The Australian and New Zealand Society of Cardiac and Thoracic Surgeons Database Program - Two Decades of Quality Assurance Data.

Over two decades, the Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) cardiac surgery database program has evolved from a single state-based database to a national clinical quality registry program and is now the most comprehensive cardiac surgical registry in Australia. We report the current structure and governance of the program and its key activities.

Structured Feedback: Acceptability and Feasibility of a Strategy to Enhance the Role of a Clinical Quality Registry to Drive Change in Cardiac Surgical Practice.

BACKGROUND: The Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) Database collects and monitors preoperative, operative, and 30-day outcome data on patients undergoing cardiac surgery, and delivers regular performance feedback reports to key personnel with intent to drive quality improvement. The current feedback approach appears to be ineffective in driving change to minimise Unit performance variation. We sought to determine the acceptability and feasibility of providing structured feedback in addition. METHODS: Cardiac surgeons were surveyed to assess their evaluation of the current feedback reports and assist in developing the content of structured feedback. We then assessed acceptability and performance outcomes of control Units receiving current feedback reports via email, versus intervention Units that in addition received structured feedback. RESULTS: Survey respondents assessing the current feedback report agreed that the content is relevant (95%), key performance indicators (KPIs) are useful (85%), and that it would be beneficial to compare surgeons' KPIs (75%). Survey respondents rating method of feedback, requested structured feedback sessions one to two times annually (67%; control Units), and future structured feedback (83%; intervention Units). With combined report and structured feedback, improved performance was noted for an under-performing Unit. Limitations of feedback in driving quality improvement was high performance of Units at baseline, low surgeon participation, and scheduling challenges for structured feedback. CONCLUSIONS: In this pilot study, compared to the control method, structured feedback did not significantly improve communication. To maximise quality improvement efforts, a collaborative feedback approach that fosters a climate of continuous performance improvement, is recommended.

Preoperative atrial fibrillation is an independent predictor of worse early and late outcomes after isolated coronary artery bypass graft surgery.

OBJECTIVES: To evaluate the impact of preoperative atrial fibrillation (pre-op AF) on early and late mortality after isolated coronary artery bypass graft (CABG) surgery. METHODS: 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 analyzed. Patients who underwent concomitant atrial arrhythmia surgery/ablation were excluded. Demographic and operative data were compared between patients with and without pre-op AF. The independent association of pre-op AF on early mortality, perioperative complications, and late mortality was determined. RESULTS: Isolated CABG surgery was performed in 21,534 patients; 1312 (6.1%) presented with pre-op AF. Pre-op AF patients were older (mean age, 71 years vs. 65 years, p<0.001) and had more comorbidities reflected in a higher additive EuroSCORE (8.4±3.5 vs. 6.5±3.2, p=0.001). Even after accounting for confounding factors, however, pre-op AF was associated with a 63% increase in 30-day mortality [4.2% vs. 1.4%; hazard ratio (HR), 1.63; 95% confidence interval (CI), 1.17-2.29; p=0.004] and 39% increase in late mortality (5-year survival, 78% vs. 90%; HR, 1.39; 95% CI, 1.20-1.61; p<0.001). CONCLUSION: Pre-op AF is an independent predictor of poor early and late outcomes. Pre-op AF should be considered, therefore, in the development or update of risk stratification models for CABG surgery.

AusSCORE II in predicting 30-day mortality after isolated coronary artery bypass grafting in Australia and New Zealand.

OBJECTIVES: To update the Australian System for Cardiac Operative Risk Evaluation (AusSCORE) model for operative estimation of 30-day mortality risk after isolated coronary artery bypass grafting in the Australian population. METHODS: Data were collected by the Australian and New Zealand Society of Cardiac and Thoracic Surgeons registry from 2001 to 2011 in 25 hospitals. A total of 31,250 patients underwent isolated coronary artery bypass grafting and the outcome was 30-day mortality. A total of 2154 (6.9%) patients had 1 or multiple missing values. Missing values were estimated assuming missing completely at random and logistic regression with a generalized estimating equation was used to address within-hospital variance. Bootstrapping methods were used to construct and validate the updated model (AusSCORE II). Also the model was validated on an out-of-creation sample of 4700 patients who underwent bypass surgery in 2012. RESULTS: The average age of the patients was 65.6±12.9 years and 78.6% were male. Thirteen variables were selected in the updated model. The bootstrap discrimination and calibration of the AusSCORE II was very good (receiver operating characteristics [ROC], 82.0%; slope calibration, 0.987). The overall observed/AusSCORE II predicted mortality was 1.63% compared with the original AusSCORE predicted mortality of 1.01%. The validation of the AusSCORE II on the out-of-sample data also showed a high performance of the model (ROC, 84.5%; Hosmer-Lemoshow P value, .7654). CONCLUSIONS: The AusSCORE II model provides improved prediction of 30-day mortality and successfully stratifies patient risk. The model will be useful to improve the preoperative consultation regarding risk stratification in terms of 30-day mortality.

Impact of smoking status on outcomes after concomitant aortic valve replacement and coronary artery bypass graft surgery.

BACKGROUND: There is a paucity of data on the impact of smoking status on outcomes after concomitant aortic valve replacement and coronary artery bypass graft (AVR-CABG) surgery. 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 were retrospectively analyzed. Demographic and operative data were compared between patients who were nonsmokers, previous smokers, and current smokers using chi-square test and t-test. 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: Concomitant AVR-CABG surgery was performed in 2,563 patients; smoking status was recorded in 2,558 (99.8%) patients. Of these, 1,052 (41.1%) patients had no previous smoking history, 1,345 (52.6%) patients were previous smokers, and 161 (6.3%) patients were current smokers. The 30-day mortality rate was 3.5% in nonsmokers, 4.1% in previous smokers, and 3.1% in current smokers (p = nonsignificant). The incidence of perioperative complications was similar in the three groups. The mean follow-up period for this study was 36 months (range, 0-105 months). After adjusting for differences in patient variables, the incidence of late mortality was higher in previous smokers (hazard ratio [HR], 1.44; 95% confidence interval [CI], 1.14-1.81; p = 0.002) compared with nonsmokers. A trend toward increased late mortality in current smokers was noted (HR, 1.34; 95% CI, 0.86-2.08; p = 0.201). CONCLUSION: Smoking is not associated with adverse outcomes after concomitant AVR-CABG surgery. Smoking status should not, therefore, preclude these patients from undergoing this procedure. Given the adverse effect of smoking on overall cardiovascular morbidity and mortality and late postoperative mortality, patients should be encouraged to quit smoking.

Impact of left ventricular dysfunction on early and late outcomes in patients undergoing concomitant aortic valve replacement and coronary artery bypass graft surgery.

BACKGROUND: An increasing proportion of patients present for concomitant aortic valve replacement (AVR) and coronary artery bypass grafting (CABG) with left ventricular (LV) dysfunction. The aim of this study was to evaluate the early outcomes and late survival of patients with different degrees of LV function undergoing concomitant AVR and CABG. METHODS: Between June 2001 and December 2009, patients undergoing concomitant AVR-CABG were identified from the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database Program. Demographic, operative data and post-operative outcomes were compared between patients with normal (> 60%), moderately impaired (30- -60%), and severely impaired (< 30%) estimated LV ejection fraction (LVEF). Independent risk factors for short- and long-term mortality were identified using binary logistic and Cox regression, respectively. RESULTS: AVR-CABG was performed in 2,563 patients with a mean follow up of 36 months (range 0-106). 144 (5.6%) had severely impaired LVEF, 983 (38.3%) had moderately impaired LVEF while the remaining 1377 (53.7%) had normal LVEF. The 30-day mortality in patients with severely impaired, moderately impaired and normal LVEF was 9.0%, 4.3% and 2.9%, respectively. This was significant on univariate (p < 0.001) but not multivariate analysis (p = NS). Severely impaired, moderately impaired and normal LVEF patients experienced 5-year survivals of 63.7%, 77.1% and 82.5%, respectively. Severely impaired LVEF was an independent multivariable predictor of late mortality (HR 1.71; 95% CI 1.22-2.40; p = 0.002). CONCLUSIONS: Patients with severely impaired LVEF experience worse outcomes. However, in the era of modern surgery, this alone should not predicate exclusion, given the established benefits of surgery in this high-risk group.

Impact of smoking status on early and late outcomes after isolated aortic valve replacement surgery.

BACKGROUND AND AIM OF THE STUDY: Currently, insufficient data exist relating to the impact of smoking status on outcomes after isolated aortic valve replacement (AVR) surgery. METHODS: Data obtained prospectively between June 2001 and December 2009 by the Australian and New Zealand Society of Cardiac and Thoracic Surgeons (SCTS) Cardiac Surgery Database Program was analyzed retrospectively. Demographic and operative data were compared between patients who were non-smokers, previous smokers and current smokers, using chi-square and t-tests. 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 AVR surgery was performed in 2,790 patients; smoking status was recorded in 2,784 cases (99.8%). Of these patients 1,346 (48.3%) had no previous smoking history, 1,232 (44.3%) were previous smokers, and 206 (7.4%) were current smokers. The 30-day mortality rate was 2.3% in nonsmokers, 2.7% in previous smokers, and 0.5% in current smokers (p = NS). The incidence of perioperative complications was generally similar in the three groups, but current smokers were at an increased risk of pneumonia (p = 0.030) and postoperative myocardila infarction (p = 0.007). The mean follow up period for the study was 37 months (range: 0-105 months). After adjusting for differences in patient variables, the incidence of late mortality was not higher in previous smokers (HR 1.13; 95% CI 0.87-1.46; p = 0.372) or current smokers (HR 1.25; 95% CI 0.66-2.36; p = 0.494) compared to non-smokers. CONCLUSION: Smoking status does not necessarily portend a poorer perioperative outcome in patients undergoing isolated AVR.

Impact of smoking status on early and late outcomes after isolated coronary artery bypass graft surgery.

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.

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.

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.

Excellent short- and long-term outcomes after concomitant aortic valve replacement and coronary artery bypass grafting performed by surgeons in training.

OBJECTIVE: No previous studies have specifically addressed the effect of training on outcomes after concomitant aortic valve replacement and coronary artery bypass grafting. This study evaluated the early and late outcomes after concomitant aortic valve replacement and coronary artery bypass grafting performed by surgeons in training. METHODS: A retrospective analysis of data collected prospectively by the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database between June 2001 and December 2009 was performed. Concomitant aortic valve replacement and coronary artery bypass grafting was performed in 2540 patients; of these procedures, 290 (11.4%) were by trainees. Patient demographics, intraoperative characteristics, and early morbidity were compared between trainee and staff cases using chi-square analysis and t tests. Multivariate analyses were used to determine the independent association of training status with 30-day and late mortality. RESULTS: Compared with staff cases, trainee cases were younger (mean age, 73.0 vs 74.2 years; P = .025) and less likely to present with triple vessel disease (27.9% vs 38.3%, P = .001) or previous cardiac surgery (6.3% vs 2.8%, P = .016). Trainee cases had longer mean perfusion (160.4 vs 144.6 minutes, P < .001) and crossclamp (125.2 vs 114.6 minutes, P < .001) times. The incidence of early complications was similar between the 2 groups. On multivariate analysis, trainee status was not associated with an increased risk of 30-day mortality (2.4% vs 4.0%, P = .348). Moreover, there was no significant difference in long-term outcomes, and 5-year survival was comparable in both groups (79.6% vs 77.4%, P = .200). CONCLUSIONS: Concomitant aortic valve replacement and coronary artery bypass grafting can be safely and effectively performed by properly supervised trainees in the contemporary era. It is imperative to offer training opportunities to junior surgeons in this complex procedure to ensure quality patient outcomes in the future.

Does preoperative atrial fibrillation portend a poorer prognosis in patients undergoing isolated aortic valve replacement? A multicentre Australian study.

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.

Postoperative atrial fibrillation after isolated aortic valve replacement: a cause for concern?

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.

Early and late outcomes after isolated aortic valve replacement in octogenarians: an Australasian Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database Study.

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

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).

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.

Critical analysis of early and late outcomes after isolated coronary artery bypass surgery in elderly patients.

BACKGROUND: The proportion of elderly (≥80 years) patients undergoing coronary artery bypass surgery (CABG) is increasing. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

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.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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). CONCLUSION: Female gender is not associated with poorer short- or long-term outcomes after concomitant CABG and AVR surgery.

Impact of prosthesis--patient mismatch after mitral valve replacement: a multicentre analysis of early outcomes and mid-term survival.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Training in mitral valve surgery need not affect early outcomes and midterm survival: a multicentre analysis.

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

An Australian risk prediction model for determining early mortality following aortic valve replacement.

OBJECTIVE: To develop a multivariable logistic risk model for predicting early mortality following aortic valve replacement (AVR) in adults, and to compare its performance against existing AVR-dedicated models. METHODS: Prospectively collected data from the Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) database project were used. Thirty-five preoperative variables from AVR literature were considered for analysis by chi-square method and multiple logistic regression. Using the bootstrap re-sampling technique for variable selection, five plausible models were identified. Based on models' calibration, discrimination and predictive capacity during n-fold validation, a final model, the AVR-Score, was chosen. An additive score, derived from the final model, was also validated externally in a consecutive cohort. The performance of AVR-dedicated risk models from the North West Quality Improvement Program (NWQIP) and the Northern New England Cardiovascular Study (NNE) groups were also assessed using the receiver operating characteristic (ROC) curve and the Hosmer-Lemeshow (H-L) chi-square test. RESULTS: Between July 2001 and June 2008, a total of 3544 AVR procedures were performed. Early mortality was 4.15%. The AVR-Score contained the following predictors: age, New York Heart Association class, left main disease, infective endocarditis, cerebrovascular disease, renal dysfunction, previous cardiac surgery and estimated ejection fraction. Our final model (AVR-Score) obtained an average area under ROC curve of 0.78 (95% confidence interval (CI): 0.76, 0.80) and an H-L p-value of 0.41 (p>0.05) during internal validation, indicating good discrimination and calibration capacity. External validation of the additive score on a consecutive cohort of 1268 procedures produced an ROC of 0.73 (0.62, 0.84) and an H-L p-value of 0.48 (p>0.05). The NWQIP and NNE risk models achieved acceptable discrimination of ROC of 0.77 (0.73, 0.81). However, both models obtained H-L p-values of 0.002 (p<0.05), indicating a poor fit in our cohort. CONCLUSION: Existing AVR-dedicated risk models were deemed inappropriate for risk prediction in the Australian population. A preoperative risk model was developed using prospective data from a contemporary AVR cohort.