Byrom MJ, Sivakumaran Y, Vallely MP, Wilson MK, Bannon PG
J. Thorac. Cardiovasc. Surg. 2014 Dec;
PMID: 25626952
Neurologic Injury and Protection in Adult Cardiac and Aortic Surgery
Seco M, Edelman JJ, Boxtel BV, Forrest P, Byrom MJ, Wilson MK, Fraser J, Bannon PG, Vallely MP
J. Cardiothorac. Vasc. Anesth. 2015 Feb;29(1):185-195
PMID: 25620144
Abstract
Comparative transcriptome profiling in human bicuspid aortic valve disease using RNA-sequencing
Padang R, Bagnall RD, Tsoutsman T, Bannon PG, Semsarian C
Physiol. Genomics 2014 Dec;:physiolgenomics.00115.2014
PMID: 25547111
Abstract
Intrinsic valvular degeneration and dysfunction is the most common complication of bicuspid aortic valve (BAV) disease. Phenotypically, it ranges from calcific aortic stenosis to redundant or prolapsing regurgitant leaflets. The underlying molecular mechanism underpinning phenotype heterogeneity of valvular degeneration in BAV is poorly understood. We used RNA-sequencing to identify genes and pathways responsible for valvular degeneration in BAV, compared to tricuspid aortic valve (TAV). Comparative transcriptome analysis on total RNA of aortic valve tissues of patients with diseased BAV (n=5) and calcified TAV (n=3). A total of 59 and 177 genes were significantly up- and downregulated, respectively, in BAV compared to TAV. Hierarchical clustering indicated heterogeneity within the BAV group, separating those with heavy calcification (BAVc) from those with redundant leaflets and/or minimal calcification (BAVr). Interestingly, the gene expression profile of the BAVc group closely resembled the TAV, with shared up- and downregulation of inflammatory and NOTCH1 signaling pathways, respectively. Downregulation of matrix protease ADAMTS9 and protein aggrecan were observed in BAVr compared to TAV. Dysregulation of fetal gene programs were also present, with notable downregulation of SEMA6B and SEMA3F in BAVr and BAVc compared to TAV, respectively. Upregulation of TBX20 was observed exclusively in BAVr compared to BAVc. In conclusion, diverging molecular mechanisms underpin phenotype heterogeneity of valvular degeneration in BAV and data from the present study suggest that there may be shared mechanisms leading to calcification in BAV and TAV. Recognition of these pathways is fundamental to improve our understanding of the molecular basis of human BAV disease.
Position Statement for the Operator and Institutional Requirements for a Transcatheter Aortic Valve Implantation (TAVI) Program
Walters DL, Webster M, Pasupati S, Walton A, Muller D, Stewart J, Williams M, MacIsaac A, Scalia G, Wilson M, Gamel AE, Clarke A, Bennetts J, Bannon P
Heart Lung Circ 2014 Oct;
PMID: 25488705
Abstract
The Cardiac Society of Australia and New Zealand (CSANZ) and the Australia and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) have joined together to provide recommendations for institutions and individual operators to assess their ability to initiate and maintain a transcatheter valve program. Transcatheter aortic valve replacement has been developed as an alternative to traditional surgical replacement of the aortic valve in high risk patients, particularly the frail elderly. The position paper has endorsed the important role of a multi-disciplinary “Heart Team” in selecting patients for TAVI as fundamental to the establishment of a successful program. The paper outlines recommendations for the cardiologist to have a background in structural intervention and the surgeon to have experience in high-risk aortic valve replacement. It is further recommended that TAVI programs be established in high volume cardiac surgical centres where on site valve surgery is performed. The paper is intended to provide guidance to individual operators and prospective institutions considering the establishment of a successful TAVI program.
Replacement of the aortic root with a composite valve-graft conduit: risk factor analysis in 246 consecutive patients
Woldendorp K, Starra E, Seco M, Hendel PN, Jeremy RW, Wilson MK, Vallely MP, Bannon PG
Heart Lung Circ 2014 Dec;23(12):1187-93
PMID: 25038031
Abstract
BACKGROUND: Composite valve-graft (CVG) replacement of the aortic root is a well-studied and recognised treatment for various aortic root conditions, including valvular disease with associated aortopathy. There have been few previous studies of the procedure in large numbers in an Australian setting.
METHOD: From January 2006 to June 2013, 246 successive patients underwent CVG root replacements at our institution. Mean age was 56.8 years, 85.4% were male, and 87 had evidence of bicuspid aortic valve. Indications for operation included ascending aortic aneurysm in 222 patients, annuloaortic ectasia in 67 patients, and aortic dissection in 38 patients.
RESULTS: The overall unit 30-day mortality was 5.7%, including: elective 30-day mortality of 2.2%, and emergent 30-day mortality of 17.2%. Statistically significant multivariate predictors of 30-day mortality were: acute aortic dissection (OR=20.07), peripheral vascular disease (OR=11.17), new ventricular tachycardia (OR=30.17), re-operation for bleeding (OR=14.42), concomitant mitral stenosis (OR=68.30), and cerebrovascular accident (OR=144.85).
CONCLUSIONS: Low postoperative mortality in our series matches closely with results from similar sized international studies, demonstrating that this procedure can be performed with low risk in centres with sufficient experience in the operative procedure.
The Freestyle Aortic Bioprosthesis: A Systematic Review
Sherrah AG, Edelman JJ, Thomas SR, Brady PW, Wilson MK, Jeremy RW, Bannon PG, Vallely MP
Heart Lung Circ 2014 Dec;23(12):1110-1117
PMID: 25047283
Abstract
BACKGROUND: The Medtronic Freestyle bioprosthesis (FSB) provides an alternative to other prostheses for both aortic valve and aortic root surgery. This paper is a systematic review of the post-operative outcomes in patients with aortic valve and/or aortic root disease following FSB implantation.
METHODS: Electronic databases were searched for primary analysis, prospective randomised studies comparing the FSB with an alternative aortic prosthesis were included. Additionally, case series that included data for at least 100 individual operated patients were used for secondary analysis.
RESULTS: Among three identified randomised studies, 199 FSB cases were compared with homografts, and stented and an alternative stentless bioprosthesis. The FSB showed comparable hospital mortality (4.5% vs 5.3%) and eight-year actuarial survival (80±5.0% versus 77±6.0%) with the homograft (respectively) and comparable reduction in left ventricular mass index relative to other prosthesis types. Over 6000 individual patients were included in the selected 15 case series. Weighted mean operative mortality, neurological event rate and five-year actuarial survival was 5.2%, 5.5% and 77.8%, respectively.
CONCLUSION: The FSB performed comparably against alternative prostheses regarding in-hospital mortality, long-term survival and reduction in left ventricular mass index. Included case series demonstrated robust post-operative outcomes in both the short and long term.
Should clopidogrel be discontinued before coronary artery bypass grafting for patients with acute coronary syndrome? A systematic review and meta-analysis
Cao C, Indraratna P, Ang SC, Manganas C, Park J, Bannon PG, Yan TD
J. Thorac. Cardiovasc. Surg. 2014 Dec;148(6):3092-8
PMID: 24954178
Abstract
OBJECTIVE: Patients presenting with acute coronary syndrome (ACS) are treated with dual antiplatelet agents, including aspirin and clopidogrel, to prevent mortality and recurrent ischemia. However, those who require coronary artery bypass grafting (CABG) could have increased postoperative bleeding and bleeding-related adverse outcomes. The current guidelines on clinical management differ significantly. The present meta-analysis examined the evidence for clopidogrel in the treatment of patients presenting with ACS requiring CABG, with a focus on the timing of medication cessation before surgery.
METHODS: A systematic review of 9 electronic databases was performed to identify all relevant studies with comparable outcomes for patients with ACS treated with clopidogrel before CABG. The endpoints included reoperation, major bleeding, mortality, and a composite endpoint of mortality and recurrent myocardial infarction.
RESULTS: Five relevant studies were identified according to the predefined selection criteria. Patients who had received clopidogrel had a significantly lower incidence of composite endpoints than those who had not. However, patients who underwent CABG < 5 days after the last dose of clopidogrel had a significantly greater incidence of reoperation, major bleeding, and combined adverse outcomes than those who had had a washout period >5 days.
CONCLUSIONS: The results from the present meta-analysis suggest that patients who present with ACS should be treated with dual antiplatelet therapy, including clopidogrel. However, for patients subsequently referred for CABG, a minimum washout period of 5 days should be observed to minimize perioperative bleeding and bleeding-related complications, unless emergency indications exist. These results differ from those of previous studies and guidelines.
Transcatheter Valve-in-Valve Replacement in Complex Cyanotic Congenital Heart Disease With a Single Ventricle
Martínez GJ, Ng BH, Wilson MK, Pasupati S, Robinson DA, Cartwright BL, Adams MR, Celermajer DS, Ng MK
JACC Cardiovasc Interv 2014 Oct;7(10):e133-5
PMID: 25240545
Abstract
Prognostic coronary surgery in a case of malignant mesothelioma previously managed with trimodality treatment
Dhurandhar V, Robinson BM, McCaughan BC, Bulliard C, Bannon PG
Heart Lung Circ 2014 Oct;23(10):e198-201
PMID: 24996387
Abstract
We report a case of malignant pleural mesothelioma treated with trimodality treatment. At three years after the extrapleural pneumonectomy, coronary artery revascularisation surgery for NSTEMI was performed in view of favourable long term prognostic and survival outcome. Five years following pleuropneumonectomy there is no clinical or radiological evidence of mesothelioma and the patient remains free of cardiac symptoms.
Extracorporeal membrane oxygenation for very high-risk transcatheter aortic valve implantation
Seco M, Forrest P, Jackson SA, Martinez G, Andvik S, Bannon PG, Ng M, Fraser JF, Wilson MK, Vallely MP
Heart Lung Circ 2014 Oct;23(10):957-62
PMID: 24954708
Abstract
BACKGROUND: Transcatheter aortic valve implantation (TAVI) can cause profound haemodynamic perturbation in the peri-operative period. Veno-arterial extracorporeal membrane oxygenation (ECMO) can be used to provide cardiorespiratory support during this time, either prophylactically or emergently.
METHOD: 100 TAVI procedures were performed between 2009 and 2013 in our institution. ECMO was used in 11 patients, including eight prophylactic and three rescue cases. Rescue ECMO was required for ventricular fibrillation after valvuloplasty, and aortic annulus rupture. The criteria for prophylactic ECMO included heart failure requiring stabilisation pre-TAVI, haemodynamic instability with balloon aortic valvuloplasty performed to improve heart function pre-TAVI, moderate or severe left and/or right ventricular failure, or borderline haemodynamics at procedure. Differences in preoperative characteristics and postoperative outcomes between ECMO and non-ECMO TAVI patients were compared, and significant results were further assessed controlling for EuroSCORE.
RESULTS: Compared to TAVI patients who did not require ECMO, ECMO patients had significantly higher mean EuroSCORE (51 vs. 30%, p.05). ECMO patients were more likely to develop acute renal failure than non-ECMO patients (36 vs. 8%, p<.05), which was most likely due to haemodynamic collapse and end-organ dysfunction in patients that required ECMO rescue.
CONCLUSIONS: Instituting prophylactic ECMO in selected very high-risk patients may help avoid consequences of intra-operative complications and the need for emergent rescue ECMO.
