The Aortic Root Replacement Procedure: 12-year Experience from the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Database.

BACKGROUND: The aortic root replacement procedure (ARR), is often considered the gold standard in the management of aortic root and ascending aorta aneurysms. Our aim was to review the Australian experience with this procedure to ascertain early and late outcomes of mortality and morbidity. METHODS: We reviewed the Australian and New Zealand Society of Cardiac and Thoracic Surgeons' (ANZSCTS) database for patients undergoing ARR. Preoperative, intraoperative and postoperative variables were analysed. Multiple regression was performed to determine independent predictors of 30-day mortality and permanent stroke, and predictors of late death. Survival estimates were obtained by cross-linking the ANZSCTS database with the Australian Institute of Health and Welfare's National Death Index database. RESULTS: Between January 2001 and December 2011, 954 patients underwent ARR with a mean age of 56±15.2 years. The overall 30-day mortality was 5.9% (n=56) with a permanent stroke rate of 2.3% (n=21). The elective surgery mortality was 3.6%. Long-term survival was estimated as 84.4% and 68.7% at 5 and 10 years, respectively. CONCLUSIONS: Aortic root replacement surgery reveals acceptable early mortality, low postoperative stroke rates, and acceptable long-term survival.

Early and Late Outcomes Following Valve Sparing Aortic Root Reconstruction: The ANZSCTS Database.

BACKGROUND: Valve sparing aortic root reconstruction (VSARR) has become an alternative to traditional aortic root replacement with a valved conduit. There have been various modifications but the two broad types are aortic root reimplantation and the aortic root remodelling procedure. We present the early and late outcomes following valve sparing aortic root reconstruction surgery in Australia. METHODS: We reviewed the ANZSCTS database for patients undergoing these procedures. Preoperative, intraoperative and postoperative variables were analysed. Multivariable regression was performed to determine independent predictors of 30-day mortality. We also obtained five- and 10-year survival estimates by cross-linking the ANZSCTS database with the Australian Institute of Health and Welfare's National Death Index. RESULTS: Between January 2001 and January 2012, 169 consecutive patients underwent VSARR procedures. The mean age of the study population was 54.4 years with 31.4% being females. Overall, nine patients (5.9%) died within 30 days post procedure and five patients (3%) had permanent strokes. However, out of 132 elective cases, only five patients died (3.8%). Independent predictors of 30-day mortality were female gender [OR 5.65(1.24-25.80), p=0.025], preoperative atrial arrhythmia [OR 6.07(1.14-32.35), p=0.035] and acute type A aortic dissection [OR 7.71(1.63-36.54), p=0.01]. Long-term survival was estimated as 85.3% and 72.7% at five- and 10-years, respectively. CONCLUSIONS: Along with an acceptable rate of early mortality and stroke, VSARR procedures provide good long-term survival according to the ANZSCTS database. As promising procedure for pathologies that impair the aortic root integrity, they can be adopted more widely, especially in Australian and New Zealand centres with experienced aortic units. Future studies are planned to assess freedom from valve deterioration and repeat surgery.

Comparison of the Safety and Efficacy of On-Pump (ONCAB) versus Off-Pump (OPCAB) Coronary Artery Bypass Graft Surgery in the Elderly: A Review of the ANZSCTS Database.

BACKGROUND: The elderly population (age >70 years) incurs greater mortality and morbidity following CABG. Off-pump coronary artery bypass (OPCAB) may mitigate these outcomes. A retrospective analysis of the results of OPCAB in this population was performed. METHODS: We reviewed the Australian and New Zealand Society of Cardiac and Thoracic Surgeons' (ANZSCTS) database for elderly patients (n=12697) undergoing isolated CABG surgery and compared the on-pump coronary artery bypass (ONCAB) (n=11676) with OPCAB (n=1021) technique. Preoperative and intraoperative risk factors, and postoperative outcomes were analysed. Survival analyses was performed after cross-matching the database with the national death registry to identify long-term mortality. RESULTS: High-risk patients were more prevalent in the ONCAB group (p<0.05). OPCAB patients received fewer distal anastomoses than ONCAB patients (2.4±1.1 vs 3.3±1.0, p<0.001). Thirty-day mortality and stroke rates between OPCAB and ONCAB were not significantly different (2% vs 2.5% and 1.1% vs 1.8%, respectively). There was a non-significant trend towards improved 10-year survival in OPCAB patients using multivariate analysis (78.8% vs. 73.3%, p=0.076, HR 0.83; 95% CI 0.67-1.02). CONCLUSIONS: Mortality and stroke rates following CABG surgery are extremely low in the elderly suggesting that surgery is a safe management option for coronary artery disease in this population. OPCAB did not offer a significant advantage over ONCAB with regards to 30-day mortality, stroke and long-term survival. Further prospective randomised trials will be necessary to clarify risks or benefits in the elderly.

Outcomes of On-Pump versus Off-Pump Coronary Artery Bypass Graft Surgery in the High Risk (AusSCORE > 5).

BACKGROUND: Coronary artery bypass graft surgery (CABG) has been established as the preferred intervention for coronary revascularisation in the high-risk population. Off-pump coronary artery bypass (OPCAB) may further reduce mortality and morbidity in this population subgroup. This study presents the largest series of high-risk (AusSCORE > 5) OPCAB patients in Australia and New Zealand. METHODS: We reviewed the Australian and New Zealand Society of Cardiac and Thoracic Surgeons' (ANZSCTS) database for high-risk patients (n=7822) undergoing isolated CABG surgery and compared the on-pump coronary artery bypass (ONCAB) (n=7277) with the OPCAB (n=545) technique. Preoperative and intraoperative risk factors, and postoperative outcomes were analysed. Survival analysis was performed after cross-matching the database with the national death registry to identify long-term mortality. RESULTS: The ONCAB and OPCAB groups had similar risk profiles based on the AusSCORE. Thirty-day mortality (ONCAB vs OPCAB 3.9% vs 2.4%, p=0.067) and stroke (ONCAB vs OPCAB 2.4% vs 1.3%, p=0.104) were similar between the two groups. OPCAB patients received fewer distal anastomoses than ONCAB patients (2.5±1.2 vs 3.3±1.0, p<0.001). The rates of new postoperative atrial arrhythmia (28.3% vs 33.3%, p=0.017) and blood transfusion requirements (52.1% vs 59.5%, p=0.001) were lower in the OPCAB group, while duration of ICU stay in hours (97.4±187.8 vs 70.2±152.8, p<0.001) was longer. There was a non-significant trend towards improved 10-year survival in OPCAB patients (74.7% vs. 71.7%, p=0.133). CONCLUSIONS: In the high-risk population, CABG surgery has a low rate of mortality and morbidity suggesting that surgery is a safe option for coronary revascularisation. OPCAB reduces postoperative morbidity and is a safe procedure for 30-day mortality, stroke and long-term survival in high-risk patients.

Housing type, location of residence and health status in Australian baby boomers: results from the Australian Baby Boomer (ABBA) Study.

INTRODUCTION: Baby Boomers are working and living longer than their pre-war counterparts, and are more likely to live in high density urban housing. This paper examines the relationship between housing type, working status and location of residence on health status in Baby Boomers. METHODS: We investigated location of residence and housing type in 1009 participants of the Ageing Baby Boomers in Australia (ABBA) Study to identify any predictors of, or correlations between, these variables and health status. RESULTS: Current workers were less likely to report depression than retirees. We found a significantly higher rate of diabetes, obesity and hypertension in retirees than in current workers however rates of obesity, diabetes and hypertension were higher than predicted in current workers. CONCLUSION: The rates of chronic disease are higher than previous estimates and provide evidence to inform health promotion programs designed to increase physical activity and improve eating habits in baby boomers.

Moderate concentrations of supplemental oxygen worsen hypercapnia in obesity hypoventilation syndrome: a randomised crossover study.

INTRODUCTION: In people with obesity hypoventilation syndrome (OHS), breathing 100% oxygen increases carbon dioxide (PCO2), but its effect on pH is unknown. This study investigated the effects of moderate concentrations of supplemental oxygen on PCO2, pH, minute ventilation (VE) and physiological dead space to tidal volume ratio (VD/VT) among people with stable untreated OHS, with comparison to healthy controls. METHODS: In a double-blind randomised crossover study, participants breathed oxygen concentrations (FiO2) 0.28 and 0.50, each for 20 min, separated by a 45 min washout period. Arterialised-venous PCO2 (PavCO2) and pH, VE and VD/VT were measured at baseline, then every 5 min. Data were analysed using general linear model analysis. RESULTS: 28 participants were recruited (14 OHS, 14 controls). Among OHS participants (mean ± SD arterial PCO2 6.7 ± 0.5 kPa; arterial oxygen 8.9 ± 1.4 kPa) FiO2 0.28 and 0.50 maintained oxygen saturation 98-100%. After 20 min of FiO2 0.28, PavCO2 change (ΔPavCO2) was 0.3 ± 0.2 kPa (p = 0.013), with minimal change in VE and rises in VD/VT of 1 ± 5% (p = 0.012). FiO2 0.50 increased PavCO2 by 0.5 ± 0.4 kPa (p = 0.012), induced acidaemia and increased VD/VT by 3 ± 3% (p = 0.012). VE fell by 1.2 ± 2.1 L/min within 5 min then recovered individually to varying degrees. A negative correlation between ΔVE and ΔPavCO2 (r = -0.60, p = 0.024) suggested that ventilatory responses were the key determinant of PavCO2 rises. Among controls, FiO2 0.28 and 0.50 did not change PavCO2 or pH, but FiO2 0.50 significantly increased VE and VD/VT. CONCLUSION: Commonly used oxygen concentrations caused hypoventilation, PavCO2 rises and acidaemia among people with stable OHS. This highlights the potential dangers of this common intervention in this group.