Publications (22)57.24 Total impact
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Article: Does the addition of a radial artery graft improve survival after higher risk coronary artery bypass grafting? A propensity-score analysis of a multicentre database.
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ABSTRACT: OBJECTIVES: The use of the radial artery as a second arterial graft during coronary surgery has grown in popularity due to high patency and low harvest site complication rates. We sought to assess whether higher risk patients derive prognostic benefit. METHODS: From 2001 to 2009, 11 388 patients underwent isolated primary multivessel coronary surgery. We identified a higher risk subgroup (n = 2581) according to emergent status, coronary instability, low ejection fraction and/or aortic counterpulsation. Among these, 1832 (71%) received at least one radial artery graft in addition to a left internal thoracic artery (LITA). The remaining 749 (29%) received LITA and veins only. RESULTS: Patients not receiving a radial artery were more likely to be elderly, female, have poor left ventricular function or be of emergent status. These patients experienced higher unadjusted 30-day mortality (radial: 2% vs vein: 8%, P < 0.0001) with lower unadjusted 7-year survival (80 ± 1.3 vs 67 ± 2.4%, P < 0.0001). Subsequently, 515 patients in the radial group were propensity-matched to 515 receiving LITA + veins (mean logistic EuroSCORE, radial: 11.6 ± 9.7% vs vein: 11.6 ± 10.3%, P = 0.99). At 30 days, there were comparable rates of mortality (radial: 4% vs vein: 3%, P > 0.99), stroke (1 vs 1%, P > 0.99), myocardial infarction (1 vs 2%, P = 0.79), and any morbidity/mortality (34 vs 35%, P = 0.95). At 7 years, survival rates between the radial and vein groups were similar (radial: 75 ± 2.6% vs vein: 74 ± 2.9%, P = 0.65). CONCLUSIONS: Patients with the greatest coronary instability, urgency of surgery or impairment of ventricular function are not disadvantaged in early outcomes or mid-term survival by the use of only a single arterial graft.European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 03/2013; · 2.40 Impact Factor -
Article: Impact of smoking status on early and late outcomes after isolated coronary artery bypass graft surgery.
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ABSTRACT: BACKGROUND: There are limited data on the impact of smoking status on outcomes after isolated coronary artery bypass graft (CABG) surgery. METHODS: Data obtained prospectively between June 2001 and December 2009 by the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database Program were retrospectively analyzed. Demographic and operative data were compared between patients who were non-smokers, previous smokers, and current smokers. The independent impact of smoking status on 14 short-term complications and long-term mortality was determined using binary logistic and Cox regression, respectively. RESULTS: Isolated CABG surgery was performed in 21 534 patients; smoking status was recorded in 21486 (99.8%). Of these, 7023 (32.6%) had no previous smoking history, 11183 (59.1%) were previous smokers, and 3290 (15.2%) were current smokers. The 30-day mortality rate was 1.8% in non-smokers, 1.5% in previous smokers, and 1.5% in current smokers (p=NS). The incidence of peri-operative complications was generally similar in the three groups, but current smokers were at an increased risk of pneumonia (p<0.001), and multisystem failure (p=0.003). The mean follow-up period for this study was 37 months (range, 0-106 months). After adjusting for differences in patient variables, the incidence of late mortality was higher in previous smokers [hazard ratio (HR), 1.73; 95% confidence interval (CI), 1.47-2.05; p<0.001] or current smokers (HR, 1.41; 95% CI, 1.26-1.59; p<0.001) compared to non-smokers. CONCLUSION: Smoking status is not associated with early mortality after isolated CABG. It is, however, associated with an increased risk of pulmonary complications and reduced long-term survival.Journal of Cardiology 02/2013; · 1.28 Impact Factor -
Dataset: 15 editorial comment
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Article: Postoperative Atrial Fibrillation After Isolated Aortic Valve Replacement: A Cause for Concern?
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ABSTRACT: BACKGROUND: Several studies have shown that postoperative atrial fibrillation (POAF) is associated with poorer short-term and long-term outcomes after general cardiac operations. There is, however, a paucity of data on the impact of POAF on outcomes after isolated aortic valve replacement (AVR). METHODS: Data for all patients undergoing isolated first-time AVR between June 2001 and December 2009 was obtained from the Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) National Cardiac Surgery Database Program and a retrospective analysis was conducted. Preoperative characteristics, early postoperative outcome, and late survival were compared between patients in whom POAF developed and those in whom it did not. Propensity score matching was performed to correct for differences between the 2 groups. RESULTS: Excluding patients with preoperative arrhythmia, isolated first-time AVR was performed in 2,065 patients. POAF developed in 725 (35.1%) of them. Patients with POAF were significantly older (mean age, 72 versus 65 years; p < 0.001) and presented more often with comorbidities, including hypertension, respiratory disease, and hypercholesterolemia (all p < 0.05). From the initial study population, 592 propensity-matched patient pairs were derived; the overall matching rate was 81.7%. In the matched groups, 30-day mortality was not significantly different between the POAF and non-POAF groups (1.5% versus 1%; p = 0.48). Patients with POAF were, however, at an independently increased risk of perioperative complications, including new renal failure, gastrointestinal complications, and 30-day readmission (p < 0.05). Seven-year mortality was not significantly different between POAF and non-POAF groups (78% versus 83%; p = 0.63). CONCLUSIONS: POAF is a risk factor for short-term morbidity but is not associated with a higher rate of early or late mortality after isolated AVR.The Annals of thoracic surgery 11/2012; · 3.74 Impact Factor -
Article: Does Preoperative Atrial Fibrillation Portend a Poorer Prognosis in Patients Undergoing Isolated Aortic Valve Replacement? A Multicentre Australian Study.
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ABSTRACT: BACKGROUND: Preoperative atrial fibrillation (preop-AF) has been associated with poorer early and late outcomes after cardiac surgery. Few studies, however, have evaluated the impact of preop-AF on early and late outcomes after isolated aortic valve replacement (AVR). METHODS: Data obtained prospectively between June 2001 and December 2009 by the Australian and New Zealand Society of Cardiac and Thoracic Surgeons National Cardiac Surgery Database Program was retrospectively analyzed. Patients who underwent concomitant atrial arrhythmia surgery/ablation were excluded. Demographic and operative data were compared between patients undergoing isolated AVR who presented with preop-AF and those in sinus rhythm. The independent effect of preop-AF on 12 short-term complications and long-term survival was determined using binary logistic and cox regression, respectively. RESULTS: Isolated AVR surgery was performed in 2789 patients; 380 (13.6%) presented with preop-AF. Preop-AF patients were generally older (mean age, 73 vs 68 years; P < 0.001) and presented more often with comorbidities including congestive heart failure, diabetes, and cerebrovascular disease (all P < 0.05). There was a trend toward increased 30-day mortality in patients with preop-AF on multivariate analysis (P = 0.051). The incidence of early complications was similar in both groups on multivariate analysis (P > 0.05). Preop-AF was independently associated with reduced long-term survival (hazard ratio, 1.36; 95% confidence interval, 1.01-1.83; P = 0.041). CONCLUSIONS: Preop-AF is associated with an increased risk of late mortality after isolated AVR. As such, concomitant atrial ablation with AVR should be prospectively studied.The Canadian journal of cardiology 11/2012; · 3.36 Impact Factor -
Article: Usefulness of postoperative atrial fibrillation as an independent predictor for worse early and late outcomes after isolated coronary artery bypass grafting (multicenter Australian study of 19,497 patients).
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ABSTRACT: Several studies have shown that postoperative atrial fibrillation (POAF) is associated with poorer short- and long-term outcomes after isolated coronary artery bypass grafting surgery. Nevertheless, there is considerable debate as to whether this reflects an independent association of POAF with poorer outcomes or confounding by other factors. We sought to investigate this issue. Data obtained from June 2001 through December 2009 by the Australasian Society of Cardiac and Thoracic Surgeons National Cardiac Surgery Database Program were retrospectively analyzed. Demographic and operative data were compared between patients who developed POAF and those who did not using chi-square and t tests. The independent impact of POAF on 14 short-term complications and long-term mortality was determined using binary logistic and Cox regression, respectively. Excluding patients with preoperative arrhythmia, isolated coronary artery bypass grafting surgery was performed in 19,497 patients. Of these, 5,547 (28.5%) developed POAF. Patients with POAF were generally older (mean age 69 vs 65 years, p <0.001) and presented more often with co-morbidities including congestive heart failure (p <0.001), hypertension (p <0.001), cerebrovascular disease (p <0.001), and renal failure (p = 0.046). Patients with POAF demonstrated a greater 30-day mortality on univariate analysis but not on multivariate analysis (p = 0.376). Patients with POAF were, however, at an independently increased risk of perioperative complications including permanent stroke (p <0.001), new renal failure (p <0.001), infective complications (p <0.001), gastrointestinal complications (p <0.001), and return to the theater (p <0.001). POAF was also independently associated with shorter long-term survival (p = 0.002). In conclusion, POAF is a risk factor for short-term morbidity and decreased long-term survival. Rigorous evaluation of various therapies that prevent or decrease the impact of POAF is imperative. Moreover, patients who develop POAF should undergo strict surveillance and be routinely screened for complications after discharge.The American journal of cardiology 01/2012; 109(2):219-25. · 3.58 Impact Factor -
Article: Critical analysis of early and late outcomes after isolated coronary artery bypass surgery in elderly patients.
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ABSTRACT: The proportion of elderly (≥80 years) patients undergoing coronary artery bypass surgery (CABG) is increasing. A retrospective analysis of data, collected by the Australasian Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database Program between June 2001 and December 2009 was performed. Isolated CABG was performed in 21,534 patients; of these, 1,664 (7.7%) were at least 80 years old (group 1). Patient characteristics, morbidity, and short-term mortality of these patients were compared with those aged less than 80 years (group 2). The long-term outcome of group 1 patients after CABG surgery was compared with an age and sex-matched Australian population. Patients over 80 years old were more likely to be female (36.6% vs 17.3%, p < 0.001) and presented significantly more often with heart failure, hypertension, and triple-vessel disease (all p < 0.05). The 30-day mortality was higher in group 1 patients (4.2% vs 1.5%, p < 0.001). Group 1 patients also had an increased risk of complications, including prolonged (>24 hours) ventilation (14.2% vs 8.2%, p < 0.001), renal failure (7.3% vs 3.4%, p < 0.001), and mean intensive care unit stay (60.7 vs 42.5 hours, p < 0.001). The 5-year survival of elderly patients (73%) was comparable with the age-matched Australian population. Independent risk factors for 30-day mortality in group 1 patients included preoperative renal failure (p = 0.010), congestive heart failure (p = 0.014), and a nonelective procedure (p = 0.016). Elderly patients who undergo isolated CABG have significantly lower perioperative risks than have been previously reported. The long-term survival of these patients is comparable with an age-adjusted population.The Annals of thoracic surgery 11/2011; 92(5):1703-11. · 3.74 Impact Factor -
Article: Does patient gender affect outcomes after concomitant coronary artery bypass graft and aortic valve replacement? An Australian Society of Cardiac and Thoracic Surgeons Database study.
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ABSTRACT: Women undergoing isolated coronary artery bypass graft (CABG) surgery have been previously shown to be at an independently increased risk for post-operative morbidity and mortality. However, there are considerably less data on whether this trend remains true in patients undergoing concomitant aortic valve replacement (AVR) and CABG surgery. The aim of our study was to investigate this pertinent issue. Data obtained between June 2001 and December 2009 by the Australasian Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database Program were retrospectively analysed. Demographic, operative data and post-operative complications were compared between male and female patients using χ(2) and t tests. Long-term survival analysis was performed using Kaplan-Meier survival curves and the log-rank test. Independent risk factors for short- and long-term mortality were identified using binary logistic and Cox regression, respectively. Concomitant AVR and CABG surgery was undertaken in 2,563 patients; 31.8% were female. Female patients were older (mean age 76 vs. 73 years; p < 0.001) and presented more often with hypertension (p < 0.001) but less often with severely impaired ejection fraction (p < 0.001), peripheral vascular disease (p < 0.001) and triple vessel disease (p < 0.001). Women did not demonstrate an increased risk of 30-day mortality (4.8 vs. 3.3%) on univariate (p = 0.069) or multivariate (p = 0.236) analysis. Female gender was independently associated with post-operative myocardial infarction (p = 0.022) and red blood cell transfusion (p < 0.001). There was no difference in long-term survival between men and women on multivariate analysis (p = 0.413). Female gender is not associated with poorer short- or long-term outcomes after concomitant CABG and AVR surgery.Cardiology 09/2011; 119(2):116-23. · 1.71 Impact Factor -
Article: Impact of prosthesis--patient mismatch after mitral valve replacement: a multicentre analysis of early outcomes and mid-term survival.
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ABSTRACT: Prosthesis-patient mismatch (PPM) is characterised by the effects of inadequate prosthesis size relative to body surface area (BSA). It is uncertain whether PPM after mitral valve replacement impacts upon clinical outcome. This was examined in an Australian population. From 2001 to 2009, 1006 mechanical and bioprosthetic mitral valves were implanted across 10 institutions. Effective orifice areas (EOA) were obtained from a literature review of in vivo echocardiographic data. Absent, moderate and severe PPM was defined as an indexed EOA (EOA/BSA) of >1.20 cm(2)/m(2), >0.90 to ≤1.20 cm(2)/m(2) and ≤0.9 cm(2)/m(2), respectively. Early outcomes and 7-year survival were compared between these three groups. PPM was absent in 34%, moderate in 53% and severe in 13% of patients. Patients with PPM were more likely to be male (42% vs 52% vs 62%, p<0.0001) and obese (14% vs 20% vs 56%, p<0.0001). Postoperatively there was similar 30-day mortality (5% vs 5% vs 6%, p=0.83) and early any mortality/morbidity (24% vs 27% vs 29%, p=0.40). Seven-year survival was similar between groups (72±4.1% vs 76±3.2% vs 69±10.3%, p=0.76). PPM did not predict adverse events after logistic and Cox regressions with and without propensity score adjustment. Subgroup analyses of those with isolated mitral valve surgery, patients with preoperative congestive heart failure and non-obese patients failed to show an association between PPM and mid-term mortality. Overall, PPM was not associated with poorer early outcomes or mid-term survival. Oversizing valves may be technically hazardous and do not yield superior outcomes. Easier implantation by appropriate sizing appears justified.Heart (British Cardiac Society) 07/2011; 97(13):1074-81. · 4.22 Impact Factor -
Article: Early and late outcomes after isolated aortic valve replacement in octogenarians: an Australasian Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database Study.
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ABSTRACT: The advent of percutaneous aortic valve implantation has increased interest in the outcomes of conventional aortic valve replacement in elderly patients. The current study critically evaluates the short-term and long-term outcomes of elderly (≥80 years) Australian patients undergoing isolated aortic valve replacement. Data obtained prospectively between June 2001 and December 2009 by the Australasian Society of Cardiac and Thoracic Surgeons National Cardiac Surgery Database Program were retrospectively analysed. Isolated aortic valve replacement was performed in 2791 patients; of these, 531 (19%) were at least 80 years old (group 1). The patient characteristics, morbidity and short-term mortality of these patients were compared with those of patients who were <80 years old (group 2). The long-term outcomes in elderly patients were compared with the age-adjusted Australian population. Group 1 patients were more likely to be female (58.6% vs 38.0%, p<0.001) and presented more often with co-morbidities including hypertension, cerebrovascular disease and peripheral vascular disease (all p<0.05). The 30-day mortality rate was not independently higher in group 1 patients (4.0% vs 2.0%, p=0.144). Group 1 patients had an independently increased risk of complications including new renal failure (11.7% vs 4.2%, p<0.001), prolonged (≥24 h) ventilation (12.4% vs 7.2%, p=0.003), gastrointestinal complications (3.0% vs 1.3%, p=0.012) and had a longer mean length of intensive care unit stay (64 h vs 47 h, p<0.001). The 5-year survival post-aortic valve replacement was 72%, which is comparable to that of the age-matched Australian population. Conventional aortic valve replacement in elderly patients achieves excellent outcomes with long-term survival comparable to that of an age-adjusted Australian population. In an era of percutaneous aortic valve implantation, it should still be regarded as the gold standard in the management of aortic stenosis.European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 05/2011; 41(1):63-8. · 2.40 Impact Factor -
Article: Training in mitral valve surgery need not affect early outcomes and midterm survival: a multicentre analysis.
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ABSTRACT: Mitral valve surgery may be regarded as less favourable for training, due to greater mortality risk, technical complexity, and difficulty for the supervisor to observe. We examined this perception by reviewing a multicentre experience. We analysed a multicentre database over a 7-year period containing 2216 isolated and combined mitral procedures. Of these, 2048 were performed by consultants and 168 by trainees (92% vs 8%) of varying seniority. Preoperative characteristics, early postoperative outcomes and 6-year survival were compared between groups. Propensity-score matching was performed to correct for group differences. Trainees were less likely to operate on patients, who had previously undergone coronary surgery (consultant 4.3% vs trainee 1.2%, p=0.043) and those with moderate to severe mitral regurgitation (86% vs 81%, p=0.012). There were no other statistically significant differences in preoperative variables, such as urgency, endocarditis and left-ventricular dysfunction. There were similar rates of mitral valve repair (48% vs 51%, p=0.48). Trainees were more likely to operate on rheumatic valve pathology (20% vs 28%, p=0.012). Intra-operatively, trainees had longer aortic cross-clamp times (119 ± 52 vs 136 ± 50 min, p=0.0001). At 30 days, mortality was comparable (4.5% vs 3.6%, p=0.56) with a trend towards higher any mortality/morbidity in consultant procedures (33% vs 26%, p=0.059). At 6 years, survival was similar (79 ± 1.4% vs 78 ± 4.0%, p=0.73). After derivation of 142 propensity-score-matched patient pairs, trainees cases still experienced longer cross-clamp times (121 ± 58 vs 137 ± 52 min, p=0.023), but there was similar 30-day mortality (4.2% vs 3.5%, p>0.99) and any mortality/morbidity (28% vs 24%, p=0.52). Six-year survival between matched pairs was also similar (74 ± 7.2% vs 80 ± 4.4%, p=0.64). Trainee status did not predict early or late adverse events after multivariate Cox regression with and without propensity-score adjustment. Trainee outcomes are not inferior even when corrected for risk. This suggests that excellent operative training and supervision can be achieved in mitral valve surgery.European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 03/2011; 40(4):826-33. · 2.40 Impact Factor -
Article: Progress towards a National Cardiac Procedure Database--development of the Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) and Melbourne Interventional Group (MIG) registries.
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ABSTRACT: Since the call for a National Cardiac Procedures Database in 2001, much work has been accomplished in both cardiac surgery and interventional cardiology in an attempt to establish a unified, systematic approach to data collection, defining a common minimum dataset pertinent to the Australian context, and instituting quality control measures to ensure integrity and privacy of data. In this paper we outline the aims of the Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) and the Melbourne Interventional Group (MIG) registries, and propose a comprehensive set of standardised data elements and their definitions to facilitate transparency in data collection, consistency between these and other data sets, and encourage ongoing peer-review. The aims are to improve outcomes for patients by determining key performance indicators and standards of performance for hospital units, to allow estimation of procedural risks and likelihood of outcomes for patients, and to report outcomes to relevant stake-holders and the public.Heart Lung & Circulation 11/2010; 20(1):10-8. · 1.20 Impact Factor -
Article: Ligand-supported purification of the urotensin-II receptor.
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ABSTRACT: A crucial limitation for structural and biophysical analysis of G protein-coupled receptors (GPCRs) is the inherent challenge of purifying and stabilizing these receptors in an active (agonist-bound) conformation. Peptide ligands, such as the vasoactive, cyclic hormone urotensin-II (U-II), may provide new purification tools, via high affinity, pseudo-irreversible binding suitable for ligand-based affinity purification. We show that the U-II receptor (UT) is resistant to desensitization as a result of low phosphorylation and diminished endocytosis. UT also displays an unusual proclivity to remain active with vasoconstriction sustained despite extensive washout of the ligand. To exploit these properties for ligand-supported purification, we modified the U-II ligand by attaching a biotin moiety and spacer arm to the N terminus, creating a novel affinity ligand (Bio-U-II) to interface with streptavidin media. Bio-U-II bound to UT with pharmacological properties analogous to those of the unmodified U-II ligand (high-affinity, pseudo-irreversible binding). The prebinding of Bio-U-II to UT (before exposure to detergent) facilitated specific capture of UT by stabilizing the receptor structure during solubilization with detergent. Solubilization of UT with the most compatible detergent, n-dodecyl β-d-maltoside, was dependent on the critical micelle concentration, and Gα(q/11) protein was copurified with captured Bio-U-II-UT complexes. Furthermore, captured Bio-U-II-UT complexes were resistant to dissociation at elevated temperatures, suggesting that UT is relatively thermostable, making it an ideal candidate for future structural and biophysical studies. This work demonstrates the utility of pseudo-irreversible ligands to support the purification of a GPCR during detergent extraction, resulting in the first successful purification of the UT.Molecular pharmacology 10/2010; 78(4):639-47. · 4.53 Impact Factor -
Article: Measuring safety and quality to improve clinical outcomes--current activities and future directions for the Australian Cardiac Procedures Registry.
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ABSTRACT: Routine monitoring of performance in the provision of cardiac services aids quality assurance and enables comparisons of performance to national and international standards. The Australasian Society of Cardiac and Thoracic Surgeons conducts a surgical registry that has grown from six hospitals participating in 2001 to 21 contributing in 2010. Variation in performance is monitored on a quarterly basis through the use of control chart methodology, and a peer-review mechanism and governance process for reporting have been established. Proposed future developments of the registry include its expansion to include interventional cardiology procedures, such as implantation of stents and cardiac devices, and a modular format, with the patient rather than the procedure being the key element of the system. An Australian Cardiac Procedures Registry will provide information to stakeholders, including consumers, clinicians, health funders and policymakers, on performance standards and quality of care of medical services affecting an ever-increasing number of Australians.The Medical journal of Australia 10/2010; 193(8 Suppl):S107-10. · 2.81 Impact Factor -
Article: Does prior percutaneous coronary intervention adversely affect early and mid-term survival after coronary artery surgery?
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ABSTRACT: To determine the association between previous percutaneous coronary intervention (PCI) and results after coronary artery bypass graft surgery (CABG). Increasing numbers of patients undergoing CABG have previously undergone PCI. We analyzed consecutive first-time isolated CABG procedures within the Australasian Society of Cardiac and Thoracic Surgeons Database from June 2001 to May 2008. Logistic regression and propensity score analyses were used to assess the risk-adjusted impact of prior PCI on in-hospital mortality and major adverse cardiac events. Cox regression model was used to assess the effect of prior PCI on mid-term survival. Of 13,184 patients who underwent CABG, 11,727 had no prior PCI and 1,457 had prior PCI. Mean follow-up was 3.3 +/- 2.1 years. Patients without prior PCI had a higher EuroSCORE value (4.4 +/- 3.3 vs. 3.6 +/- 3.0, p < 0.001), were older, and more likely to have left main stem stenosis and recent myocardial infarction. There was no difference in unadjusted in-hospital mortality (1.65% vs. 1.55%, p = 0.78) or major adverse cardiac events (3.0% vs. 3.0%, p = 0.99) between patients with or without prior PCI. After adjustment, prior PCI was not a predictor of in-hospital (odds ratio: 1.22, 95% confidence interval [CI]: 0.76 to 2.0, p = 0.41) or mid-term mortality at 6-year follow-up (hazard ratio: 0.94, 95% CI: 0.75 to 1.18, p = 0.62). In this large registry study, prior PCI was not associated with increased short- or mid-term mortality after CABG. Good outcomes can be obtained in the group of patients undergoing CABG who have had previous PCI.08/2009; 2(8):758-64. · 1.07 Impact Factor -
Article: Contemporary results show repeat coronary artery bypass grafting remains a risk factor for operative mortality.
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ABSTRACT: Reoperative coronary artery bypass grafting (redo CABG) shows improving outcomes, but with varying degrees of improvement. We assessed contemporary outcomes after redo CABG to determine if redo status is still a risk factor for early postoperative complications and midterm survival. Isolated CABG procedures (June 1, 2001 to May 31, 2008) within the Australasian Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database were included. Redo status as a predictor for early outcomes was assessed with logistic regression analysis. Midterm survival was determined from the National Death Index. Effect of redo status on midterm survival was assessed using a Cox proportional hazards model. Inclusion criteria were met by 13,436 patients, and 458 (3.4%) underwent redo CABG. Operative mortality was 4.8% for redo CABG and 1.8% for first-time CABG (p < 0.001). After adjustment, redo status remained a predictor for operative mortality (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.3 to 3.6), myocardial infarction (OR, 2.8; 95% CI, 1.6 to 6.0), and prolonged ventilation (OR, 1.5; 95% CI, 1.1 to 2.0). Unadjusted survival was lower for the redo CABG group vs the first-time CABG group at up to 6 years (p = 0.01, log-rank test. After adjusting for differences in patient variables, redo status was not a predictor of midterm survival (OR, 1.03; 95% CI, 0.78 to 1.35; p = 0.85). Early postoperative outcomes of redo CABG are encouraging. Midterm survival is excellent; however, redo remains a significant risk factor for operative mortality in contemporary practice.The Annals of thoracic surgery 06/2009; 87(5):1386-91. · 3.74 Impact Factor -
Article: Major complications related to the use of transesophageal echocardiography in cardiac surgery.
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ABSTRACT: The purpose of this study was to determine the incidence of injury associated with transesophageal echocardiography (TEE injuries) in cardiac surgery. Retrospective. University-affiliated hospitals. Four thousand seven hundred eighty-four patients, 89% of all public hospital cardiac surgery patients in Victoria, from the Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) database undergoing cardiac surgery with TEE between July 1, 2005, and June 30, 2007. Because ASCTS did not record TEE use before July 2005, it was assumed that 89% of an additional 11,719 cardiac surgery patients between July 2001 and June 2005 also had TEE. The authors searched the ASCTS database for cardiac surgery patients who also had endoscopy and/or noncardiac surgery. The files of these patients were screened for possible esophageal or gastric tears or perforations. An expert panel determined likely TEE injuries. There were 6 TEE complications from July 1, 2005, to June 30, 2007 (13/10,000 patients). There were a further 8 TEE complications before June 30, 2005, an extrapolated overall rate of 9/10,000 TEE (95% confidence interval, 5-16/10,000). TEE complications were more frequent in patients more than 70 years old (relative risk [RR], 3.7; p = 0.03) and women (RR, 6.5; p < 0.001). Three patients with TEE injury died (2/10,000). TEE is associated with an incidence of major injuries of about 1 per 1,000 patients, with older women having a much higher risk. TEE use in cardiac surgery should be evaluated in the light of practice guidelines and morbidity and mortality data and not considered routine.Journal of cardiothoracic and vascular anesthesia 01/2009; 23(1):62-5. · 1.06 Impact Factor -
Article: Trends in coronary artery bypass graft surgery in Victoria, 2001-2006: findings from the Australasian Society of Cardiac and Thoracic Surgeons database project.
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ABSTRACT: To examine trends in preoperative clinical characteristics, risk profiles and postoperative outcomes of patients undergoing isolated coronary artery bypass graft (CABG) surgery in Victoria. A prospective analysis of 9372 patients undergoing isolated CABG surgery between 1 July 2001 and 30 June 2006 in six Victorian public hospitals, using the Australasian Society of Cardiac and Thoracic Surgeons database. Trends in patient baseline characteristics and risk factors, postoperative morbidity and 30-day mortality rate. Over the 5 years, the mean age of patients undergoing isolated CABG surgery increased, from 65.4 years in 2001-02 to 66.0 years in 2005-06 (P < 0.001). There was also an increase in the proportion of patients with hypertension (70.2% to 75.8%; P < 0.001), respiratory disease (83.2% to 89.5%; P < 0.001) and left main coronary artery disease (22.1% to 26.1%; P = 0.03), while the number of patients undergoing repeat CABG surgery decreased (4.4% to 2.6%; P = 0.002). The overall 30-day mortality rate remained unchanged (2.2% to 1.8%; P = 0.983). Rates of other major postoperative complications showed no significant change over the study period. Rates of 30-day mortality and postoperative morbidity after CABG surgery have remained steady, despite the surgical population being older. Short-term outcomes after CABG surgery in Victoria remain among the most favourable reported in any population undergoing this surgery.The Medical journal of Australia 02/2008; 188(4):214-7. · 2.81 Impact Factor -
Article: Helix I of beta-arrestin is involved in postendocytic trafficking but is not required for membrane translocation, receptor binding, and internalization.
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ABSTRACT: beta-Arrestins bind to phosphorylated, seven-transmembrane-spanning, G protein-coupled receptors (GPCRs), including the type 1 angiotensin II receptor (AT(1)R), to promote receptor desensitization and internalization. The AT(1) R is a class B GPCR that recruits both beta-arrestin1 and beta-arrestin2, forming stable complexes that cotraffic to deep-core endocytic vesicles. beta-Arrestins contain one amphipathic and potentially amphitropic (membrane-targeting) alpha-helix (helix I) that may promote translocation to the membrane or influence receptor internalization or trafficking. Here, we investigated the trafficking and function of beta-arrestin1 and beta-arrestin2 mutants bearing substitutions in both the hydrophobic and positively charged faces of helix I. The level of expression of these mutants and their cytoplasmic localization (in the absence of receptor activation) was similar to wild-type beta-arrestins. After angiotensin II stimulation, both wild-type and beta-arrestin mutants translocated to the cell membrane, although recruitment was weaker for mutants of the hydrophobic face of helix I. For all beta-arrestin mutants, the formation of deep-core vesicles was less observed compared with wild-type beta-arrestins. Furthermore, helix I conjugated to green fluorescent protein is not membrane-localized, suggesting that helix I, in isolation, is not amphitropic. Bioluminescence resonance energy transfer analysis revealed that both wild-type and beta-arrestin mutants retained a capacity to interact with the AT(1)R, although the interaction with the mutants was less stable. Finally, wild-type and mutant beta-arrestins fully supported receptor internalization in human embryonic kidney cells and mouse embryonic fibroblasts deficient in beta-arrestin1 and -2. Thus, helix I is implicated in postmembrane trafficking but is not strongly amphitropic.Molecular Pharmacology 03/2005; 67(2):375-82. · 4.88 Impact Factor -
Article: Evidence for activation of the renin-angiotensin system in the human prostate: increased angiotensin II and reduced AT(1) receptor expression in benign prostatic hyperplasia.
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ABSTRACT: The expression and cellular localization of angiotensin II (Ang II) and AT(1) receptor proteins were examined in the normal human prostate and benign prostatic hyperplasia (BPH) by immunohistochemistry. In the normal prostate, Ang II immunoreactivity was localized to the basal layer of the epithelium and AT(1) receptor immunostaining was found predominantly on stromal smooth muscle and also on vascular smooth muscle of prostatic blood vessels. Ang II immunoreactivity was markedly increased in hyperplastic acini in BPH compared with acini in the normal prostate (normal: 7.4+/-0.2%, n=5 vs. BPH: 22.7+/-1.9%, n=5, p<0.001). However, AT(1) receptor immunoreactivity was significantly decreased in BPH compared with the normal prostate [normal: 16.4+/-2.2%, n=4 vs. BPH: 9.4+/-1.3%, n=5, p<0.05 (p=0.025)]. The present study demonstrates the presence of Ang II peptide in the basal layer of the epithelium and AT(1) receptors on stromal smooth muscle, suggesting that Ang II may mediate paracrine functions on cellular growth and smooth muscle tone in the human prostate. Furthermore, AT(1) receptor down-regulation in BPH may be due to receptor hyperstimulation by increased local levels of Ang II in BPH. These data extend previous findings in support of the novel concept that overactivity of the renin-angiotensin system (RAS) may be involved in the pathophysiology of BPH.The Journal of Pathology 02/2002; 196(2):213-9. · 6.32 Impact Factor
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Institutions
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2011–2013
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Austin Health
- Department of Cardiac Surgery
Melbourne, Victoria, Australia -
St. Vincent's Hospital Melbourne
- Department of Cardiothoracic Surgery
Melbourne, Victoria, Australia
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2008–2012
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Monash University
- Department of Epidemiology and Preventive Medicine
Melbourne, Victoria, Australia
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2002–2011
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University of Melbourne
- • Department of Surgery
- • Department of Medicine
Melbourne, Victoria, Australia
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2009
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Goulburn Valley Health
Shepparton, Victoria, Australia
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2005
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Baker IDI Heart and Diabetes Institute
Melbourne, Victoria, Australia
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