1292 Aortic Valve Neocuspidization Using Glutaraldehyde-Treated Autologous Pericardium: A Literature Review

Background

Aortic Valve Neocuspidization using glutaraldehyde-treated autologous pericardium was first performed by Ozaki et al. in 2007. This technique has become an alternative to tissue and mechanical valve as long-term anticoagulation is not required and shows promising midterm results and durability.

Method

A comprehensive search was performed on the major database using search terms “Ozaki technique” AND “Aortic Valve Neocuspidization” AND “AV Neocuspidization” AND “Autologous pericardium” AND “glutaraldehyde-treated autologous pericardium”. Articles up to 1st of August 2020 were included in this study.

Results

A total of 9 studies with a total of 1342 patients were included. The mean age was 67.36 and 54.23% were male. 66.32% and 23.92% of patients had aortic stenosis and aortic regurgitation, respectively. 66% of patients had a native tricuspid aortic valve and 31.37 % patients’ native aortic valve was bicuspid. Three studies reported their experience performing Aortic Valve Neocuspidization via mini sternotomy.

Conclusions

Aortic Valve Neocuspidization is an alternative to biological and mechanical prostheses for surgical aortic valve replacement. The short and mid-term outcome are comparable without the need for long term oral anticoagulation. Long term follow-up data is required for this novel approach to be widely adopted.

624 Twenty Years' Experience of Coronary Artery Bypass Grafting in Patients with Reduced Left Ventricular Ejection Fraction

Aim

Reduced Left Ventricular Ejection Fraction (LVEF) is a risk factor for patients undergoing Coronary Artery Bypass Grafting (CABG). The aim of our study was to compare short term outcomes and long-term (20 years) survival rates of patients with reduced LVEF undergoing CABG.

Method

Between 1996 and 2015, 5016 patients with reduced LVEF underwent CABG: 1024 (20.4%) had poor LVEF (< 30%) and 3992 (79.6%) had moderate LVEF dysfunction (30-49%). After excluding reoperations and combined procedures, the final sample consisted of 3867 patients. Our primary outcomes were early in-hospital mortality and complications and long-term survivals.

Results

In-hospital mortality rate was 4.4%, stroke rate 1.4% and renal failure 2.9%. Survival rates at 1, 5, 10 and 20 years were 91.1%, 76.7%, 55.1% and 22.1% respectively. Additive Euroscore and Logistic Euroscore (AUC 0.78) is less reliable compared to normal LV patients. Complete revascularization was an independent factor affecting long term survival (HR: 0.85). No difference between OPCABG and ONCABG were found.

Conclusions

CABG is still safe and most likely the best treatment option for patients with reduced LVEF. Completeness of revascularization plays an important role in long term outcomes while OPCABG has no significant advantages. Euroscore has a reduced predicting ability in this group of patients.

1269 Five Year Propensity Matched Outcomes of Minimally Invasive vs Conventional Isolated Aortic Valve Surgery

Aim

To analyse the early and mid-term outcomes of the patients undergoing conventional isolated aortic valve replacement (CAVR) versus minimally invasive isolated aortic valve replacement (MIAVR).

Method

This is a single centre retrospective study involving 653 patients who underwent isolated aortic valve replacement either via CAVR (n = 516) or MIAVR (n = 137) between August 2015 and March 2020. Using pre-operative characteristics, patients were propensity matched (PM) to produce 114 matched pairs. Assessment of peri-operative outcomes, early and mid-term survival and echocardiographic parameters was performed.

Results

PM analysis showed the larger sized aortic valve prosthesis were inserted in the MIAVR group (22.8±2.5mm) compared to CAVR group (22.0±2.2mm)(p = 0.010). CPB time was longer with MIAVR (94.4±19.5mins) compared to CAVR (83.1 + 33.3; p = 0.003). There were no differences in the early post-operative complications and mortality between the two groups. Follow-up echocardiographic data showed significant difference in mean aortic valve gradients between CAVR and MIAVR groups (17.3±8.2mmHg and13.0±5.1mmHg, respectively; p = 0.001). There was no significant difference between CAVR and MIAVR in the mid-term survival at 3 years. (log-rank test p = 0.314).

Conclusions

This study found that larger aortic valve sizes with lower mean gradients are being implanted in the MIAVR group. Despite the longer CPB time in the MIAVR group, there was no significant difference in the early complications, mortality, and mid-term survival between MIAVR and CAVR. Further studies will be required to analyse the long-term survival.

586 Subxiphoid Incisional Hernias Post Median Sternotomy: A Literature Review

Background

Subxiphoid incisional hernias are one of the complications following a median sternotomy, a surgical procedure to provide access to the mediastinum. Incidence has been reported between 1-4%, although the true incidence is not well known due to its asymptomatic nature.

Method

A comprehensive search was performed on multiple sites. Keywords included “incisional hernia OR Subxiphoid hernia” AND “Median sternotomy OR Cardiac Surgery OR Coronary artery bypass graft OR Transplant OR Valve replacement”. Articles up to 1st of August 2020 were included in this study.

Results

8 articles were included in the study, with a total number of 132 patient identified. The incidence ranged from 0.81% to 3.44%. There was a mixture of repair method and follow up period reported. Recurrence post-repair ranged from 10% to 43%.

Conclusions

Subxiphoid incisional hernias are rare, however, remain challenging to manage. A mixture of open and laparoscopic techniques was reported with a mixed recurrence or failure rate. Further work should be done with a large patient cohort comparing both the open and laparoscopic technique.

Severe Asthma Toolkit: an online resource for multidisciplinary health professionals-needs assessment, development process and user analytics with survey feedback

OBJECTIVES

Severe asthma imposes a significant burden on individuals, families and the healthcare system. New treatment and management approaches are emerging as effective options for severe asthma. Translating new knowledge to multidisciplinary healthcare professionals is a priority. We developed 'The Severe Asthma Toolkit' (https://toolkit.severeasthma.org.au) to increase awareness of severe asthma, provide evidence-based resources and support decisionmaking by healthcare providers.

SETTING

Roundtable discussions and a survey of Australians clinicians were conducted to determine clinician preferences, format and content for a severe asthma resource.

PARTICIPANTS

A reference group from stakeholder and consumer bodies and severe asthma experts provided advice and feedback. A multidisciplinary team of international experts was engaged to develop content. Written content was based on up-to-date literature. Peer and editorial review were performed to finalise content and inform web design. Website design focused on user experience, navigation, engagement, interactivity and tailoring of content for a clinical audience.

RESULTS

A web-based resource was developed. Roundtable discussions and a needs assessment survey identified the need for dedicated severe asthma management resources to support skills training. The end-product, which launched 26 March 2018, includes an overview of severe asthma, diagnosis and assessment, management, medications, comorbidities, living with severe asthma, establishing a clinic, paediatrics/adolescents and clinical resources. Analytics indicate access by users worldwide (32 169 users from 169 countries). User survey results (n=394) confirm access by the target audience (72% health professionals), who agreed the toolkit increased their knowledge (73%) and confidence in managing severe asthma (66%), and 75% are likely to use the resource in clinic.

CONCLUSIONS

The Severe Asthma Toolkit is a unique, evidence-based internet resource to support healthcare professionals providing optimal care for people with severe asthma. It is a comprehensive, accessible and independent resource developed by leading severe asthma experts to improve clinician knowledge and skills in severe asthma management.

Upper Airway Cell Transcriptomics Identify a Major New Immunological Phenotype with Strong Clinical Correlates in Young Children with Acute Wheezing

Asthma exacerbations are triggered by rhinovirus infections. We employed a systems biology approach to delineate upper-airway gene network patterns underlying asthma exacerbation phenotypes in children. Cluster analysis unveiled distinct IRF7^hi versus IRF7^lo molecular phenotypes, the former exhibiting robust upregulation of Th1/type I IFN responses and the latter an alternative signature marked by upregulation of cytokine and growth factor signaling and downregulation of IFN-γ. The two phenotypes also produced distinct clinical phenotypes. For IRF7^lo children, symptom duration prior to hospital presentation was more than twice as long from initial symptoms (p = 0.011) and nearly three times as long for cough (p < 0.001), the odds ratio of admission to hospital was increased more than 4-fold (p = 0.018), and time to recurrence was shorter (p = 0.015). In summary, our findings demonstrate that asthma exacerbations in children can be divided into IRF7^hi versus IRF7^lo phenotypes with associated differences in clinical phenotypes.

Prospective Assessment of Rhinovirus Symptoms and Species Recurrence in Children With and Without an Acute Wheezing Exacerbation

To assess if the difference in species-specific immune response to RV-C correlates with a higher frequency of reinfection, shorter time to reinfection, or different symptom severity than infections with RV-A or RV-B. Forty-three patients were enrolled of which 34 were successfully tracked longitudinally over 3 months, with nasal swabs and symptom questionnaires provided every 2 weeks to identify rhinovirus (RV) strains and the concurrent symptomatology. No difference was found in the time to reinfection with an RV species between RV-C and RV-A or RV-B (p = 0.866). There was a trend toward more rapid reinfection with the same species in RV-C than RV-A (55.1 days vs. 67.9 days), but this failed to reach statistical significance (p = 0.105). RV infections were generally associated with only minor symptoms, with rhinorrhea being the only significantly associated symptom (p = 0.01). RV-C was shown to have higher levels of lethargy and wheeze than other RV species. Time to reinfection with subsequent RV is not influenced by the species of the preceding RV.