Relationship between donor ejection fraction, left ventricular wall thickness and mortality in heart transplants recipients

This study explored the impact of donor left ventricular ejection fraction (EF) and left ventricular wall thickness (LVWT) on mortality among heart transplant (HTx) recipients. Utilizing data from the United Network for Organ Sharing (UNOS) registry, adult HTx recipients between 2006-2022 were analyzed. Patients were categorized into four groups based on donor EF(>50 % or ≤50 %) and LVWT(<1.4 cm or ≥1.4 cm). 21,012 patients were included. There were significant differences in baseline characteristics among the groups. Unadjusted mortality was 6.3 %, 6.0 %, 6.0 %, and 2.4 %(p=0.86) at 30-days; 16.2 %, 13.5 %, 16.8 %, and 7.3 %(p=0.08) at 1-year; and 32.2 %, 29.2 %, 35.4 %, and 29.0 %(p=0.18) at 5-years, respectively. In addition, adjusted mortality did not differ across the groups. There were no significant differences in recipient mortality in groups based on donor EF and LVWT. Expanding the donor selection criteria would allow for increase in the donor pool and assist in decreasing the mortality, while on the waitlist for HTx.

Heart Failure at Admission Complicating ST-Elevation Myocardial Infarction in a Middle-Income Country. Experience of the ARGEN-IAM-ST Registry

Despite advances in the management of ST-elevation myocardial infarction (STEMI), when associated with heart failure (HF) its prognosis remains ominous. This study assessed the differences in admission and mortality of HF complicating STEMI at admission (HFad) in a middle-income country. Data from the National Registry of STEMI of Argentina (ARGEN-IAM-ST) from January 1, 2016, to September 30, 2020, were analyzed. HFad was defined by the identification of Killip/Kimball ≥2 at admission. About 3174 patients were analyzed (22.3% had HFad). Patients with HFad were older, more often women, hypertensive, and diabetic. Received less reperfusion (87.6% vs 92.6%, P < 0.001) and had increased in-hospital mortality (28.4% vs 3.0%, P < 0.001). In multivariate analysis HFad was an independent predictor of death (OR: 4.88 [95%CI: 3.33-7.18], P < 0.001) and reperfusion adjusted to HFad was associated with lower mortality (OR: 0.57 [95%CI: 0.34-0.95], P = 0.03). HFad in STEMI is associated with a worse clinical profile, receives fewer reperfusion strategies, and carries a higher risk of in-hospital mortality while reperfusion reduces mortality.

Guesstimate of thymoquinone diversity in Nigella sativa L. genotypes and elite varieties collected from Indian states using HPTLC technique

Thymoquinone is a valuable metabolite derived from the Nigella sativa L. seeds and has a variety of therapeutic properties. Thymoquinone was estimated using n-hexane:ethyl acetate (8:2, v/v) green solvent system and computed at a wavelength of 254 nm using the high-performance thin-layer chromatography densitometry method in distinct varieties and genotypes congregated from different geographical regions. Genotype Ajmer Nigella-13 has the paramount thymoquinone content (247.60 µg/100 mg seed) followed by Ajmer Nigella 19 (244.5 µg/100 mg seed), while the lowest amount of thymoquinone was recorded in the genotype Ajmer Nigella-6 (42.88 µg/100 mg seed). The hierarchical cluster analysis found that the collected genotypes and elite varieties were classified into four broad clusters, and the identified chemotypes with elevated thymoquinone proportion were positioned in cluster D. Significant genotypic variation in thymoquinone content is available, that can be used in exploiting pharmaceutical applications of N. sativa L. as well as a breeding programme for specific metabolite improvement perspective.

Retrospective analysis of the impact of pre-transplant implantable cardioverter-defibrillator status on long-term prognosis in heart transplant patients

BACKGROUND

Sudden cardiac death (SCD) post-heart transplantation affects 8%-35% of patients; however, the risk profile remains to be completely elucidated. While pre-transplant ICDs are typically removed during transplantation, no information exists to suggest if this pre-transplant risk stratification is also associated with post-transplant outcomes. The objective of this study was to assess the impact of pre-transplant ICD status on long-term prognosis post-heart transplant.

METHODS

The United Network for Organ Sharing registry was queried for all adult heart transplant recipients from 2010 to 2018. Patients were categorized as with versus without ICD prior to heart transplantation. Survival was compared using Kaplan-Meier analysis. Proportional hazards regression analysis assessed the impact of ICDs adjusting for clinical and demographic covariates.

RESULTS

Of 19 026 patients included, 78.6% (n = 14 960) had received an ICD at time of registration. Patients with an ICD were older [54.9 (±11.6) years vs. 48.6 (±15.3) years, p < .001], less likely to be female [25.7% (n = 3842) vs. 31.2% (n = 1269), p < .001], and more commonly diabetic [29.3% (n = 4376) vs 23.5% (n = 954), p < .001]. Kaplan-Meier analysis showed no difference in unadjusted survival trajectory by ICD status (chi-square = .48, p = .49). Survival was unrelated to ICD status in the multivariable model (HR = .98; 95% CI .90-1.07).

CONCLUSIONS

Patients receiving an ICD pre-transplant had a higher prevalence of risk factors for SCD than non-ICD patients, yet ICD status prior to heart transplantation was not associated with a change in long-term prognosis post-heart transplantation.

Cardiopulmonary Injury in the Syrian Hamster Model of COVID-19

The Syrian hamster has proved useful in the evaluation of therapeutics and vaccines for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). To advance the model for preclinical studies, we conducted serial sacrifice of lungs, large pulmonary vessels, and hearts from male and female Syrian hamsters for days 1–4, and 8 post-infection (dpi) following infection with a high dose of SARS-CoV-2. Evaluation of microscopic lung histopathology scores suggests 4 and 8 dpi as prime indicators in the evaluation of moderate pathology with bronchial hyperplasia, alveolar involvement and bronchiolization being key assessments of lung disease and recovery, respectively. In addition, neutrophil levels, red blood cell count and hematocrit showed significant increases during early infection. We present histological evidence of severe damage to the pulmonary vasculature with extensive leukocyte transmigration and the loss of endothelial cells and tunica media. Our evidence of endothelial and inflammatory cell death in the pulmonary vessels suggests endothelialitis secondary to SARS-CoV-2 epithelial cell infection as a possible determinant of the pathological findings along with the host inflammatory response. Lastly, pathological examination of the heart revealed evidence for intracardiac platelet/fibrin aggregates in male and female hamsters on 8 dpi, which might be indicative of a hypercoagulative state in these animals.

Detection of cytomegalovirus disease by real-time quantitative PCR targeting immediate early gene (ppUL83) in different samples among post-renal-transplant recipients

Renal transplantation is a treatment option for end-stage renal disease (ESRD). Cytomegalovirus (CMV) infection was analysed among symptomatic and asymptomatic post-renal-transplant recipients (PRTRs). A total of 30 PRTRs were enrolled. DNA was extracted and quantitative real-time PCR for CMV (CMV R-Gene, France) targeting ppUL83 gene was performed on whole blood, urine and saliva. The detection rate of CMV was found to be 27% (n = 8) in different samples, including whole blood, urine and saliva. Among 30 PRTRs, 53% (n = 16) of the PRTRs did not shed virus in saliva. About 7% of CMV was detected only in saliva among PRTRs who were symptomatic.

Surgical considerations for the explantation of the Parachute left ventricular partitioning device and the implantation of the HeartMate II left ventricular assist device

Chronic heart failure is the leading cause of death in the world. With newer therapies, the burden of this disease has decreased; however, a significant number of patients remain refractive to existing therapies. Myocardial infarction often leads to ventricular remodeling and eventually contributes to heart failure. The Parachute™ (Cardiokinetix, Menlo Park, CA) is the first device designed for percutaneous ventricular restoration therapy, which reduces left ventricular volume and minimizes the risk of open surgical procedures. For the first time, we report a case of explantation of the Parachute ventricular partitioning device and transition to a HeartMate II™ left ventricular assist device and the surgical considerations for a successful outcome.

Successful heart transplantation using a donor heart afflicted by takotsubo cardiomyopathy

Takotsubo cardiomyopathy, also known as apical ballooning syndrome, stress cardiomyopathy, or broken heart syndrome, is a disease characterized by transient ventricular dysfunction in the absence of obstructive coronary artery disease. Herein, we present a case in which a heart with mild takotsubo cardiomyopathy was utilized as the donor organ for an orthotopic heart transplant.

Abstract 601: Circulating Platelet Aggregate Damages Endothelial Cells in Culture

Background: The presence of circulating endothelial cells (CECs) in systemic circulation might be an indicator of endothelial damage and/or denudation, and thus the body’s response to repair and revascularization. Thus, we hypothesized that aggregated platelets (AgPlts) can disrupt and denude the endothelium, and contribute to the presence of CEC and EC-derived particles (ECDP). In this study, we used endothelial cells and sheep carotid artery segments.

Methods: Endothelial cells (sheep aortic and human umbilical vein) were grown in glass tubes and tagged with/without 0.5 μm fluorescent beads. These glass tubes as well as sheep carotid artery segments were connected to a Mini-Pump Variable Flow System to study the effect of circulating AgPlts on the endothelium. ECs in glass tube/artery segment were exposed to medium alone, non-aggregated platelets (NAgPlts), AgPlts and 90 micron polystyrene beads at a flow rate of 20-85 ml/minute for various time intervals (0, 30 seconds, 1, and 5 min). Collected effluents were cultured and incubated for 72 hrs to analyze the growth potential of dislodged but intact ECs. Inflammatory genes of the damaged endothelium were analyzed by RT-PCR and the presence of ECDP was further assessed by western blot analysis using an antibody to human von Willebrand factor (VWF).

Results: No ECs and ECDP were observed in effluents collected after injecting medium alone or medium and NAgPlts, whereas AgPlts and Polybeads drastically dislodged ECs and released ECs and ECDP in effluents. There were no ECs and ECDP in samples collected at 0 and 30 seconds. However, the number of ECs and EDCP in samples collected at 1 and 5 minutes was proportionately increased. Effluents collected when endothelial cell damage was seen showed an increased presence of VWF as compared to control effluents.

Conclusion: Our study demonstrates that circulating AgPlts denude the endothelium and release ECs and ECDP. Direct mechanical disruption and shear stress caused by circulating AgPlts could be the underlying mechanism of the observed endothelial damage. Moreover, a major source of the CECs in the blood circulation could be the damaged endothelium.

Dysregulation of PTEN in cardiopulmonary vascular remodeling induced by pulmonary hypertension

Pulmonary hypertension (PH) is a disorder of lung vasculature characterized by arterial narrowing. Phosphatase-and-tensin homolog on chromosome 10 (PTEN), associated in the progression of multiple cancers, is implicated in arterial remodeling. However, the involvement of PTEN in PH remains unclear. The objective of the present study was to determine the role of PTEN in pulmonary vascular remodeling using established models of PH. The study used rat models of PH, induced by monocrotaline (MCT) administration (60 mg/kg) or continuous hypoxic exposure (10% oxygen) for 3 weeks. Pulmonary artery smooth muscle cells (SMCs) were used for in vitro confirmation. Development of PH was verified by hemodynamic, morphological and histopathology analyses. PTEN and key downstream proteins in pulmonary and cardiac tissues were analyzed by western blotting and RT-PCR. PTEN was significantly decreased (MCT, 53%; Hypoxia, 40%), pAkt was significantly increased (MCT, 42%; Hypoxia, 55%) in tissues of rats with PH. Similar results were observed in SMCs exposed to hypoxia (1% oxygen) for 48 h. Ubiquitination assay showed that PTEN degradation occurs via proteasomal degradation pathway. Western blotting demonstrated a significant downregulation of cell-cycle regulatory proteins p53 and p27, and upregulation of cyclin-D1 in the lungs of both models. The results showed that PTEN-mediated modulation of PI3K pathway was independent of the focal adhesion kinase and fatty acid synthase. The study, for the first time, established that PTEN plays a key role in the progression of pulmonary hypertension. The findings may have potential for the treatment of pulmonary hypertension using PTEN as a target.

Type of Valvular Heart Disease Requiring Surgery in the 21st Century: Mortality and Length-of-Stay Related to Surgery

Aim:

While the incidence of rheumatic heart disease has declined dramatically over the last half-century, the number of valve surgeries has not changed. This study was undertaken to define the most common type of valvular heart disease requiring surgery today, and determine in-hospital surgical mortality and length-of-stay (LOS) for isolated aortic or mitral valve surgery in a United States tertiary-care hospital.

Methods:

Patients with valve surgery between January 2002 to June 2008 at The Ohio State University Medical Center were studied. Patients only with isolated aortic or mitral valve surgery were analyzed.

Results:

From 915 patients undergoing at least aortic or mitral valve surgery, the majority had concomitant cardiac proce-dures mostly coronary artery bypass grafting (CABG); only 340 patients had isolated aortic (n=204) or mitral (n=136) valve surgery. In-hospital surgical mortality for mitral regurgitation (n=119), aortic stenosis (n=151), aortic insufficiency (n=53) and mitral stenosis (n=17) was 2.5% (replacement 3.4%; repair 1.6%), 3.9%, 5.6% and 5.8%, respectively (p=NS). Median LOS for aortic insufficiency, aortic stenosis, mitral regurgitation, and mitral stenosis was 7, 8, 9 (replacement 11.5; repair 7) and 11 days, respectively (p<0.05 for group). In-hospital surgical mortality for single valve surgery plus CABG was 10.2% (p<0.005 compared to single valve surgery).

Conclusions:

Aortic stenosis and mitral regurgitation are the most common valvular lesions requiring surgery today. Surgery for isolated aortic or mitral valve disease has low in-hospital mortality with modest LOS. Concomitant CABG with valve surgery increases mortality substantially. Hospital analysis is needed to monitor quality and stimulate improvement among Institutions.

Pulmonary hypertension secondary to left-heart failure involves peroxynitrite-induced downregulation of PTEN in the lung

Pulmonary hypertension (PH) that occurs after left-heart failure (LHF), classified as Group 2 PH, involves progressive pulmonary vascular remodeling induced by smooth muscle cell (SMC) proliferation. However, mechanisms involved in the activation of SMCs remain unknown. The objective of this study was to determine the involvement of peroxynitrite and phosphatase-and-tensin homolog on chromosome 10 (PTEN) in vascular SMC proliferation and remodeling in the LHF-induced PH (LHF-PH). LHF was induced by permanent ligation of left anterior descending coronary artery in rats for 4 weeks. MRI, ultrasound, and hemodynamic measurements were performed to confirm LHF and PH. Histopathology, Western blot, and real-time polymerase chain reaction analyses were used to identify key molecular signatures. Therapeutic intervention was demonstrated using an antiproliferative compound, HO-3867. LHF-PH was confirmed by significant elevation of pulmonary artery pressure (mean pulmonary artery pressure/mm Hg: 35.9±1.8 versus 14.8±2.0, control; P<0.001) and vascular remodeling. HO-3867 treatment decreased mean pulmonary artery pressure to 22.6±0.8 mm Hg (P<0.001). Substantially higher levels of peroxynitrite and significant loss of PTEN expression were observed in the lungs of LHF rats when compared with control. In vitro studies using human pulmonary artery SMCs implicated peroxynitrite-mediated downregulation of PTEN expression as a key mechanism of SMC proliferation. The results further established that HO-3867 attenuated LHF-PH by decreasing oxidative stress and increasing PTEN expression in the lung. In conclusion, peroxynitrite and peroxynitrite-mediated PTEN inactivation seem to be key mediators of lung microvascular remodeling associated with PH secondary to LHF.