Long-term Clinical and Echocardiographic Outcomes in Young and Middle-aged Adults Undergoing the Ross Procedure.

Importance: There is no ideal valve substitute for young adults requiring aortic valve replacement. Multicenter data supporting use of the Ross procedure with respect to long-term postoperative valve-related mortality and reintervention, as well as function of the autograft and pulmonary homograft, are needed. Objective: To determine the long-term clinical and echocardiographic outcomes in young and middle-aged patients undergoing the Ross procedure. Design, Setting, and Participants: A retrospective multicenter international cohort study with a median follow-up period of 9.2 years was conducted in 5 experienced centers regularly performing the Ross procedure. Consecutive patients aged 18 to 65 years were included by each center between 1991 and 2018. Main Outcomes and Measures: Survival and autograft-related and homograft-related reintervention. Serial echocardiographic measurements of valve function were analyzed using mixed-effects modeling. Results: During the study period, 1431 patients (74.3% men; n = 1063) were operated on at a median age of 48.5 years (mean [SD], 47.7 [9.5]; range, 18.1-65; interquartile range, 42.7-54.0). Implantation techniques were root inclusion in 355 (24.9%), root replacement in 485 (34.0%), and subcoronary implantation in 587 (41.1%). Right ventricular outflow tract reconstruction was performed with homografts in 98.6% (n = 1189) and bioprostheses in 1.4% (n = 17). Ten patients (0.7%) died before discharge. Median follow-up was 9.2 years (13 015 total patient-years). Survival after 10 and 15 years was 95.1% (95% CI, 93.8%-96.5%) and 88.5% (95% CI, 85.9%-91.1%), respectively. Freedom from autograft and homograft reintervention after 15 years was 92.0% and 97.2%, respectively. Late events were autograft endocarditis in 14 patients (0.11% per patient-year), homograft endocarditis in 11 patients (0.08% per patient-year), and stroke in 37 patients (0.3% per patient-year). Conclusions and Relevance: Given its excellent short-term and long-term outcome in young and middle-aged adults in this study, the Ross procedure should be considered in young and middle-aged adults who require aortic valve replacement. Patients should be referred to an experienced center with a program dedicated to the Ross procedure.

Pulmonary Valve Function Late After Ross Procedure in 443 Adult Patients.

BACKGROUND: Limited data exist on long-term pulmonary valve function after the Ross procedure. This study sought to determine the long-term function of the pulmonary valve in 443 consecutive adult patients who underwent a Ross procedure. METHODS: All 443 patients who underwent a Ross procedure between November 1992 and March 2018 were reviewed retrospectively. All underwent pulmonary valve replacement using a cryopreserved pulmonary allograft. Freedom from the study's outcomes were calculated using Kaplan Meier survival. Risk factors for valve failure were analyzed using Cox regression. RESULTS: Mean age at time of operation was 39 years (range: 15-66 years). There was 1 (0.2%, 1 of 443) operative mortality. Nine patients required reintervention on the pulmonary allograft at a mean 6.1 years (range: 1-12 years) after Ross procedure. Patients required pulmonary allograft reintervention for infective endocarditis (n = 4), severe pulmonary stenosis (n = 4), or severe pulmonary regurgitation (n = 1). Freedom from pulmonary allograft reintervention was 98.9% (95% confidence interval [CI] 97.1%-99.6%), 97.7% (95% CI 95.1%-98.9%), 96.6% (95% CI 93.3%-98.3%), and 96.6% (95% CI 93.3%-98.3%) at 5, 10, 15, and 20 years, respectively. Freedom from pulmonary allograft dysfunction (at least moderate pulmonary regurgitation and/or mean systolic gradient ≥ 25 mm Hg and/or reintervention) was 94.5% (95% CI 91.6%-96.4%), 88.1% (95% CI 83.6%-91.4%), 84.9% (95% CI 79.6%-88.9%), and 78.3% (95% CI 69.5%-84.9%) at 5, 10, 15, and 20 years, respectively. No risk factors were identified to influence pulmonary valve durability. CONCLUSIONS: The pulmonary valve allograft gives excellent long-term function when used in adults undergoing the Ross procedure. Reintervention on the pulmonary valve is rare and significant pulmonary allograft dysfunction is uncommon.

The Ross procedure in adults presenting with bicuspid aortic valve and pure aortic regurgitation: 85% freedom from reoperation at 20 years.

OBJECTIVES: The Ross procedure has demonstrated excellent results when performed in patients with aortic stenosis or mixed aortic valve disease [aortic stenosis and aortic regurgitation (AR)]. However, due to its reported risk of late reoperation, it is not recommended under current guidelines for patients presenting with bicuspid aortic valve and pure AR. We have analysed our own results in light of this recommendation. METHODS: Between 1993 and 2016, 129 consecutive patients with a mean age of 34.7 ± 10.6 years (range 16-64 years) presented with bicuspid aortic valve and pure AR and underwent the Ross procedure. Patients were reviewed annually and had 2nd yearly transthoracic echocardiograms during follow-up. The unit had a liberal reoperation policy where reoperation was performed if patients developed recurrent moderate or greater AR during follow-up. RESULTS: There was 1 inpatient death, and 3 late deaths over a mean follow-up duration of 9.6 ± 6.8 years. Late survival at 10 and 20 years post-surgery were 99% [95% confidence interval (CI) 94-100] and 95% (95% CI 85-99), respectively. Eleven patients underwent redo aortic valve replacement (AVR) and 4 patients had redo pulmonary valve replacement. Freedom from reoperation for AVR and more-than-mild AR at 10 and 20 years post-surgery were 89% (95% CI 81-94) and 85% (95% CI 74-92), respectively. Having longer aortic cross-clamp (hazard ratio 1.03, 95% CI 1.00-1.06; P = 0.05) and cardiopulmonary bypass times (hazard ratio 1.02, 95% CI 1.00-1.05; P = 0.05), and having a larger preoperative sinotubular junction diameter (hazard ratio 1.15, 95% CI 1.03-1.30; P = 0.02) were significant predictors of having redo AVR or significant AR at follow-up. CONCLUSIONS: With a 20-year freedom from redo AVR and greater-than-mild residual AR of 85%, the utilization of the Ross procedure in bicuspid aortic valve patients with pure AR should be considered.

Improved Survival After the Ross Procedure Compared With Mechanical Aortic Valve Replacement.

BACKGROUND: It is unclear whether the Ross procedure offers superior survival compared with mechanical aortic valve replacement (AVR). OBJECTIVES: This study evaluated experience and compared long-term survival between the Ross procedure and mechanical AVR. METHODS: Between 1992 and 2016, a total of 392 Ross procedures were performed. These were compared with 1,928 isolated mechanical AVRs performed during the same time period as identified using the University of Melbourne and Australia and New Zealand Society of Cardiac and Thoracic Surgeons' Cardiac Surgery Databases. Only patients between 18 and 65 years of age were included. Propensity-score matching was performed for risk adjustment. RESULTS: Ross procedure patients were younger, and had fewer cardiovascular risk factors. The Ross procedure was associated with longer cardiopulmonary bypass and aortic cross-clamp times. Thirty-day mortality was similar (Ross, 0.3%; mechanical, 0.8%; p = 0.5). Ross procedure patients experienced superior unadjusted long-term survival at 20 years (Ross, 95%; mechanical, 68%; p < 0.001). Multivariable analysis showed the Ross procedure to be associated with a reduced risk of late mortality (hazard ratio: 0.34; 95% confidence internal: 0.17 to 0.67; p < 0.001). Among 275 propensity-score matched pairs, Ross procedure patients had superior survival at 20 years (Ross, 94%; mechanical, 84%; p = 0.018). CONCLUSIONS: In this Australian, propensity-score matched study, the Ross procedure was associated with better long-term survival compared with mechanical AVR. In younger patients, with a long life expectancy, the Ross procedure should be considered in centers with sufficient expertise.

Total Arterial Revascularization: A Superior Strategy for Diabetic Patients Who Require Coronary Surgery.

BACKGROUND: Recent large randomized trials and metaanalyses have shown that, for patients with diabetes mellitus and advanced coronary artery disease, coronary artery bypass graft surgery (CABG) was superior to percutaneous intervention. We investigated whether total arterial revascularization (TAR) conferred an additional survival advantage for diabetic patients having CABG. METHODS: We reviewed 63,592 cases from an audited, collaborative Australian cardiac surgical database. A total of 34,181 patients undergoing first time isolated CABG from 2001 to 2012 were identified. Of the 34,181, 11,642 (34.1%) were diabetic patients, and TAR was performed in 12,271 of 34,181 (35.9%). Of the 11,642 diabetic patients, TAR was performed in 3,795 (32.6%) and non-TAR in 7,847 (67.4%). Propensity matching resulted in 6,232 matched pairs of patients who did and patients who did not have TAR. Data were linked to the National Death Index. RESULTS: In the propensity matched sample, of 6,232 diabetic patients, 2,017 (32.4%) underwent TAR and 1,967 (31.6%) did not (p = 0.337). Mean follow-up was 4.9 years. Perioperative mortality, including 30-day mortality, was similar: 1.2% (24 of 2,017) for TAR and 1.4% (28 of 1,967) for non-TAR (p = 0.506). Late mortality was less among diabetic patients who underwent TAR, 10.2% (205 of 2,017), than no TAR, 12.2% (240 of 1,967; p = 0.041). Kaplan-Meier survival for the diabetic TAR group at 1, 5, and 10 years was 96.2%, 88.9%, and 82.2%, respectively, versus 95.4%, 87.5%, and 78.3% for the diabetic non-TAR group (log rank, p = 0.036). CONCLUSIONS: In a large propensity matched cohort of patients having CABG, TAR demonstrated further long-term prognostic benefit for diabetic patients, in the context of equivalent perioperative mortality.

Total Arterial Revascularization: Achievable and Prognostically Effective-A Multicenter Analysis.

BACKGROUND: Total arterial revascularization (TAR) is adopted to overcome late vein graft atherosclerosis, and occlusion. Uptake of TAR remains low despite reports suggesting superior survival. Previous studies primarily involved single sites and short-term follow-up. We report the influence of TAR on long-term survival in a large multicenter patient cohort. METHODS: We reviewed 63,592 cases from an audited collaborative multicenter database. Of those, 34,181 consecutive patients undergoing first-time isolated coronary artery bypass (CABG) from 2001 to 2012 were studied. The data were linked to the National Death Index. We compared outcomes in patients who underwent TAR (n = 12,271) with outcomes in those who did not (n = 21,910). The influence of TAR on 10-year all-cause late mortality was assessed by propensity score analyses in 6,232 matched pairs. RESULTS: The 30-day mortality was 0.8% (96/12,271) for TAR patients and 1.8% (398/21,910) for non-TAR patients (p < 0.001). Late mortality was 7.5% (918/12,271) for TAR patients and 8.9% (1,952/21,910) for non-TAR patients (p < 0.001). The mean follow-up time was 4.9 years. In the propensity-matched cohort, the perioperative mortality was 0.9% (53/6,232) for TAR patients versus 1.2% (76/6,232) for non-TAR patients (p < 0.001). Kaplan-Meier survival in the matched cohort at 1, 5, and 10 years was 97.2%, 91.3%, and 85.4% for TAR patients and 96.5%, 90.1%, and 81.2% for non-TAR patients (p < 0.001). Late mortality was 8.0% (n = 500) for TAR patients and 10.0% (n = 622) for non-TAR patients (p < 0.001). Stratified Cox proportional hazards models showed lower risk for all-cause late mortality in the TAR group (TAR:HR 0.80, 95% confidence interval 0.71 to 0.90, p < 0.001). CONCLUSION: TAR is associated with low perioperative mortality and, importantly, improved long-term survival and could be used more liberally.

The Ross procedure using autologous support of the pulmonary autograft: techniques and late results.

OBJECTIVES: It is hypothesized that by performing radical aortic root manipulation and then autologous support for the pulmonary autograft in the Ross procedure, this will maintain aortic root size and should, in turn, lead to the demonstrated low incidence of late aortic regurgitation and need for reoperation on the aortic root and valve. METHODS: Aortic root size was measured echocardiographically both preoperatively and then at second yearly intervals in 322 consecutive patients who underwent a Ross operation between October 1992 and June 2013 with autologous support of the pulmonary autograft root using the patient's own aorta. This technique, a variant of the inclusion cylinder method, has been developed with the aim of minimizing prosthetic materials in the aortic root. RESULTS: Measures to reduce aortic root size included annulus reduction in 201 patients (62.4%) and reduction in aortic sinus or sinotubular junction in 159 patients (49.4%). Maximal aortic root diameter postoperatively at 5, 10, and 15 years was 34.0, 34.6, and 34.7 mm, respectively. Eleven reoperations were required during the study period for progressive aortic regurgitation (none for aortic root enlargement), with freedom from reoperation being 96% at both 15 years and 18 years. Preoperative pure aortic regurgitation, aortic annulus, and sinotubular junction enlargement were risk factors for reoperation. CONCLUSIONS: This inclusion method of pulmonary autograft implantation leads to minimal increases in aortic root size over time, with no reoperations for aortic root dilatation and a low requirement for aortic valve reoperation. The Ross procedure deserves to remain on the surgical menu for aortic valve replacement.

Twenty-year analysis of autologous support of the pulmonary autograft in the Ross procedure.

BACKGROUND: The Ross procedure is seldom offered to adults less than 60 years of age who require aortic valve replacement except in a few high-volume centers with documented expertise. Inserting the pulmonary autograft as an unsupported root replacement may lead to increasing reoperations on the aortic valve in the second decade. METHODS: Of 333 patients undergoing the Ross procedure between October 1992 and June 2012, the study group of 310 consecutive patients (mean age ± standard deviation, 39.3±12.7 years (limits 16-63) had the aortic root size adjusted to match the pulmonary autograft, which was inserted as a root replacement, with the aorta closed up around it to provide autologous support. RESULTS: The mean follow-up time was 9.4 years; the actuarial survival was 97% at 16 years; and freedom from the composite of all reoperations on the aortic valve and late echocardiographic-detected aortic regurgitation greater than mild was 95% at 5 years, 94% at 10 years, and 93% at 15 years. Overall freedom from all reoperations on aortic and pulmonary valves was 97% at 5 years, 94% at 10 years, and 93% at 15 years. All results were better for the patients presenting with predominant aortic stenosis (98% freedom at 15 years) than for those with aortic regurgitation (p=0.01). CONCLUSIONS: Autologous support of the pulmonary autograft leads to excellent results in the groups presenting with aortic stenosis and mixed aortic stenosis/regurgitation and to good results for those presenting with pure aortic regurgitation. The Ross procedure, using one of the proven, durable techniques available, should be considered for more widespread adoption.

Inclusion cylinder method for aortic valve replacement utilising the Ross operation in adults with predominant aortic stenosis - 99% freedom from re-operation on the aortic valve at 15 years.

BACKGROUND: To report our experience with the Ross operation in patients with predominant aortic stenosis (AS) using an inclusion cylinder (IC) method. METHODS: Out of 324 adults undergoing a Ross operation, 204 patients of mean age of 41.3 years (limits 16-62) underwent this procedure for either AS or mixed AS and regurgitation (AS/AR) between October, 1992 and February, 2012, implanting the PA with an IC method. Clinical follow up and serial echo data for this group is 97% complete with late mortality follow up 99% complete. RESULTS: There has been zero (0%) early mortality, and late survival at 15 years is 98% (96%, 100%). Only one re-operation on the aortic valve for progressive aortic regurgitation (AR) has been required with freedom from re-operation on the aortic valve at 15 years being 99% (96%, 100%). The freedom from all re-operations on the aortic and pulmonary valves at 15 years is 97% (94%, 100%). Echo analysis at the most recent study shows that 98% have nil, trivial or mild AR. Aortic root size has remained stable, shown by long-term (15 year) echo follow up. CONCLUSIONS: In an experience spanning 19 years, the Ross operation used for predominant AS using the IC method described, results in 99% freedom from re-operation on the aortic valve at 15 years, better than any other tissue or mechanical valve. For adults under 65 years without significant co-morbidities who present with predominant AS, the pulmonary autograft inserted with this technique gives excellent results.

Does prior percutaneous coronary intervention adversely affect early and mid-term survival after coronary artery surgery?

OBJECTIVES: To determine the association between previous percutaneous coronary intervention (PCI) and results after coronary artery bypass graft surgery (CABG). BACKGROUND: Increasing numbers of patients undergoing CABG have previously undergone PCI. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Contemporary results show repeat coronary artery bypass grafting remains a risk factor for operative mortality.

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

Short- and midterm outcomes of coronary artery bypass surgery performed by surgeons in training.

OBJECTIVE: The effect of training on outcomes in cardiac surgery is poorly studied. We aimed to study the results of coronary artery bypass grafting procedures performed by surgeons in training across our state with respect to short- and midterm postoperative outcomes. METHODS: All coronary artery bypass grafting surgeries performed by trainee surgeons between July 2001 and December 2006 were compared with those performed by consultant surgeons using mandatory prospectively collected statewide data. Early mortality; prolonged ventilation or intensive care unit stay; return to operating theater for bleeding, stroke, myocardial infarction, or renal failure; and 5-year survival were compared using propensity score analysis. RESULTS: A total of 7745 surgeries were included in this study. Trainees performed 983 (13%) surgeries. Trainee surgeries had longer perfusion and crossclamp times. Crude early postoperative outcomes were similar between trainee and consultant surgeries. After propensity score adjustment, early outcomes remained similar, with the exception of myocardial infarction (0.8% in trainee surgeries vs 0.4% in consultant surgeries, P = .046). Adjusted 1-, 3-, and 5-year survivals were similar between trainee and consultant surgeries: 95.3% versus 95.5%, 90.8% versus 92.0%, and 86.3% versus 87.1%, respectively. CONCLUSION: Coronary artery bypass grafting performed by trainee surgeons within a supervised program is safe with acceptable short- and midterm outcomes.

Clinical characteristics and early mortality of patients undergoing coronary artery bypass grafting compared to percutaneous coronary intervention: insights from the Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) and the Melbourne Interventional Group (MIG) Registries.

OBJECTIVES: Controversy continues over the optimal revascularisation strategy for patients with multi-vessel coronary artery disease. Clinical characteristics, risk profile, and mortality of patients undergoing coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) are thought to differ but there are limited contemporary comparative data. METHODS: We compared clinical characteristics, in-hospital and 30-day mortality of 3841 consecutive patients undergoing isolated CABG and 4417 undergoing PCI. Independent predictors of 30-day mortality were determined by multiple logistic regression analysis. RESULTS: CABG patients were older (p<0.01). The CABG group had a higher incidence of diabetes, heart failure, left ventricular ejection fraction <45%, multi-vessel coronary artery, peripheral vascular and cerebro-vascular disease (all p<0.01). Patients undergoing PCI had a higher incidence of recent myocardial infarction (MI) as the indication for revascularisation (p<0.01). In-hospital and 30-day mortality was 1.8% and 1.7% in the CABG group, and 1.4% and 1.8% in the PCI group, respectively. Independent predictors of 30-day mortality after CABG were age (odds ratio 1.1 per year, 95% confidence interval 1.0-1.1), cardiogenic shock (4.10, 1.7-10.5) and previous CABG (6.6, 2.4-17.7). Predictors after PCI were diabetes (2.7, 1.4-5.1), female gender (3.0, 1.6-5.5), renal failure (3.2, 1.2-8.0), MI<24h (4.0, 2.2-7.6), left main intervention (5.4, 1.0-27.7), heart failure (6.0, 2.6-14.0) and cardiogenic shock (11.7, 5.4-25.2). CONCLUSIONS: In contemporary clinical practice, CABG is preferred in patients with multi-vessel coronary and associated non-coronary vascular disease, while PCI is the dominant strategy for acute MI. Despite this, in-hospital and 30-day mortality rates were similar. Predictors of early mortality after CABG differ to those of PCI.

Human leukocyte antigen mismatch and other factors affecting cryopreserved allograft valve function.

The causes of cryopreserved allograft heart valve degeneration are poorly understood. We investigated HLA mismatch and other factors implicated in allograft valve degeneration. For this study we recruited 110 adult recipients of allograft heart valves who underwent surgery between June 1998 and March 2003 in the state of Victoria, Australia. Recipients and donors were HLA typed using serological and molecular methods. Valve function at most recent echocardiographic follow-up was examined for an association with the following variables using univariate and multivariate methods: HLA-A,-B, and -DR donor-recipient mismatch; HLA class I mismatch; total HLA mismatch; valve ischemic time; recipient age; donor age; ABO blood group donor-recipient match; and allograft size. Mean recipient age was 45 years (18-75 years), 75% were men. Seventy-four pulmonary (62 Ross procedure) and 36 aortic allografts were examined. Median valve ischemic time was 31 hours, range 20-48 hours. Echocardiographic follow-up was complete at a mean of 41 (+/-18) months, range 6-85 months. At univariate analysis longer ischemic time and younger recipient age were associated with valve dysfunction. HLA-A, -B, or DR mismatch, HLA class I mismatch, total HLA mismatch, donor age, ABO mismatch, and allograft size were not associated with valve dysfunction. Only younger recipient age remained significant at multivariate analysis. In conclusion, longer ischemic times and younger patient age predicted valve dysfunction at a mean of 3 years follow-up. Recipient age remained the strongest predictor of valve dysfunction. These results indicate that allograft ischemic times should be minimized.

Anti-HLA antibodies after cryopreserved allograft valve implantation does not predict valve dysfunction at three-year follow up.

BACKGROUND AND AIM OF THE STUDY: As the cause of allograft heart valve degeneration is poorly understood, the study aim was to investigate the host antibody response to allograft valve implantation. METHODS: Sera were obtained from 92 recipients of allograft heart valves (61 pulmonary, 31 aortic). Sera were tested for anti-HLA class I antibodies by ELISA and complement-dependent cytotoxicity (CDC) methods, and anti-HLA class II antibodies by ELISA. Specificities of recipient anti-HLA class I antibodies were defined by standard CDC testing against a panel of T lymphocytes from 80 blood donors. Donor valve HLA typing was performed on stored donor DNA samples using molecular methods. The presence of donor-specific anti-HLA class I antibodies was hence defined in recipient sera. The presence of anti-HLA antibodies and donor-specific anti-HLA class I antibodies were correlated with function of allograft valves at the most recent echocardiographic follow up. RESULTS: At a mean of 3.0 years (range: 0.3-5.4 years) after allograft implantation, 96% (87/92) and 82% (75/92) of patients were positive for anti-HLA class I and II antibodies, respectively, by ELISA testing. Some 68% (61/90) of patients were positive for anti-HLA class I antibody (PRA > 5%) by CDC testing. PRA levels decreased with greater postoperative interval (r = -0.31, p = 0.003). In 68 recipients where donor HLA type was defined, 54% (37/68) of patients had antibodies specific to at least one donor HLA class I antigen. In 87 patients with a recent echocardiographic examination available for analysis (at a mean of 3.5 +/- 1.6 years postoperatively), there was no association between valve dysfunction and antibody status. CONCLUSION: Anti-HLA class I and II antibodies were detected by ELISA methods in most patients after allograft implantation extending to 5.4 years. The clinical significance of these findings is unclear, as no correlation was found between the prevalence of anti-HLA antibody and echocardiographic parameters of valve dysfunction at a mean of 3.5 years follow up.

Validation of the EuroSCORE model in Australia.

OBJECTIVE: There is an important role for accurate risk prediction models in current cardiac surgical practice. Such models enable benchmarking and allow surgeons and institutions to compare outcomes in a meaningful way. They can also be useful in the areas of surgical decision-making, preoperative informed consent, quality assurance and healthcare management. The aim of this study was to assess the performance of the European System for Cardiac Operative Risk Evaluation (EuroSCORE) model on the Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) patient database. METHODS: The additive and logistic EuroSCORE models were applied to all patients undergoing cardiac surgery at six institutions in the state of Victoria between 1st July 2001 and 4th July 2005 within the ASCTS database who have complete data. The entire cohort and a subgroup of patients undergoing coronary artery bypass grafting (CABG) only were analysed. Observed and predicted mortalities were compared. Model discrimination was tested by determining the area under the receiver operating characteristic (ROC) curve. Model calibration was tested by the Hosmer-Lemeshow chi-square test. RESULTS: Eight thousand three hundred and thirty-one patients with complete data were analysed. There were significant differences in the prevalence of risk factors between the ASCTS and European cardiac surgical populations. Observed mortality was 3.20% overall and 2.00% for the CABG only group. The EuroSCORE models over estimated mortality (entire cohort: additive predicted 5.31%, logistic predicted 8.76%; CABG only: additive predicted 4.25%, logistic predicted 6.19%). Discriminative power of both models was very good. Area under ROC curve was 0.83 overall and 0.82 for the CABG only group. Calibration of both models was poor as mortality was over predicted at nearly all risk deciles. Hosmer-Lemeshow chi-square test returned P-values less than 0.05. CONCLUSIONS: The additive and logistic EuroSCORE does not accurately predict outcomes in this group of cardiac surgery patients from six Australian institutions. Hence, the use of the EuroSCORE models for risk prediction may not be appropriate in Australia. A model, which accurately predicts outcomes in Australian cardiac surgical patients, is required.