoplasmic reticulum (SR) Ca²⁺ homeostasis and cardiac contractility. The PLN-R14del variant in specific is recognized as the cause in an increasing number of patients worldwide, and extensive investigations have enabled rapid advances towards the delineation of PLN-R14del disease pathogenesis and discovery of an effective treatment. We provide a critical overview of current knowledge on PLN-R14del disease pathophysiology, including clinical, animal model, cellular and biochemical studies, as well as diverse therapeutic approaches that are being pursued. The milestones achieved in <20 years, since the discovery of the PLN R14del mutation (2006), serve as a paradigm of international scientific collaboration and patient involvement towards finding a cure.

Impact of Rheumatic Process in Left and Right Ventricular Function in Patients with Mitral Regurgitation

Background

Mitral regurgitation (MR) burdens the left and right ventricles with a volume or pressure overload that leads to a series of compensatory adaptations that eventually lead to ventricular dysfunction, and it is well known that in rheumatic heart disease (RHD) that the inflammatory process not only occurs in the valve but also involves the myocardial and pericardial layers. However, whether the inflammatory process in rheumatic MR is associated with ventricular function besides hemodynamic changes is not yet established.

Purpose

Evaluate whether rheumatic etiology is associated with ventricular dysfunction in patients with chronic MR.

Methods

The study population comprised patients aged 18 years or older included in the registry who had echocardiography performed at the National Cardiovascular Center Harapan Kita in Indonesia during the study period with isolated primary MR due to rheumatic etiology and degenerative process with at least moderate regurgitation.

Results

The current study included 1,130 patients with significant isolated degenerative MR and 276 patients with rheumatic MR. Patients with rheumatic MR were younger and had a higher prevalence of atrial fibrillation and pulmonary hypertension, worse left ventricle (LV) ejection fraction and tricuspid annular plane systolic excursion (TAPSE) value, and larger left atrium (LA) dimension compared to patients with degenerative mitral regurgitation (MR). Gender, age, LV end-systolic diameter, rheumatic etiology, and TAPSE were independently associated with more impaired LV ejection fraction. Whereas low LV ejection fraction, LV end-systolic diameter, and tricuspid peak velocity (TR) peak velocity >3.4 m/s were independently associated with more reduced right ventricle (RV) systolic function (Table 3).

Conclusions

Rheumatic etiology was independently associated with more impaired left ventricular function; however, rheumatic etiology was not associated with reduced right ventricular systolic function in a patient with significant chronic MR.

Elevated Plasma Immunoglobulin Levels Prior to Heart Transplantation Are Associated with Poor Post-Transplantation Survival

Cardiac allograft vasculopathy (CAV) and antibody-mediated rejection are immune-mediated, long-term complications that jeopardize graft survival after heart transplantation (HTx). Interestingly, increased plasma levels of immunoglobulins have been found in end-stage heart failure (HF) patients prior to HTx. In this study, we aimed to determine whether increased circulating immunoglobulin levels prior to transplantation are associated with poor post-HTx survival. Pre-and post-HTx plasma samples of 36 cardiac transplant recipient patients were used to determine circulating immunoglobulin levels. In addition, epicardial tissue was collected to determine immunoglobulin deposition in cardiac tissue and assess signs and severity of graft rejection. High levels of IgG1 and IgG2 prior to HTx were associated with a shorter survival post-HTx. Immunoglobulin deposition in cardiac tissue was significantly elevated in patients with a survival of less than 3 years. Patients with high plasma IgG levels pre-HTx also had significantly higher plasma levels after HTx. Furthermore, high pre-HTX levels of IgG1 and IgG2 levels were also significantly increased in patients with inflammatory infiltrate in CAV lesions. Altogether the results of this proof-of-concept study suggest that an activated immune response prior to transplantation negatively affects graft survival.

Small molecule-mediated rapid maturation of human induced pluripotent stem cell-derived cardiomyocytes

BACKGROUND

Human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs) do not display all hallmarks of mature primary cardiomyocytes, especially the ability to use fatty acids (FA) as an energy source, containing high mitochondrial mass, presenting binucleation and increased DNA content per nuclei (polyploidism), and synchronized electrical conduction. This immaturity represents a bottleneck to their application in (1) disease modelling-as most cardiac (genetic) diseases have a middle-age onset-and (2) clinically relevant models, where integration and functional coupling are key. So far, several methods have been reported to enhance iPSC-CM maturation; however, these protocols are laborious, costly, and not easily scalable. Therefore, we developed a simple, low-cost, and rapid protocol to promote cardiomyocyte maturation using two small molecule activators of the peroxisome proliferator-activated receptor β/δ and gamma coactivator 1-alpha (PPAR/PGC-1α) pathway: asiatic acid (AA) and GW501516 (GW). METHODS AND RESULTS: Monolayers of iPSC-CMs were incubated with AA or GW every other day for ten days resulting in increased expression of FA metabolism-related genes and markers for mitochondrial activity. AA-treated iPSC-CMs responsiveness to the mitochondrial respiratory chain inhibitors increased and exhibited higher flexibility in substrate utilization. Additionally, structural maturity improved after treatment as demonstrated by an increase in mRNA expression of sarcomeric-related genes and higher nuclear polyploidy in AA-treated samples. Furthermore, treatment led to increased ion channel gene expression and protein levels.

CONCLUSIONS

Collectively, we developed a fast, easy, and economical method to induce iPSC-CMs maturation via PPAR/PGC-1α activation. Treatment with AA or GW led to increased metabolic, structural, functional, and electrophysiological maturation, evaluated using a multiparametric quality assessment.

Electrocardiogram-based deep learning improves outcome prediction following cardiac resynchronization therapy

AIMS

This study aims to identify and visualize electrocardiogram (ECG) features using an explainable deep learning-based algorithm to predict cardiac resynchronization therapy (CRT) outcome. Its performance is compared with current guideline ECG criteria and QRSAREA.

METHODS AND RESULTS

A deep learning algorithm, trained on 1.1 million ECGs from 251 473 patients, was used to compress the median beat ECG, thereby summarizing most ECG features into only 21 explainable factors (FactorECG). Pre-implantation ECGs of 1306 CRT patients from three academic centres were converted into their respective FactorECG. FactorECG predicted the combined clinical endpoint of death, left ventricular assist device, or heart transplantation [c-statistic 0.69, 95% confidence interval (CI) 0.66-0.72], significantly outperforming QRSAREA and guideline ECG criteria [c-statistic 0.61 (95% CI 0.58-0.64) and 0.57 (95% CI 0.54-0.60), P < 0.001 for both]. The addition of 13 clinical variables was of limited added value for the FactorECG model when compared with QRSAREA (Δ c-statistic 0.03 vs. 0.10). FactorECG identified inferolateral T-wave inversion, smaller right precordial S- and T-wave amplitude, ventricular rate, and increased PR interval and P-wave duration to be important predictors for poor outcome. An online visualization tool was created to provide interactive visualizations (https://crt.ecgx.ai).

CONCLUSION

Requiring only a standard 12-lead ECG, FactorECG held superior discriminative ability for the prediction of clinical outcome when compared with guideline criteria and QRSAREA, without requiring additional clinical variables. End-to-end automated visualization of ECG features allows for an explainable algorithm, which may facilitate rapid uptake of this personalized decision-making tool in CRT.

The readiness of public primary health care (PUSKESMAS) for cardiovascular services in Makasar city, Indonesia

Backgrounds

The increasing burden of cardiovascular disease (CVD) has become a major challenge globally, including in Indonesia. Understanding the readiness of primary health care facilities is necessary to confront the challenge of providing access to quality CVD health care services. Our study aimed to provide information regarding readiness to deliver CVD health services in public primary health care namely Puskesmas.

Methods

The study questionnaire was adapted from the World Health Organization (WHO) Service Availability and Readiness Assessment (SARA), modified based on the package of essentials for non-communicable disease (PEN) and the Indonesian Ministry of health regulation. Data were collected from all Puskesmas facilities (N = 47) located in Makassar city. We analysed relevant data following the WHO-SARA manual to assess the readiness of Puskesmas to deliver CVD services. Human resources, diagnostic capacity, supporting equipment, essential medication, infrastructure and guidelines, and ambulatory services domain were assessed based on the availability of each tracer item in a particular domain. The mean domain score was calculated based on the availability of tracer items within each domain. Furthermore, the means of all domains’ scores are expressed as an overall readiness index. Higher scores indicate greater readiness of Puskesmas to deliver CVD-related health care.

Results

Puskesmas delivers health promotion, disease prevention, and prompt diagnosis for cardiovascular-related diseases, including hypertension, diabetes, coronary heart disease (CHD), and stroke. Meanwhile, basic treatments were observed in the majority of the Puskesmas. Long-term care for hypertension and diabetes patients and rehabilitation for CHD and stroke were only observed in a few Puskesmas. The readiness score of Puskesmas to deliver CVD health care ranged from 60 to 86 for. Furthermore, there were 11 Puskesmas (23.4%) with a score below 75, indicating a sub-optimal readiness for delivering CVD health services. A shortage of essential medicines and a low capacity for diagnostic testing were the most noticeable shortcomings leading to suboptimal readiness for high-quality CVD health services.

Conclusion

Close cooperation with the government and other related stakeholders is required to tackle the identified shortcomings, especially the continuous monitoring of adequate supplies of medicines and diagnostic tools to achieve better CVD care for patients in Indonesia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-08499-w.

Revascularization strategies for patients with established chronic coronary syndrome

Coronary artery disease is the most common type of cardiovascular disease, leading to high mortality rates worldwide. Although the vast majority can be treated effectively and safely by medical therapy, revascularization strategies remain essential for numerous patients. Outcomes of both percutaneous coronary intervention and coronary artery bypass grafting improve in a rapid pace, resulting from technical innovation and ongoing research. Progress has been achieved by technical improvements in coronary stents, optimal coronary target and graft selection, and the availability of minimally invasive surgical strategies. Besides technical progress, evidence-based patient-tailored decision-making by the Heart Team is the basic precondition for optimal outcome. The combination of fast innovation and long-term clinical evaluations creates a dynamic field. Research outcomes should be carefully interpreted according to the techniques used and the trial's design. Therefore, more and more trial outcomes suggest that revascularization strategies should be tailored towards the specific patient. Although the European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines on myocardial revascularization date from 2018 and a large variety of trial outcomes on revascularization strategies in chronic coronary syndrome have been published since, we aim to provide an updated overview within this review.

Improving explainability of deep neural network-based electrocardiogram interpretation using variational auto-encoders. Eur Heart J Digit Health 2022;3:390-404. [PMID: 36712164 PMCID: PMC9707974 DOI: 10.1093/ehjdh/ztac038]

Aims

Deep neural networks (DNNs) perform excellently in interpreting electrocardiograms (ECGs), both for conventional ECG interpretation and for novel applications such as detection of reduced ejection fraction (EF). Despite these promising developments, implementation is hampered by the lack of trustworthy techniques to explain the algorithms to clinicians. Especially, currently employed heatmap-based methods have shown to be inaccurate.

Methods and results

We present a novel pipeline consisting of a variational auto-encoder (VAE) to learn the underlying factors of variation of the median beat ECG morphology (the FactorECG), which are subsequently used in common and interpretable prediction models. As the ECG factors can be made explainable by generating and visualizing ECGs on both the model and individual level, the pipeline provides improved explainability over heatmap-based methods. By training on a database with 1.1 million ECGs, the VAE can compress the ECG into 21 generative ECG factors, most of which are associated with physiologically valid underlying processes. Performance of the explainable pipeline was similar to 'black box' DNNs in conventional ECG interpretation [area under the receiver operating curve (AUROC) 0.94 vs. 0.96], detection of reduced EF (AUROC 0.90 vs. 0.91), and prediction of 1-year mortality (AUROC 0.76 vs. 0.75). Contrary to the 'black box' DNNs, our pipeline provided explainability on which morphological ECG changes were important for prediction. Results were confirmed in a population-based external validation dataset.

Conclusions

Future studies on DNNs for ECGs should employ pipelines that are explainable to facilitate clinical implementation by gaining confidence in artificial intelligence and making it possible to identify biased models.

Life-threatening ventricular arrhythmia prediction in patients with dilated cardiomyopathy using explainable electrocardiogram-based deep neural networks

Aims

While electrocardiogram (ECG) characteristics have been associated with life-threatening ventricular arrhythmias (LTVA) in dilated cardiomyopathy (DCM), they typically rely on human-derived parameters. Deep neural networks (DNNs) can discover complex ECG patterns, but the interpretation is hampered by their ‘black-box’ characteristics. We aimed to detect DCM patients at risk of LTVA using an inherently explainable DNN.

Methods and results

In this two-phase study, we first developed a variational autoencoder DNN on more than 1 million 12-lead median beat ECGs, compressing the ECG into 21 different factors (F): FactorECG. Next, we used two cohorts with a combined total of 695 DCM patients and entered these factors in a Cox regression for the composite LTVA outcome, which was defined as sudden cardiac arrest, spontaneous sustained ventricular tachycardia, or implantable cardioverter-defibrillator treated ventricular arrhythmia. Most patients were male (n = 442, 64%) with a median age of 54 years [interquartile range (IQR) 44–62], and median left ventricular ejection fraction of 30% (IQR 23–39). A total of 115 patients (16.5%) reached the study outcome. Factors F₈ (prolonged PR-interval and P-wave duration, P < 0.005), F₁₅ (reduced P-wave height, P = 0.04), F₂₅ (increased right bundle branch delay, P = 0.02), F₂₇ (P-wave axis P < 0.005), and F₃₂ (reduced QRS-T voltages P = 0.03) were significantly associated with LTVA.

Conclusion

Inherently explainable DNNs can detect patients at risk of LTVA which is mainly driven by P-wave abnormalities.

Hypertensive response to exercise in adult patients with repaired aortic coarctation

OBJECTIVE

The clinical and prognostic implications of a hypertensive response to exercise after repair of coarctation of the aorta (CoA) remain controversial. We aimed to determine the prevalence of a hypertensive response to exercise, identify factors associated with peak exercise systolic blood pressure (SBP) and explore the association of peak exercise SBP with resting blood pressure and cardiovascular events during follow-up.

METHODS

From the Dutch national CONgenital CORvitia (CONCOR) registry, adults with repaired CoA who underwent exercise stress testing were included. A hypertensive response to exercise was defined as a peak exercise SBP ≥210 mm Hg in men and ≥190 mm Hg in women. Cardiovascular events consisted of coronary artery disease, stroke, aortic complications and cardiovascular death.

RESULTS

Of the original cohort of 920 adults with repaired CoA, 675 patients (median age 24 years (range 16-72 years)) underwent exercise stress testing. Of these, 299 patients (44%) had a hypertensive response to exercise. Mean follow-up duration was 10.1 years. Male sex, absence of a bicuspid aortic valve and elevated resting SBP were independently associated with increased peak exercise SBP. Peak exercise SBP was positively predictive of office SBP (β=0.11, p<0.001) and 24-hour SBP (β=0.05, p=0.03) at follow-up, despite correction for baseline SBP. During follow-up, 100 patients (15%) developed at least 1 cardiovascular event. Peak exercise SBP was not significantly associated with the occurrence of cardiovascular events (HR 0.994 (95% CI 0.987 to 1.001), p=0.11).

CONCLUSIONS

A hypertensive response to exercise was present in nearly half of the patients in this large, prospective cohort of adults with repaired CoA. Risk factors for increased peak exercise SBP were male sex, absence of a bicuspid aortic valve and elevated resting SBP. Increased peak exercise SBP independently predicted hypertension at follow-up. These results support close follow-up of patients with a hypertensive response to exercise to ensure timely diagnosis and treatment of future hypertension.

Follistatin-like 1 promotes proliferation of matured human hypoxic iPSC-cardiomyocytes and is secreted by cardiac fibroblasts

The human heart has limited regenerative capacity. Therefore, patients often progress to heart failure after ischemic injury, despite advances in reperfusion therapies generally decreasing mortality. Depending on its glycosylation state, Follistatin-like 1 (FSTL1) has been shown to increase cardiomyocyte (CM) proliferation, decrease CM apoptosis, and prevent cardiac rupture in animal models of ischemic heart disease. To explore its therapeutic potential, we used a human in vitro model of cardiac ischemic injury with human induced pluripotent stem cell-derived CMs (iPSC-CMs) and assessed regenerative effects of two differently glycosylated variants of human FSTL1. Furthermore, we investigated the FSTL1-mediated interplay between human cardiac fibroblasts (cFBs) and iPSC-CMs in hypoxia. Both FSTL1 variants increased viability, while only hypo-glycosylated FSTL1 increased CM proliferation post-hypoxia. Human fetal cardiac fibroblasts (fcFBs) expressed and secreted FSTL1 under normoxic conditions, while FSTL1 secretion increased by iPSC-cFBs upon hypoxia but decreased in iPSC-CMs. Co-culture of iPSC-CMs and cFBs increased FSTL1 secretion compared with cFB mono-culture. Taken together, we confirm that FSTL1 induces iPSC-CM proliferation in a human cardiac in vitro hypoxia damage model. Furthermore, we show hypoxia-related FSTL1 secretion by human cFBs and indications for FSTL1-mediated intercellular communication between cardiac cell types in response to hypoxic conditions.

Circadian Dependence of the Acute Immune Response to Myocardial Infarction

Circadian rhythms influence the recruitment of immune cells and the onset of inflammation, which is pivotal in the response to ischemic cardiac injury after a myocardial infarction (MI). The hyperacute immune response that occurs within the first few hours after a MI has not yet been elucidated. Therefore, we characterized the immune response and myocardial damage 3 hours after a MI occurs over a full twenty-four-hour period to investigate the role of the circadian rhythms in this response. MI was induced at Zeitgeber Time (ZT) 2, 8, 14, and 20 by permanent ligation of the left anterior descending coronary artery. Three hours after surgery, animals were terminated and blood and hearts collected to assess the immunological status and cardiac damage. Blood leukocyte numbers varied throughout the day, peaking during the rest-phase (ZT2 and 8). Extravasation of leukocytes was more pronounced during the active-phase (ZT14 and 20) and was associated with greater chemokine release to the blood and expression of adhesion molecules in the heart. Damage to the heart, measured by Troponin-I plasma levels, was elevated during this time frame. Clock gene oscillations remained intact in both MI-induced and sham-operated mice hearts, which could explain the circadian influence of the hyperacute inflammatory response after a MI. These findings are in line with the clinical observation that patients who experience a MI early in the morning (i.e., early active phase) have worse clinical outcomes. This study provides further insight on the immune response occurring shortly after an MI, which may contribute to the development of novel and optimization of current therapeutic approaches.

Modifiable risk factors in adults with and without prior cardiovascular disease: findings from the Indonesian National Basic Health Research

Backgrounds

The majority of risk factors for cardiovascular diseases (CVDs) are modifiable. Continuous monitoring and control of these factors could significantly reduce the risk of CVDs-related morbidity and mortality. This study estimated the prevalence of modifiable risk factors in Indonesia and its co-occurence of multiple risk factors stratified by prior CVDs diagnosis status and sex.

Methods

Adult participants (> 15 years, N = 36,329, 57% women) with median age of 40 years were selected from a nationwide Indonesian cross-sectional study called Basic Health Research or Riset Kesehatan Dasar (Riskesdas) conducted in 2018. Thirteen risk factors were identified from the study, including smoking, a high-risk diet, inadequate fruit and vegetable consumption, a low physical activity level, the presence of mental-emotional disorders, obesity, a high waist circumference (WC), a high waist-to-height ratio (WtHR), hypertension, diabetes, a high total cholesterol level, a high low-density lipoprotein (LDL) cholesterol level, and a low high-density lipoprotein (HDL) cholesterol level. Age-adjusted prevalence ratios stratified by CVDs status and sex were calculated using Poisson regression with the robust covariance estimator.

Results

CVDs were found in 3% of the study population. Risk factor prevalence in the overall population ranged from 5.7 to 96.5% for diabetes and inadequate fruit and vegetable consumption respectively. Smoking, a high-risk food diet, and a low HDL cholesterol level were more prevalent in men, whereas a low physical activity level, the presence of mental-emotional disorders, obesity, a high WC, a high WtHR, hypertension, diabetes, a high total cholesterol level, and a high LDL cholesterol level were more prevalent in women. Approximately 22% of men and 18% of women had at least 4 risk factors, and these proportions were higher in participants with prior CVDs diagnosis.

Conclusions

There is a high prevalence of modifiable risk factors in the Indonesian adult population. Sex, age, and the presence of CVD are major determinants of the variations in risk factors. The presence of multiple risk factors, which are often inter-related, requires a comprehensive approach through health promotion, lifestyle modification and patient education.

Deep neural networks reveal novel sex-specific electrocardiographic features relevant for mortality risk

Aims

Incorporation of sex in study design can lead to discoveries in medical research. Deep neural networks (DNNs) accurately predict sex based on the electrocardiogram (ECG) and we hypothesized that misclassification of sex is an important predictor for mortality. Therefore, we first developed and validated a DNN that classified sex based on the ECG and investigated the outcome. Second, we studied ECG drivers of DNN-classified sex and mortality.

Methods and results

A DNN was trained to classify sex based on 131 673 normal ECGs. The algorithm was validated on internal (68 500 ECGs) and external data sets (3303 and 4457 ECGs). The survival of sex (mis)classified groups was investigated using time-to-event analysis and sex-stratified mediation analysis of ECG features. The DNN successfully distinguished female from male ECGs {internal validation: area under the curve (AUC) 0.96 [95% confidence interval (CI): 0.96, 0.97]; external validations: AUC 0.89 (95% CI: 0.88, 0.90), 0.94 (95% CI: 0.93, 0.94)}. Sex-misclassified individuals (11%) had a 1.4 times higher mortality risk compared with correctly classified peers. The ventricular rate was the strongest mediating ECG variable (41%, 95% CI: 31%, 56%) in males, while the maximum amplitude of the ST segment was strongest in females (18%, 95% CI: 11%, 39%). Short QRS duration was associated with higher mortality risk.

Conclusion

Deep neural networks accurately classify sex based on ECGs. While the proportion of ECG-based sex misclassifications is low, it is an interesting biomarker. Investigation of the causal pathway between misclassification and mortality uncovered new ECG features that might be associated with mortality. Increased emphasis on sex as a biological variable in artificial intelligence is warranted.

Electrocardiogram-based mortality prediction in patients with COVID-19 using machine learning

Background and purpose

The electrocardiogram (ECG) is frequently obtained in the work-up of COVID-19 patients. So far, no study has evaluated whether ECG-based machine learning models have added value to predict in-hospital mortality specifically in COVID-19 patients.

Methods

Using data from the CAPACITY-COVID registry, we studied 882 patients admitted with COVID-19 across seven hospitals in the Netherlands. Raw format 12-lead ECGs recorded within 72 h of admission were studied. With data from five hospitals (n = 634), three models were developed: (a) a logistic regression baseline model using age and sex, (b) a least absolute shrinkage and selection operator (LASSO) model using age, sex and human annotated ECG features, and (c) a pre-trained deep neural network (DNN) using age, sex and the raw ECG waveforms. Data from two hospitals (n = 248) was used for external validation.

Results

Performances for models a, b and c were comparable with an area under the receiver operating curve of 0.73 (95% confidence interval [CI] 0.65–0.79), 0.76 (95% CI 0.68–0.82) and 0.77 (95% CI 0.70–0.83) respectively. Predictors of mortality in the LASSO model were age, low QRS voltage, ST depression, premature atrial complexes, sex, increased ventricular rate, and right bundle branch block.

Conclusion

This study shows that the ECG-based prediction models could be helpful for the initial risk stratification of patients diagnosed with COVID-19, and that several ECG abnormalities are associated with in-hospital all-cause mortality of COVID-19 patients. Moreover, this proof-of-principle study shows that the use of pre-trained DNNs for ECG analysis does not underperform compared with time-consuming manual annotation of ECG features.

Supplementary Information

The online version of this article (10.1007/s12471-022-01670-2) contains supplementary material, which is available to authorized users.

Preclinical Comparison of Distal Off-Pump Anastomotic Remodeling: Hand-Sewn Versus ELANA Heart Bypass

Objective: The ELANA Heart Bypass System is a new sutureless technique for coronary anastomoses. A titanium clip connects the graft with the coronary artery, whereafter the arteriotomy is performed by excimer laser. Since this anastomotic construction evidently differs from the standard hand-sewn anastomosis, we aim to evaluate the process of anastomotic healing and remodeling. Methods: Preclinical evaluation of anastomotic remodeling in 42 pigs who underwent off-pump left internal mammary artery to left anterior descending artery anastomosis by either the ELANA Heart Bypass (n = 24) or the hand-sewn (n = 18) technique. Anastomotic remodeling was evaluated by scanning electron microscopy and histology in short-term follow-up intervals up to 3 months. Anastomotic patency is determined by coronary angiography at latest follow-up before termination. Results: The nonendothelial surface of both the ELANA and the hand-sewn anastomoses were covered with neointima from 14 days onwards. Only half the amount of intima hyperplasia was present in the anastomotic surface of the patent ELANA anastomosis, compared with the hand-sewn anastomosis (98 [48–1358] vs 218 [108–296] µm, P = 0.001). Yet patency of the ELANA was inferior to the hand-sewn anastomoses (79% vs 100%, P = 0.06). Conclusions: This study shows the technical perioperative feasibility of the ELANA Heart Bypass System. Although limited intima hyperplasia was observed, hand-sewn anastomoses had superior patency during follow-up. The results of this trial suggest that an additional study with a new prototype is required before clinical implementation.

Will our cardiomyopathy patients accept gene therapy?

Novel techniques such as gene therapy are becoming available in an attempt to cure inherited diseases. Before these new therapies can be offered to patients, we need to be aware of potential reservations or objections, not only from patients and their surroundings but also from the public. In addition, legal issues and costs need attention before curative gene therapy can be applied in the clinic. As this therapeutic approach is closer to becoming a reality, now is the right time to start the debate.

Generation of human induced 4x44 stem cell (iPSC) lines derived from five patients carrying the pathogenic phospholamban-R14del (PLN-R14del) variant and three non-carrier family members

The R14del pathogenic variant in the phospholamban (PLN) gene (PLN-R14del), has been identified in families with hereditary cardiomyopathy, including dilated and arrhythmogenic cardiomyopathies. Here we have generated human iPSC lines from five PLN-R14del carriers and three non-carrier family members. Peripheral blood mononuclear cells (PBMC) were obtained from the eight individuals and reprogrammed using Sendai viral vector system carrying the Yamanaka factors. All eight lines show typical iPSC morphology, normal karyotype, high expression of pluripotency markers, and possess the ability to differentiate into all three germ layers. These lines represent valuable resources for studying the pathophysiological mechanisms of PLN-R14del associated cardiomyopathy.

NSTEMI with total left circumflex occlusion: how the N-wave might help (case report)

A rise and/or fall in troponin level is an indication of type 1 or 2 myocardial infarct. A 62-year-old male physician presented to emergency room with chest discomfort followed by thought to be normal electrocardiogram (ECG) and normal echocardiography results. His serial hs-troponin test showed remarkable escalation three hours from the initial (107 ng/l into 4.978 ng/l), suggesting a high-risk non-ST-segment myocardial infarction (NSTEMI). An early invasive procedure was performed, showing acute total occlusion (TO) in the obtuse marginal 1 branch. We retrospectively reviewed our examination to diagnose better the presence of TO in NSTEMI patients presented with non-diagnostic examination. Our evaluation showed a minor change in the form of an ‘N-wave’ pattern on the ECG, which was not yet an established guideline criterion for prompt angiography. Although ECG pattern is often normal in LCx occlusion, recent study shows the presence of ‘N-wave’ ECG pattern in 10% of NSTEMI cases following TO at LCx.

Sutureless versus Hand-Sewn Coronary Anastomoses: A Systematic Review and Meta-Analysis

Background: Sutureless coronary anastomotic devices are intended to facilitate minimally invasive coronary artery bypass grafting (MICS-CABG) by easing and eventually standardizing the anastomotic technique. Within this systematic review and meta-analysis, we aim to determine patency and to evaluate safety outcomes for the sutureless anastomoses. Methods: CENTRAL, MEDLINE, and EMBASE were searched from database start till August 2021 in a predefined search strategy combining the key concepts: ‘coronary artery bypass grafting’, ‘sutureless coronary anastomoses’, and ‘hand-sewn coronary anastomoses’ by the Boolean operation ‘AND’. Study characteristics, patient demographics, interventional details, and all available outcome data were extracted. A meta-analysis was performed on patency at longest follow-up. Safety outcomes were presented. Results: A total of eleven trials towards six sutureless anastomotic devices were included, comprising 3724 patients (490 sutureless and 3234 hand-sewn). There was no significant difference in patency at a mean follow-up duration of 546.3 (range 1.5–2691) days, with a risk ratio of 0.77 (95% CI 0.55–1.06). MACE was reported in 4.5% sutureless and 3.9% hand-sewn patients, including all-cause mortality (resp. 1.3 vs. 1.9%), myocardial infarction (resp. 1.6 vs. 1.7%), and coronary revascularization (resp. 1.8 vs. 0.5%). Incomplete hemostasis occurred in 24.8% of the sutureless anastomoses. Intra-operative device failure forced conversion to hand-sewn or redo-anastomosis in 5.8% of the sutureless cases. Conclusion: Based on the systematic review and meta-analysis including six devices, we conclude that sutureless coronary anastomotic devices appear safe and effective when used by well-trained and dedicated surgical teams.

Sarcomere Disassembly and Transfection Efficiency in Proliferating Human iPSC-Derived Cardiomyocytes

Contractility of the adult heart relates to the architectural degree of sarcomeres in individual cardiomyocytes (CMs) and appears to be inversely correlated with the ability to regenerate. In this study we utilized multiple imaging techniques to follow the sequence of sarcomere disassembly during mitosis resulting in cellular or nuclear division in a source of proliferating human pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). We observed that both mono- and binuclear hiPSC-CMs give rise to mononuclear daughter cells or binuclear progeny. Within this source of highly proliferative hiPSC-CMs, treated with the CHIR99021 small molecule, we found that Wnt and Hippo signaling was more present when compared to metabolic matured non-proliferative hiPSC-CMs and adult human heart tissue. Furthermore, we found that CHIR99021 increased the efficiency of non-viral vector incorporation in high-proliferative hiPSC-CMs, in which fluorescent transgene expression became present after the chromosomal segregation (M phase). This study provides a tool for gene manipulation studies in hiPSC-CMs and engineered cardiac tissue. Moreover, our data illustrate that there is a complex biology behind the cellular and nuclear division of mono- and binuclear CMs, with a shared-phenomenon of sarcomere disassembly during mitosis.

Characteristics and time course of acute and chronic myocardial lesion formation after electroporation ablation in the porcine model

INTRODUCTION

Electroporation ablation creates deep and wide myocardial lesions. No data are available on time course and characteristics of acute lesion formation.

METHODS

For the acute phase of myocardial lesion development, 7 pigs were investigated. Single 200J applications were delivered at 4 different epicardial right ventricular sites using a linear suction device, yielding a total of 28 lesions. Timing of applications was designed to yield lesions at 7 time points: 0, 10, 20, 30, 40, 50, 60 minutes, with 4 lesions per time point. After euthanization, lesion characteristics were histologically investigated. For the chronic phase of myocardial lesion development, tissue samples were used from previously conducted studies where tissue was obtained at 3 weeks and 3 months after electroporation ablation.

RESULTS

Acute myocardial lesions induce a necrosis pattern with contraction band necrosis and interstitial edema, immediately present after electroporation ablation. No further histological changes such as hemorrhage or influx of inflammatory cells occurred in the first hour. After 3 weeks, the lesions consisted of sharply demarcated loose connective tissue that further developed to more fibrotic scar tissue after 3 months without additional changes. Within the scar tissue arteries and nerves were unaffected.

CONCLUSION

Electroporation ablation immediately induces contraction band necrosis and edema without additional tissue changes in the first hour. After 3 weeks a sharply demarked scar has been developed that remains stable during follow up of 3 months. This is highly relevant for clinical application of electroporation ablation in terms of the electrophysiological endpoint and waiting period after ablation. This article is protected by copyright. All rights reserved.

Controlled delivery of gold nanoparticle-coupled miRNA therapeutics via an injectable self-healing hydrogel

Differential expression of microRNAs (miRNAs) plays a role in many diseases, including cancer and cardiovascular diseases. Potentially, miRNAs could be targeted with miRNA-therapeutics. Sustained delivery of these therapeutics remains challenging. This study couples miR-mimics to PEG-peptide gold nanoparticles (AuNP) and loads these AuNP-miRNAs in an injectable, shear thinning, self-assembling polymer nanoparticle (PNP) hydrogel drug delivery platform to improve delivery. Spherical AuNPs coated with fluorescently labelled miR-214 are loaded into an HPMC-PEG-b-PLA PNP hydrogel. Release of AuNP/miRNAs is quantified, AuNP-miR-214 functionality is shown in vitro in HEK293 cells, and AuNP-miRNAs are tracked in a 3D bioprinted human model of calcific aortic valve disease (CAVD). Lastly, biodistribution of PNP-AuNP-miR-67 is assessed after subcutaneous injection in C57BL/6 mice. AuNP-miRNA release from the PNP hydrogel in vitro demonstrates a linear pattern over 5 days up to 20%. AuNP-miR-214 transfection in HEK293 results in 33% decrease of Luciferase reporter activity. In the CAVD model, AuNP-miR-214 are tracked into the cytoplasm of human aortic valve interstitial cells. Lastly, 11 days after subcutaneous injection, AuNP-miR-67 predominantly clears via the liver and kidneys, and fluorescence levels are again comparable to control animals. Thus, the PNP-AuNP-miRNA drug delivery platform provides linear release of functional miRNAs in vitro and has potential for in vivo applications.

Cardiovascular Morbidity and Mortality in Adult Patients With Repaired Aortic Coarctation

Background The long-term burden of cardiovascular disease after repair of coarctation of the aorta (CoA) has not been elucidated. We aimed to determine the incidence of and risk factors for cardiovascular events in adult patients with repaired CoA. Additionally, mortality rates were compared between adults with repaired CoA and the general population. Methods and Results Using the Dutch Congenital Corvitia (CONCOR) registry, patients aged ≥16 years with previous surgical or transcatheter CoA repair from 5 tertiary referral centers were included. Cardiovascular events were recorded, comprising coronary artery disease, stroke/transient ischemic attack, aortic complications, arrhythmias, heart failure hospitalizations, endocarditis, and cardiovascular death. In total, 920 patients (median age, 24 years [range 16-74 years]) were included. After a mean follow-up of 9.3±5.1 years, 191 patients (21%) experienced at least 1 cardiovascular event. A total of 270 cardiovascular events occurred, of which aortic complications and arrhythmias were most frequent. Older age at initial CoA repair (hazard ratio [HR], 1.017; 95% CI, 1.000-1.033 [P=0.048]) and elevated left ventricular mass index (HR, 1.009; 95% CI, 1.005-1.013 [P<0.001]) were independently associated with an increased risk of cardiovascular events. The mortality rate was 3.3 times higher than expected based on an age- and sex-matched cohort from the Dutch general population (standardized mortality ratio, 3.3; 95% CI, 2.3-4.4 [P<0.001]). Conclusions This large, prospective cohort of adults with repaired CoA showed a high burden of cardiovascular events, particularly aortic complications and arrhythmias, during long-term follow-up. Older age at initial CoA repair and elevated left ventricular mass index were independent risk factors for the occurrence of cardiovascular events. Mortality was 3.3-fold higher compared with the general population. These results advocate stringent follow-up after CoA repair and emphasize the need for improved preventive strategies.

Interpretable uncertainty estimation for automated triage of 12-lead electrocardiogram using deep convolutional neural networks

Background

Interpretation of electrocardiograms (ECGs) using artificial intelligence (AI) has shown very promising results recently, such as comprehensive triage of ECGs. Despite this progress, remarkably few of these AI algorithms have been implemented in clinical practice. Mayor challenges before safe widespread implementation is possible, are uncertainty estimation and interpretability. Without these, algorithms are forced to always provide a diagnosis or prediction. When the algorithm has never seen such an ECG before or when it is noisy or contains a difficult or ambiguous case, this could lead to unrecognized erroneous results.

Purpose

We propose a novel deep neural network (DNN) architecture that is able to overcome both the interpretability and uncertainty estimation challenges in automated diagnosis of ECGs.

Methods

A dataset with 320.000 raw 10s 12-lead ECGs was used to train and validate the DNN in separate 90:10 splits. All ECGs were interpreted by a physician and these free-text annotations were translated into 6 categories from normal to acute based on how quickly a cardiologist needs to be consulted.

Using a novel variational autoencoder DNN, the ECG is compressed into a latent space with 64 parameters. In the compressed space, each category has a separate distribution, instead of a single distribution for the whole dataset.

For clinical use, the ECG is represented in the compressed space and the category prior distribution that is the most likely to produce the input ECG representation is the predicted category. The smaller the probability of generating the data point under any of the known categories, the more uncertain the prediction. The compressed space is reduced using principal component analysis (PCA) to visualize where the input is represented in the compressed landscape.

Performance of the uncertainty estimation is assessed in the validation set by ranking the uncertainty in 10 bins from highest to lowest and comparing with the accuracy.

Results

We demonstrate that the accuracy of the algorithm decreases for ECGs where the model is more uncertain about its predictions (Figure 1). Prediction accuracies range from 90% for the ECGs where the algorithm is most certain, to 50% where it is most uncertain. The PCA of the latent space appears to be able to visually represent the categories in the latent space (Figure 2). Moreover, it indicates whether the new ECG belongs to a known category, the algorithm is doubting between categories or the ECG belongs to none of the categories.

Conclusion

The proposed novel method is promising in estimating uncertainty in an interpretable way, which could allow for safer implementation of AI-based ECG interpretation. Further research is needed to improve the baseline performance of the model, to compare to existing methods and to examine the detection of noisy or new ECGs. The interpretability can be further extended to highlight the uncertain regions on the ECGs.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): ZonMw Figure 1. Uncertainty versus accuracyFigure 2. Representation of ECG