Ground glass opacity: can we correlate radiological and histological features to plan clinical decision making?

BACKGROUND: The spectrum of ground glass opacity (GGO) is a diagnostic and clinical management quandary. The role of computed tomographic scans in detecting malignant GGO has inter-observer variability. Pure GGO have been traditionally thought to be predominantly benign in nature and has long volume doubling times. This study was undertaken to correlate the findings of radiology and histology of ground glass opacities at our institute. METHODS: This study is a retrospective observational study of patients who underwent lung resection surgery for radiology proven ground glass opacities between January 2010 and December 2018. A total of 115 patients were included in the study based on inclusion and exclusion criteria and were analysed. RESULTS: The patients were divided into two groups; pure GGO (n = 50), mixed GGO (n = 65). The pathological tumour size was ≤ 2 cm in 51% of the patients and 27 patients had the size between 2.1 and 3.0 cm. The predominant histopathologic feature was lepidic predominance in 54 patients followed by 24 patients with acinar predominance. Among patients with radiological tumour size of ≤ 2 cm, pure GGO was present in 48% of the patients. Among patients with pure GGO, 96% of the patients had no solid component. 44 patients had only single CT scan before proceeding to surgery. All these patients had mixed GGO. CONCLUSION: Our study concludes pure GGOs, though lacking solid component have a high propensity to be malignant. The role of repeated CT surveillance in this context without offering curative surgery may be questionable.

Meta-Analysis of Mitral Valve Repair Versus Replacement for Rheumatic Mitral Valve Disease.

BACKGROUND: Rheumatic heart disease remains one of the leading causes of heart valve disease worldwide despite being a preventable condition. Mitral valve repair is superior to replacement in severe degenerative mitral valve disease, however its role in rheumatic valve disease remains controversial. This meta-analysis compared mitral valve repair and replacement in rheumatic heart disease. METHODS: Medline, EMBASE, Cochrane and Scopus were searched from January 1980 to June 2016 for original studies reporting outcomes of both mitral valve repair and replacement in rheumatic heart disease in adults, children or both. Two (2) authors independently assessed studies for inclusion, followed by data extraction and analysis. RESULTS: The search yielded 930 articles, with 98 full-texts reviewed after initial screening and 13 studies subsequently included for analysis, totalling 2,410 mitral valve repairs and 3,598 replacements. Pooled rates and odds ratio (95% confidence interval) for operative mortality of repair versus replacement was 3.2% versus 4.3%, 0.68 (0.50-0.92; p=0.01). Pooled odds ratios (95% confidence interval) were for long-term mortality 0.41 (0.30-0.56; p<0.001); reoperation 3.02 (1.72-5.31; p<0.001); and bleeding 0.26 (0.11-0.63; p=0.003). There was a trend towards lower thrombo-embolism 0.42 (0.17-1.03; p=0.06), and no significant difference in endocarditis (p=0.76), during follow-up. CONCLUSION: Mitral valve repair is associated with reduction in operative and long-term mortality and bleeding, so is recommended in rheumatic mitral valve disease where feasible, but it does entail a higher rate of reoperation during follow-up.

Surgery for Type A Aortic Dissection: 14-Year Contemporary Cohort Study.

BACKGROUND: Type A aortic dissection is a fatal condition warranting emergency surgery to prevent complications and death. We reviewed the contemporary trends, characteristics, outcomes and predictors of this operation at our centre over a 14-year period. METHODS: Consecutive patients undergoing type A aortic dissection surgery at Auckland City Hospital during March 2003-March 2017 were studied, and relevant characteristics and outcomes collected prospectively for statistical analyses. RESULTS: There were 327 patients included, and the number of operations each year remained similar from 2003-2010, and steadily increased thereafter. Median age was 60.6 years, with 124 (37.9%) females, 136 (41.6%) Maori or Pacific ethnicity, 319 (97.6%) emergency surgeries, 62 (19.0%) in a critical preoperative state and 154 (47.1%) having a malperfusion syndrome. Operative mortality occurred in 65 (19.9%), although this has decreased from 23.3% before 2014 to 14.0% since. Composite morbidity occurred in 212 (65.0%), predominantly acute kidney injury 134 (41.0%), ventilation >24 hours (129 (39.6%), return to theatre 94 (28.8%) and stroke 63 (19.3%). Survival at 1, 5 and 10 years was 79.0%, 71.7% and 57.8% respectively. Critical preoperative state and malperfusion syndrome were independent predictors of operative and long-term mortality and composite morbidity. CONCLUSION: Surgery for acute type A aortic dissection has been increasing since 2011 and continues to have high rates of operative mortality and morbidities, although the former has decreased since 2014. Critical preoperative state and malperfusion were the key predictors of adverse outcomes. After surviving the perioperative period, prognosis was good with low rates of late mortality.

Characteristics and Outcomes of Patients With Severe Aortic Stenosis Discussed by the Multidisciplinary "Heart Team" According to Treatment Allocation.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is an alternative and effective contemporary intervention to surgical aortic valve replacement (SAVR) for patients with severe aortic valve disease at increased surgical risk. Guidelines recommend a multidisciplinary "Heart Team" (MHT) review of patients considered for a TAVI procedure, but this has been little studied. We reviewed the characteristics, treatments and outcomes of such patients reviewed by the MHT at our centre. METHODS: Data on consecutive patients with severe aortic valve stenosis discussed by the Auckland City Hospital MHT from June 2011 to August 2016 were obtained from clinical records. Patient characteristics, treatment and outcomes were analysed using standard statistical methods. RESULTS: Over the 5-year period 243 patients (mean age 80.2 ± 8.0 years, 60% male) were presented at the MHT meeting. TAVI was recommended for 200, SAVR for 26 and medical therapy for 17 patients, with no significant difference in mean age (80.2 ± 8.3, 80.4 ± 6.1, 80.4 ± 7.3 years, respectively) or EuroSCORE II (6.5 ± 4.7%, 5.3 ± 3.6%, 6.7 ± 4.3%, respectively). Over time, there was an increase in the number of patients discussed and treated, with no change in their mean age, but the mean EuroSCORE II significantly decreased (TAVI p = 0.026, SAVR p = 0.004). Survival after TAVI and SAVR was similar to that of the age-matched general population, but superior to medical therapy p = 0.002 (93% (n = 162), 84% (n = 21) and 73% (n = 18) at one year and 85% (n = 149), 84% (n = 21) and 54% (n = 13) at 2 years, respectively). CONCLUSIONS: An increasing number of patients were discussed at the MHT meeting with the majority undergoing TAVI, with a similar age and EuroSCORE II to those allocated SAVR or medical therapy. Survival following TAVI and SAVR was superior to medical therapy and similar to the age-matched general population. These findings suggest that the MHT process is robust, consistent and appropriately allocating a limited treatment resource.

Transcatheter Aortic Valve Implantation In Patients With a Large Aortic Annulus.

BACKGROUND: As the indications for transcatheter aortic valve implantation (TAVI) have expanded, so to have the demands on interventionists to allow as many patients to access this technology as possible. METHODS: We retrospectively reviewed our TAVI database for patients who had received a 29mm SAPIEN 3 valve despite having an annular area greater than the manufacturer-recommended upper limit of 683mm2, as determined by multi-detector computed tomography (MDCT). Procedural and inpatient outcome data were collected. RESULTS: The study population was 5 of 121 patients receiving a SAPIEN 3 valve since it became available in March 2015. Their annular area ranged from 691 to 800mm2. Valve deployment was successful in all patients. The deployment balloon volume was nominal, except for an additional 1ml in one patient. No patient had a new indication for permanent pacing, and no significant valvular or paravalvular regurgitation (PVR) was identified on post-procedure transthoracic echocardiography. All patients survived to hospital discharge. CONCLUSIONS: In this select group of patients we have demonstrated that it is safe and feasible to use the 29mm SAPIEN 3 in patients with annular dimensions greater than those recommended, with minimal balloon overfilling.

Performance of contemporary surgical risk scores for mitral valve surgery.

BACKGROUND: Risk stratification for mitral valve repair or replacement (MVR) is important in the decision-making for treating several mitral valve disease but is rarely studied. We compared the prognostic utility of EuroSCORE, EuroSCORE II, and Society of Thoracic Surgeons (STS) Score for MVR. METHODS: The three scores were retrospectively calculated for consecutive patients undergoing isolated MVR at Auckland City Hospital during 2005-2012 and their discrimination and calibration for mortality and morbidities assessed. RESULTS: There were 408 patients (mitral valve repair 48.1% and replacement 51.9%) followed-up for 6.0 ± 2.6 years. The operative mortality was 2.5%. Mean EuroSCORE, EuroSCORE II, and STS Score were 7.6%, 3.4%, and 3.5%. C-statistics were 0.844, 0.817, and 0.850 for operative mortality. Hosmer-Lemeshow test p values were 0.076, 0.541, and 0.306, and Brier scores 0.0246, 0.0035, and 0.0075, respectively, for operative mortality. The numerically highest c-statistic for predicting complications include EuroSCORE for return to the operating room (c = 0.673); EuroSCORE II for stroke (c = 0.669) and mediastinitis (c = 0.801); and STS for renal failure (c = 0.828), ventilation >24 hours (c = 0.789), and composite morbidity (c = 0.732). The individual STS complication models for MVR had a numerically higher c-statistic only for stroke (c = 0.737). CONCLUSIONS: All scores discriminated mortality and most morbidities after MVR, although EuroSCORE over-estimated operative mortality. The STS Score was the best overall predictor of mortality and morbidity in the MVR cohort.

Long-Term Outcomes in Patients Undergoing Consecutive Bioprosthetic Aortic Valve Replacement.

BACKGROUND AND AIM OF THE STUDY: Worldwide, there is increased use of bioprosthetic valves in the aortic position. Part of this increase has been patient-driven for quality of life reasons. More recently, bioprosthetic valves have been chosen by progressively younger patients, with a strategy of performing a valve-in-valve TAVI if the prosthesis should wear out. Thus, a review was undertaken of the present authors' experience with patients whose first two aortic valve replacements (AVRs) were with bioprosthetic valves. METHODS: Patients receiving consecutive bioprosthetic AVRs at the Green Lane Cardiothoracic Surgical Unit were identified from a departmental database. Data were retrieved from prospective databases, electronic and archived clinical records. Outcomes of interest were overall survival and freedom from a third or more AVR. RESULTS: A total of 267 patients met the inclusion criteria, with a mean follow up of 22.3 years. Concurrent procedures (e.g., coronary artery bypass grafting) were performed in 65.2% of patients that underwent two bioprosthetic AVRs, and in 79.8% of patients undergoing three or more bioprosthetic AVRs. Median survival of the cohort was 31.7 years. Age at operation was the best predictor of needing a third or more AVR. Receiver operating characteristic curve analysis identified that age <45 years at the first operation and <56 years at the second operation were the optimal cut-off point for the likelihood of needing a third or more aortic valve intervention. CONCLUSIONS: Overall survival for consecutive bioprosthetic AVRs was remarkably good. Data relating to consecutive bioprosthetic AVRs is of particular interest in the context of TAVI and valve-in-valve TAVI, which will likely significantly increase the number of patients receiving consecutive bioprosthetic valves. However, it must be noted that the majority of patients in this cohort required concurrent cardiac surgical procedures. The study results provided encouraging data for consecutive bioprosthetic AVRs, as well as data that may be of interest in the setting of TAVI being performed in younger cohorts of patients.

Relationship Between Diabetic Variables and Outcomes After Coronary Artery Bypass Grafting in Diabetic Patients.

BACKGROUND: Nearly half of the patients undergoing coronary artery bypass grafting (CABG) have diabetes. There is mixed data as to whether preoperative (haemoglobin A1c{HbA1c}) and/or perioperative diabetes control is associated with mortality and morbidity after CABG. We reviewed the characteristics and outcomes of diabetic patients undergoing CABG with a focus on HbA1c, perioperative glucose levels and diabetic treatment regimens. METHODS: Diabetic patients undergoing CABG during July 2010 to June 2012 were studied (n=306). The last preoperative HbA1c levels, and perioperative glucose levels (mean and coefficient of variation {CV}) were retrospectively recorded, as well as the pre-existing and perioperative diabetes treatment regimens for analyses. RESULTS: Mean HbA1c was 7.7+/-1.6%, and 11.1% (34), 56.2% (172), and 32.7% (100) of patients were managed preoperatively with diet only, oral diabetic medications and insulin respectively. For operative mortality which occurred in 2.0%, C-statistics (95% confidence interval) was only significant for HbA1c, 0.855 (0.757-0.975), and glucose CV on the day of surgery, 0.722 (0.567-0.877). HbA1c also detected postoperative renal failure, C-statistic 0.617 (0.504-0.730), but not other complications or mortality during follow-up. In multivariate analysis, HbA1c was the only diabetes-related independent predictor of operative mortality, hazards ratio 4.13 (1.04-16.4), and none of the diabetes-related variables predicted mortality during follow-up or other postoperative complications. CONCLUSION: Preoperative HbA1c was the only diabetic variable to independently predict operative mortality after CABG, suggesting medium-term preoperative diabetes control is more important and prognostic of operative outcomes than perioperative diabetes control.

Aortic Valve Replacement With or Without Concurrent Coronary Artery Bypass Grafting in Octogenarians: Eight-Year Cohort Study.

BACKGROUND: With the introduction of transcatheter aortic valve implantation (TAVI), there is increasing interest in evaluating outcomes of aortic valve replacement (AVR) with or without (+/-) concurrent coronary artery bypass grafting (CABG) particularly in high-risk patients. We reviewed the characteristics and outcomes of octogenarians undergoing isolated AVR and AVR+CABG. METHODS: All patients 80 years of age or older undergoing AVR+/-CABG at Auckland City Hospital during 2005-2012 were included, and their characteristics and outcomes analysed. RESULTS: There were 93 and 104 octogenarians respectively undergoing isolated AVR and AVR+CABG with mean follow-up of 4.4+/-2.2 years and 4.1+/-2.3 years. Significant differences in baseline and operative characteristics contributed to higher EuroSCORE II (5.9 vs 6.4%, P=0.016) and STS Score (4.9 vs 6.9%, P<0.001) for AVR+CABG patients. They also had a significantly higher rate of 30-day mortality (0.0% vs 6.7%, P=0.015) and prolonged ventilation>24hours (10.7% vs 23.1%, P<0.001), but not composite morbidity (P=0.248) or stroke (P=0.709). Long-term survival was similar at one, three and five years; 94.6%, 82.6% and 73.0% for AVR and 91.3%, 86.1% and 67.6% for AVR+CABG. Independent predictors of 30-day mortality included reduced creatinine clearance and history of myocardial infarction. CONCLUSION: AVR+CABG had significantly higher but acceptable 30-day mortality in octogenarians than AVR. We have identified prognostic factors important in the decision-making of treatment modality, where age alone should not preclude surgery.

Comparing Performance of Risk Scores for Combined Aortic Valve Replacement and Coronary Bypass Grafting Surgery.

BACKGROUND: Aortic valve replacement (AVR) and/or coronary artery bypass grafting (CABG) make up the majority of cardiac surgery with increasing demand as the population ages. Accuracy of risk stratification is important, in predicting adverse outcomes and selecting modality of intervention, but has been rarely studied for the combined AVR+CABG operation. We compared the prognostic utility of EuroSCORE, EuroSCORE II and Society of Thoracic Surgeons' (STS) Score for AVR+CABG. METHODS: All patients (n=450) undergoing AVR+CABG at Auckland City Hospital during 2005-2012 with mean follow-up of 4.7+/-2.5 years were included. The three risk scores were calculated and their discrimination and calibration for mortality and morbidities assessed. RESULTS: Operative mortality was 6.4% (29), and mean scores were EuroSCORE 12.5+/-11.1%, EuroSCORE II 6.6+/-6.1% and STS Score 5.5+/-4.4%. C-statistics were 0.587, 0.669 and 0.699 respectively for operative mortality, Hosmer-Lemeshow test P-values were 0.064, 0.718 and 0.567, and Brier Score 0.716, 0.585 and 0.588. Independent predictors of operative mortality were history of myocardial infarction and impaired renal function. Society of Thoracic Surgeons' score also was the most accurate score for predicting mortality during follow-up (c=0.663), composite morbidity (c=0.627), stroke (c=0.642), prolonged ventilation>24hours (c=0.642), and return to theatre (c=0.612). CONCLUSION: The STS score has the best discriminative ability for mortality and the majority of complications after AVR+CABG, while its calibration was similar to EuroSCORE II and superior to EuroSCORE. It should therefore be used for risk stratification and when considering surgical versus percutaneous intervention in those with concurrent aortic valve and coronary artery disease.

Early outcome of patients undergoing transcatheter aortic valve implantation (TAVI): The Auckland City Hospital experience 2011-2015.

AIMS: Transcatheter aortic valve implantation (TAVI) is an alternative to surgical aortic valve replacement (AVR) in high-risk patients. We report the initial TAVI experience at Auckland City Hospital. METHODS: The records of patients undergoing TAVI between 2011 and 2015 at Auckland City Hospital were reviewed. We report the procedural success and outcome, including major adverse events (death, stroke, myocardial infarction, bleeding, vascular complications and rehospitalisations), degree of aortic regurgitation and symptom status up to 1-year follow-up. RESULTS: Mean age was 80.7 years and mean Euroscore II and Society of Thoracic Surgeons' scores were 8.2% and 6.3% respectively; 50% had undergone previous cardiac surgery. Successful deployment of the valve was achieved in all patients. The cumulative mortality rates at 30 days, 6 months and 1 year were 2.4%, 6.1% and 12.2% and cumulative stroke rates 1.2%, 3% and 8.2% respectively. Severe aortic regurgitation occurred in 2.3% CONCLUSION: TAVI is available in the New Zealand public hospital system for patients who are high-risk candidates for AVR. Early results are excellent and indicate that the technology is being used appropriately, according to current access criteria. If the early cost effectiveness data are confirmed, the indications for TAVI may widen.

Preoperative atrial fibrillation predicts mortality and morbidity after aortic valve replacement.

OBJECTIVES: Atrial fibrillation (AF) is the commonest cardiac arrhythmia, becoming increasingly prevalent as the population ages. There is conflicting information around whether AF is associated with adverse outcomes after aortic valve replacement (AVR) from the few studies that have investigated this. We compared the characteristics and outcomes of patients undergoing AVR with their history of AF. METHODS: Isolated AVR patients at Auckland City Hospital 2005-2012 were divided into those with and without preoperative AF for comparative analyses. RESULTS: Of 620 consecutive patients, 19.2% (119) had permanent or paroxysmal AF preoperatively. Patients with AF were significantly older (70.5 vs 63.4 years, P < 0.001) and were more likely to be New Zealand European (82.4 vs 68.1%, P = 0.004). They also had higher prevalence of NYHA class III-IV (55.4 vs 37.4%, P = 0.004), inpatient operation (62.1 vs 48.3%, P = 0.008), history of stroke (10.9 vs 5.0%, P = 0.031), lower creatinine clearance (73 vs 82, P = 0.001) and higher EuroSCORE II (5.2 vs 3.4%, P < 0.001). Operative mortality (6.7 vs 2.0%, P = 0.012) and composite morbidity (27.7 vs 16.5%, P = 0.006) were also higher in patients with AF. After adjusting for significant variables, preoperative AF remained an independent predictor of operative mortality with an odds ratio of 3.44 (95% confidence interval 1.29-9.13), composite morbidity of 1.79 (1.05-3.04) and a mortality during follow-up hazards ratio of 2.36 (1.44-3.87). CONCLUSIONS: AF was associated with several cardiovascular and cardiac surgery risk factors, but remained independently associated with short- and long-term mortality. AF should be incorporated into cardiac surgery risk models and surgical AF ablation may be considered with AVR.

Comparison of four risk scores for contemporary isolated coronary artery bypass grafting.

BACKGROUND: EuroSCORE and the Society of Thoracic Surgeons' (STS) Score have been the most widely used risk scores for cardiac surgery. The revised EuroSCORE II and the AusSCORE, based on an Australasian population, were recently developed. We compared the prognostic utility of these four scores for mortality as well as morbidity in patients undergoing isolated coronary artery bypass grafting (CABG). METHODS: The scores were retrospectively calculated for isolated CABG patients at Auckland City Hospital during July 2010-June 2012. Discrimination and calibration of outcomes were assessed. RESULTS: 818 patients were followed for 1.6+/-0.6 years. Mortality at 30 days was 1.6% and 2.9% on follow up. Median predicted 30 day mortality (Interquartile range) for EuroSCORE I were 2.8% (1.6%, 5.2%), EuroSCORE II 1.6% (1.0%, 2.8%), STS Score 2.3% (1.3%, 4.5%) and AusSCORE 0.5% (0.2%, 1.1%). C-statistics and Hosmer-Lemeshow test p-values for these scores for 30-day mortality were Euro score I 0.675 (95%CI 0.531-0.819)/0.061, EuroSCORE II 0.642 (0.503-0.780)/0.150, STS Score 0.641 (0.507-0.775)/0.243 and AusSCORE 0.661 (0.516-0.807)/0.420. Only EuroSCORE I and STS scores were significant for predicting mortality at follow-up (c=0.639 and 0.666). All scores predicted composite morbidity. C-statistics were EuroSCORE I 0.678, EuroSCORE II 0.634, STS score 0.584 and AusSCORE 0.645. CONCLUSION: EuroSCORE II, STS Score and AusSCORE had slightly improved calibration but similar discrimination for 30-day mortality compared to EuroSCORE I. Revision of risk models to fit contemporary surgical outcomes is important, but there may only be modest room for improvement in discrimination.

Isolated aortic valve replacement in octogenarians before and after the introduction of trans-catheter aortic valve implantation.

BACKGROUND: Trans-catheter aortic valve implantation (TAVI) became available at Auckland City Hospital in 2011 for patients with severe aortic stenosis in whom surgical aortic valve replacement (AVR) was deemed at high risk. We assessed whether introduction of TAVI affected the characteristics and outcomes of octogenarians undergoing AVR. METHODS: Isolated AVR performed in patients ≥80 years of age during 2008-2012 were divided into two groups, pre- and post-TAVI introduction, for analyses. RESULTS: Isolated AVR was undertaken in 35 and 33 octogenarians pre- and post-TAVI introduction. The post-TAVI group were older (84.2 vs 82.3 years, P=0.003), had lower ejection fraction (P=0.026), more had inpatient surgery (76% vs 29%, P<0.001), with higher EuroSCORE II (5.4 vs 3.9%, P=0.033). Operative mortality was 0.0% in both groups. One-year survival was similar (97.6% vs 94.3%, P=0.613), but composite morbidity was lower in the post-TAVI group (9.1% vs 31.4%, P=0.035). Chronic respiratory disease (P=0.043) independently predicted mortality during follow-up, while number of coronary vessel>50% stenosis (P=0.050), creatinine clearance (P=0.016) and being in the pre-TAVI era group (P=0.022) predicted composite morbidity. CONCLUSIONS: Since TAVI was introduced, mean age and risk scores significantly increased in octogenarians undergoing AVR, while mortality rates remained similar and composite morbidity decreased.

Higher mortality in women undergoing coronary artery bypass grafting.

AIMS: While men have higher rates of cardiovascular disease, several studies report women having higher mortality after cardiac surgery, reasons for which are unclear. We compared characteristics and outcomes of coronary artery bypass grafting (CABG) by sex. METHODS: All patients undergoing isolated CABG during July 2010-June 2012 were grouped by sex for retrospective analyses. RESULTS: A total of 168 (20.5%) women and 650 (79.4%) men were included, followed-up for 1.4 plus or minus 0.6 years. Women were older (66.4 vs 64.0 years; p=0.007), with higher body mass index (30.1 vs 28.8 kg/m²; p=0.004), increased prevalence of hypertension (78.9% vs 67.8%; p=0.008), current smoking (20.2% vs 13.1%; p=0.027), chronic respiratory disease (22.6% vs 15.4%; p=0.028) and estimated glomerular filtration rate (74 vs 81 ml/min/1.73 m²; p=0.007). Women had less grafts performed (3.1 vs 3.3; p=0.014) and less use of radial grafts (14.9% vs 25.2%; p=0.004). Female sex was independently associated with higher 30-day mortality (4.8% vs 0.8%) odds ratio 5.63, 95% confidence interval 1.67-19.0; p=0.005 and medium-term mortality hazards ratio 2.49, 1.06-5.84; p=0.037 (1-year survival 93.9% vs 98.1%); but not surgical morbidity (21.4% vs 16.9%; p=0.661). CONCLUSION: Women had higher 30-day and medium-term mortality after CABG even after adjusting for higher prevalence of risk factors and comorbidities.

Lack of relationship between obesity and mortality or morbidity after coronary artery bypass grafting.

AIMS: Obesity has significant adverse effects on cardiovascular health. Conflicting results have been reported regarding relationships between body mass index (BMI) and outcomes after coronary artery bypass grafting (CABG). We compared outcomes of CABG patients by BMI categories. METHODS: Isolated CABG performed between July 2010-June 2012 at Auckland City Hospital were categorised into four groups of BMI ≤25 (normal), >25-30 (overweight), >30-35 (obese) and >35 kg/m² (morbidly obese) retrospectively for analyses. RESULTS: The four groups had 181(22.4%), 320 (39.6%), 205 (25.3%) and 103 (12.7%) patients respectively. Increasing BMI was associated with younger age (p<0.001) and increasing creatinine clearance (p<0.001). Obesity was associated with a higher proportion of patients of Maori or Pacific ethnicity and patients with more hypertension. Morbid obesity was associated with female sex, higher mean New Zealand Deprivation Index, diabetes, longer operation time and sternal wound infection. Thirty-day mortality (p=0.702), composite morbidity (p=0.904) and survival (p=0.112) during 1.4 ± 0.6 years of follow-up were similar across BMI categories. CONCLUSION: Obesity was common and was present in over a third of patients undergoing CABG with 13% of the entire cohort being morbidly obese. Mortality and morbidity rates did not differ across BMI categories. Obesity should not be considered a risk factor for adverse outcomes after CABG and should not be a contraindication for surgery.

Diagnosis of MI after CABG with high-sensitivity troponin T and new ECG or echocardiogram changes: relationship with mortality and validation of the universal definition of MI.

AIMS: Criteria for diagnosing myocardial infarction (MI) after coronary artery bypass grafting (CABG) are controversial. Uncertainties remain around the optimal threshold for biomarker elevation and the need for associated criteria. There are no studies of high-sensitivity troponin (hs-TnT) after CABG. We assessed whether using hs-TnT to define MI after CABG was associated with 30-day and medium-term mortality and evaluated the utility of adding to the troponin criteria new Q-waves or imaging evidence of new wall motion abnormality as suggested in the Universal Definition of MI. METHODS: Isolated CABG was performed in 818 patients from July 2010 to June 2012 and hs-TnT was measured 12-24 hours after CABG. Patients with rising baseline or missing troponins (n=258) were excluded. Thresholds of 140 ng/l (10-times 99th percentile upper reference limit) and 500 ng/l (10-times coefficient of variation of 10% for fourth-generation troponin T applied to hs-TnT) were prespecified. RESULTS: Mean follow up was 1.8±0.6 years. On multivariate analyses, isolated hs-TnT rise >140 ng/l (n=360) or >500 ng/l (n=162) were not associated with mortality. Additional ECG and/or echocardiographic criteria plus hs-TnT >140 ng/l was associated with 30-day mortality (hazard ratio, HR, 4.92, 95% CI 1.34-18.1; p=0.017) and medium-term mortality (HR 3.44, 95% CI 1.13-10.5; p=0.030), whereas ECG and/or echocardiographic abnormalities with hs-TnT >500 ng/l was not (p=0.281 and p=0.123 for 30-day and medium-term mortality, respectively). CONCLUSIONS: A definition for MI following CABG using hs-TnT with a cut point of 10-times 99th percentile upper reference limit and ECG and/or echocardiographic criteria predicts 30-day and medium-term mortality. These findings validate the Third Universal Definition of type 5 MI.