Current state of artificial intelligence-based algorithms for hospital admission prediction in patients with heart failure: a scoping review. Eur Heart J Digit Health 2022;3:415-425. [PMID: 36712159 PMCID: PMC9707890 DOI: 10.1093/ehjdh/ztac035]

AIMS

Patients with congestive heart failure (HF) are prone to clinical deterioration leading to hospital admissions, burdening both patients and the healthcare system. Predicting hospital admission in this patient group could enable timely intervention, with subsequent reduction of these admissions. To date, hospital admission prediction remains challenging. Increasing amounts of acquired data and development of artificial intelligence (AI) technology allow for the creation of reliable hospital prediction algorithms for HF patients. This scoping review describes the current literature on strategies and performance of AI-based algorithms for prediction of hospital admission in patients with HF.

METHODS AND RESULTS

PubMed, EMBASE, and the Web of Science were used to search for articles using machine learning (ML) and deep learning methods to predict hospitalization in patients with HF. After eligibility screening, 23 articles were included. Sixteen articles predicted 30-day hospital (re-)admission resulting in an area under the curve (AUC) ranging from 0.61 to 0.79. Six studies predicted hospital admission over longer time periods ranging from 6 months to 3 years, with AUC's ranging from 0.65 to 0.78. One study prospectively evaluated performance of a disposable sensory patch at home after hospitalization which resulted in an AUC of 0.89 for unplanned hospital admission prediction.

CONCLUSION

AI has the potential to enable prediction of hospital admission in HF patients. Improvement of data management, adding new data sources such as telemonitoring data and ML models and prospective and external validation of current models must be performed before clinical applicability is possible.

A novel receptor-interacting protein-1 (RIP1) inhibitor (547) protects human cardiac cells from ischemia/reperfusion-triggered necroptotic cell death

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): M.M.C.P. is supported by a Netherlands Cardiovascular Research Initiative (CVON) grant (REMAIN 2014B27) and J.P.G.S is supported by Horizon2020 ERC-2016-COG-EVICARE [725229] and BRAVE (grant number 874827.

Purpose

Restoring perfusion, either by coronary angioplasty or bypass anastomosis, is performed around 2 million times per year throughout Europe to treat patients after myocardial infarction. Although this treatment is highly efficient to resolve myocardial ischemia, reperfusion is accompanied by damage through the release of reactive oxygen species (ROS). This ischemia/reperfusion (I/R) injury is manifested by cardiomyocyte death, caused to a certain extent by necroptosis. As a potential means of cardioprotection, we applied the small molecule compound 547 inhibiting RIP1-kinase, a central mediator of the necroptosis pathway, in an in vitro model of human cardiac I/R injury.

Methods

Human foetal cardiomyocyte progenitor cells (hfCPCs) were cultured and characterized for cell type defining markers before being subjected to simulated I/R damage using hydrogen peroxide (H2O2). Cardioprotective effects of 547 were assessed 24 hours after induction of damage and application of the compound. Cell viability and necroptosis pathway activation were assessed by flow cytometry, immunocytochemistry, and western blotting. Furthermore, mitochondrial damage was determined by JC-1 staining.

Results

hfCPCs expressed indicative markers SCA1, GATA4, PECAM-1, VEGF and C-KIT. Treatment with compound 547 significantly protected hfCPCs from H2O2 induced damage (viable cells: 84,3 ± 4,3% vs 1,6 ± 0,31%; P<0,0001). 547 decreased the necrotic cell population (DAPI+ AnnV-) (3,0 ± 1,1% vs 10,1 ± 1,5%, P<0,0001) and reduced phosphorylation of necrosome components RIP1 (1,3 ±  0,35 fold vs 3,7 ±  0,78 fold; P< 0,01), RIP3 (1,0 ± 0,46 fold vs 4,3 ± 1,5 fold; P< 0,05), and MLKL (1,1 ± 0,15 fold vs 5,7 ± 1,7 fold; P< 0,01) without decreasing unphosphorylated protein or mRNA levels. Interestingly, 547 treatment prevented oxidative stress induced loss of nuclear RIP1 and RIP3 as measured by immunocytochemistry and western blotting of cell fractions (nuclear/cytoplasmic ratio RIP1: 0,80 ±  0,0006 [Control] vs 1,5 ±  0,17 fold [547]; P< 0,01; nuclear/cytoplasmic ratio RIP3: 0,76 ±  0,10 [Control] vs 1,6 ± 0,18 fold [547]; P< 0,01). Remarkably, compound 547 also decreased H2O2–induced mitochondrial depolarization (JC-1 staining/membrane depolarization index: 4,5 ± 0,85% vs 1,2 ±  0,38%; P< 0,05)) and expression and activation of CAMKII (0,46 ± 0,13 fold; P<0,01), a protein mediating mitochondria-dependent cell death.

Conclusions

Administration of compound 547 led to inhibition of necroptosis, increased cell viability and reduced mitochondrial damage in an in vitro human cardiac I/R injury model, emphasizing the potential of necroptosis inhibition for cardioprotection. Assessing clinical applicability will require further studies in relevant in vivo models.

The impact of valvular heart disease in patients referred for suspected coronary artery disease

Funding Acknowledgements

Type of funding sources: None.

Introduction

The most recent European Society of Cardiology guideline on coronary syndromes recommends echocardiography in all patients with suspected coronary artery disease (CAD). Whereas left ventricular function (LVF) is recognized as an important determinant of major adverse cardiovascular events (MACE) in these patients, little is known about the role of valvular heart disease (VHD).

Purpose

  The aim of this study was to evaluate the prevalence and impact on the prognosis of VHD in patients referred for suspected CAD.

Method

Baseline, treatment and event in follow-up data of patients with suspected CAD who underwent transthoracic echocardiography (TTE) in a tertiary center between 2014 and 2021 were collected. MACE were defined as all-cause death, nonfatal stroke and nonfatal myocardial infarction (MI). VHD was defined as moderate-or-severe aortic stenosis (AS) or mitral regurgitation (MR). LV dysfunction was defined an ejection fraction less than 50%. Time-to-first-event analysis was performed with Kaplan-Meier survival curves and Cox proportional hazard analysis adjusting for significant covariates and time-dependent interventions.

Results

A total of 845 patients (57% men) with mean age of 65 years were identified. The median follow-up time was 2.8 years (1.1 – 4.8). In total 144 MACE (108 all-cause death, 14  nonfatal stroke, 22 nonfatal MI) occurred. VHD was prevalent in 132 (16%) patients of which 95 patients had moderate or severe AS and 44 had moderate or severe MR, see Figure 1. Independent determinants of MACE in VHD patients included moderate or severe VHD (HR 1.5, p = 0,05), LV dysfunction (HR 2.1, p < 0.001), age older than 70 years (HR 1.7, p = 0.003) and diabetes (HR 2.0, p < 0.001).

Conclusion

There is a high prevalence of VHD in patients referred for suspected CAD. Moderate to severe VHD strongly determines the prognosis. Future studies are needed to determine whether valvular interventions can improve the long-term outcome. Abstract Figure.

Predictive value of the left ventricular function in coronary artery disease: should we tailor risk-stratification for men and women?

Introduction

Left ventricular function (LVF) is a well-known recognized predictor of major adverse cardiovascular events (MACE) in patients with coronary artery disease (CAD) and is recommended in all CAD patients by the guidelines of the European Society of Cardiology. As non-obstructive CAD is more common among women, the predictive value of LVF might differ between men and women.

Purpose

The aim of this study is to evaluate sex-related differences in the predictive value of LVF in patients with suspected or documented CAD.

Methods

Patients with suspected or documented CAD who underwent transthoracic echocardiography (TTE) with LVF assessment in a tertiary center between 2014 and 2021 were included. LVF was classified with left ventricular ejection fraction (LVEF) as normal (≥52%) or impaired (LVEF <52%). MACE were defined as death, heart failure (HF), acute coronary syndrome (ACS) and stroke. Time-to-first-event analysis was performed with Kaplan-Meier survival analysis and multivariate Cox proportional hazard analysis adjusting for age as covariate.

Results

In total, 1763 patients were included of which 59% were men (age 65±12 years) and 41% were women (age 65±13 years). 225 (22%) men and 100 (14%) women had impaired LVF (p<0.001). Median follow-up time was 1.9 years (1.2–3.8); median event-free survival for men and women was 1.6 years (1.0–3.3) and 1.6 years (1.0–3.0), respectively (p=0.8). MACE and deaths were reported in 422 patients (23% of men, 25% of women) and 15 patients (12% of men, 10% of women), respectively. Impaired LVF was associated with a significantly higher risk of MACE in both men (HR 1.3, 95% CI: 1.2–1.4, p<0.005) and women (HR 1.2, 95% CI: 1.0–1.3, p=0.02).

Conclusions

Impaired LVF was more common in men with suspected or documented CAD. In patients with impaired LVF, the predictive value of LVF is similar for both men and women.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): Amsterdam UMC, Amsterdam MACE_men_women

Modeling ischemic heart disease: only matured human iPS-derived cardiomyocytes are sensitive to ischemic injury

Background

Ischemic heart disease remains the leading cause of death worldwide due to irreversible loss of cardiomyocytes (CMs) during ischemic injury. To test potential factors that can stimulate cardiac repair, murine and porcine animal models or in vitro assays are often used. However, clinical translation remains ineffective as the CMs in the human heart differ signifantly from those in animal hearts1. Human induced pluripotent stem cell (hiPSC) derived CMs have been considered a very promising tool but their immature nature remains a roadblock for human cardiac disease modeling. A media to improve maturation of hiPSC-CMs has recently been developed2.

Purpose

To test whether we can model human myocardial ischemia, we assess the effect of metabolic maturation on ischemia susceptibility of hiPSC-CMs.

Methods

hiPSCs were differentiated into CMs and matured either in RPMI/B27 media or in maturation media (MM)2. Ischemia was induced by exposure to 5% or 1% oxygen for 4 to 24 hours in one of 5 types of media (DMEM/10%KOSR; RPMI/B27; RPMI pur/B27; RPMI pur/lactate; starvation MM) to assess the effect of media nutrient content on ischemia susceptibility.

Results

CMs matured in RPMI/B27 media did not show a significant increase in cell death independent of media glucose or serum content during ischemia (ratio dead/live RPMI pur/lactate: 0,02±0,004 [24 hours 21% O2]; 0,11±0,04 [24 hours 1% O2], p>0,05). CMs matured in MM did show an increase in cell death with increasing duration of ischemia for both 5% and 1% O2 (0,58±0,06 [0h]; 1,1±0,09 [24h 1%]). Furthermore, only metabolically matured CMs showed increased TUNEL+ CMs (7,5±1,3% [control]; 42,2±11,0%, p<0,001 [24 hours 1% O2]) and decreased viability measured by flow cytometry (90,8±0,71% [control]; 76,3±2,2% [24 hours 1% O2], p<0,01) compared to immature CMs (84,5±2,0% [control]; 73,7±3,4% [24 hours 1% O2], p>0,05). Although cardiomyocytes matured in MM showed stable α-actinin expression after 24 hours 1% oxygen (92,7±3,35 [24 hour 21%]; 93,8±1,7 [24 hour 1%]), both incubation in 5% and 1% oxygen led to decreased myofibrillar organization as seen by α-actinin and cardiac troponin T (cTnT) immunoreactivity. Assessment of metabolites in the media showed increased lactate production after 24 hours incubation in 1% oxygen but not in 5% oxygen (from 11,8±0,31mM [24 hour 21%], 11,7±0,3mM [24 hour 5%] to 19,9±1,4 mM [24 hour 1%], p<0,001) indicating that even though 5% oxygen levels were sufficient to induce ischemic damage, further lowering oxygen saturation does have an additional effect on the cardiomyocyte metabolic response to ischemia.

Conclusion

Taken together, we have shown improvement of metabolic maturation of hiPSC-CMs increases the susceptibility to ischemia and therefore their use to mimic ischemic heart disease. It would be of interest to further investigate the underlying metabolic mechanisms of cardiac ischemia.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): MMCP is supported by a Netherlands CardioVascular ResearchInitiative (CVON) grant

Retrospective analysis of endocarditis patients to investigate the eligibility for oral antibiotic treatment in routine daily practice

Background

According to the current guidelines of the European Society of Cardiology, patients with left-sided infective endocarditis are treated with intravenous antibiotics for 4–6 weeks, leading to extensive hospital stay and high costs. Recently, the Partial Oral Treatment of Endocarditis (POET) trial suggested that partial oral treatment is effective and safe in selected patients. Here, we investigated if such patients are seen in our daily clinical practice.

Methods

We enrolled 119 adult patients diagnosed with left-sided infective endocarditis in a retrospective, observational study. We identified those that would be eligible for switching to partial oral antibiotic treatment as defined in the POET trial (e.g. stable clinical condition without signs of infection). Secondary objectives were to provide insight into the time until each patient was eligible for partial oral treatment, and to determine parameters of longer hospital stay and/or need for extended intravenous antibiotic treatment.

Results

Applying the POET selection criteria, the condition of 38 patients (32%) was stable enough to switch them to partial oral treatment, of which 18 (47.3%), 8 (21.1%), 9 (23.7%) and 3 patients (7.9%) were eligible for switching after 10, 14, 21 days or 28 days of intravenous treatment, respectively.

Conclusion

One-third of patients who presented with left-sided endocarditis in routine clinical practice were possible candidates for switching to partial oral treatment. This could have major implications for both the patient’s quality of life and healthcare costs. These results offer an interesting perspective for implementation of such a strategy, which should be accompanied by a prospective cost-effectiveness analysis.

Electronic supplementary material

The online version of this article (10.1007/s12471-020-01490-2) contains supplementary material, which is available to authorized users.

Invasive coronary physiology: a Dutch tradition

Invasive coronary physiology has been applied since the early days of percutaneous transluminal coronary angioplasty, and has become a rapidly emerging field of research. Many physiology indices have been developed, tested in clinical studies, and are now applied in daily clinical practice. Recent clinical practice guidelines further support the use of advanced invasive physiology methods to optimise the diagnosis and treatment of patients with acute and chronic coronary syndromes. This article provides a succinct review of the history of invasive coronary physiology, the basic concepts of currently available physiological parameters, and will particularly highlight the Dutch contribution to this field of invasive coronary physiology.

P5620Clinical and hemodynamic determinants of coronary flow reserve in non-obstructed coronary arteries - A patient level pooled analysis of the DEBATE and ILIAS studies

Aim

Coronary Flow Reserve (CFR) is a valuable physiological index for the assessment of myocardial flow impairment due to focal or microcirculatory coronary artery disease (CAD). Coronary flow capacity (CFC) is another flow-based concept in diagnosing ischemic heart disease (IHD), based on hyperemic average peak velocity (hAPV) and CFR. We evaluated clinical and hemodynamic factors which potentially influence CFR and CFC in non-obstructed coronary arteries.

Methods

We analysed CFR and CFC of 396 non-obstructed vessels of patients from two large multi-center trials (DEBATE and ILIAS) with stable CAD who were scheduled for percutaneous coronary intervention (PCI). Doppler flow measurements were performed after inducing hyperemia with either intracoronary or intravenous infusion of adenosine.

Results

Akaike's Information Criterion (AIC) revealed the parameters age, female gender, a history of myocardial infarction, hypercholesterolemia, current or previous smoking and rate pressure product (RPP) as independent predictors in the best model of fit for CFR in an angiographically non-obstructed vessel. After multivariate regression analysis age, female gender and RPP remained as determinants of CFR in angiographically non-obstructed vessels. Subsequently, ordered logistic regression analysis revealed that age is associated with a worse CFC.

Conclusion

Clinical and hemodynamic parameters are associated with CFR and to a lesser extent CFC in an angiographically non-obstructed coronary artery. CFC is less sensitive to variations in clinical and hemodynamic parameters than CFR and therefore a promising tool in contemporary clinical decision making in the cardiac catheterization laboratory.

Acknowledgement/Funding

DEBATE: Cardiometrics INC. ILIAS: Dutch Health Insurance Board; RADI Medical Systems, Uppsala, Sweden; and Endosonics, Rancho Cordova, CA.

Global longitudinal strain to predict left ventricular dysfunction in asymptomatic patients with severe mitral valve regurgitation: literature review

The optimal treatment strategy for asymptomatic patients with severe mitral valve regurgitation (MR) and preserved left ventricular (LV) function is challenging. This manuscript reviews the available literature on the value of left ventricular global longitudinal strain (LV-GLS) in predicting LV dysfunction after mitral valve surgery in these patients and discusses its current place in the treatment strategy. Studies were identified from Cochrane Library, SCOPUS, PubMed and Web of Science up to February 2018. The domain used was MR. The determinant was LV-GLS; other methods of deformation imaging were excluded. The examined outcome was LV dysfunction after surgery. A total of 144 articles were retrieved, of which 11 publications met the inclusion criteria, including a total of 2415 patients. Ten studies showed a significant correlation between preoperative LV-GLS and LV dysfunction postoperatively; one study reported a negative correlation. These studies suggest that LV-GLS is a predictor of LV dysfunction after surgery in asymptomatic patients with chronic MR. Hence, incorporation of LV-GLS for clinical decision-making in these patients might be of additional value. Further research is needed to confirm the role of LV-GLS in postoperative patients, and additionally in asymptomatic MR patients during a ‘watchful waiting’ strategy.

Intramyocardial bone marrow cell injection does not lead to functional improvement in patients with chronic ischaemic heart failure without considerable ischaemia

Background

It has been suggested that bone marrow cell injection may have beneficial effects in patients with chronic ischaemic heart disease. However, previous trials have led to discrepant results of cell-based therapy in patients with chronic heart failure. The aim of this study was to evaluate the efficacy of intramyocardial injection of mononuclear bone marrow cells in patients with chronic ischaemic heart failure with limited stress-inducible myocardial ischaemia.

Methods and results

This multicentre, randomised, placebo-controlled trial included 39 patients with no-option chronic ischaemic heart failure with a follow-up of 12 months. A total of 19 patients were randomised to autologous intramyocardial bone marrow cell injection (cell group) and 20 patients received a placebo injection (placebo group). The primary endpoint was the group difference in change of left ventricular ejection fraction, as determined by single-photon emission tomography. On follow-up at 3 and 12 months, change of left ventricular ejection fraction in the cell group was comparable with change in the placebo group (P = 0.47 and P = 0.08, respectively). Also secondary endpoints, including left ventricle volumes, myocardial perfusion, functional and clinical parameters did not significantly change in the cell group as compared to placebo. Neither improvement was demonstrated in a subgroup of patients with stress-inducible ischaemia (P = 0.54 at 3‑month and P = 0.15 at 12-month follow-up).

Conclusion

Intramyocardial bone marrow cell injection does not improve cardiac function, nor functional and clinical parameters in patients with severe chronic ischaemic heart failure with limited stress-inducible ischaemia.

Clinical Trial Registration: NTR2516

Electronic supplementary material

The online version of this article (10.1007/s12471-018-1213-2) contains supplementary material, which is available to authorized users.

Longitudinal echocardiographic and clinical follow-up of patients undergoing mitral valve surgery without concomitant tricuspid valve repair

Background

In patients with mild to moderate functional tricuspid regurgitation (TR) and absence of right ventricular dysfunction or tricuspid annulus (TA) dilatation, there is currently no indication for concomitant tricuspid valve (TV) repair during elective mitral valve (MV) surgery. However, long-term results are conflicting. Here, we sought to determine the clinical outcome of this cohort, the rate of TR progression after MV surgery and the role of MV aetiology.

Methods

Patients for elective MV surgery without concomitant TV repair were retrospectively analysed with longitudinal echocardiographic and clinical follow-up, focusing on TR progression and MV aetiology. Linear regression analysis was performed for change in TR at follow-up, using pre-determined variables and confounders.

Results

In total 204 patients without TV repair were analysed. Development of more than moderate TR after a median of 3.1 [1.6–4.6] years was rarely seen: only in 2 out of 161 patients (1.2%) with known TR grade at follow-up. Overall, median preoperative and late postoperative TR grade were equal (p = 0.116). Subanalysis showed no significant difference in MV aetiology subgroups. Preoperative TR grade and male gender were inversely correlated to change in TR. Mortality was not influenced by the 1‑year postoperative TR severity.

Conclusion

Our data showed that in a study population of patients with mild to moderate TR undergoing MV surgery without concomitant TV repair, significant late TR was rarely seen. Based on our study, it is safe to waive concomitant TV repair in this specific patient cohort.

Electronic supplementary material

The online version of this article (10.1007/s12471-018-1159-4) contains supplementary material, which is available to authorized users.

Evaluation of mitral regurgitation by an integrated 2D echocardiographic approach in patients undergoing transcatheter aortic valve replacement

The purpose of this study was to evaluate mitral regurgitation (MR) severity in patients undergoing transcatheter aortic valve replacement (TAVR) by standardized assessment of two-dimensional (2D) transthoracic echocardiography (TTE) and 1-year echocardiographic and clinical outcomes. Pre- and post-procedural TTE's of patients undergoing TAVR between 2008 and 2014 were analyzed. MR was graded according to current guidelines with a systematic and integrated approach. Longitudinal echocardiographic and clinical results were analyzed. Regression analysis was performed for change in MR grade at follow-up, using pre-determined variables and confounders. Pre- and post-procedural TTE were available in 213 subjects. Significant MR was seen in 22% at baseline and 15% at follow-up; MR grade ≥ 3 in < 10%. Severity did not change in 61%, and decreased in 20% of the patients. Overall, the prevalence of MR grades pre- and post TAVR was not significantly different, nor influenced by MR etiology or TAVR prosthesis type. However, higher MR grades and pacemaker absence at baseline, were independently correlated to more improvement of MR after TAVR. Regarding clinical outcomes, NYHA class improved in two-thirds of the patients, irrespective of the baseline MR grade. Overall survival was not significantly different amongst MR grades post-TAVR. MR grading using an systematic 2D echocardiographic approach in patients undergoing TAVR is feasible in clinical practice. Our data revealed a relatively frequent prevalence of significant MR (although grade ≥ 3 was scarce), overall no change in the MR grade at 1 year follow-up, improvement of functional NYHA class, and no significant differences in long-term survival amongst the post-TAVR MR grades.

Optimization of large animal MI models; a systematic analysis of control groups from preclinical studies

Large animal models are essential for the development of novel therapeutics for myocardial infarction. To optimize translation, we need to assess the effect of experimental design on disease outcome and model experimental design to resemble the clinical course of MI. The aim of this study is therefore to systematically investigate how experimental decisions affect outcome measurements in large animal MI models. We used control animal-data from two independent meta-analyses of large animal MI models. All variables of interest were pre-defined. We performed univariable and multivariable meta-regression to analyze whether these variables influenced infarct size and ejection fraction. Our analyses incorporated 246 relevant studies. Multivariable meta-regression revealed that infarct size and cardiac function were influenced independently by choice of species, sex, co-medication, occlusion type, occluded vessel, quantification method, ischemia duration and follow-up duration. We provide strong systematic evidence that commonly used endpoints significantly depend on study design and biological variation. This makes direct comparison of different study-results difficult and calls for standardized models. Researchers should take this into account when designing large animal studies to most closely mimic the clinical course of MI and enable translational success.

Haemodynamic and functional consequences of the iatrogenic atrial septal defect following Mitraclip therapy

Percutaneous MitraClip placement for treatment of severe mitral regurgitation in high surgical risk patients is a commonly performed procedure and requires a transseptal puncture to reach the left atrium. The resulting iatrogenic atrial septal defect (iASD) is not routinely closed, yet the haemodynamic and functional consequences of a persisting defect are not fully understood. Despite positive effects such as acute left atrial pressure relief, persisting iASDs are associated with negative consequences, namely significant bidirectional shunting and subsequent worse clinical outcome. Percutaneous closure of the iASD may therefore be desirable in selected cases. In this review we discuss the available literature on this matter.

Three dimensional fusion of electromechanical mapping and magnetic resonance imaging for real-time navigation of intramyocardial cell injections in a porcine model of chronic myocardial infarction

For cardiac regenerative therapy intramyocardial catheter guided cell transplantations are targeted to the infarct border zone (IBZ) i.e. the closest region of viable myocardium in the vicinity of the infarct area. For optimal therapeutic effect this area should be accurately identified. However late gadolinium enhanced magnetic resonance imaging (LGE-MRI) is the gold standard technique to determine the infarct size and location, electromechanical mapping (EMM) is used to guide percutaneous intramyocardial injections to the IBZ. Since EMM has a low spatial resolution, we aim to develop a practical and accurate technique to fuse EMM with LGE-MRI to guide intramyocardial injections. LGE-MRI and EMM were obtained in 17 pigs with chronic myocardial infarction created by balloon occlusion of LCX and LAD coronary arteries. LGE-MRI and EMM datasets were registered using our in-house developed 3D CartBox image registration software toolbox to assess: (1) the feasibility of the 3D CartBox toolbox, (2) the EMM values measured in the areas with a distinct infarct transmurality (IT), and (3) the highest sensitivity and specificity of the EMM to assess IT and define the IBZ. Registration of LGE-MRI and EMM resulted in a mean error of 3.01 ± 1.94 mm between the LGE-MRI mesh and EMM points. The highest sensitivity and specificity were found for UV <9.4 mV and bipolar voltage <1.2 mV to respectively identify IT of ≥5 and ≥97.5 %. The 3D CartBox image registration toolbox enables registration of EMM data on pre-acquired MRI during the EMM guided procedure and allows physicians to easily guide injections to the most optimal injection location for cardiac regenerative therapy and harness the full therapeutic effect of the therapy.

Autologous Mesenchymal Stem Cells Show More Benefit on Systolic Function Compared to Bone Marrow Mononuclear Cells in a Porcine Model of Chronic Myocardial Infarction

Cardiac cell therapy is a strategy to treat patients with chronic myocardial infarction (MI). No consensus exists regarding the optimal cell type. First, a comparison between autologous bone marrow-derived mononuclear cells (BMMNC) and mesenchymal stem cells (MSC) on therapeutic efficacy after MI was performed. Next, the effect of repetitive, NOGA-guided transendocardial injection was determined via a crossover design. Nineteen pigs were allocated in three groups: (1) placebo (at 4 and 8 weeks), (2) MSC (followed by placebo at 8 weeks), or (3) BMMNC (followed by MSC at 8 weeks) delivery including a priming strategy to enhance MSC effect. At 4 weeks, ejection fraction (EF) was significantly improved after MSC injection and not by BMMNC injection. After 8 weeks, no difference was observed in EF between cell-treated groups demonstrating the positive systolic effect of MSC. This study showed that MSC rather than BMMNC injection improves systolic function in chronic MI.

The role of exercise echocardiography in the management of mitral valve disease

PURPOSE

Exercise echocardiography can assess the dynamic component of mitral valve (MV) disease and may therefore be helpful for the clinical decision-making by the heart team. The purpose of this study is to determine the role of exercise echocardiography in the management of disproportionately symptomatic or otherwise atypical patients with mitral regurgitation (MR) and stenosis (MS) in clinical practice.

METHODS

Data of 14 MR and 14 MS patients, including echocardiograms at rest, were presented retrospectively to an experienced heart team to determine treatment strategy. Subsequently, exercise echo data were provided whereupon once again the treatment strategy was determined. This resulted in: value of exercise echo by means of 1) alteration or 2) confirmation of treatment strategy or 3) no additional value.

RESULTS

During exercise the echocardiographic severity of MV disease increased in 9 (64 %) MR and 8 (57 %) MS patients. Based upon alteration or confirmation of the treatment strategy, the value of exercise echocardiography in the management of MR and MS was 86 % and 57 %, respectively.

CONCLUSION

This study showed that physical exercise echo can have an important role in the clinical decision-making of challenging patients with MV disease. Exercise echocardiography had additional value to the treatment strategy in 71 % of these patients.

Early mitral valve repair versus watchful waiting in patients with severe asymptomatic organic mitral regurgitation; rationale and design of the Dutch AMR trial, a multicenter, randomised trial

BACKGROUND

Asymptomatic severe mitral valve (MV) regurgitation with preserved left ventricular function is a challenging clinical entity as data on the recommended treatment strategy for these patients are scarce and conflicting. For asymptomatic patients, no randomised trial has been performed for objectivising the best treatment strategy.

METHODS

The Dutch AMR (Asymptomatic Mitral Regurgitation) trial is a multicenter, prospective, randomised trial comparing early MV repair versus watchful waiting in asymptomatic patients with severe organic MV regurgitation. A total of 250 asymptomatic patients (18-70 years) with preserved left ventricular function will be included. Intervention will be either watchful waiting or MV surgery. Follow-up will be 5 years. Primary outcome measures are all-cause mortality and a composite endpoint of cardiovascular mortality, congestive heart failure, and hospitalisation for non-fatal cardiovascular and cerebrovascular events. Secondary outcome measures are total costs, cost-effectiveness, quality of life, echocardiographic and cardiac magnetic resonance parameters, exercise tests, asymptomatic atrial fibrillation and brain natriuretic peptide levels. Additionally, the complication rate in the surgery group and rate of surgery in the watchful waiting group will be determined.

IMPLICATIONS

The Dutch AMR trial will be the first multicenter randomised trial on this topic. We anticipate that the results of this study are highly needed to elucidate the best treatment strategy and that this may prove to be an international landmark study.

Cardiomyocyte progenitor cell-derived exosomes stimulate migration of endothelial cells

Patients suffering from heart failure as a result of myocardial infarction are in need of heart transplantation. Unfortunately the number of donor hearts is very low and therefore new therapies are subject of investigation. Cell transplantation therapy upon myocardial infarction is a very promising strategy to replace the dead myocardium with viable cardiomyocytes, smooth muscle cells and endothelial cells, thereby reducing scarring and improving cardiac performance. Despite promising results, resulting in reduced infarct size and improved cardiac function on short term, only a few cells survive the ischemic milieu and are retained in the heart, thereby minimizing long-term effects. Although new capillaries and cardiomyocytes are formed around the infarcted area, only a small percentage of the transplanted cells can be detected months after myocardial infarction. This suggests the stimulation of an endogenous regenerative capacity of the heart upon cell transplantation, resulting from release of growth factor, cytokine and other paracrine molecules by the progenitor cells--the so-called paracrine hypothesis. Here, we focus on a relative new component of paracrine signalling, i.e. exosomes. We are interested in the release and function of exosomes derived from cardiac progenitor cells and studied their effects on the migratory capacity of endothelial cells.

Mesenchymal stromal cells to treat cardiovascular disease: strategies to improve survival and therapeutic results

Following myocardial infarction, damage due to ischemia potentially leads to heart failure. Stem cell transplantation has emerged as a potential treatment to repair the injured heart, due to the inherent characteristics of stem cells such as self-renewal, unlimited capacity for proliferation and ability to differentiate to various cell lineages. Most promising results have been reported thus far on mesenchymal stem cells (MSC). Following transplantation in the heart, stem cells are expected to 1) reduce the damage; 2) activate the endogenous regenerative potential of the heart; and 3) participate in the regeneration of the tissue. Until now, the results of intervention with stem cells in animals were promising, but clinical studies have failed to live up to those expectations. Current problems limiting the efficacy of cellular therapy are: 1) limited knowledge on the time and mode of administration; 2) loss of homing receptors on culture-expanded cells as a consequence of the culture conditions; 3) massive cell death in the transplanted graft in the damaged heart, due to the hostile environment, 4) lack of knowledge on MSC behaviour in the heart. Since generally only 1-5% of delivered cells were found to actually engraft within the infarct zone, there is an urgent need for improvement. In animal models, strategies to precondition MSC before transplantation to survive in the damaged heart were applied successfully. These include exposure of cells to physical treatments (hypoxia and heat shock), pharmacological agents, "priming" of cells with growth factors, and genetic modification by over-expression of anti-apoptotic proteins, growth factors or pro-survival genes. To develop the strategy with maximal engraftment, survival and function of cells in the heart is the ultimate challenge for years to come.

Obstructive sleep apnoea is associated with impaired pictorial memory task acquisition and retention in children

The aim of our study was to evaluate whether obstructive sleep apnoea (OSA) is associated with impaired acquisition and recall of a pictorial-based memory tasks in children. 54 children with OSA and 17 controls matched for age, sex and ethnicity underwent a sleep study (overnight polysomnogram). Before the sleep study subjects completed a 15-min pictorial memory task acquisition consisting of four trials, followed by a free-recall period to assess retention after 10 min and the following morning upon awakening. Children with OSA had a higher obstructive apnoea/hypopnoea index (6.3+/-1.5 events.h(-1) TST) than controls (0.6+/-0.1 events.h(-1) TST) (p<0.0001). Mean learning scores in controls over the four consecutive trials were incrementally better than in children with OSA for the four-trial set (p<0.0001). Both immediate (p<0.0001) and overnight recall performances were worse among OSA children (p<0.0001), who also exhibited declines in recall performance that was absent in controls (p<0.001). Differences in pictorial task acquisition trajectories suggest that children with OSA require more time and an increased number of learning opportunities to reach immediate and long-term recall performances that are reduced compared with controls. Thus, both acquisition and retention of newly learned material are compromised. These findings confirm and expand on the presence of known cognitive deficits in children with OSA.

A young woman with a severe bilateral pneumonia as the presenting sign of an adrenal carcinoma

A severe bilateral, culture-negative pneumonia was diagnosed in a 22-year-old woman. Additional diagnostic procedures accidentally revealed a large adrenal carcinoma and hypercortisolism. The adrenal carcinoma was surgically removed, and she received mitotane treatment. This severe and life-threatening infection was the first sign of an immunosuppressive state as part of Cushing's syndrome due to the adrenal carcinoma.

Colocalisation of intraplaque C reactive protein, complement, oxidised low density lipoprotein, and macrophages in stable and unstable angina and acute myocardial infarction

BACKGROUND

C reactive protein (CRP), an important serum marker of atherosclerotic vascular disease, has recently been reported to be active inside human atherosclerotic plaques.

AIMS

To investigate the simultaneous presence of macrophages, CRP, membrane attack complex C5b-9 (MAC), and oxidised low density lipoprotein (oxLDL) in atherectomy specimens from patients with different coronary syndromes.

METHODS

In total, 54 patients with stable angina (SA; n = 21), unstable angina (UA; n = 15), and myocardial infarction (MI; n = 18) underwent directional coronary atherectomy for coronary lesions. Cryostat sections of atherosclerotic plaques were immunohistochemically stained with monoclonal antibodies: anti-CD68 (macrophages), anti-5G4 (CRP), aE11 (MAC), and 12E7 (oxLDL). Immunopositive areas were evaluated in relation to fibrous and neointima tissues, atheroma, and media. Quantitative analysis was performed using image cytometry with systematic random sampling (percentage immunopositive/total tissue area).

RESULTS

Macrophages, CRP, MAC, and oxLDL were simultaneously present in a higher proportion of fibrous tissue and atheroma of atherectomy specimens from patients with UA and MI compared with SA (p<0.05). Quantitative analysis showed significantly higher mean percentages of macrophages in plaques from patients with MI (44%) than UA (30%; p<0.01) and SA (20%; p<0.001). Significantly higher mean percentages of CRP were also seen in MI (25%) and UA (25%) compared with SA (12%; p<0.05).

CONCLUSIONS

The presence of CRP, complement, and oxLDL in a high proportion of plaque tissue from patients with unstable coronary artery disease implies that these surrogate markers have important proinflammatory effects inside atherosclerotic plaques. This may increase vulnerability to plaque rupture and thrombosis, with subsequent clinical sequelae.

[Complications of an unrecognized myocardial infarction]

Patients with an untreated myocardial infarction may present with serious late complications. 3 patients are described. A 63-year-old woman became progressively more short of breath 4 days after an acute episode of chest pain accompanied by nausea and sweating. It proved to be a cardiogenic shock following a rupture of a papillary muscle. A man aged 65 collapsed 5 days after an episode of back pain and nausea. This was a cardiac tamponade due to rupture of the left ventricle. A woman aged 74 had transient aphasia and during investigations for this was seen to have anomalies on ECG. She had cerebral emboli and a cardiac aneurysm with associated thrombus. All 3 patients recovered following mitral-valve replacement, repair of the rupture and medicinal treatment for the clot, respectively. Around one-third of patients who have a myocardial infarction do not have chest pain but experience shortness of breath, autonomic nervous symptoms (sweating, nausea, vomiting), extreme and inexplicable tiredness and fainting. These atypical symptoms should suggest myocardial infarction. In order to avoid high morbidity and death from complications such as arrhythmias, heart failure, rupture and aneurysm formation it is important that a patient who has had a myocardial infarction should be treated as soon as possible, preferably by reperfusion therapy.

Cost-effectiveness of intracoronary flow velocity measurements and myocardial perfusion scintigraphy for management of intermediate coronary lesions

BACKGROUND

Coronary flow velocity reserve (CFVR) is an alternative for myocardial perfusion scintigraphy (SPECT) in assessing functional severity of coronary lesions. For the acceptance of CFVR in daily clinical decision-making, cost-effectiveness must be proven.

AIM

Economic evaluation of different diagnostic management strategies using CFVR compared with SPECT for making decisions regarding use of PTCA of an intermediate coronary lesion in patients with multivessel disease.

METHODS

The incremental cost-effectiveness analysis was based on data from a prospective multicentre study in 201 patients with multivessel coronary artery disease. Four management strategies, assuming performance of angioplasty after positive test result(s), were compared: SPECT alone, CFVR alone (cut-off value of 2.0), and combined strategies of SPECT and CFVR with one ('extensive') or two ('restrictive') positive test(s). Probabilistic sensitivity analyses were performed using Monte Carlo simulation. Primary outcome was the probability of a cardiac event-free first year with respect to the intermediate lesion.

RESULTS

A 10% event rate was observed, which was predominantly associated with ischaemia-driven revascularisations. A strategy based on CFVR was most effective. The restrictive strategy had the lowest costs and was most cost-effective; with increasing willingness-to-pay values (above €20,000) a CFVR-alone strategy became equally cost-effective.

CONCLUSION

It is mandatory to measure CFVR to decide upon angioplasty of the intermediate lesion in patients with multivessel coronary artery disease. This decision can be based on the restrictive strategy (i.e. performance of PTCA in case of abnormal test results of both SPECT and CFVR) or solely on CFVR, depending on society's willingness-to-pay to prevent cardiac events.

'Lost and found': a coronary guidewire remnant

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Role of plaque inflammation in acute and recurrent coronary syndromes

Inflammation plays an important role in the initiation, development, progression and complications of atherosclerotic vascular disease. Our present knowledge of the elementary role of inflammation for the onset of plaque rupture in atherosclerotic coronary lesions primarily stems from autopsy studies. However, the introduction of directional coronary atherectomy catheters has provided a unique opportunity to directly investigate the role of inflammation in coronary syndromes. In this report we describe the role of coronary plaque inflammation, as determined by immunohistochemistry, on the presentation of coronary syndromes and on the clinical outcome following percutaneous interventions.