Artificial Intelligence Assessment of Biological Age from Transthoracic Echocardiography: Discrepancies to Chronologic Age Predict Significant Excess Mortality

BACKGROUND

Age and sex can be estimated by artificial intelligence based on various sources.

OBJECTIVES

We aimed to test whether convolutional neural networks could be trained to estimate the age and predict the sex using standard transthoracic echocardiography (TTE), and to evaluate its prognostic implications.

METHODS

The algorithm was trained on 76,342 patients, validated in 22,825 patients, and tested in 20,960 patients. It was then externally validated using data from a different hospital (N=556). Finally, a prospective cohort of handheld point-of-care ultrasound (POCUS) devices (N=319; ClinicalTrials.Gov NCT05455541) was used to confirm the findings. Multivariate Cox regression model was used to investigate the association between age-estimation and chronological age with overall survival.

RESULTS

The mean average error in age estimation was 4.9 years, with a Pearson correlation coefficient of 0.922. The probabilistic value of sex had an overall accuracy of 96.1% and an area under the curve (AUC) of 0.993. External validation and prospective study cohorts yielded consistent results. Finally, survival analysis demonstrated that age prediction ≥ 5 years of chronological age was associated with an independent 34% increased risk of death during follow-up (p<0.001).

CONCLUSIONS

Applying artificial intelligence to the standard TTE allows prediction of sex and estimation of age. Machine-based estimation is an independent predictor of overall survival and, with further evaluation, can be used for risk stratification and estimation of biological age.

Sixth monovalent XBB.1.5 vaccine elicits robust immune response against emerging SARS-CoV-2 variants in heart transplant recipients

Continued circulation of severe acute respiratory syndrome coronavirus 2 has driven the selection of variants with improved ability to escape preexisting vaccine-induced responses, posing a persistent threat to heart transplant recipients (HTRs). The immunogenicity and safety of the updated XBB.1.5-containing monovalent vaccines are unknown. We prospectively enrolled 52 HTRs who had previously received a 5-dose ancestral-derived monovalent and bivalent messenger RNA (mRNA) vaccination schedule to receive the monovalent XBB.1.5 vaccine. Immunogenicity was evaluated using live virus microneutralization assays. The XBB.1.5 monovalent vaccine elicited potent and diverse neutralizing responses and broadened the reactivity spectrum to encompass newer strains, with the highest increase in neutralization activity being more pronounced against XBB.1.5 (15.8-fold) and JN.1 (13.3-fold) than against BA.5 (6.7-fold) and wild-type (4-fold). Notably, XBB.1.5 and JN.1 were resistant to neutralization by prevaccination sera. There were no safety concerns. Our findings support the updating of coronavirus disease 2019 vaccines to match antigenically divergent variants and exclude ancestral spike-antigen to protect HTRs.

Systematic adjustment of root dimensions to cusp size in aortic valve repair: a computer simulation

OBJECTIVES

Aortic valve repair requires the creation of a normal geometry of cusps and aortic root. Of the different dimensions, geometric cusp height is the most difficult to change while annular and sinotubular dimensions can be easily modified. The objective of this study was to investigate, by computer simulation, ideal combinations of annular and sinotubular junction size for a given geometric height.

METHODS

Based on a literature review of anatomical data, a computational biomechanics model was generated for a tricuspid aortic valve. We aimed to determine the ideal relationships for the root dimensions, keeping geometric height constant and creating different combinations of the annular and sinotubular junction dimensions. Using this model, 125 virtual anatomies were created, with 25 different combinations of annulus and sinotubular junction. Effective height, coaptation height and mechanical cusp stress were calculated with the valves in closed configuration.

RESULTS

Generally, within the analysed range of geometric heights, changes to the annular diameter yielded a stronger impact than sinotubular junction diameter changes for optimal valve configuration. The best results were obtained with the sinotubular junction being 2-4 mm larger than the annulus, leading to higher effective height, normal coaptation height and lower stress. Within the range tested, stenosis did not occur due to annular reduction.

CONCLUSIONS

In tricuspid aortic valves, the geometric height can be used to predict ideal post-repair annular and sinotubular junction dimensions for optimal valve configuration. Such an ideal configuration is associated with reduced cusp stress.

BNT162b2-vaccine-induced neutralization responses are immune correlates of clinical protection against SARS-CoV-2 in heart transplant recipients

BACKGROUND

Defining immune correlates of protection against COVID-19 is pivotal for optimizing the use of COVID-19 vaccines, predicting the impact of novel variants on clinical outcomes, and advancing the development of immunotherapies and next-generation vaccines. We aimed to identify vaccine-induced immune correlates of protection against COVID-19-related hospitalizations in a highly vaccinated heart transplant (HT) cohort.

METHODS

In a case-control study of HT recipients vaccinated with the BNT162b2 vaccine, patients were prospectively assessed for vaccine-induced neutralization of the wild-type virus, and the Delta and Omicron BA.1, BA.2, BA.4, and BA.5 variants. Comparative analyses with controls were conducted to identify correlates of protection against COVID-19 hospitalization. ROC analyses were performed. Primary outcomes were COVID-19 hospitalizations and severity of SARS-CoV-2 breakthrough infection.

RESULTS

The study cohort comprised 59 HT recipients aged 58 (49,65) years with breakthrough infections after three or four monovalent BNT162b2 doses; 41 (69.5%) were men. Thirty-six (61%) patients with COVID-19 were hospitalized; most cases were non-severe (58, 98%). For hospitalized (vs. non-hospitalized) COVID-19 patients, vaccine-induced neutralization titers were significantly lower against all SARS-CoV-2 variants (p < .005). Vaccine-induced neutralization of the wild-type virus and delta and omicron BA.1, BA.2, BA.4, and BA.5 variants was associated with a reduced risk for COVID-19-related hospitalization. The optimal neutralization titer thresholds that were predictive of COVID-19 hospitalizations were 96 (wild-type), 48 (delta), 12 (BA.1), 96 (BA.2), 96 (BA.4), and 48 (BA.5).

CONCLUSIONS

BNT162b2-vaccine-induced neutralization responses are immune correlates of protection and confer clinical protection against COVID-19 hospitalizations.

Anatomical and clinical risk stratification tool for mortality risk assessment following revascularization for multivessel coronary artery disease

OBJECTIVE

This study aimed to assess the prognostic ability of SYNTAX score II in left main and/or 3-vessel disease patients undergoing revascularization either by coronary artery bypass grafting or percutaneous coronary intervention in a national registry.

METHODS

This prospective registry included consecutive patients with multivessel disease enrolled between January and April 2013 from all 22 hospitals in Israel that perform coronary angiography. Of the 1112 study patients, 368 patients (33%) had a low (<25), 372 (33%) had an intermediate (25-35) and 372 patients (33%) a high (≥35) SYNTAX score II.

RESULTS

Patients with a high SYNTAX score II had higher 30-day mortality compared with those with an intermediate or low SYNTAX score II (2.8% vs 0.6% vs 0% respectively, P = .001). Each 1-unit increment in SYNTAX score II increased the odds for death at 30 days by 11% (95% CI, 1.02-1.22; P = .026). Six-year mortality was higher among patients with a high compared with an intermediate or low SYNTAX score II (34.9% vs 11% vs 3.8%; log-rank P < .001). By adding a SYNTAX score II to standard prognostic factors, we showed a significant improvement of 40.1% (P < .001) for predicting 6-year mortality. The area under the curve of the SYNTAX score II (continuous) yielded 0.79 (95% CI, 0.75-0.82) in predicting 6-year mortality.

CONCLUSIONS

Our findings show that the admission SYNTAX score II is a powerful marker of short- and long-term mortality, and therefore may be used as a risk stratification tool in patients with multivessel coronary artery disease who are candidates for revascularization.

Early tracheostomy after cardiac surgery improves intermediate- and long-term survival

OBJECTIVE

Complicated post-cardiac surgery course, can lead to both prolonged ICU stay and ventilation, and may require a tracheostomy. This study represents the single-center experience with post-cardiac surgery tracheostomy. The aim of this study was to assess the timing of tracheostomy as a risk factor for early, intermediate, and late mortality. The study's second aim was to assess the incidence of both superficial and deep sternal wound infections.

DESIGN

Retrospective study of prospectively collected data.

SETTING

Tertiary hospital.

PATIENTS

Patients were divided into 3 groups, according to the timing of tracheostomy; early (4-10 days); intermediate (11-20 days) and late (≥21 days).

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

The primary outcomes were early, intermediate, and long-term mortality. The secondary outcome was the incidence of sternal wound infection.

RESULTS

During the 17-year study period, 12,782 patients underwent cardiac surgery, of whom 407 (3.18%) required postoperative tracheostomy. 147 (36.1%) had early, 195 (47.9%) intermediate, and 65 (16%) had a late tracheostomy. Early, 30-day, and in-hospital mortality was similar for all groups. However, patients, who underwent early- and intermediate tracheostomy, demonstrated statistically significant lower mortality after 1- and 5-year (42.8%; 57.4%; 64.6%; and 55.8%; 68.7%; 75.4%, respectively; P < .001). Cox model demonstrated age [1.025 (1.014-1.036)] and timing of tracheostomy [0.315 (0.159-0.757)] had significant impacts on mortality.

CONCLUSIONS

This study demonstrates a relationship between the timing of tracheostomy after cardiac surgery and mortality: early tracheostomy (within 4-10 days of mechanical ventilation) is associated with better intermediate- and long-term survival.

Fifth bivalent omicron BA.4/BA.5 vaccination neutralization of SARS-CoV-2 in heart transplant recipients

In 2022, the antigenically divergent SARS-CoV-2 omicron variants (BA.1, BA.2, BA.4, BA.5) outcompeted previous variants and continued to cause substantial numbers of illnesses and deaths. We evaluated the safety and immunogenicity of the bivalent original/omicron BA.4/BA.5 Pfizer/BioNTech vaccine administered as a fifth dose to heart transplant recipients (HTxRs). We compared neutralization (using live virus assays) of SARS-CoV-2-infected cells in serum samples from HTxRs who had previously received 4 doses of the monovalent BNT162b2 vaccine with samples from HTxRs with breakthrough infection after 4 monovalent BNT162b2 doses. The fifth vaccination induced high neutralization efficiency against the wild-type virus and omicron BA.1, BA.2, BA.4, and BA.5 variants, with significantly higher neutralization efficiency being induced in HTxRs with breakthrough infection than in those without. Neutralizing titers in those with breakthrough infection were sustained above the level induced by the fifth dose in the uninfected. We conclude that the fifth bivalent vaccine is immunogenic, including to variants, with higher vaccine immunogenicity conferred by breakthrough infection. Nevertheless, the clinical protection conferred by the fifth dose is yet to be determined. The sustained neutralization responses in those with breakthrough infection support the notion of delaying booster in those with natural breakthrough infection.

Timing of Lung Transplant Referral in Patients with Severe COVID-19 Lung Injury Supported by ECMO

Severe respiratory failure caused by COVID-19 often requires mechanical ventilation, including extracorporeal membrane oxygenation (ECMO). In rare cases, lung transplantation (LTx) may be considered as a last resort. However, uncertainties remain about patient selection and optimal timing for referral and listing. This retrospective study analyzed patients with severe COVID-19 who were supported by veno-venous ECMO and listed for LTx between July 2020 and June 2022. Out of the 20 patients in the study population, four who underwent LTx were excluded. The clinical characteristics of the remaining 16 patients were compared, including nine who recovered and seven who died while awaiting LTx. The median duration from hospitalization to listing was 85.5 days, and the median duration on the waitlist was 25.5 days. Younger age was significantly associated with a higher likelihood of recovery without LTx after a median of 59 days on ECMO, compared to those who died at a median of 99 days. In patients with severe COVID-19-induced lung damage supported by ECMO, referral to LTx should be delayed for 8-10 weeks after ECMO initiation, particularly for younger patients who have a higher probability of spontaneous recovery and may not require LTx.

Subclinical postoperative atrial fibrillation: a randomized trial

Background

Postoperative atrial fibrillation (POAF) is the most common complication of cardiac surgery, requiring interventions and prolonging hospital stay. POAF is associated with increased mortality and a higher rate of systemic thrombo-embolism. The rates of recurrent AF, optimal follow-up and management remain unclear. We aimed to evaluate the incidence of recurrent atrial fibrillation (AF) events, during long term follow-up in patients with POAF following cardiac surgery.

Methods

Patients with POAF and a CHA₂DS₂-VASc score of ≥2 were randomized in a 2:1 ratio to either implantation of a loop recorder (ILR) or ECG monitoring using periodic Holters. Participants were followed prospectively for 2 years. The primary end point was the occurrence of AF longer than 5 min.

Results

The final cohort comprised of 22 patients, of whom 14 received an ILR. Over a median follow up of 25.7 (IQR of 24.7-44.4) months, 8 patients developed AF, representing a cumulative annualized risk of AF recurrence of 35.7%. There was no difference between ILR (6 participants, 40%) and ECG/Holter (2 participants, 25% p = 0.917). All 8 patients with AF recurrence were treated with oral anticoagulation. There were no cases of mortality, stroke or major bleeding. Two patients underwent ILR explantation due to pain at the implantation site.

Conclusions

The rate of recurrent AF in patients with POAF after cardiac surgery and a CHA₂DS₂-VASc score of ≥2 is approximately 1 in 3 when followed systematically. Further research is need to assess the role of ILRs in this population.

Surgical ablation for atrial fibrillation: impact of Diabetes Mellitus type 2

BACKGROUND

Diabetes mellitus (DM) type 2 is an independent risk factor for atrial fibrillation (AF). Surgical ablation or "maze procedure" is an option for patients with AF undergoing concomitant or isolated cardiac surgery. The aim of this study was to evaluate the impact of DM type 2 on early and long-term outcomes of patients following surgical AF ablation.

METHODS

We performed an observational cohort study in Israel's largest tertiary care center. All data of patients who underwent surgical AF ablation, between 2006 and 2021 were extracted from our departmental database. Patients were divided into Group I (non-diabetic patients) and Group II (DM type 2 patients). We compared the two groups with respect to freedom from recurrent atrial arrhythmia, and mortality rate.

RESULTS

The study population included 606 patients. Group I (non-DM patients), consisting of 484 patients, and Group II (DM type 2 patients), comprised 122 patients. Patients with DM were older, had more hypertension and incidence of cerebrovascular accident (CVA)/transient ischemic attack (TIA), higher EuroSCORE (p < .05 for all), and a longer bypass time-130 ± 40 vs. 122 ± 36 min (p = 0.028). The mean follow-up duration was 39.0 ± 22.7 months. Freedom from atrial fibrillation was similar between the non-DM and DM type 2 groups after a 1-year follow-up, 414 (88.2%) vs. 101 (87.1%) (p = 0.511), after a 3-year follow-up, 360 (86.3%) vs. 84 (79.9%) (p = 0.290) and after a 5-year follow-up, 226 (74.1%) vs. 55 (71.5%) (p = 0.622) respectively. Furthermore, 1- and 3-year mortality was similar between non-DM and DM type 2 groups, 2.5% vs. 4.9%, (p = 0.226) and 5.6% vs. 10.5% (p = 0.076) respectively. 5-year mortality was higher in Group II (DM type 2 patients) compared with Group I (non-DM patients), 11.1% vs. 23.4% (p = 0.009).

CONCLUSION

Surgical ablation had a high success rate, with freedom from recurrent atrial arrhythmia at 1- 3- and 5- years follow-up in both the DM type 2 and non-DM groups. Furthermore,1- and 3-year mortality after surgical ablation was also similar in both groups. However, 5-year mortality was higher in the DM type 2 group.

Heart Valve Surgery in Antiphospholipid Syndrome Patients—Morbidity and Mortality

Objectives: To assess valve surgery outcomes in antiphospholipid syndrome (APS). Methods: A retrospective study assessing complications and mortality rate and possible factors associated with adverse outcomes of APS patients undergoing valve surgery in two tertiary medical centers. Results: Twenty-six APS patients (median age at surgery 47.5 years) who underwent valve surgery were detected, of whom 11 (42.3%) had secondary APS. The mitral valve was most commonly involved (n = 15, 57.7%). A valve replacement was performed in 24 operations (92.3%), 16 of which (66.7%) were mechanical valves. Fourteen (53.8%) patients sustained severe complications, and four of them died. The presence of mitral regurgitation (MR) was associated with severe complications and mortality (odds ratio (95% confidence interval) 12.5 (1.85–84.442), p = 0.008, for complications. All deceased patients had MR (p = 0.033). The presence of Libman-Sacks endocarditis (LSE) (7.333 (1.272–42.294), p = 0.045), low C3 (6.667 (1.047–42.431), p = 0.05) and higher perioperative prednisone doses (15 ± 21.89 vs. 1.36 ± 3.23 mg/day, p = 0.046) were also associated with complications. A lower glomerular filtration rate (GFR) was associated with mortality (30.75 ± 19.47 vs. 70.68 ± 34.44 mL/min, p = 0.038). Conclusions: Significant morbidity and mortality were observed among APS patients undergoing valve surgery. MR was associated with mortality and complications. LSE, low complement and higher doses of corticosteroids were associated with complications, while a low GFR was associated with mortality.

CRISPR-Cas9 editing of TLR4 to improve the outcome of cardiac cell therapy

Inflammation and fibrosis limit the reparative properties of human mesenchymal stromal cells (hMSCs). We hypothesized that disrupting the toll-like receptor 4 (TLR4) gene would switch hMSCs toward a reparative phenotype and improve the outcome of cell therapy for infarct repair. We developed and optimized an improved electroporation protocol for CRISPR-Cas9 gene editing. This protocol achieved a 68% success rate when applied to isolated hMSCs from the heart and epicardial fat of patients with ischemic heart disease. While cell editing lowered TLR4 expression in hMSCs, it did not affect classical markers of hMSCs, proliferation, and migration rate. Protein mass spectrometry analysis revealed that edited cells secreted fewer proteins involved in inflammation. Analysis of biological processes revealed that TLR4 editing reduced processes linked to inflammation and extracellular organization. Furthermore, edited cells expressed less NF-ƙB and secreted lower amounts of extracellular vesicles and pro-inflammatory and pro-fibrotic cytokines than unedited hMSCs. Cell therapy with both edited and unedited hMSCs improved survival, left ventricular remodeling, and cardiac function after myocardial infarction (MI) in mice. Postmortem histologic analysis revealed clusters of edited cells that survived in the scar tissue 28 days after MI. Morphometric analysis showed that implantation of edited cells increased the area of myocardial islands in the scar tissue, reduced the occurrence of transmural scar, increased scar thickness, and decreased expansion index. We show, for the first time, that CRISPR-Cas9-based disruption of the TLR4-gene reduces pro-inflammatory polarization of hMSCs and improves infarct healing and remodeling in mice. Our results provide a new approach to improving the outcomes of cell therapy for cardiovascular diseases.

Kinetics of cellular and humoral responses to third BNT162B2 COVID-19 vaccine over six months in heart transplant recipients - implications for the omicron variant

BACKGROUND

The durability of the immune response following the 3-dose BNT162b2 vaccination is unknown. The complexity of the situation is enhanced by the threat that highly transmissible variants may further accelerate the decline in the protection afforded by mRNA vaccines.

METHODS

One hundred and three 3-dose-vaccinated heart transplant recipients were longitudinally assessed for the kinetics of variant-specific neutralization (Cohort 1, n = 60) and SARS-CoV-2-specific-T-cell response (Cohort 2, n = 54) over 6 months. Neutralization and T-cell responses were compared between paired samples at 2 time points, using the Kruskal-Wallis test followed by Dunn's multiple comparison test for continuous variables and McNemar's test for dichotomous variables. The Bonferroni method of p values adjustment for multiple comparison was applied.

RESULTS

The third dose induced high neutralization of the wild-type virus and delta variant (geometric mean titer [GMT], 137.2 [95% CI, 84.8-221.9] and 80.6, [95% CI, 49.3-132.0], respectively), and to a lesser degree of the omicron variant (GMT, 10.3 [95% CI, 5.9-17.9]). At 6 months, serum neutralizing activity declined but was still high for the wild-type virus and for the delta variant (GMTs 38.1 [95% CI, 21.2-69.4], p = 0.011; and 28.9 [95% CI, 16.6-52.3], p = 0.022, respectively), but not for the omicron variant (GMT 5.9 [95% CI, 3.4-9.8], p = 0.463). The percentages of neutralizing sera against the wild-type virus, delta and omicron variants increased from 70%, 65%, and 38%, before the third dose, to 93% (p < 0.001), 88% (p < 0.001), and 48% (p = 0.021) at 3 weeks after, respectively; and remained high through the 6 months for the wild-type (80%, p = 0.06) and delta (77%, p = 0.102). The third dose induced the development of a sustained SARS-CoV-2-specific-T-cell population, which persisted through 6 months.

CONCLUSIONS

The third BNT162b2 dose elicited a durable SARS-CoV-2-specific T-cell response and induced effective and durable neutralization of the wild-type virus and the delta variant, and to a lesser degree of the omicron variant.

Usefulness of Coronary Artery Calcium Score to Rule Out Obstructive Coronary Artery Disease Before Transcatheter Aortic Valve Implantation

Pretranscatheter aortic valve implantation (pre-TAVI) coronary evaluation using computed tomography coronary angiography (CTA) remains suboptimal. We aimed to evaluate whether coronary artery calcium score (CAC) may rule out obstructive coronary artery disease (CAD) pre-TAVI. TAVI candidates (n = 230; mean age 80 ± 8 years), 49% men, underwent preprocedural CTA and invasive coronary angiography. Obstructive CAD was defined as luminal diameter stenosis of ≥50% of left main or 3 major vessels ≥70%. Vessels with coronary stents or bypass were excluded. CAC score was calculated using the Agatston method. Receiver operating characteristic was applied to establish the CAC threshold for obstructive CAD. Multivariable analysis with adjustment for clinical covariates was applied. Net reclassification for nonobstructive disease using CAC score was calculated among nondiagnostic CT scans. Median CAC score was 1,176 (interquartile range 613 to 1,967). Receiver operating characteristic analysis showed high negative predictive value (NPV) for obstructive CAD as follows: left main CAC score 252, NPV 99%; left anterior descending CAC score 250, NPV 97%; left circumflex CAC score 297, NPV 92%; and right coronary artery CAC score 250, NPV 91%. Multivariate analysis showed the highest tertile of CAC score (≥1,670) to be an independent predictor of obstructive CAD (odds ratio 10.7, 95% confidence interval 4.6 to 25, p <0.001). Among nondiagnostic CTA, net reclassification showed reclassification of 76%, 13%, 45%, and 34% of left main, left anterior descending, left circumflex, and right coronary artery for nonobstructive CAD, respectively. In conclusion, CAC score cutoffs can be used to predict nonobstructive CAD. Implementing CAC score on pre-TAVI imaging can reduce a significant proportion of invasive coronary angiography.

Revascularization outcomes in diabetic patients presenting with acute coronary syndrome with non-ST elevation

Background

To compare the outcomes of diabetic patients hospitalized with non-ST elevation myocardial infarction (NSTEMI) or unstable angina (UA) referred for revascularization by either coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) in a real-life setting.

Methods

The study included 1987 patients with diabetes mellitus enrolled from the biennial Acute Coronary Syndrome Israeli Survey between 2000 and 2016, who were hospitalized for NSTEMI or UA, and underwent either PCI (N = 1652, 83%) or CABG (N = 335, 17%). Propensity score-matching analysis compared all-cause mortality in 200 pairs (1:1) who underwent revascularization by either PCI or CABG.

Results

Independent predictors for CABG referral included 3-vessel coronary artery disease (OR 4.9, 95% CI 3.6–6.8, p < 0.001), absence of on-site cardiac surgery (OR 1.4, 95% CI 1.1–1.9, p = 0.013), no previous PCI (OR 1.5, 95% CI 1.1–2.2, p = 0.024) or MI (OR 1.7, 95% CI 1.2–2.6, p = 0.002). While at 2 years of follow-up, survival analysis revealed no differences in mortality risk between the surgical and percutaneous revascularization groups (log-rank p = 0.996), after 2 years CABG was associated with a significant survival benefit (HR 1.53, 95% CI 1.07–2.21; p = 0.021). Comparison of the propensity score matching pairs also revealed a consistent long-term advantage toward CABG (log-rank p = 0.031).

Conclusions

In a real-life setting, revascularization by CABG of diabetic patients hospitalized with NSTEMI/UA is associated with better long-term outcomes. Prospective randomized studies are warranted in order to provide more effective recommendations in future guidelines.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01595-5.

Frailty and clinical outcomes following aortic valve replacement

Background and Aims

The Norton score is a well‐known scale to assess frailty. Frailty and a low Norton score are associated with complications and mortality in hospitalized patients. We aimed to evaluate whether a low Norton score is associated with surgical complications and death after aortic valve replacement (AVR).

Methods

From 2004 through 2020, we performed an observational study in a large tertiary medical center, which included all patients who had undergone isolated AVR surgery. Of the 1469 study patients, 618 patients (42%) had a low (<18) and 851 patients (58%) a high Norton score (≥18).

Results

Frailer patients with a low Norton score had higher in‐hospital mortality compared to those with a high Norton score (5.5% vs. 0.8%, p < .001). The Norton score was significantly higher among patients who survived compared to those who died (17.5 ± 2.4 vs. 11.5 ± 5.2, p < .001). A low Norton score was associated with a threefold increased risk of in‐hospital mortality (odds ratio 3.03; 95% confidence interval [CI] 1.14–0.09, p = .034). Ten‐year mortality rate was higher among frailer patients with a low compared with a high Norton score (25.9%, 13.3%; hazard ratio 0.69, CI 0.48‐0.82, p < .001). By adding a Norton score to standard prognostic factors (age, gender, comorbidities, left ventricular ejection fraction, functional class) we showed a significant improvement of 59.4% (p < .001) for predicting 1‐year mortality, and 40.6% (p < .001) for predicting 10‐year mortality.

Conclusions

Our findings show that the admission Norton score is a powerful marker of short‐ and long‐term mortality, and, therefore, should be considered as a risk stratification tool in patients who are candidates for AVR.

Surgical treatment on infective endocarditis: impact of diabetes on mortality

BACKGROUND

Type 2 diabetes mellitus (DM) is a frequent co-morbidity among patients suffering from infective endocarditis (IE). The aim of the study was to evaluate the impact of type 2 DM on the early-, intermediate- and long-term mortality of patients who underwent surgical treatment of endocarditis.

METHODS

We performed an observational cohort study in the large tertiary center in Israel during 14 years. All data of patients who underwent surgical treatment of endocarditis, performed between 2006 and 2020 were extracted from the departmental database. Patients were divided into two groups: Group I (non-diabetic patients), and Group II (diabetic patients).

RESULTS

The study population includes 420 patients. Group I (non-diabetic patients), comprise 326 patients, and Group II (diabetic patients), comprise 94 patients. Mean follow-up duration was 39.3 ± 28.1 months. Short-term, 30-day and in-hospital mortality, also intermediate-term mortality (1- and 3-year) was higher in the DM group compared with the non-DM group, but did not reach statistical significance: 11.7% vs. 7.7%. (p = 0.215); 12.8% vs. 8.3% (p = 0.285); 20.2% vs. 13.2% (p = 0.1) and 23.4% vs. 15.6% (p = 0.09) respectively. Long-term, 5-year mortality was significantly higher in the DM group, compared to the non-DM group: 30.9% vs. 16.6% (p = 0.003). Furthermore, predictors for long-term mortality included diabetes (CI 1.056-2.785, p = 0.029), as demonstrated by regression analysis.

CONCLUSIONS

Diabetic patients have trend to increasing mortality at the short- and intermediate period post-surgery for IE, but this is not statistically significant. Survival of diabetic patients deteriorates after more than three years follow surgery. Diabetes is an independent predictor for long-term, 5-year mortality after surgical treatment of endocarditis, regardless of the patients age and comorbidities. Trial registration Ethical Committee of Sheba Medical Centre, Israel on 02.12. 2014, Protocol 4257.

The impact of diabetes on short-, intermediate- and long-term mortality following left ventricular assist device implantation

OBJECTIVES

Type 2 diabetes mellitus (DM) is a frequent comorbidity among patients suffering from advanced heart failure necessitating a left ventricular assist device (LVAD) implant. The goal of this study was to evaluate the impact of type 2 DM on early and long-term outcomes of patients following an LVAD implant.

METHODS

We performed an observational cohort study in a large tertiary care centre in Israel. All data of patients who underwent a continuous flow LVAD implant between 2006 and 2020 were extracted from our departmental database. Patients were divided into 2 groups: group I (patients without diabetes) and group II (patients with diabetes). We compared short-term (30-day and 3-month) mortality, intermediate-term (1- and 3-year) mortality and long-term (5 year) mortality between the 2 groups.

RESULTS

The study population included 154 patients. Group I (patients without diabetes) comprised 88 patients and group II (patients with diabetes) comprised 66 patients. The mean follow-up duration was 38.2 ± 30.3 months. Short- and intermediate-term mortality (30 days, 1 year and 3 years) was higher in the group with DM compared with the group without DM but did not reach any statistically significant difference: 16.1% vs 9.8% (P = 0.312), 24.2% vs 17.3% (P = 0.399) and 30.6% vs 21.9% (P = 0.127) respectively. Long-term 5-year mortality was significantly higher in the group with DM compared to the group without: 38.7% vs 24.4% (P = 0.038). Furthermore, predictors of long-term mortality included diabetes (hazard ratio 2.09, confidence interval 1.34-2.84, P = 0.004), as demonstrated by regression analysis.

CONCLUSIONS

Patients with diabetes and those without diabetes have similar 30-day and short- and intermediate-term mortality rates. The mortality risk of diabetic patients begins to increase 3 years after an LVAD implant. Diabetes is an independent predictor of long-term, 5-year mortality after an LVAD implant.

CLINICAL TRIAL REGISTRATION

Ethical Committee of Sheba Medical Centre, Israel, on 2 December 2014, Protocol 4257.

OUP accepted manuscript

Pulmonary artery angiosarcoma is a rare malignant vascular tumour with a poor prognosis and a grim clinical course. Common clinical presentations include shortness of breath, coughing and haemoptysis. Differential diagnosis includes thromboembolism and lung carcinoma. Rarity of the tumour and the consequent lack of treatment guidelines further worsen the prognosis. We report a case of pulmonary artery angiosarcoma involving the main pulmonary artery and its bifurcation with emphasis on the surgical treatment.

Chronic thromboembolic pulmonary hypertension in patients with antiphospholipid syndrome: Risk factors and management

BACKGROUND

Antiphospholipid syndrome (APS) may cause chronic thromboembolic pulmonary hypertension (CTEPH). Current knowledge regarding prevalence and risk factors for CTEPH among APS patients is limited. We sought to determine clinical features and biomarkers that could identify APS subjects suffering from CTEPH, and describe the prevalence, course and treatment outcomes of patients with APS-CTEPH.

METHODS

504 APS patients were treated in our center during 2008 to 2019. We studied clinical and laboratory features of 69 APS patients, comparing 19 patients diagnosed with CTEPH (APS-CTEPH) and treated accordingly, with 50 consecutive age and gender matched patients with no evidence of pulmonary hypertension (APS-No-CTEPH).

RESULTS

CTEPH prevalence was 3.8% in our APS cohort and was linked with the following parameters: primary APS (p < 0.05); prior pulmonary embolism (p < 0.001); recurrent venous thromboembolism (VTE) (p < 0.001); lower platelet counts (p < 0.001); triple anti-phospholipid antibodies positivity (p < 0.001), higher titers of anti-cardiolipin IgG (p < 0.001), anti-B2GPI IgG (p < 0.001), and high Russell viper venom time ratio (RVVT-ratio) (p < 0.05). Additionally, history of catastrophic APS was more prevalent in APS-CTEPH vs APS-No-CTEPH (p < 0.05). Of APS-CTEPH patients, 15/19 underwent pulmonary endarterectomy (PEA): In 12/15 the procedure was elective and resulted in good perioperative and long-term outcomes, while only 1 of 3 patients that underwent urgent PEA survived.

CONCLUSIONS

CTEPH is relatively common in APS. Primary APS, prior PE, recurrent VTE, thrombocytopenia and specific anti-phospholipid antibodies predict CTEPH in APS. Active assessment for CTEPH in APS patients should be considered, as PEA was found to be effective and relatively safe, especially if electively performed.

Third dose of the BNT162b2 vaccine in heart transplant recipients: Immunogenicity and clinical experience

BACKGROUND

The repeated waves of the COVID-19 pandemic have highlighted the necessity to optimize vaccine responses in immunocompromised populations. We investigated the safety and immunogenicity of a third, booster, dose of the Pfizer BNT162b2 vaccine in heart transplant (HT) patients.

METHODS

The cohort comprised 96 adult HT patients who received a third homologous dose of the BNT162b2 vaccine 168 days after the second dose. The vaccine-induced antibody responses of both receptor-binding domain (RBD) IgG and neutralizing antibodies were assessed in all patients, with a positive antibody response being defined as the presence of either IgG anti-RBD or neutralizing antibodies. For a subset of patients, T cell response was also studied.

RESULTS

The third dose was associated with a low rate of adverse events, mostly mild pain at the injection site. No serious adverse events were recorded, and there were no episodes of rejection. At 18 days following the third dose of the vaccine, the positive antibody response increased from 23% to 67%, with a corresponding increase in neutralizing capacity. The third dose elicited SARS-CoV-2 neutralization titers >9-fold and IgG anti-RBD antibodies >3-fold of the range achieved after the two primary doses. Mycophenolate use, lower eGFR and higher C-reactive protein were independently associated with a reduced likelihood of generating an immune response. Importantly, a specific T-cell response following the third dose was evident in the majority of transplant recipients.

CONCLUSIONS

An homologous third booster dose of the BNT162b2 vaccine gave overall consistent tolerability and a good safety profile, while eliciting humoral and cellular immune responses.

Coronary Artery Bypass Grafting Following Acute Coronary Syndrome: Impact of Gender

The impact of gender on clinical outcomes after coronary artery bypass grafting (CABG) has generated conflicting results. We investigated the impact of gender, on 30 day mortality, complications and late survival in patients with acute coronary syndrome (ACS) undergoing CABG. The study included 1308 patients enrolled from the biennial Acute Coronary Syndrome Israeli Survey between 2000 and 2016, who were hospitalized for ACS and underwent CABG. Of them, 1045 (80%) were men and 263 (20%) women. While women were older and had more hypertension and hyperlipidemia, they demonstrated less diabetes mellitus, previous ischemic heart disease, smoking, and fewer implicated coronary arteries. Women presented with more atypical symptoms as compared to men (26.3% vs 19.4%, p = 0.017). Overall multivariable-adjusted 30 day mortality was higher in women than in men (OR 2.47 95% CI 1.19-5.1, p = 0.015). Among patients with ST-elevation myocardial infarction (STEMI) or non-STEMI, women had a higher 10 year mortality rate than men (42.5% vs 19.2%, log-rank p < 0.001 and 31.5% vs 20.7%, log-rank, p = 0.012). However, in patients with unstable angina pectoris on admission, these differences were not seen (16.9% vs 13.4%, log-rank p = 0.540). Multivariable analysis demonstrated that female gender was a significant predictor for 10 year mortality (HR 1.39, 95% CI 1.02-1.9, p = 0.038). In a real-life setting, women constitute an independent predictor for short- and long-term mortality following ACS treated by CABG surgery. The reasons for a higher mortality in women should be further investigated as well as specific and/or more intensive therapies after CABG in this high-risk group of patients.

Coronary artery bypass graft surgery in patients on ticagrelor therapy is not associated with adverse perioperative outcomes

BACKGROUND

Management of patients treated with Ticagrelor is challenging, as stopping Ticagrelor prior to coronary bypass graft surgery (CABG) may increase the risk of acute stent thrombosis. The aim of the study was to compare bleeding complications in patients treated with ticagrelor combined with acetylsalicylic acid (ASA) versus ASA alone until 1 day before surgery.

METHODS

Bleeding complications, defined as the composite of red blood cell transfusion ≥1000 ml, chest drainage ≥2000 ml, and bleeding requiring surgical re-exploration, were compared in 161 patients, with 101 on preoperative acetylsalicylic acid (ASA) alone (group A) and 65 on ticagrelor + ASA (group B).

RESULTS

There were no differences in bleeding complications between the two groups (26% vs. 27% in group A and B, respectively), with similar chest drainage in the first 24 h (569 ± 393 ml and 649 ± 427 ml, respectively).

CONCLUSIONS

Continuing ticagrelor until coronary artery bypass surgery was not associated with increased bleeding complications, suggesting that continued management with ticagrelor until surgery may be safe.

The predictive value of creatinine clearance for mortality in patients undergoing revascularization

Background

Renal function plays a significant role in the prognosis and management of patients with multi-vessel coronary artery disease (CAD) referred for revascularization. Current data lack precise risk stratification using estimated glomerular filtration rate (eGFR) and creatinine clearance.

Methods

This prospective study includes a three-year follow-up of 1112 consecutive patients with multi-vessel CAD enrolled in the 22 hospitals in Israel that perform coronary angiography.

Results

The Mayo formula yielded the highest mean eGFR (90 ± 26 mL/min per 1.73m²) and chronic kidney disease-epidemiology collaboration (CKD-EPI) the lowest (76 ± 24 mL/min per 1.73m²). Consequently, the Mayo formula classified more patients (56%) as having normal renal function. There was a significant and strong correlation between the values obtained from all five formulas using Cockcroft-Gault as the reference formula: Mayo: r = 0.80, p < 0.001; CKD-EPI: r = 0.87, p < 0.001; modification of diet in renal disease (MDRD): r = 0.84, p < 0.001; inulin clearance-based: r = 0.99, p < 0.001). Multivariable analysis demonstrated that decreased renal function is an independent predictor of 3-year mortality in all five formulas, with risk increasing by 15–25% for each 10-unit decrease in eGFR. Despite the similarities between the formulas, the ability to predict mortality was highest in the Mayo formula and lowest in MDRD.

Conclusions

Our data suggest that while the Mayo formula is not currently recommended by any nephrology guidelines, it may be an alternative formula to predict mortality among patients with multivessel CAD, including to the widely used MDRD formula.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01502-1.

BNT162b2 vaccination in heart transplant recipients: Clinical experience and antibody response

BACKGROUND

Data on the safety and efficacy of SARS-CoV-2 vaccines in immunocompromised populations are sparse.

METHODS

We conducted a prospective study of 77 heart transplant (HT) recipients vaccinated with two doses of BNT162b2 vaccine and monitored for adverse events following both doses, the receptor-binding domain (RBD) IgG response, and neutralizing antibodies.

RESULTS

BNT162b2 vaccination was associated with a low rate of adverse events, characterized mostly by pain at the injection site. By a mean 41 days post second dose there were no clinical episodes of rejection, as suggested by a troponin leak or allograft dysfunction. At a mean 21 days following the second dose, IgG anti-RBD antibodies were detectable in 14 (18%) HT recipients. Immune sera neutralized SARS-CoV-2 pseudo-virus in 8 (57%) of those with IgG anti-RBD antibodies. Immunosuppressive regimen containing mycophenolic acid was associated with lower odds of an antibody response (OR = 0.12, p = 0.042).

CONCLUSIONS

Whether a longer time-frame for observation of an antibody response is required after vaccination in immunosuppressed individuals remains unknown.

Numerical Biomechanics Models of the Interaction Between a Novel Transcatheter Mitral Valve Device and the Subvalvular Apparatus

Objective

Mitral valve regurgitation (MR) is a common valvular heart disease where improper closing causes leakage. Currently, no transcatheter mitral valve device is commercially available. Raanani (co-author) and colleagues have previously proposed a unique rotational implantation, ensuring anchoring by metallic arms that pull the chordae tendineae. This technique is now being implemented in a novel device design. The aim of this study is to quantify the rotational implantation effect on the mitral annulus kinematics and on the stresses in the chordae and papillary muscles.

Methods

Finite element analysis of the rotational step of the implantation in a whole heart model is employed to compare 5 arm designs with varying diameters (25.9 mm to 32.4 mm) and rotation angles (up to 140°). The arm rotation that grabs the chordae was modeled when the valve was in systolic configuration.

Results

An increase in the rotation angle results in reduced mitral annulus perimeters. Larger rotation angles led to higher chordae stresses with the 29.8 mm experiencing the maximum stresses. The calculated chordae stresses suggest that arm diameter should be <27.8 mm and the rotation angle <120°.

Conclusions

The upper limit of this diameter range is preferred in order to reduce the stresses in the papillary muscles while grabbing more chords. The findings of this study can help improving the design and performance of this unique device and procedural technique.

Extracellular Vesicles From Epicardial Fat Facilitate Atrial Fibrillation

BACKGROUND

The role of epicardial fat (eFat)-derived extracellular vesicles (EVs) in the pathogenesis of atrial fibrillation (AF) has never been studied. We tested the hypothesis that eFat-EVs transmit proinflammatory, profibrotic, and proarrhythmic molecules that induce atrial myopathy and fibrillation.

METHODS

We collected eFat specimens from patients with (n=32) and without AF (n=30) during elective heart surgery. eFat samples were grown as organ cultures, and the culture medium was collected every 2 days. We then isolated and purified eFat-EVs from the culture medium, and analyzed the EV number, size, morphology, specific markers, encapsulated cytokines, proteome, and microRNAs. Next, we evaluated the biological effects of unpurified and purified EVs on atrial mesenchymal stromal cells and endothelial cells in vitro. To establish a causal association between eFat-EVs and vulnerability to AF, we modeled AF in vitro using induced pluripotent stem cell-derived cardiomyocytes.

RESULTS

Microscopic examination revealed excessive inflammation, fibrosis, and apoptosis in fresh and cultured eFat tissues. Cultured explants from patients with AF secreted more EVs and harbored greater amounts of proinflammatory and profibrotic cytokines, and profibrotic microRNA, as well, than those without AF. The proteomic analysis confirmed the distinctive profile of purified eFat-EVs from patients with AF. In vitro, purified and unpurified eFat-EVs from patients with AF had a greater effect on proliferation and migration of human mesenchymal stromal cells and endothelial cells, compared with eFat-EVs from patients without AF. Last, whereas eFat-EVs from patients with and without AF shortened the action potential duration of induced pluripotent stem cell-derived cardiomyocytes, only eFat-EVs from patients with AF induced sustained reentry (rotor) in induced pluripotent stem cell-derived cardiomyocytes.

CONCLUSIONS

We show, for the first time, a distinctive proinflammatory, profibrotic, and proarrhythmic signature of eFat-EVs from patients with AF. Our findings uncover another pathway by which eFat promotes the development of atrial myopathy and fibrillation.

Secondary chordal resection with septal myectomy for treatment of symptomatic obstructive hypertrophic cardiomyopathy

 

OBJECTIVES

Left ventricular outflow tract obstruction causes symptoms of heart failure in most patients with hypertrophic cardiomyopathy. Resection of the secondary mitral valve (MV) chordae has recently been shown to move the MV apparatus posteriorly, thereby eradicating the outflow gradient. The aim of this study was to evaluate whether secondary chordal resection concomitant to septal myectomy improves outcomes.

METHODS

Between 2005 and 2020, a total of 165 patients underwent septal myectomy without MV repair or replacement in our Medical Center. Secondary MV chordal resection was performed in 60 patients, and their outcomes were compared with those of the remaining 105 patients who did not undergo chordal resection (controls). Mean age was 61 ± 13 and 58 ± 16 years, respectively (P = 0.205).

RESULTS

There were no in-hospital deaths throughout the entire cohort. Of those patients who underwent secondary chordal resection, New York Heart Association functional class decreased from 3 (interquartile range 2-3) preoperatively to 1 (interquartile range 1-2) postoperatively (P < 0.001), and resting outflow gradient decreased from 91 ± 39 mmHg to 13 ± 8 mmHg (86% change, P < 0.001). Compared with controls, patients who underwent secondary chordal resection had a significant lower resting outflow gradient at follow-up (14 ± 7 mmHg vs 21 ± 15 mmHg, P = 0.002). The rate of moderate or more than moderate mitral regurgitation at 5 years was 2% in the secondary chordal resection group and 5% in the controls (hazard ratio 1.05, confidence interval 0.11-10.32; P = 0.965).

CONCLUSIONS

In this observational study, we report that secondary chordal resection concomitant to septal myectomy for left ventricular outflow tract obstruction is safe, relieves heart failure symptoms and reduces left ventricular outflow tract gradient in appropriately selected patients.

Acute pulmonary embolism following acute type A aortic dissection in a patient with COVID-19

Acute aortic dissection and acute pulmonary embolism (PE) are life-threatening emergencies that can mimic each other at presentation. Immediate and accurate diagnosis of these scenarios is crucial to initiate the appropriate interventions. In this case report we present a 73-year-old patient, who was admitted to our Medical Center with acute type A aortic dissection. She was tested for coronavirus disease 2019 (COVID-19) infection and was found to be positive. During her admission in the COVID-19 designated intensive care unit, she diagnosed with acute PE in the main right and left pulmonary arteries. She underwent surgery that included bilateral pulmonary embolectomy and aortic dissection repair. The patient was discharged from our hospital on the ninth postoperative day without any complications. Frequency of simultaneous presentation of acute aortic dissection and acute PE is increased with a history of coagulation abnormalities as seen in patients with COVID-19.

Heart Team/Guidelines Discordance Is Associated With Increased Mortality: Data From a National Survey of Revascularization in Patients With Complex Coronary Artery Disease

BACKGROUND

Practice guidelines emphasize the role of the SYNTAX score (SS; Synergy Between PCI With TAXUS and Cardiac Surgery) in choosing between percutaneous coronary intervention and coronary artery bypass graft surgery in cases of complex coronary artery disease. There is paucity of data on the implementation of these recommendations in daily practice, and on the consequences of guideline discordant revascularization.

METHODS

This was a retrospective analysis of a prospective national survey of consecutive real world patients undergoing coronary revascularization for complex coronary artery disease according to decisions of local heart team at each center. SS was calculated at a dedicated CoreLab, and patients were classified as heart team/guidelines agreement/discordant.

RESULTS

Nine hundred seventy-nine patients (571 percutaneous coronary intervention and 408 coronary artery bypass graft) were included. Mean age was 65 years and the mean SS was 22. Heart team/guidelines discordance occurred in 170 (17.3%) patients. Independent predictors of heart team/guidelines discordance were age, admission to a center with no cardiac surgery service, SS, and previous percutaneous coronary intervention/myocardial infarction. A multivariate model based on these characteristics had a C statistic of 0.83. Thirty-day outcomes were similar in the agreement/discordance groups, however, heart team/guidelines discordance was associated with a significant increase in 3 year mortality (17.6% versus 8.4%; hazard ratio, 2.05; P=0.002) after multivariate adjustment.

CONCLUSIONS

Heart team/guidelines discordance is not infrequent in real world patients with complex coronary artery disease undergoing revascularization. This is more likely to occur in elderly patients, those with more complex coronary disease (as determined by the SS), and those treated at centers with no cardiac surgery service. These patients have a higher risk for mid-term mortality.

The Impact of Initiation of an Intensivist-Led Patient Management Protocol on Outcomes After Cardiac Surgery

OBJECTIVES

Prolonged intensive care unit stay after cardiac surgery is associated with high mortality. The aim of this study was to evaluate the impact of the introduction of a quality improvement program under the supervision of an intensivist on the long-term mortality of high-risk patients with prolonged intensive care unit (ICU) stay after cardiac surgery.

DESIGN

Retrospective study of prospectively collected data.

SETTING

Cardiac surgery ICU.

PARTICIPANTS

A total of 7,549 patients after cardiac surgery.

INTERVENTIONS

Patients were divided into two periods: 2004 to 2007, before introducing the quality improvement program (3,315 patients), and 2009 to 2014, after introduction of the program (4,234 patients). In the period from 2004 to 2007, patients were divided into group I (ICU stay ≥ seven days), which included 242 patients, and group III (ICU stay < seven days), which included 3,073 patients. Also, in the period from 2009 to 2014 patients, were divided into group II (ICU stay ≥seven days), which included 326 patients, and group IV (ICU stay < seven days), which included 3,908 patients. Patient outcomes were compared. Follow-up was five years for each group.

MEASUREMENTS AND MAIN RESULTS

The European System for Cardiac Operative Risk Evaluation did not differ significantly among the groups. When comparing between group I and group II, 30-day mortality decreased significantly from 24.8% to 16.6%, six-month mortality from 27.3% to 19.3%, one-year mortality from 42.1% to 32.2%, 3-year mortality from 54.5% to 43.3%, and 5-year mortality from 61.2% to 51.8%. In comparing between group III and group IV, the authors did not observe a statistically significant decrease of mortality.

CONCLUSIONS

Intensivist-led patient management protocol is associated with decreased long-term mortality in high-risk patients with a prolonged ICU stay.

A unique proteomic signature of extracellular vesicles derived from mesenchymal stromal cells of epicardial fat from patients with and without ischemic heart disease

Background

Mesenchymal stromal cells (MSCs) have been implicated in the development and progression of myocardial diseases. However, the role of extracellular vesicles (EVs) secreted from human MSCs (hMSCs) of epicardial fat (eFat) in the pathogenesis of ischemic heart disease (IHD) has never been studied.

Purpose

We sought to characterize EVs from eFat-hMSCs of patients with and without IHD.

Methods

We collected eFat specimens from 12 patients with (n=7) and without (n=5) IHD who underwent open heart surgery. We isolated and cultured hMSCs by enzymatic digestion and adherence to plastic. EVs were separated from the culture media by differential ultra-centrifugation. We assessed EV size and structure by electron microscopy and nanoparticle tracking analysis. Finally, we evaluated the proteomic profile of EVs from ischemic and non-ischemic patients by mass spectrometry.

Results

eFat-hMSCs from ischemic patients, secreted higher amounts of small EVs (size range of 70–200 nm) compared with non-ischemic controls (Figure 1A+B). Proteomic analysis revealed over 1,000 proteins inside isolated EVs. We identified 13 proteins that were significantly differentially expressed between patients with and without IHD, including apolipoprotein E, transforming growth factor-β and collagen α-1 (Figure 1C). We performed an enrichment analysis which showed that EVs from eFat-hMSCs from ischemic patients encapsulated functional protein networks associated with immune activation. Unlike IHD patients, EVs from non-ischemic patients carried functional protein networks that regulate angiogenesis.

Conclusions

eFat-hMSCs of patients with IHD secrete higher amounts of small EVs with a unique proteomic signature related to immune activation. EVs derived from eFat-hMSCs should be further studied for their potential role in the initiation and progression of cardiovascular diseases, such as coronary artery disease, heart failure and arrhythmias.

Figure 1

Funding Acknowledgement

Type of funding source: None

Small extracellular vesicles from epicardial fat of patients with atrial fibrillation induce inflammation, fibrosis and re-entrant arrhythmias

Background and aim

Epicardial fat (eFat) has been linked to atrial remodeling and fibrillation (AF). Small extracellular vesicles (sEVs) are heterogeneous membrane vesicles released by all cell types. They can both protect and damage tissues by the delivery of multiple different messengers. Surprisingly, the role of sEVs in the pathogenesis of AF has not been studied. Thus, we aimed to determine whether sEVs derived from eFat play a role in the pathogenesis of AF.

Methods and results

We collected eFat specimens from patients with and without chronic or paroxysmal AF undergoing open-heart surgery. Isolated eFat specimens were cut into small pieces and incubated as organ cultures. We isolated sEVs from the medium of the explant by differential ultra-centrifugation, high-density gradient or size exclusion chromatography (SEC), and characterized vesicle size distribution, morphology, specific markers, histology and molecular cargo. Immunostaining for macrophage accumulation, fibrosis and apoptosis confirmed the pro-inflammatory and pro-fibrotic properties of eFat sEVs from patients with AF (Fig. 1). eFat sEVs labeled with PKH26 were massively up taken by endothelial cells (Fig. 2). Real-time PCR showed an increased level of oxidative stress genes in endothelial cells. eFat sEVs from patients with AF caused more fibrosis after injection into rat hearts than those without AF. (Fig. 3). Finally, while eFat sEVs from patients with and without AF induced shorter action potential duration, only eFat sEVs from patients with AF induced sustained re-entry (rotor) in human induced pluripotent stem cell (iPS)-derived cardiomyocytes (Fig. 4)

Conclusion

We show, for the first time, that sEVs from eFat of patients with AF demonstrate unique pro-inflammatory, pro-fibrotic and pro-arrhythmic properties. Our findings suggest that eFat sEVs can induce cellular, molecular and electrophysiological remodeling that can subsequently lead to the development of AF.

Funding Acknowledgement

Type of funding source: None

The impact of COVID-19 pandemic on cardiac surgery in Israel

Background

Ever since the coronavirus disease 2019 (COVID-19) has become a pandemic, worldwide efforts are being made to “flatten the curve”. Israel was amongst the first countries to impose significant restrictions. As a result, cardiac surgeons have been required to scale down their routine practice, resulting in a significant reduction in the number of cardiac surgeries. The aim of this study is to characterize the impact of COVID-19 on cardiac surgery in Israel.

Methods

This is a retrospective observational study performed in two cardiac surgery departments in Israel and includes all patients who underwent cardiac surgery in March and April during the years 2019 and 2020. The patient cohort was divided into two groups based on the year of operation. Analysis of the patients’ baseline characteristics, operative data, and postoperative outcome, was performed.

Results

The 2019 group (n = 173), and the 2020 group (n = 108) were similar regarding their baseline characteristics, previous medical history, and rates of previous revascularization interventions. However, compared to the 2019 group, patients in the 2020 group were found to be more symptomatic (NYHA class IV; 2.4% vs. 6.2%, p = 0.007). While all patients underwent similar procedures, patients in the 2020 group had significantly longer procedural time (p < 0.001). In-hospital mortality rate was found to be significantly higher in group 2020 (13% vs. 5.2%, p = 0.037).

Conclusions

While the number of patients undergoing cardiac surgery declined during the outbreak period, the rate of surgical mortality increased. One explanation for this might be delayed hospital arrival.