Defining left bundle branch block according to the new 2021 European Society of Cardiology criteria.

Correctly diagnosing left bundle branch block (LBBB) is fundamental, as LBBB occurs frequently in heart failure and may trigger a vicious cycle of progressive left ventricular dysfunction. Moreover, a correct diagnosis of LBBB is pivotal to guide cardiac resynchronisation therapy. Since the LBBB diagnostic criteria were recently updated by the European Society of Cardiology (ESC), we assessed their diagnostic accuracy compared with the previous ESC 2013 definition. We further discuss the complexity of defining LBBB within the context of recent insights into the electromechanical pathophysiology of LBBB.

Long-Term Changes in Free Nipple Graft Morphology and Patient-Reported Outcomes in Gender-Affirming Mastectomies.

BACKGROUND: After gender-affirming mastectomies with free nipple grafts, satisfaction with nipples tends to fall short behind chest outcomes. This might be related to changes in nipple areolar complex (NAC) dimensions over time. Therefore, the aim of this study is to establish the long-term changes in NAC morphology and compare these to cisgender male NAC outcomes. MATERIALS: An observational, cross-sectional study was performed. Data from two prospective cohorts were collected: (1) transgender men after a mastectomy with free nipple grafts and (2) cisgender men (reference sample). Demographics and 3-D images were collected for both groups. NAC measurements were performed on the 3-D images at 4 time points (7-, 30-, 90- and 365-days postoperative) in transgender men and once in cisgender men. Furthermore, the BODY-Q (nipple module) was administered postoperatively at 30-, 90- and 365-days in transgender men. RESULTS: In total, 67 transgender and 150 cisgender men were included. NAC width and height in trans men changed from 21.5 mm (±2.7) to 23.8 mm (±3.9, p<0.001) and 16.2 mm (±2.5) to 14.7 mm (±3.0, p=0.01) within a year, respectively. On average, the NACs increasingly rotated 21 degrees in the latero-caudal direction (p<0.001). The mean NAC width and height in cisgender men were 28.1 mm (±5) and 20.7 mm (±4), being significantly larger than in transgender men. Satisfaction for size, shape and flatness decreased significantly after postoperative day 30 (p=<0.05) in transgender men. CONCLUSIONS: Morphology of and satisfaction with the NACs in transgender men significantly changed over time. Understanding and incorporating these differences into pre-operative counseling and surgical planning might help increase patient satisfaction. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Patient-Reported Long-Term Outcomes After Free Vascularized Fibula Graft in Spinal Reconstruction: a 24-year Cohort.

PURPOSE: The use of free vascularized fibula grafts (FVFG) in complex spinal deformity surgery intends to allow for life-long stability of the spine with good long-term clinical outcome. However, these long-term outcomes of this technique are still lacking. The objective of this study is to report the long-term postoperative outcomes and establish the long-term viability of this method for spinal reconstruction. METHODS: A retrospective cohort study was conducted in all patients who underwent spinal reconstructive surgery utilizing a FVFG at a tertiary medical centre. Questionnaires taken from the participants were the Numeric Pain Rating Scale (NPRS), Oswestry Low Back Pain Disability (also known as Oswestry Disability Index (ODI)), Scoliosis Research Society 22r (SRS-22), the EQ-5D-5L and a self-assembled questionnaire regarding donor site comorbidities and patient satisfaction. RESULTS: Over a period of 24 years (1995-2019), we used FVFG for spinal reconstruction in 31 patients. A total of 25 patients were included in this study, 8 patients were deceased at the time of this study, and sixteen patients responded to the questionnaires. Patient satisfaction was rated 6.8 out of 10, the average SRS-22r score was 3.6, EQ-5D-5L score was 0.725, and the ODI score showed a minimal disability (0-20%) postoperatively. Overall complication-free survival was 8.9 years. Nine patients underwent a re-operation in the spinal area; five for the removal of the spinal instrumentation. CONCLUSION: Patients reported satisfied and good long-term outcomes following FVFG surgical procedure for complex spinal deformities. Therefore, considering the alternatives, this procedure provides a good long-term solution for complex spinal deformity surgery.

Within-patient randomized clinical trial comparing incisional negative-pressure wound therapy with suction drains in gender-affirming mastectomies.

BACKGROUND: Incisional negative-pressure wound therapy (iNPWT) is widely adopted by different disciplines for multiple indications. Questions about the most appropriate uses and value of iNPWT have been raised. METHODS: An open-label within-patient RCT was conducted in transgender men undergoing gender-affirming mastectomies. The objective was to determine the effect of iNPWT as a substitute for standard dressing and suction drains on wound healing complications. One chest side was randomized to receive the iNPWT intervention, and the other to standard dressing with suction drain. The primary endpoints were wound healing complications (haematoma, seroma, infection, and dehiscence) after three months. Additional outcomes were pain according to a numerical rating scale and patient satisfaction one week after surgery. RESULTS: Eighty-five patients were included, of whom 81 received both the iNPWT and standard treatment. Drain removal criteria were met within 24 h in 95 per cent of the patients. No significant decrease in wound healing complications was registered on the iNPWT side, but the seroma rate was significantly increased. In contrast, patients experienced both significantly less pain and increased comfort on the iNPWT side. No medical device-related adverse events were registered. CONCLUSION: Substituting short-term suction drains with iNPWT in gender-affirming mastectomies increased the seroma rates and did not decrease the amount of wound healing complications. Registration number: NTR7412 (Netherlands Trial Register).

Aortic valve implantation-induced conduction block as a framework towards a uniform electrocardiographic definition of left bundle branch block.

INTRODUCTION: New-onset left bundle branch block (LBBB) following transcatheter or surgical aortic valve replacement (LBBBAVI) implies a proximal pathogenesis of LBBB. This study compares electrocardiographic characteristics and concordance with LBBB definitions between LBBBAVI and non-procedure-induced LBBB controls (LBBBcontrol). METHODS: All LBBBAVI patients at Ghent University Hospital between 2013 and 2019 were enrolled in the study. LBBBAVI patients were matched for age, sex, ischaemic heart disease and ejection fraction to LBBBcontrol patients in a 1:2 ratio. For inclusion, a non-strict LBBB definition was used (QRS duration ≥ 120 ms, QS or rS in V1, absence of Q waves in V5-6). Electrocardiograms were digitally analysed and classified according to three LBBB definitions: European Society of Cardiology (ESC), Strauss and American Heart Association (AHA). RESULTS: A total of 177 patients (59 LBBBAVI and 118 LBBBcontrol) were enrolled in the study. LBBBAVI patients had more lateral QRS notching/slurring (100% vs 85%, p = 0.001), included a higher percentage with a QRS duration ≥ 130 ms (98% vs 86%, p = 0.007) and had a less leftward oriented QRS axis (-15° vs -30°, p = 0.013) compared to the LBBBcontrol group. ESC and Strauss criteria were fulfilled in 100% and 95% of LBBBAVI patients, respectively, but only 18% met the AHA criteria. In LBBBcontrol patients, concordance with LBBB definitions was lower than in the LBBBAVI group: ESC 85% (p = 0.001), Strauss 68% (p < 0.001) and AHA 7% (p = 0.035). No differences in electrocardiographic characterisation or concordance with LBBB definitions were observed between LBBBAVI and LBBBcontrol patients with lateral QRS notching/slurring. CONCLUSION: Non-uniformity exists among current LBBB definitions concerning the detection of proximal LBBB. LBBBAVI may provide a framework for more consensus on defining proximal LBBB.

The ideal location of the male nipple-areolar complex: A pinpointing algorithm.

Background: In the treatment of gender dysphoria, appropriate nipple-areola complex (NAC) positioning is essential for achieving a natural appearing male chest after subcutaneous mastectomy. An accurate predictive model for the ideal personalized position of the NAC is still lacking. The aim of this study is to determine the anthropometry of the male chest to create individualized guidelines for appropriate NAC positioning in the preoperative setting. Materials and methods: Cisgender male participants were recruited. Multiple chest measurements were manually recorded. Best subset regression using linear models was used to select predictors for the horizontal coordinate (nipple-nipple distance; NN) and vertical coordinate (sternal notch-nipple distance; SNN) of the NAC. Internal validation was assessed using bootstrapping. Furthermore, a cohort of transgender men who had received a mastectomy with replantation of nipples according to current practice was identified. Comparison testing between the algorithm and standard practice was performed to test the limitations of standard practice. Results: One hundred and fifty cis male participants were included (median age: 26, IQR: 22-34 years). Four predictors were found to predict NN (age, weight, chest circumference (CC), anterior-axillar fold to anterior-axillar fold (AUX-AUX)) and reads as follows: NN = 4.11 + 0.035*age + 0.041*weight + 0.093*CC + 0.140*AUX-AUX Two predictors were found to predict SNN (NN and weight), and reads as follows: SNN = 7.248 + 0.303*NN + 0.072*weight. Both models performed well (Bootstrapped R2: 0.63 (NN), 0.50 (SNN)) and outperformed previous models predicting NAC position. Ninety-six transgender men were eligible for evaluation of current practice and showed an average placement error of -0.9 cm for NN and +2.2 cm for SNN. Conclusion: The non-standardized approach of NAC repositioning results in a significant error of nipple placement. We suggest that the two predictive models for NN and SNN can be used to optimize NAC positioning on the masculinized chest wall.Supplemental data for this article is available online at https://doi.org/10.1080/26895269.2021.1884926.

SEM-Raman image cytometry of cells.

Correlative and integrated scanning electron microscopy (SEM) and Raman micro-spectroscopy is presented that enables the characterization and identification of different cancer and non-cancer cells through SEM-Raman image cytometry. The hybrid microscopy system enables the acquisition of high resolution SEM images of uncoated cells and the spatial correlation with chemical information as obtained from Raman micro-spectroscopic imaging. A sample preparation protocol and a workflow are presented that are compatible with the demands of hybrid SEM-Raman microscopy. Stainless steel cell substrates were used that are both conductive and give a low optical response in Raman scattering. Correlative and integrated SEM-Raman micro-spectroscopy is illustrated with cells from blood and cells from a SKBR-3 breast cancer cell line.

The urgent need for a harmonized severity scoring system for acute allergic reactions.

The accurate assessment and communication of the severity of acute allergic reactions are important to patients, clinicians, researchers, the food industry, and public health and regulatory authorities. Severity has different meanings to different stakeholders with patients and clinicians rating the significance of particular symptoms very differently. Many severity scoring systems have been generated, most focusing on the severity of reactions following exposure to a limited group of allergens. They are heterogeneous in format, none has used an accepted developmental approach, and none has been validated. Their wide range of outcome formats has led to difficulties with interpretation and application. Therefore, there is a persisting need for an appropriately developed and validated severity scoring system for allergic reactions that work across the range of allergenic triggers and address the needs of different stakeholder groups. We propose a novel approach to develop and then validate a harmonized scoring system for acute allergic reactions, based on a data-driven method that is informed by clinical and patient experience and other stakeholders' perspectives. We envisage two formats: (i) a numerical score giving a continuum from mild to severe reactions that are clinically meaningful and are useful for allergy healthcare professionals and researchers, and (ii) a three-grade-based ordinal format that is simple enough to be used and understood by other professionals and patients. Testing of reliability and validity of the new approach in a range of settings and populations will allow eventual implementation of a standardized scoring system in clinical studies and routine practice.

EAACI Guidelines on Allergen Immunotherapy: Allergic rhinoconjunctivitis.

Allergic rhinoconjunctivitis (AR) is an allergic disorder of the nose and eyes affecting about a fifth of the general population. Symptoms of AR can be controlled with allergen avoidance measures and pharmacotherapy. However, many patients continue to have ongoing symptoms and an impaired quality of life; pharmacotherapy may also induce some side-effects. Allergen immunotherapy (AIT) represents the only currently available treatment that targets the underlying pathophysiology, and it may have a disease-modifying effect. Either the subcutaneous (SCIT) or sublingual (SLIT) routes may be used. This Guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on AIT for AR and is part of the EAACI presidential project "EAACI Guidelines on Allergen Immunotherapy." It aims to provide evidence-based clinical recommendations and has been informed by a formal systematic review and meta-analysis. Its generation has followed the Appraisal of Guidelines for Research and Evaluation (AGREE II) approach. The process included involvement of the full range of stakeholders. In general, broad evidence for the clinical efficacy of AIT for AR exists but a product-specific evaluation of evidence is recommended. In general, SCIT and SLIT are recommended for both seasonal and perennial AR for its short-term benefit. The strongest evidence for long-term benefit is documented for grass AIT (especially for the grass tablets) where long-term benefit is seen. To achieve long-term efficacy, it is recommended that a minimum of 3 years of therapy is used. Many gaps in the evidence base exist, particularly around long-term benefit and use in children.

Allergen immunotherapy for allergic rhinoconjunctivitis: A systematic review and meta-analysis.

BACKGROUND: The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of developing Guidelines on Allergen Immunotherapy (AIT) for Allergic Rhinoconjunctivitis. To inform the development of clinical recommendations, we undertook a systematic review to assess the effectiveness, cost-effectiveness, and safety of AIT in the management of allergic rhinoconjunctivitis. METHODS: We searched nine international biomedical databases for published, in-progress, and unpublished evidence. Studies were independently screened by two reviewers against predefined eligibility criteria and critically appraised using established instruments. Our primary outcomes of interest were symptom, medication, and combined symptom and medication scores. Secondary outcomes of interest included cost-effectiveness and safety. Data were descriptively summarized and then quantitatively synthesized using random-effects meta-analyses. RESULTS: We identified 5960 studies of which 160 studies satisfied our eligibility criteria. There was a substantial body of evidence demonstrating significant reductions in standardized mean differences (SMD) of symptom (SMD -0.53, 95% CI -0.63, -0.42), medication (SMD -0.37, 95% CI -0.49, -0.26), and combined symptom and medication (SMD -0.49, 95% CI -0.69, -0.30) scores while on treatment that were robust to prespecified sensitivity analyses. There was in comparison a more modest body of evidence on effectiveness post-discontinuation of AIT, suggesting a benefit in relation to symptom scores. CONCLUSIONS: AIT is effective in improving symptom, medication, and combined symptom and medication scores in patients with allergic rhinoconjunctivitis while on treatment, and there is some evidence suggesting that these benefits are maintained in relation to symptom scores after discontinuation of therapy.

Observation of whispering gallery modes through electron beam-induced deposition.

Surprisingly intense spectra of whispering gallery modes were observed in polymer microbeads after illumination with electrons in a scanning electron microscope and subsequent laser illumination and spectral analysis. It will be proposed that whispering gallery mode resonances became visible after local deposition of hydrocarbon material through electron beam-induced deposition. The illumination of deposited material with a near infrared laser generates a broad light spectrum, acting as a local "white light" source that couples, for favorable wavelengths, with the WGM sustained by the sphere. This facilitates a spectroscopic analysis of the WGM and provides the Q-factor and free spectral range for all investigated particles. The analysis by an integrated SEM and Raman micro-spectrometer offers a direct approach to the analysis of WGM resonators as they are, for instance, used in sensing.

Allergen immunotherapy for IgE-mediated food allergy: a systematic review and meta-analysis.

BACKGROUND: The European Academy of Allergy and Clinical Immunology (EAACI) is developing Guidelines for Allergen Immunotherapy (AIT) for IgE-mediated Food Allergy. To inform the development of clinical recommendations, we sought to critically assess evidence on the effectiveness, safety and cost-effectiveness of AIT in the management of food allergy. METHODS: We undertook a systematic review and meta-analysis that involved searching nine international electronic databases for randomized controlled trials (RCTs) and nonrandomized studies (NRS). Eligible studies were independently assessed by two reviewers against predefined eligibility criteria. The quality of studies was assessed using the Cochrane Risk of Bias tool for RCTs and the Cochrane ACROBAT-NRS tool for quasi-RCTs. Random-effects meta-analyses were undertaken, with planned subgroup and sensitivity analyses. RESULTS: We identified 1814 potentially relevant papers from which we selected 31 eligible studies, comprising of 25 RCTs and six NRS, studying a total of 1259 patients. Twenty-five trials evaluated oral immunotherapy (OIT), five studies investigated sublingual immunotherapy, and one study evaluated epicutaneous immunotherapy. The majority of these studies were in children. Twenty-seven studies assessed desensitization, and eight studies investigated sustained unresponsiveness postdiscontinuation of AIT. Meta-analyses demonstrated a substantial benefit in terms of desensitization (risk ratio (RR) = 0.16, 95% CI 0.10, 0.26) and suggested, but did not confirm sustained unresponsiveness (RR = 0.29, 95% CI 0.08, 1.13). Only one study reported on disease-specific quality of life (QoL), which reported no comparative results between OIT and control group. Meta-analyses revealed that the risk of experiencing a systemic adverse reaction was higher in those receiving AIT, with a more marked increase in the risk of local adverse reactions. Sensitivity analysis excluding those studies judged to be at high risk of bias demonstrated the robustness of summary estimates of effectiveness and safety of AIT for food allergy. None of the studies reported data on health economic analyses. CONCLUSIONS: AIT may be effective in raising the threshold of reactivity to a range of foods in children with IgE-mediated food allergy whilst receiving (i.e. desensitization) and post-discontinuation of AIT. It is, however, associated with a modest increased risk in serious systemic adverse reactions and a substantial increase in minor local adverse reactions. More data are needed in relation to adults, long term effects, the impact on QoL and the cost-effectiveness of AIT.

Correlative SEM SERS for quantitative analysis of dimer nanoparticles.

A Raman microscope integrated with a scanning electron microscope was used to investigate plasmonic structures by correlative SEM-SERS analysis. The integrated Raman-SEM microscope combines high-resolution electron microscopy information with SERS signal enhancement from selected nanostructures with adsorbed Raman reporter molecules. Correlative analysis is performed for dimers of two gold nanospheres. Dimers were selected on the basis of SEM images from multi aggregate samples. The effect of the orientation of the dimer with respect to the polarization state of the laser light and the effect of the particle gap size on the Raman signal intensity is observed. Additionally, calculations are performed to simulate the electric near field enhancement. These simulations are based on the morphologies observed by electron microscopy. In this way the experiments are compared with the enhancement factor calculated with near field simulations and are subsequently used to quantify the SERS enhancement factor. Large differences between experimentally observed and calculated enhancement factors are regularly detected, a phenomenon caused by nanoscale differences between the real and 'simplified' simulated structures. Quantitative SERS experiments reveal the structure induced enhancement factor, ranging from ∼200 to ∼20 000, averaged over the full nanostructure surface. The results demonstrate correlative Raman-SEM microscopy for the quantitative analysis of plasmonic particles and structures, thus enabling a new analytical method in the field of SERS and plasmonics.

Contributed review: Review of integrated correlative light and electron microscopy.

New developments in the field of microscopy enable to acquire increasing amounts of information from large sample areas and at an increased resolution. Depending on the nature of the technique, the information may reveal morphological, structural, chemical, and still other sample characteristics. In research fields, such as cell biology and materials science, there is an increasing demand to correlate these individual levels of information and in this way to obtain a better understanding of sample preparation and specific sample properties. To address this need, integrated systems were developed that combine nanometer resolution electron microscopes with optical microscopes, which produce chemically or label specific information through spectroscopy. The complementary information from electron microscopy and light microscopy presents an opportunity to investigate a broad range of sample properties in a correlated fashion. An important part of correlating the differences in information lies in bridging the different resolution and image contrast features. The trend to analyse samples using multiple correlated microscopes has resulted in a new research field. Current research is focused, for instance, on (a) the investigation of samples with nanometer scale distribution of inorganic and organic materials, (b) live cell analysis combined with electron microscopy, and (c) in situ spectroscopic and electron microscopy analysis of catalytic materials, but more areas will benefit from integrated correlative microscopy.

Anaphylaxis: guidelines from the European Academy of Allergy and Clinical Immunology.

Anaphylaxis is a clinical emergency, and all healthcare professionals should be familiar with its recognition and acute and ongoing management. These guidelines have been prepared by the European Academy of Allergy and Clinical Immunology (EAACI) Taskforce on Anaphylaxis. They aim to provide evidence-based recommendations for the recognition, risk factor assessment, and the management of patients who are at risk of, are experiencing, or have experienced anaphylaxis. While the primary audience is allergists, these guidelines are also relevant to all other healthcare professionals. The development of these guidelines has been underpinned by two systematic reviews of the literature, both on the epidemiology and on clinical management of anaphylaxis. Anaphylaxis is a potentially life-threatening condition whose clinical diagnosis is based on recognition of a constellation of presenting features. First-line treatment for anaphylaxis is intramuscular adrenaline. Useful second-line interventions may include removing the trigger where possible, calling for help, correct positioning of the patient, high-flow oxygen, intravenous fluids, inhaled short-acting bronchodilators, and nebulized adrenaline. Discharge arrangements should involve an assessment of the risk of further reactions, a management plan with an anaphylaxis emergency action plan, and, where appropriate, prescribing an adrenaline auto-injector. If an adrenaline auto-injector is prescribed, education on when and how to use the device should be provided. Specialist follow-up is essential to investigate possible triggers, to perform a comprehensive risk assessment, and to prevent future episodes by developing personalized risk reduction strategies including, where possible, commencing allergen immunotherapy. Training for the patient and all caregivers is essential. There are still many gaps in the evidence base for anaphylaxis.

Paediatric rhinitis: position paper of the European Academy of Allergy and Clinical Immunology.

Rhinitis is a common problem in childhood and adolescence and impacts negatively on physical, social and psychological well-being. This position paper, prepared by the European Academy of Allergy and Clinical Immunology Taskforce on Rhinitis in Children, aims to provide evidence-based recommendations for the diagnosis and therapy of paediatric rhinitis. Rhinitis is characterized by at least two nasal symptoms: rhinorrhoea, blockage, sneezing or itching. It is classified as allergic rhinitis, infectious rhinitis and nonallergic, noninfectious rhinitis. Similar symptoms may occur with other conditions such as adenoidal hypertrophy, septal deviation and nasal polyps. Examination by anterior rhinoscopy and allergy tests may help to substantiate a diagnosis of allergic rhinitis. Avoidance of relevant allergens may be helpful for allergic rhinitis (AR). Oral and intranasal antihistamines and nasal corticosteroids are both appropriate for first-line AR treatment although the latter are more effective. Once-daily forms of corticosteroids are preferred given their improved safety profile. Potentially useful add-on therapies for AR include oral leukotriene receptor antagonists, short bursts of a nasal decongestant, saline douches and nasal anticholinergics. Allergen-specific immunotherapy is helpful in IgE-mediated AR and may prevent the progression of allergic disease. There are still a number of areas that need to be clarified in the management of rhinitis in children and adolescents.

Towards a European registry of severe allergic reactions: current status of national registries and future needs.

The incidence of severe allergic reactions is largely unknown and information about triggering allergens, aggravating factors, demography of patients and medical care is lacking. A European wide registry could provide a powerful tool to improve the management of severe allergic reactions from both a medical and a public health perspective. Analysis of existing registries regarding the type and quality of data being collected was used to develop a plan for a pan-European registry, including the type of system to be used and the range of data to be entered. Surveillance will provide evidence for the efficacy of risk management measures and may identify the emergence of new allergenic foods, and aid monitoring of novel foods, ingredients and technologies. Patients need a clear indication of factors that may increase their risk of having an adverse reaction, which such a registry can help compile. Based on the collected data, food businesses will be able to develop educational programmes for allergen risk assessment and allergen risk communication. Finally, and most importantly preventive measures can be developed and government agencies receive population based data which may be relevant for legislative purposes.

Thresholds for food allergens and their value to different stakeholders.

Thresholds constitute a critical piece of information in assessing the risk from allergenic foods at both the individual and population levels. Knowledge of the minimum dose that can elicit a reaction is of great interest to all food allergy stakeholders. For allergic individuals and health professionals, individual threshold data can inform allergy management. Population thresholds can help both the food industry and regulatory authorities assess the public health risk and design appropriate food safety objectives to guide risk management. Considerable experience has been gained with the double-blind placebo-controlled food challenge (DBPCFC), but only recently has the technique been adapted to provide data on thresholds. Available data thus vary greatly in quality, with relatively few studies providing the best quality individual data, using the low-dose DBPCFC. Such high quality individual data also form the foundation for population thresholds, but these also require, in addition to an adequate sample size, a good characterization of the tested population in relation to the whole allergic population. Determination of thresholds at both an individual level and at a population level is influenced by many factors. This review describes a low-dose challenge protocol developed as part of the European Community-funded Integrated Project Europrevall, and strongly recommends its wider use so that data are generated that can readily increase the power of existing studies.

Stem cells for the heart, are we there yet?

Although several repair mechanisms have been described in the human heart, all fall too short to prevent clinical heart disease in most acute or chronic pathological cardiac conditions. Moreover, despite many breakthroughs in cardiovascular medicine, the complications of a myocardial infarction such as chronic heart failure remains a serious worldwide problem. Bone marrow stem cells could provide for a promising strategy to restore myocardial infarctions and prevent postinfarct congestive heart failure, because there is growing body of evidence that bone marrow stem cells, such as mesenchymal stem cells, can generate new cardiomyocytes in animals and humans. In this review, we will discuss important issues on stem cell therapy for cardiac regeneration after myocardial infarction, which might be of paramount importance when considering future human trials.