Optimal Conduit Diameter Selection in Coronary Bypass Grafting Using Saphenous Vein.

BACKGROUND: Predictors of long-term saphenous vein graft (SVG) patency following coronary artery bypass grafting (CABG) include harvesting technique, degree of proximal coronary stenosis, and target vessel diameter and runoff. The objective of this study was to evaluate the association between vein graft diameter and long-term survival. METHODS: Patients undergoing primary CABG (2000-2017) at Flinders Medical Centre, Adelaide, Australia, were categorised into three groups according to average SVG diameter (<3.5 mm [small], 3.5-4 mm [medium], >4 mm [large]). Survival data was obtained from the Australian Institute of Health and Welfare National Death Index. To determine the association of SVG diameter with long-term survival we used Kaplan-Meier survival analysis and Cox proportional hazard models adjusted for preoperative variables associated with survival. RESULTS: Vein graft diameter was collected in 3,797 patients. Median follow-up time was 7.6 years (interquartile range, 3.9-11.8) with 1,377 deaths. SVG size >4 mm was associated with lower rates of adjusted survival up to 4 years postoperatively (hazard ratio 1.48; 95% confidence interval 1.05-2.1; p=0.026). CONCLUSIONS: Vein graft diameter >4mm was found to be associated with lower rates of survival following CABG.

Cardiopulmonary bypass parameters improve the prediction of 30-day mortality following cardiac surgery.

Currently 30-day mortality is commonly used as a quality indicator for cardiac surgery; however, prediction models have not included the role of cardiopulmonary bypass (CPB). We hypothesized that reproducing currently utilised prediction model methods of 30-day mortality using the Australian and New Zealand Collaborative Perfusion Registry (ANZCPR) would identify relevant CPB predictors. Nine centers in Australia and New Zealand collected data using the ANZCPR between 2011-2020. CPB parameter selection was determined by evaluating association with 30-day mortality. Data were divided into model creation (n = 15,073) and validation sets (n = 15,072). Bootstrap sampling and automated variable selection methods were used to develop candidate models. The final model was selected using prediction mean square error and Bayesian Information Criteria. The average receiver operating characteristic (ROC), p-value for Hosmer-Lemeshow chi-squared test and MSE were obtained from multifold validation. In total, 30,145 patients were included, of which 735 (2.4%) died within 30 day of surgery. The area under the ROC curve for the model including CPB parameters was significantly greater than preoperative risk factors only (0.829 vs 0.783, p < 0.001). CPB parameters included in the predictive model were CPB time, red blood cell transfusion, mean arterial pressure <50 mmHg, minimum oxygen delivery, cardiac index <1.6 L/min/m2. CPB parameters improve the prediction of 30-day mortality. Randomised trials designed to evaluate modifiable CPB parameters will determine their impact on mortality.

Quantification of the internal mammary artery size in Aboriginal and Torres Strait islanders.

BACKGROUND: Variation in size of the internal mammary artery has been demonstrated in ethnic groups, but not reported in Aboriginal patients. We hypothesised that the left internal mammary artery is smaller in Aboriginal patients compared to non-Aboriginal patients and aimed to determine the impact on survival following coronary artery bypass graft (CABG) surgery. METHODS: Left internal mammary artery size was compared between Aboriginal (n = 345) and non-Aboriginal (n = 1819) in 2343 patients undergoing CABG at Flinders Medical Centre from January 2010 to June 2021. To determine the association with-survival we used Kaplan-Meier survival analysis and Cox proportional hazard models adjusted for preoperative variables. RESULTS: There was a significant difference in left internal mammary artery (LIMA) size-Aboriginal 1.8 ± 0.4 mm; non-Aboriginal 2.1 ± 0.4 mm (P < 0.001)-and left anterior descending (LAD) artery size-Aboriginal 1.7 ± 0.3 mm; non-Aboriginal 1.9 ± 0.3 mm (P < 0.001). Aboriginal patients were more likely to have the LIMA discarded (9.3% vs. 0.4%) and to receive a LAD vein graft (17% versus 3%) (P < 0.001). There was no difference in 30-day mortality or survival <5 years. CONCLUSION: This study supports the hypothesis that the left internal mammary artery is smaller in Aboriginal patients compared to non-Aboriginal patients. Although Aboriginal patients were more likely to receive a venous conduit to the LAD, we observed no difference in survival up to 5 years. This data contrasts with reported outcomes of other ethnic groups.

Transcatheter mitral valve-in-valve: treatment of rheumatic heart disease in young patients.

BACKGROUND: Rheumatic heart disease (RHD) in young people presents a complex management problem. In Australia a significant proportion of those affected are Aboriginal and Torres Strait Islanders. Transcatheter mitral valve-in-valve (TMViV) replacement has emerged as an alternative to redo surgery in high-risk patients with degenerated mitral bioprostheses. The aim of this study is to review outcomes of TMViV replacement in young patients with RHD. METHODS: A single-centre, retrospective review of prospectively collected data on patients undergoing TMViV from December 2017 to June 2021. Primary outcome was major adverse cardiovascular events. Secondary outcome was post-operative trans-thoracic echocardiogram (TTE) results. RESULTS: There were seven patients with a mean age of 33 years and predominantly female (n = 5). Pre-operative comorbidities included diabetes (29%), chronic obstructive pulmonary disease (43%), left ventricular dysfunction (43%) and current smoking status (80%). Post-operative median length of hospital stay was 4 days with no post-operative renal failure, stroke, return to theatre, valve embolization or in hospital mortality. Post-operative TTE showed either nil or trivial central mitral regurgitation, no paravalvular leak and a median gradient of 5 mmHg (IQR 4.5, 7) across the new bioprosthesis; sustained at median follow-up of 22 months. CONCLUSION: Current literature of TMViV replacement is focused on an older population with concurrent comorbidities. This study provides a unique insight into TMViV replacement in a young cohort of patients with complex social and geographical factors which sometimes prohibits the use of a mechanical valve. The prevalence of RHD remains high for Aboriginal and Torres Strait Islanders, planning for future repeat valve operations should be considered from the outset. We consider TMViV as a part of a staged procedural journey for young patients with RHD.

Del Nido cardioplegia in adult cardiac surgery: analysis of myocardial protection and post-operative high-sensitivity Troponin T.

BACKGROUND: del Nido cardioplegia has been adopted for use in adult cardiac surgery, despite a lack of robust randomised evidence supporting equivalence or superiority to conventional hyperkalaemic blood cardioplegia. We investigated the clinical surrogates of myocardial protection, and performed an extensive analysis of post-operative high-sensitivity Troponin T (hs-TnT) values in a general adult cardiac surgery population receiving del Nido, in comparison to a historical hyperkalaemic blood cohort. METHOD: 171 consecutive patients of a single surgeon from between November 2018 and June 2020 received del Nido, and were compared to a historical cohort of 326 patients between January 2016 and November 2018 who received hyperkalaemic blood cardioplegia. Clinical markers of myocardial protection were compared, as were hs-TnT values at 6, 12, 24, and 72-h post-operatively. Equivalence between groups was determined using the two one-sided tests procedure. RESULTS: There was no difference between the groups in the incidence of post-operative low cardiac output state, inotropic support, or myocardial infarction. Del Nido patients had less defibrillation requirement, and more spontaneous resumption of normal sinus rhythm. High-sensitivity Troponin T values were similar at all time-points including in a coronary artery bypass graft subgroup, and in those patients with elevated pre-operative hs-TnT. CONCLUSION: In a broad cohort of adult cardiac surgery patients, including those undergoing coronary artery bypass surgery and those with recent myocardial infarction, del Nido provides equivalent myocardial protection and clinical outcomes when compared to hyperkalemic blood cardioplegia. Post-operative high-sensitivity Troponin T values were also equivalent between the groups.

Acute kidney injury, stroke and death after cardiopulmonary bypass surgery: the role of perfusion flow and pressure.

INTRODUCTION: Acute kidney injury after cardiopulmonary bypass surgery is associated with morbidity and mortality. This study aims to evaluate the role of low perfusion flow and pressure in the development of cardiopulmonary bypass-associated acute kidney injury, stroke and death, using multicentre registry data. METHODS: We identified patients from the Australian and New Zealand Collaborative Perfusion Registry who underwent coronary artery bypass grafting and/or valvular surgery between 2008 and 2018. Primary predictor variables were the length of time the perfusion flow was <1.6 L/min/m2 and the length of time perfusion pressure was < 50mmHg. The primary outcome was new postoperative acute kidney injury defined by the risk-injury-failure-loss-end stage criteria. Secondary outcomes were stroke and in-hospital death. The influence of perfusion flow and pressure during cardiopulmonary bypass on the primary and secondary outcomes was estimated using separate multivariate models. RESULTS: A total of 16,356 patients were included. The mean age was 66 years and 75% were male. Acute kidney injury was observed in 1,844 patients (11%), stroke in 204 (1.3%) and in-hospital death in 286 (1.8%). Neither the duration of the time spent for perfusion flow (<1.6 L/minute/m2) nor the duration of the time spent for perfusion pressure (<50 mmHg) was associated with postoperative acute kidney injury, stroke or death in adjusted models. CONCLUSIONS: Neither low perfusion pressure nor low perfusion flow during cardiopulmonary bypass were predictive of postoperative acute kidney injury, stroke or death.

Cardiopulmonary bypass management and acute kidney injury in 118 Jehovah's Witness patients: a retrospective propensity-matched multicentre cohort from 30,942 patients.

INTRODUCTION: Patients refusing blood products in cardiac surgery present challenges for cardiopulmonary bypass. Accurate detail of the modifiable factors of cardiopulmonary bypass relating to acute kidney injury is previously unreported in this patient population. METHODS: A total of 118 adult Jehovah's Witness patients refusing transfusion were propensity matched to 118 adult patients accepting transfusion from the 30,942 patients in the Australian and New Zealand Collaborative Perfusion Registry. The primary endpoint was acute kidney injury. Intraoperative and bypass management characteristics were also compared between early (2007-2012) and late (2013-2018) cohorts along with the acceptance or refusal of transfusion. RESULTS: In patients accepting transfusion, 49% received a blood product. In patients refusing transfusion, acute kidney injury was lower (8% vs. 22%; p = 0.003) cell salvage use was higher (70% vs. 22%; p < 0.001), as was use of haemofiltration (8% vs. 4%; p = 0.03) and tranexamic acid in the early period (87% vs. 62%, p = 0.004) but not late (100% vs. 97%; p = 0.15). There was no difference in modifiable cardiopulmonary bypass factors (mean arterial pressure, minimum oxygen delivery (DO2i), retrograde autologous prime, circuit prime volume) between the two groups; however, prime volume decreased and DO2i increased over time for both. Patients refusing transfusion had lower postoperative blood loss (p = 0.02) and shorter postoperative length of stay (p < 0.001) with no difference in morbidity (p = 0.46) or mortality (p = 0.68). CONCLUSION: Refusal of transfusion in patients undergoing cardiopulmonary bypass was associated with reduced acute kidney injury, hospital stay and postoperative blood loss, while not impacting mortality.

Predictive Capacity of Oxygen Delivery During Cardiopulmonary Bypass on Acute Kidney Injury.

BACKGROUND: The randomized goal-directed perfusion trial confirmed retrospective findings that a goal-directed perfusion strategy to maintain oxygen delivery index (DO2i) during cardiopulmonary bypass greater than 280 mL/min/m2 reduces the incidence of acute kidney injury (AKI). We developed a predictive model for AKI using data from the Australian and New Zealand Collaborative Perfusion Registry to determine whether these findings could be validated in a real-world clinical setting and to identify an optimal DO2i threshold for predictive diagnostic accuracy. METHODS: Data in 19,410 cardiopulmonary bypass procedures were randomly divided into training (n = 9705) and validation (n = 9705) datasets. Multivariate logistic regression was used to determine the best predictive models for AKI (RIFLE [renal Risk, Injury, Failure, Loss of renal function and End-stage renal disease] classification), incremental predictive value of minimum cardiopulmonary bypass DO2i, and optimal threshold. RESULTS: Minimum DO2i was significantly associated with any AKI, AKI risk, and AKI injury or greater class in both datasets (validation dataset; any AKI odds ratio [OR], 0.993; 95% confidence interval [CI], 0.991-0.995; P < .001; AKI risk OR, 0.994; 95% CI, 0.992-0.996; P < .001, AKI injury or greater 0.993; 95% CI, 0.991-0.996; P < .001), representing on average a 7% increase in the likelihood of AKI for every 10-mL/min/m2 decrease in DO2i. Diagnostic accuracy was similar for both datasets, with an optimal DO2i threshold of 270 mL/min/m2. The odds of any AKI were increased by 52% in those below the threshold (OR, 1.52; 95% CI, 1.29-1.77; P < .001). CONCLUSIONS: This study confirms previous findings that minimum DO2i during cardiopulmonary bypass is independently associated with AKI, supporting previous findings in a broader-risk, multicenter cohort.

Outcomes of Redo Valve Surgery in Indigenous Australians.

BACKGROUND: Rheumatic heart disease often leads to valve surgery at a young age in our Indigenous population. Anticoagulation can be problematic and therefore repeat surgery to replace degenerated bioprosthetic valves is common. We sought to examine outcomes following redo valve surgery in this population. METHODS: Data from our institutional database was reviewed from 1992 to 2017. During this period, 82 redo valve surgeries were performed in 73 patients identifying as Aboriginal and Torres Strait Islander. We compared this study group to Indigenous patients undergoing primary valve surgery (n=389) and non-Indigenous patients undergoing redo valve surgery (n=154). RESULTS: Redo patients had a median age of 29.5 years (IQR 24, 44), 59% were female, and they had significant comorbidities. The 30-day mortality in this cohort was 6% (EuroSCORE II 3.57), and they had significant morbidity. The median time to repeat surgery in those who had previous mitral valve surgery was 6.3 years, with no difference between mitral valve repair or replacement at the index procedure. Compared to non-Indigenous patients undergoing redo valve surgery, the Indigenous patients were significantly younger with higher left ventricular function but a greater proportion of pulmonary hypertension. There were no significant differences in short-term outcomes. Compared to Indigenous patients undergoing primary valve surgery, the Indigenous redo patients were significantly younger with more co-morbidities. There was no difference in 30-day mortality, but the redo patients did have significantly greater resource utilisation (increased hospital and intensive care unit (ICU) lengths of stay, ventilation and blood transfusion) and poorer long-term survival. CONCLUSIONS: Indigenous patients presenting for redo valve surgery represent a complex and comorbid group of patients, with outcomes worse than expected in a young population, albeit comparable within study groups. Time from original surgery was short at 6 years, and thus a strategy must be in place in terms of planning future surgeries in this cohort of predominantly young rheumatic heart disease patients.

Is Conventional Bypass for Coronary Artery Bypass Graft Surgery a Misnomer?

Although recent trials comparing on vs. off-pump revascularization techniques describe cardiopulmonary bypass (CPB) as "conventional," inadequate description and evaluation of how CPB is managed often exist in the peer-reviewed literature. We identify and subsequently describe regional and center-level differences in the techniques and equipment used for conducting CPB in the setting of coronary artery bypass grafting (CABG) surgery. We accessed prospectively collected data among isolated CABG procedures submitted to either the Australian and New Zealand Collaborative Perfusion Registry (ANZCPR) or Perfusion Measures and outcomes (PERForm) Registry between January 1, 2014, and December 31, 2015. Variation in equipment and management practices reflecting key areas of CPB is described across 47 centers (ANZCPR: 9; PERForm: 38). We report average usage (categorical data) or median values (continuous data) at the center-level, along with the minimum and maximum across centers. Three thousand five hundred sixty-two patients were identified in the ANZCPR and 8,450 in PERForm. Substantial variation in equipment usage and CPB management practices existed (within and across registries). Open venous reservoirs were commonly used across both registries (nearly 100%), as were "all-but-cannula" biopassive surface coatings (>90%), whereas roller pumps were more commonly used in ANZCPR (ANZCPR: 85% vs. PERForm: 64%). ANZCPR participants had 640 mL absolute higher net prime volumes, attributed in part to higher total prime volume (1,462 mL vs. 1,217 mL) and lower adoption of retrograde autologous priming (20% vs. 81%). ANZCPR participants had higher nadir hematocrit on CPB (27 vs. 25). Minimal absolute differences existed in exposure to high arterial outflow temperatures (36.6°C vs. 37.0°C). We report substantial center and registry differences in both the type of equipment used and CPB management strategies. These findings suggest that the term "conventional bypass" may not adequately reflect real-world experiences. Instead of using this term, authors should provide key details of the CPB practices used in their patients.

Integration of Electronic Perfusion Data for Perfusion Registries.

Although the potential for the utilization of electronic perfusion data (EPD) from proprietary software to facilitate the understanding and improvement of cardiopulmonary bypass (CPB) has been recognized, the generalizability of previous reports of EPD integration are limited by superceded software or lack of sufficient detail for reproducibility. To date, the Australian and New Zealand Collaborative Perfusion Registry (ANZCPR) is the only multicentre perfusion registry to have reported the integration of EPD. The inclusion of EPD in analyses of the impact of CPB on patient outcome is important in improving the understanding of CPB practice. Perfusion registries play an important role in this process, and the incorporation of EPD into perfusion registries could make a significant contribution toward this objective. By sharing the methodology used to integrate EPD from the CONNECT™ software into the ANZCPR, our intent is to diminish some of the barriers to adoption of EPD integration into other perfusion registries, by providing an example of how EPD integration may be achieved.

Goal-directed perfusion to reduce acute kidney injury: A randomized trial.

OBJECTIVE: To determine whether a goal-directed perfusion (GDP) strategy aimed at maintaining oxygen delivery (DO2) at ≥280 mL·min-1·m-2 reduces the incidence of acute kidney injury (AKI). METHODS: This multicenter randomized trial enrolled a total of 350 patients undergoing cardiac surgery in 9 institutions. Patients were randomized to receive either GDP or conventional perfusion. A total of 326 patients completed the study and were analyzed. Patients in the treatment arm were treated with a GDP strategy during cardiopulmonary bypass (CPB) aimed to maintain DO2 at ≥280 mL·min-1·m-2. The perfusion strategy for patients in the control arm was factored on body surface area and temperature. The primary endpoint was the rate of AKI. Secondary endpoints were intensive care unit length of stay, major morbidity, red blood cell transfusions, and operative mortality. RESULTS: Acute Kidney Injury Network (AKIN) stage 1 was reduced in patients treated with GDP (relative risk [RR], 0.45; 95% confidence interval [CI], 0.25-0.83; P = .01). AKIN stage 2-3 did not differ between the 2 study arms (RR, 1.66; 95% CI, 0.46-6.0; P = .528). There were no significant differences in secondary outcomes. In a prespecified analysis of patients with a CPB time between 1 and 3 hours, the differences in favor of the treatment arm were more pronounced, with an RR for AKI of 0.49 (95% CI, 0.27-0.89; P = .017). CONCLUSIONS: A GDP strategy is effective in reducing AKIN stage 1 AKI. Further studies are needed to define perfusion interventions that may reduce more severe levels of renal injury (AKIN stage 2 or 3).

Low Oxygen Delivery as a Predictor of Acute Kidney Injury during Cardiopulmonary Bypass.

Low indexed oxygen delivery (DO2i) during cardiopulmonary bypass (CPB) has been associated with an increase in the likelihood of acute kidney injury (AKI), with critical thresholds for oxygen delivery reported to be 260-270 mL/min/m2. This study aims to explore whether a relationship exists for oxygen delivery during CPB, in which the integral of amount and time below a critical threshold, is associated with the incidence of postoperative AKI. The area under the curve (AUC) with DO2i during CPB above or below 270 mL/min/m2 was calculated as a metric of oxygen delivery in 210 patients undergoing CPB. To determine the influence of low oxygen delivery on AKI, a multivariate logistic regression model was developed including AUC < 0, Euroscore II to provide preoperative risk factor adjustment, and incidence of red blood cell transfusion to adjust for the influence of transfusion. Having an AUC < 0 for an oxygen delivery threshold of 270 mL/min/m2 during CPB was an independent predictor of AKI, after adjustment for Euroscore II and transfusion [OR 2.74, CI {1.01-7.41}, p = .047]. These results support that a relationship exists for oxygen delivery during CPB, in which the integral of amount and time below a critical threshold is associated with the incidence of postoperative AKI.

Rewarming Temperature During Cardiopulmonary Bypass and Acute Kidney Injury: A Multicenter Analysis.

BACKGROUND: Acute kidney injury (AKI) after cardiopulmonary bypass (CPB) is associated with a requirement for dialysis, a longer stay in the intensive care unit, a longer hospital length of stay, and mortality. An oxygenator arterial outlet temperature greater than 37°C has been reported to be associated with AKI; however, the influence of other rewarming temperatures is unclear. Using multicenter registry data, this study aimed to evaluate the role of CPB rewarming temperatures on AKI. METHODS: Data from 8,407 adult patients undergoing coronary artery bypass grafting (CABG) or valve repair or replacement, or a combination, were collected using the Perfusion Downunder Collaborative Database. Primary variables of interest were rewarming temperatures, defined as cumulative time the oxygenator arterial outlet temperature was greater than 36°C, greater than 36.5°C, or greater than 37°C. Propensity scores were calculated to determine the predicted probability of hyperthermic perfusion (rewarming temperature >37°C). The influence of temperature on AKI was determined using separate multivariate models adjusting for propensity score in the entire cohort (n = 6,904) and in propensity-matched patients (n = 2,044). RESULTS: Overall, 11.8% of patients acquired AKI. The duration of rewarming temperature greater than 36°C or 36.5°C was not associated with AKI. The duration of rewarming temperature greater than 37°C (hyperthermic perfusion) was independently associated with RIFLE (Risk, Injury, Failure, Loss, End-stage renal disease) risk classification or greater (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.09-1.77; p = 0.012) and injury classification or greater AKI (OR, 1.52; 95% CI, 1.09-1.97; p = 0.016) in the entire cohort, and injury classification or greater AKI (OR, 1.51; 95% CI, 1.15-1.90; p = 0.006) in propensity-matched patients. CONCLUSIONS: The duration of hyperthermic perfusion-rewarming temperature greater than 37°C-was an independent predictor of AKI. Avoidance of hyperthermic perfusion may be more beneficial in reducing AKI than avoidance of rewarming.

Should Air Bubble Detectors Be Used to Quantify Microbubble Activity during Cardiopulmonary Bypass?

Air bubble detectors (ABDs) are utilized during cardiopulmonary bypass (CPB) to protect against massive air embolism. Stockert (Munich, Germany) ABD quantify microbubbles >300 µm; however, their reliability has not been reported. The aim of this study was to assess the reliability of the microbubble data from the ABD with the SIII and S5 heart-lung machines. Microbubble counts from the ABD with the SIII (SIII ABD) and S5 (S5 ABD) were measured simultaneously with the emboli detection and classification (EDAC) quantifier in 12 CPB procedures using two EDAC detectors and two ABDs in series in the arterial line. Reliability was assessed by the Spearman correlation co-efficient (r) between measurements for each detector type, and between each ABD and EDAC detector for counts >300 µm. No correlation was found between the SIII ABD (r = .008, p = .793). A weak negative correlation was found with the S5 ABD (r = -.16, p < .001). A strong correlation was found between the EDAC detectors (SIII; r = .958, p < .001), (S5; r = .908, p < .001). With counts >300 µm, the SIII ABDs showed a correlation of small-medium effect size between EDAC detectors and ABD1 (r = .286, p < .001 [EDAC1], r = .347, p < .001 [EDAC2]). There was no correlation found between ABD2 and either EDAC detector (r = .003, p = .925 (EDAC1), r = .003, p = .929 [EDAC2]). A correlation between EDAC and the S5 ABD, was not able to be determined due to the low bubble count detected by the EDAC >300 µm. Both SIII ABD and S5 ABD were found to be unreliable for quantification of microbubble activity during CPB in comparison with the EDAC. These results highlight the importance of ensuring that data included in the CPB report is accurate and clinically relevant, and suggests that microbubble counts from devices such as the SIII ABD and S5 ABD should not be reported.

Cardiovascular risk profile before coronary artery bypass graft surgery in relation to depression and anxiety disorders: An age and sex propensity matched study.

OBJECTIVE: The cardiovascular risk profile and postoperative morbidity outcomes of anxiety disorder patients undergoing coronary artery bypass surgery is not known. METHODS: In a cross-sectional design, 114 consecutive coronary artery bypass graft surgery patients were evaluated to create four matched groups (30 with anxiety disorder, 27 with depression disorder and 57 age-sex matched coronary artery bypass surgery control patients with no depression or anxiety disorder). RESULTS: By comparison to non-depression disorder age-sex matched controls, depressed patients presented for coronary artery bypass surgery with significantly greater myocardial inflammatory markers (Troponin T>02, 33.3% vs. 11.1%, p=.03), metabolic risk (body surface area>35 (22.2% vs. 0%, p=.03), comorbid cardiovascular risk (peripheral vascular disease 18.5% vs. 0%, p=.05). Depressed patients also recorded longer intraoperative time at higher temperatures >37°C on cardiopulmonary bypass (11.1 ± 9.0 vs. 6.0 ± 4.9, p<005) and had higher maximum postoperative Troponin T (.44 ± .2 vs. .28 ± .1, p=.03). Patients with anxiety disorder on the other hand presented with significantly higher Creatinine Kinase-Muscle Brain (5 IQR 4-5 ng/ml vs. 4 IQR 3-4 ng/ml, p=.04), higher intraoperative glucose levels (7.8 ± 2.5 mmol/l vs. 7.0 ± 1.2 mmol/l, p=.05), and received fewer grafts (2.1 ± .9 vs. 2.5 ± .9 p=.04). CONCLUSIONS: A differential cardiovascular risk profile and postoperative outcome was observed dependent on anxiety and depression disorder status. There were few modifiable cardiovascular risk factors at the time of surgery other than psychiatric status, perioperative management of depression and anxiety may have promise to reduce further cardiac morbidity after coronary artery bypass surgery.

Oxygenator safety evaluation: a focus on connection grip strength and arterial temperature measurement accuracy.

This report describes the assessment of three specific safety-related specifications in the consideration of an alternate oxygenator; first the grip strength relationship between various oxygenator connectors and SMARxT tubing, second, the grip strength of various biopassive tubings and an isolated SMARxT connector, and finally, the accuracy of the arterial outlet temperature measurement. Grip strength experiments for the connections between the SMARxT tubing and the venous reservoir outlet and the oxygenator venous inlet and oxygenator arterial outlet of the Medtronic Affinity, Sorin Synthesis, Sorin Primox, and Terumo Capiox RX25 oxygenators were performed. In addition we compared the grip strength of polyvinyl chloride, Physio, Trillium, Carmeda, X-Coating, and SMARxT tubing. The accuracy of the integrated arterial outlet temperature probes was determined by comparing the temperatures measured by the integrated probe with a precision reference thermometer. Connector grip strength comparisons for the evaluation oxygenators with SMARxT tubing showed significant variation between oxygenators and connections (p = .02). Evaluation of the arterial outlet showed significant variation between evaluation oxygenators, while at the venous reservoir outlet and oxygenator inlet, there were no significant differences. Grip strength comparison data for the various tubing types demonstrated a main effect for tubing type F(5, 18) = 8.01, p = .002, eta(p)(2) = .77. Temperature accuracy measurements demonstrated that all oxygenators overread the arterial outlet temperature at 15 degrees C, whilst at temperatures > or = 25 degrees C, all oxygenators underread the arterial outlet temperature. The integrity of SMARxT tubing connection is influenced by the connector type, and may decline over time, highlighting the importance to not consider interchanging components of the bypass circuit as inconsequential.

Developing a benchmarking process in perfusion: a report of the Perfusion Downunder Collaboration.

Improving and understanding clinical practice is an appropriate goal for the perfusion community. The Perfusion Downunder Collaboration has established a multi-center perfusion focused database aimed at achieving these goals through the development of quantitative quality indicators for clinical improvement through benchmarking. Data were collected using the Perfusion Downunder Collaboration database from procedures performed in eight Australian and New Zealand cardiac centers between March 2007 and February 2011. At the Perfusion Downunder Meeting in 2010, it was agreed by consensus, to report quality indicators (QI) for glucose level, arterial outlet temperature, and pCOz management during cardiopulmonary bypass. The values chosen for each QI were: blood glucose > or =4 mmol/L and < or =10 mmol/L; arterial outlet temperature < or = 37 degrees C; and arterial blood gas pCO2 > or =35 and < or =45 mmHg. The QI data were used to derive benchmarks using the Achievable Benchmark of Care (ABC) methodology to identify the incidence of QIs at the best performing centers. Five thousand four hundred and sixty-five procedures were evaluated to derive QI and benchmark data. The incidence of the blood glucose QI ranged from 37-96% of procedures, with a benchmark value of 90%. The arterial outlet temperature QI occurred in 16-98% of procedures with the benchmark of 94%; while the arterial pCO2 QI occurred in 21-91%, with the benchmark value of 80%. We have derived QIs and benchmark calculations for the management of several key aspects of cardiopulmonary bypass to provide a platform for improving the quality of perfusion practice.

In vitro evaluation of gaseous microemboli handling of cardiopulmonary bypass circuits with and without integrated arterial line filters.

The delivery of gaseous microemboli (GME) by the cardiopulmonary bypass circuit should be minimized whenever possible. Innovations in components, such as the integration of arterial line filter (ALF) and ALFs with reduced priming volumes, have provided clinicians with circuit design options. However, before adopting these components clinically, their GME handling ability should be assessed. This study aims to compare the GME handling ability of different oxygenator/ALF combinations with our currently utilized combination. Five commercially available oxygenator/ALF combinations were evaluated in vitro: Terumo Capiox SX25RX and Dideco D734 (SX/D734),Terumo Capiox RX25R and AF125 (RX/AF125), Terumo FX25R (FX), Sorin Synthesis with 102 microm reservoir filter (SYN102), and Sorin Synthesis with 40 microm reservoir filter (SYN40). GME handling was studied by introducing air into the venous return at 100 mL/min for 60 seconds under two flow/ pressure combinations: 3.5 L/min, 150 mmHg and 5 L/min, 200 mmHg. Emboli were measured at three positions in the circuit using the Emboli Detection and Classification (EDAC) Quantifier and analyzed with the General Linear Model. All circuits significantly reduced GME. The SX/D734 and SYN40 circuits were most efficient in GME removal whilst the SYN102 handled embolic load (count and volume) least efficiently (p < .001). A greater number of emboli <70 microm were observed for the SYN102, FX and RX/AF125 circuits (p < .001). An increase in embolic load occurred with higher flow/pressure in all circuits (p < .001). The venous reservoir significantly influences embolic load delivered to the oxygenator (p < .001). The majority of introduced venous air was removed; however, significant variation existed in the ability of the different circuits to handle GME. Venous reservoir design influenced the overall GME handling ability. GME removal was less efficient at higher flow and pressure, and for smaller sized emboli. The clinical significance of reducing GME requires further investigation.