Management of a Mycotic Right Coronary Artery Aneurysm With Contained Rupture.

Infected coronary artery aneurysm is a rare complication of bacteremia with significant risk of mortality. We describe a case where contained rupture had caused purulent pericarditis and an alternative surgical approach to management was required as aortocoronary bypass grafting was unfeasible. (Level of Difficulty: Advanced.).

Pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension: a systematic review.

Background: Pulmonary thromboendarterectomy (PTE) is the gold standard treatment for patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, the results are poorly quantified outside a few registry reports and several individual centers. Methods: A systematic review was performed searching five electronic databases assessing the outcomes for adult patients undergoing PTE for CTEPH. All articles that reported mortality data were included. Primary outcome measures were early/inpatient mortality; secondary outcomes were survival, pulmonary haemodynamics, morbidity and functional status following PTE for CTEPH. Results were pooled via a meta-analysis of proportions and meta-regression. Results: A total of 5,717 studies were identified, yielding sixty-one relevant papers. Thirty-day mortality ranged from 0.8% to 24.4%, and on meta-analysis was 8.4% [95% confidence interval (CI): 7.2-9.6%]. Mortality was noted to decrease with increasing center volume of PTE cases (P<0.01). Residual pulmonary hypertension was reported in 8.2% to 44.5% of patients. Conclusions: CTEPH is associated with acceptable short-term mortality and an improvement in pulmonary hemodynamics. With increasing volume of experience and ongoing developments over time peri-operative mortality continues to decrease.

Thoracic endovascular repair of chronic type B aortic dissection: a systematic review.

BACKGROUND: At present, the optimal management strategy for chronic type B aortic dissection (CTBAD) remains unknown, as equipoise remains regarding medical management versus endovascular treatment versus open surgery. However, the results over recent years of thoracic endovascular aortic repair (TEVAR) in CTBAD appear promising. The aim of this systematic review was to provide a comprehensive analysis of the available data reporting outcomes and survival rates for TEVAR in CTBAD. METHODS: Electronic searches of six databases were performed from inception to April 2021. All studies reporting outcomes, specifically 30-day mortality rates, for endovascular repair of CTBAD were identified. Relevant data were extracted, and a random-effects meta-analysis of proportions or means was performed to aggregate the data. Survival data were pooled using data derived from original Kaplan-Meier curves, which allows reconstruction of individual patient data. RESULTS: Forty-eight studies with 2,641 patients were identified. Early (<30 days) all-cause and aortic-related mortality rates were low at 1.6% and 0.5%, respectively. Incidence of retrograde type A dissection in the post-operative period was only 1.4%. There were also low rates of cerebrovascular accidents and spinal cord injury (1.1% and 0.9%, respectively). Late follow-up all-cause mortality was 8.0%, however, late aortic-related mortality was only 2.4%. Reintervention rates were 10.1% for endovascular and 6.7% for surgical reintervention. Pooled rates of overall survival at 1-, 3-, 5- and 10-year were 91.5%, 84.7%, 77.7% and 56.3%, respectively. CONCLUSIONS: The significant heterogeneity in the available evidence and absence of consensus reporting standards are important considerations and concern when interpreting the data. Evaluation of the evidence suggests that TEVAR for CTBAD is a safe procedure with low rates of complications. However, the optimal treatment strategy for CTBAD remains debatable and requires further research. Evidence from high-quality registries and clinical trials are required to address these challenges.

The Impact of COVID-19 on the Provision of Adult Cardiac Surgery at a Dedicated COVID Hospital in Australia.

BACKGROUND: Internationally, the response to the COVID-19 pandemic has resulted in fewer cardiac surgical procedures being performed and an increase in the proportion of non-elective cases. To date there has been no study examining the impact of COVID-19 on the provision of cardiac surgery in Australia. AIM: The aim of this study was to evaluate the impact that the COVID-19 pandemic has had on the provision of cardiac surgery in a single, large major cardiac centre and dedicated COVID-19 hospital. A retrospective cohort study was undertaken utilising prospectively collected data. METHODS: Prospectively collected patient and operative data was examined to assess whether there was a reduction in the number of cases performed and whether there was a difference in patient demographics, surgical procedures or case urgency. Data was examined from the period of COVID-restrictions in 2020 and compared with data from the same time period in 2019. RESULTS: From 3 March 2020 to 30 June 2020, 136 adults underwent cardiac surgery at our institution, representing an overall reduction in operative caseload of 21%. The largest impact was noticed in May and April and coincided with statewide restrictions on elective surgery. Surgical acuity was unchanged with 58% of operations classified as non-elective procedures performed during the index admission. There was a small non-significant increase in the proportion of isolated coronary artery bypass surgery and aortic valve surgeries performed. CONCLUSION: From March to June 2020 our local hospital response to the COVID-19 pandemic resulted in a reduction in cardiac surgery service delivery. No change was seen in the urgency or type of surgeries performed.

Contemporary outcomes of continuous-flow biventricular assist devices.

BACKGROUND: Significant right ventricular failure (RVF) complicating left ventricular assist device (LVAD) placement has been reported at 10-30%. Although primarily indicated for left ventricular failure, ventricular assist devices (VADs) have become utilized in a biventricular setup to combat right ventricular failure (RVF) following LVAD implantation. With the advent of continuous-flow LVADs (CF-LVADs) superseding their pulsatile predecessors, the shift towards CF-biventricular assist devices (CF-BiVADs) come with the prospect of improved outcomes over previous pulsatile BiVADs. We aim to review the literature and determine the outcomes of CF-BiVAD recipients. METHODS: A systematic review was performed to determine the outcomes of CF-BiVADs. Pre-operative demographics and device configuration data was collected. Primary outcomes evaluated were short-term survival, long-term survival, duration of support, and survival to transplant. Secondary outcomes evaluated included intensive care unit (ICU) and hospital length of stay (ICU-LOS and HLOS, respectively), pump thrombosis, pump exchange. Median and interquartile range was reported where appropriate. A major limitation was the likely overlap of cohorts across publications, which may have contributed to some selection bias. RESULTS: Of 1,282 screened, 12 publications were evaluated. Sample size ranged from 4 to 93 CF-BiVAD recipients, and follow-up ranged from 6 to 24 months. Mean age ranged from 34 to 52 years old. Forty-five percent of CF-BiVADs had right atrial (RA-) inflow cannulation, with the remaining being right ventricular (RV). Thirty-day survival was a median of 90% (IQR 82-97.8%) and 12-month survival was a median of 58.5% (IQR 47.5-62%). Where reported, rate of pump thrombosis (predominantly the right VAD) was a median of 31% (IQR 14-36%), although pump exchange was only 9% (IQR 1.5-12.5%). CONCLUSIONS: RVF post-LVAD implantation is a high morbidity and mortality complication. There is no on-label continuous-flow RVAD currently available. Thus, the modifications of LVADs for right ventricular support to combat pump thrombosis has resulted in various techniques. BiVAD recipients are predominantly transplant candidates, and complications of pump thrombosis and driveline infection whilst on wait-list are of great consequence. This study demonstrates the need for an on-label CF-BiVAD.

Contemporary outcomes of continuous-flow left ventricular assist devices-a systematic review.

BACKGROUND: End stage heart failure is a major cause of morbidity and mortality, and its prevalence is expected to rise with the ageing population. For suitable patients, orthotopic heart transplantation remains the gold standard therapy, however, a paucity of donor organs has led to the development of left ventricular assist devices (LVAD). These devices can be utilized as either a bridge-to-transplant (BTT) or as an alternative to heart transplantation. While these devices can prolong life and improve quality of life, they are associated with a significant number of adverse events. We aim to systematically review the literature to quantify survival and the incidence of adverse events following implantation of continuous-flow LVADs (cf-LVAD). METHODS: A systematic review was performed to determine outcomes following implantation of a cf-LVAD. Primary outcomes were survival and frequency of adverse events (such as bleeding, infection, thrombosis, stroke and right ventricular failure). Secondary outcomes included quality of life and assessment of functional status. RESULTS: Sixty-three studies reported clinical outcomes of 9,280 patients. Survival after cf-LVAD varied between studies. Industry-funded trials generally reported better overall survival than the single- and multi-center case series, which showed significant variation. The largest registry report documented twelve, twenty-four and forty-eight-month survival rates of 82%, 72% and 57% respectively. The most commonly reported adverse events were gastrointestinal bleeding (GIB), device-related infection, neurological events and right heart failure (RHF). Bleeding, RHF and infection were the most frequent complications experienced by those supported with cf-LVAD, occurring in up to 35%, 40% and 55% of patients, respectively. Quality of life as measured using the Kansas City Cardiomyopathy Questionnaire (KCCQ) and functional status as measured with the 6-minute walk test (6MWT) improved after cf-LVAD implantation with no decline evident two years after implantation. CONCLUSIONS: The paucity of donor hearts has led to the development of left-ventricular assist devices as a BTT or as a destination therapy (DT). Outcomes after cf-LVAD implantation are excellent, with short-term survival comparable to heart transplantation, but long-term survival remains limited due to the incidence of post-implantation adverse events. Despite these complications, quality of life and functional status improve significantly post-implantation and remain improved over the long-term. This study demonstrates the potential benefits of cf-LVAD therapy whilst also identifying adverse events as an area of increased morbidity and mortality.

Angiofibromatoid histiosarcoma of the pulmonary artery.

We describe the surgical management of a rare pulmonary angiomatoid fibrous histiosarcoma (AFH). A 62-year-old lady presented with shortness of breath and found to have a large left main pulmonary artery defect that was positron emission tomography-avid. Following discussion in a thoracic multidisciplinary team meeting it was deemed unsafe to biopsy considering its intravascular position. The patient proceeded to theatre for a left pneumonectomy. She was successfully discharged home by Day 7. On follow-up the patient is well, and free of malignancy. AFH is an incredibly rare form of sarcoma, and in particular in the thoracic region. We have demonstrated successful oncological resection of a rare intravascular lesion in the pulmonary artery.

Epidemiology of infective endocarditis before versus after change of international guidelines: a systematic review.

INTRODUCTION: All major international guidelines for the management of infective endocarditis (IE) have undergone major revisions, recommending antibiotic prophylaxis (AP) restriction to high-risk patients or foregoing AP completely. We performed a systematic review to investigate the effect of these guideline changes on the global incidence of IE. METHODS: Electronic database searches were performed using Ovid Medline, EMBASE and Web of Science. Studies were included if they compared the incidence of IE prior to and following any change in international guideline recommendations. Relevant studies fulfilling the predefined search criteria were categorized according to their inclusion of either adult or pediatric patients. Incidence of IE, causative microorganisms and AP prescription rates were compared following international guideline updates. RESULTS: Sixteen studies were included, reporting over 1.3 million cases of IE. The crude incidence of IE following guideline updates has increased globally. Adjusted incidence increased in one study after European guideline updates, while North American rates did not increase. Cases of IE with a causative pathogen identified ranged from 62% to 91%. Rates of streptococcal IE varied across adult and pediatric populations, while the relative proportion of staphylococcal IE increased (range pre-guidelines 16-24.8%, range post-guidelines 26-43%). AP prescription trends were reduced in both moderate and high-risk patients following guideline updates. DISCUSSION: The restriction of AP to only high-risk patients has not resulted in an increase in the incidence of streptococcal IE in North American populations. The evidence of the impact of AP restriction on IE incidence is still unclear for other populations. Future population-based studies with adjusted incidence of IE, AP prescription rates and accurate pathogen identification are required to delineate findings further in these other regions.

Changes in the Preterm Heart From Birth to Young Adulthood: A Meta-analysis.

CONTEXT: Preterm birth is associated with incident heart failure in children and young adults. OBJECTIVE: To determine the effect size of preterm birth on cardiac remodeling from birth to young adulthood. DATA SOURCES: Data sources include Medline, Embase, Scopus, Cochrane databases, and clinical trial registries (inception to March 25, 2020). STUDY SELECTION: Studies in which cardiac phenotype was compared between preterm individuals born at <37 weeks' gestation and age-matched term controls were included. DATA EXTRACTION: Random-effects models were used to calculate weighted mean differences with corresponding 95% confidence intervals. RESULTS: Thirty-two observational studies were included (preterm = 1471; term = 1665). All measures of left ventricular (LV) and right ventricular (RV) systolic function were lower in preterm neonates, including LV ejection fraction (P = .01). Preterm LV ejection fraction was similar from infancy, although LV stroke volume index was lower in young adulthood. Preterm LV peak early diastolic tissue velocity was lower throughout development, although preterm diastolic function worsened with higher estimated filling pressures from infancy. RV longitudinal strain was lower in preterm-born individuals of all ages, proportional to the degree of prematurity (R 2 = 0.64; P = .002). Preterm-born individuals had persistently smaller LV internal dimensions, lower indexed LV end-diastolic volume in young adulthood, and an increase in indexed LV mass, compared with controls, of 0.71 g/m2 per year from childhood (P = .007). LIMITATIONS: The influence of preterm-related complications on cardiac phenotype could not be fully explored. CONCLUSIONS: Preterm-born individuals have morphologic and functional cardiac impairments across developmental stages. These changes may make the preterm heart more vulnerable to secondary insults, potentially underlying their increased risk of early heart failure.

Acute pericarditis: a review of current diagnostic and management guidelines.

This review examined the relevance of chest pain, pericardial friction rub, pericardial effusion and ECG changes in regard to the diagnosis of acute pericarditis. It also assessed the evidence for the management and therapeutic guidelines, specifically nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine and corticosteroids. Overall, there appears to be a lack of research into pericarditis. The bulk of high-quality research seems to have been carried out prior to the publication of the European Society of Cardiology guidelines of 2015. Diagnostically, the current combination of symptoms, clinical signs and investigations offer reasonable criteria for diagnosis, but they are not a gold standard. Research into its therapeutic treatment options is required to address the effects of specific nonsteroidal anti-inflammatory drugs (NSAIDs).

Chelating agent-free, vapor-assisted crystallization method to synthesize hierarchical microporous/mesoporous MIL-125 (Ti).

Titanium-based microporous heterogeneous catalysts are widely studied but are often limited by the accessibility of reactants to active sites. Metal-organic frameworks (MOFs), such as MIL-125 (Ti), exhibit enhanced surface areas due to their high intrinsic microporosity, but the pore diameters of most microporous MOFs are often too small to allow for the diffusion of larger reactants (>7 Å) relevant to petroleum and biomass upgrading. In this work, hierarchical microporous MIL-125 exhibiting significantly enhanced interparticle mesoporosity was synthesized using a chelating-free, vapor-assisted crystallization method. The resulting hierarchical MOF was examined as an active catalyst for the oxidation of dibenzothiophene (DBT) with tert-butyl hydroperoxide and outperformed the solely microporous analogue. This was attributed to greater access of the substrate to surface active sites, as the pores in the microporous analogues were of inadequate size to accommodate DBT. Moreover, thiophene adsorption studies suggested the mesoporous MOF contained larger amounts of unsaturated metal sites that could enhance the observed catalytic activity.

Migration of silver nanoparticles from silver decorated graphene oxide to other carbon nanostructures.

Decoration of graphene oxide (GO) sheets with Ag nanoparticles has been demonstrated using a simple sonication technique. By changing the ratio between Ag-decorated-GO and GO, a series of Ag-decorated-GO samples with different Ag loadings were synthesized. These Ag-decorated-GO samples were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD) spectroscopy, thermal gravimetric analysis (TGA), and differential scanning calorimetric (DSC) techniques. TEM analysis showed that Ag nanoparticles were evenly distributed on GO sheets, and the size analysis of the particles using multiple TEM images indicated that Ag nanoparticles have an average size of 6-7 nm. TEM analysis also showed that Ag nanoparticles migrated from Ag-decorated-GO to later-added GO sheets. In XRD, all the Ag-decorated GO samples showed the characteristic peaks related to GO and face-centered-cubic (fcc) Ag. Thermal analysis showed peaks related to the combustion of graphitic carbon shifted to lower temperatures after GO sheets were decorated with Ag nanoparticles. In addition, further experiments performed using Ag-decorated-GO and multiwalled carbon nanotubes (MWNTs) confirmed that Ag nanoparticles migrated from Ag-decorated-GO to later-added carbon nanotubes without a noticeable coalescence of Ag nanoparticles.

CO2 capture and conversion with a multifunctional polyethyleneimine-tethered iminophosphine iridium catalyst/adsorbent.

Tunable, multifunctional materials able to capture CO2 and subsequently catalyze its conversion to formic acid were synthesized by the modification of branched polyethyleneimine (PEI) with an iminophosphine ligand coordinated to an Ir precatalyst. The molecular weight of the PEI backbone was an important component for material stability and catalytic activity, which were inversely related. The amine functionalities on PEI served three roles: 1) primary amines were used to tether the ligand and precatalyst, 2) amines were used to capture CO2 , and 3) amines served as a base for formate stabilization during catalysis. Ligand studies on imine and phosphine based ligands showed that a bidentate iminophosphine ligand resulted in the highest catalytic activity. X-ray photoelectron spectroscopy revealed that an increase in Ir 4f binding energy led to an increase in catalytic activity, which suggests that the electronics of the metal center play a significant role in catalysis. Catalyst loading studies revealed that there is a critical balance between free amines and ligand-metal sites that must be reached to optimize catalytic activity. Thus, it was found that the CO2 capture and conversion abilities of these materials could be optimized for reaction conditions by tuning the structure of the PEI-tethered materials.

Carbothermal reduction of Ti-modified IRMOF-3: an adaptable synthetic method to support catalytic nanoparticles on carbon.

This work describes a novel method for the preparation of titanium oxide nanoparticles supported on amorphous carbon with nanoporosity (Ti/NC) via the post-synthetic modification of a Zn-based MOF with an amine functionality, IRMOF-3, with titanium isopropoxide followed by its carbothermal pyrolysis. This material exhibited high purity, high surface area (>1000 m(2)/g), and a high dispersion of metal oxide nanoparticles while maintaining a small particle size (~4 nm). The material was shown to be a promising catalyst for oxidative desulfurization of diesel using dibenzothiophene as a model compound as it exhibited enhanced catalytic activity as compared with titanium oxide supported on activated carbon via the conventional incipient wetness impregnation method. The formation mechanism of Ti/NC was also proposed based on results obtained when the carbothermal reduction temperature was varied.

Graphene oxide: a nonspecific enhancer of cellular growth.

There have been multiple conflicting reports about the biocompatibility and antimicrobial activity of graphene oxide. To address this, we conducted a study to characterize the antimicrobial properties of graphene oxide (GO) and its biocompatibility with mammalian cells. When GO was added to a bacterial culture at 25 µg/mL, the results showed that bacteria grew faster and to a higher optical density than cultures without GO. Scanning electron microscopy indicated that bacteria formed dense biofilms in the presence of GO. This was shown by a large mass of aggregated cells and extracellular polymeric material. Bacterial growth on filters coated with 25 and 75 µg of GO grew 2 and 3 times better than on filters without GO. Closer analysis showed that bacteria were able to attach and proliferate preferentially in areas containing the highest GO levels. Graphene oxide films failed to produce growth inhibition zones around them, indicating a lack of antibacterial properties. Also, bacteria were able to grow on GO films to 9.5 × 10(9) cells from an initial inoculation of 1.0 × 10(6), indicating that it also lacks bacteriostatic activity. Thus, silver-coated GO films were able to produce clearing zones and cell death. Also, graphene oxide was shown to greatly enhance the attachment and proliferation of mammalian cells. This study conclusively demonstrates that graphene oxide does not have intrinsic antibacterial, bacteriostatic, and cytotoxic properties in both bacteria and mammalian cells. Furthermore, graphene oxide acts as a general enhancer of cellular growth by increasing cell attachment and proliferation.