Perfusionist removal of intra-aortic balloon pump catheters improves efficiency without an increase in complication rates.

INTRODUCTION: The intra-aortic balloon pump (IABP) is one of the most utilized cardiac assist devices. Patients receiving IABP therapy are typically managed in high acuity clinical care areas with limited bed space and high demand. Our center instituted a certified clinical perfusionist (CCP) led initiative to remove IABP catheters in order to reduce IABP therapy time, hasten removal and improve efficiency. METHODS: The purpose of the study is to compare outcomes for IABP removal by a certified clinical perfusionist to a physician. The primary outcome measures were site hematoma score and limb related complications. A survey was submitted to bedside nurses, managers/patient care coordinators, CCP's and physicians. The IABP quality assurance database was interrogated for the study. RESULTS: There were 350 patients eligible for inclusion. The cohort was well balanced between CCP (n = 284) and physician (n = 66) groups for patient demographics, indication, insertion specifics and type of medical intervention. The majority of patients had no bruise or hematoma with perfusionist (n = 246, 87%) or physician (n = 58, 88%) (p = 0.78) removal. The physician group demonstrated a higher rate of grade 3 hematomas (p = 0.03). There was no statistically significant difference between CCP and physician groups for limb complications and mortality. Survey results showed an improved efficiency in bed space allocation, physician workload and a decreased IABP support time. CONCLUSION: There is no difference in limb complications between perfusionist and physician removal of IABP catheters. The survey demonstrate an improvement in resource allocation and efficiency. A perfusionist led IABP removal program can be done safely and may help improve program efficiency.

Methemoglobin as a marker of acute anemic stress in cardiac surgery.

Biological evidence supports plasma methemoglobin as a biomarker for anemia-induced tissue hypoxia. In this translational planned substudy of the multinational randomized controlled transfusion thresholds in cardiac surgery (TRICS-III) trial, which included adults undergoing cardiac surgery requiring cardiopulmonary bypass with a moderate-to-high risk of death, we investigated the relationship between perioperative hemoglobin concentration (Hb) and methemoglobin; and evaluated its association with postoperative outcomes. The primary endpoint was a composite of death, myocardial infarction, stroke, and severe acute kidney injury at 28 days. We observe weak non-linear associations between decreasing Hb and increasing methemoglobin, which were strongest in magnitude at the post-surgical time point. Increased levels of post-surgical methemoglobin were associated with a trend toward an elevated risk for stroke and exploratory neurological outcomes. Our generalizable study demonstrates post-surgical methemoglobin may be a marker of anemia-induced organ injury/dysfunction, and may have utility for guiding personalized approaches to anemia management. Clinicaltrials.gov registration NCT02042898.

An evaluation of hard-shell venous reservoir integrated pressure relief valve pressure mitigation performance.

INTRODUCTION: Vacuum assisted venous drainage (VAVD) requires the sealing of the hard-shell venous reservoir, thereby creating circumstances where reservoir pressurization may occur. Manufacturers utilize integrated pressure relief valves (IPRV) to mitigate pressurization risk; however, accidents have been reported even with these devices. We have undertaken a performance evaluation of IPRV's in a large number of hard-shell venous reservoirs. METHODS: Reservoirs were sealed and gas insufflated while measuring reservoir internal pressure. Linear regression models were developed to depict the association between internal pressure and gas inflow rate. External secondary one-way valves (ESOV) were assessed for pressure mitigation performance. An assisted venous drainage survey was circulated to Canadian Clinical Perfusionists. RESULTS: The reservoirs tested were adult (n = 9, 64%) and pediatric (n = 5, 36%) designs. Significant variability (p < 0.001) in internal reservoir pressures (range: 0.04-161.41 mmHg) was observed across the titrated gas inflow rate (0.5-10.0 l/min). The regression models demonstrate excellent predictive performance (SE: 0.008-0.309). ESOV's reduce the reservoir pressure below that of the IPRV; however, they cannot eliminate reservoir pressurization. The survey showed a majority (91%) of respondents use VAVD, and reservoir pressurization events occur regularly (18%). CONCLUSIONS: Significant variability among reservoir's IPRV to mitigate reservoir pressurization exists. The predictive models are extremely accurate at estimating the internal pressure. ESOV performance limitations moderate their utility as a backup pressure mitigation technique. A significant number of reservoir pressurization events are occurring with the use of VAVD. As a result, standardized communication from manufacturers on the purpose and performance of IPRV is recommended in order to delineate the limitations of these devices.

Current Use, Capacity, and Perceived Barriers to the Use of Extracorporeal Cardiopulmonary Resuscitation for Out-of-Hospital Cardiac Arrest in Canada.

BACKGROUND: Extracorporeal cardiopulmonary resuscitation (ECPR) is a therapeutic option for refractory cardiac arrest. We sought to perform an environmental scan to describe ECPR utilization in Canada and perceived barriers for application to out-of-hospital cardiac arrest (OHCA). METHODS: This was a national cross-sectional study. We identified all cardiovascular surgery- and extracorporeal membrane oxygenation (ECMO)-capable hospitals in Canada and emergency medical services (EMS) agencies delivering patients to those centres. We requested the medical lead from each hospital's ECMO service and each EMS agency to submit data regarding ECMO and ECPR utilization, as well as perceived barriers to ECPR provision for OHCA. RESULTS: We identified and received survey data from 39 of 39 Canadian hospital institutions and 21 of 22 EMS agencies. Of hospitals, 38 (97%) perform ECMO and 27 (69%) perform ECPR (74% of which perform ≤5 cases per year). Of the 18 (46%) sites offering ECPR for OHCA, 8 apply a formal protocol for eligibility and initiation procedures. EMS agencies demonstrate heterogeneity with intra-arrest transport practices. The primary rationale for nontransport of refractory OHCA is that hospital-based care offers no additional therapies. Perceived barriers to the use of ECPR for OHCA were primarily related to limited evidence supporting its use, rather than resources required. CONCLUSION: Many Canadian cardiovascular surgery- or ECMO-equipped hospitals use ECPR; roughly half employ ECPR for OHCAs. Low case volumes and few formal protocols indicate that this is not a standardized therapy option in most centres. Increased application may be dependent on a stronger evidence base including data from randomized clinical trials currently underway.

CONTEXTE: La réanimation cardiorespiratoire (RCR) extracorporelle est une option thérapeutique en cas d'arrêt cardiaque réfractaire. Nous avons voulu faire une analyse contextuelle de l'utilisation de la RCR extracorporelle au Canada et des obstacles perçus quant à son emploi dans les cas d'arrêt cardiaque en dehors de l'hôpital. MÉTHODOLOGIE: Il s'agissait d'une étude nationale transversale. Nous avons repéré tous les hôpitaux en mesure d'effectuer des chirurgies cardiovasculaires et d'offrir l'oxygénation extracorporelle au Canada et les fournisseurs de services médicaux d'urgence (SMU) transportant les patients vers ces centres. Nous avons demandé au chef médical du service d'oxygénation extracorporelle de chacun des hôpitaux et de chacun des fournisseurs de SMU de présenter leurs données concernant l'utilisation de l'oxygénation extracorporelle et de la RCR extracorporelle, ainsi que les obstacles perçus quant à l'emploi de la RCR extracorporelle dans les cas d'arrêt cardiaque en dehors de l'hôpital. RÉSULTATS: Nous avons obtenu les données de 39 des 39 établissements hospitaliers canadiens ciblés, et de 21 des 22 fournisseurs de SMU. Parmi les hôpitaux, 38 (97%) utilisent l'oxygénation extracorporelle et 27 (69 %), la RCR extracorporelle (74 % ayant eu recours à celle-ci dans ≤ 5 cas par année). Parmi les 18 (46 %) centres offrant la RCR extracorporelle en cas d'arrêt cardiaque en dehors de l'hôpital, 8 appliquaient un protocole officiel pour l'admissibilité et les procédures de mise en place. Les fournisseurs de SMU ont montré des pratiques hétérogènes concernant la réanimation en déplacement. La principale raison justifiant de ne pas transporter les patients présentant un arrêt cardiaque réfractaire en dehors de l'hôpital est que les soins en milieu hospitalier n'offrent pas de traitements additionnels. Les obstacles perçus quant à l'emploi de la RCR extracorporelle dans les cas d'arrêt cardiaque en dehors de l'hôpital étaient principalement liés au peu de données appuyant son utilisation, plutôt qu'aux ressources nécessaires. CONCLUSION: De nombreux hôpitaux canadiens équipés pour la chirurgie cardiovasculaire et l'oxygénation extracorporelle utilisent la RCR extracorporelle; environ la moitié d'entre eux utilisent la RCR extracorporelle en cas d'arrêt cardiaque en dehors de l'hôpital. Le faible nombre de cas et le peu de protocoles officiels indiquent qu'il ne s'agit pas d'une option de traitement standardisée dans la plupart des centres. Une utilisation plus fréquente pourrait nécessiter davantage de données probantes, y compris les résultats des études cliniques à répartition aléatoire qui sont en cours.

Extracorporeal life support rewarming rate is associated with survival with good neurological outcome in accidental hypothermia.

OBJECTIVES: Favourable outcomes have been demonstrated after extracorporeal life support (ECLS) facilitated rewarming for severe accidental hypothermia. The clinical impact of varying rewarming rates however is unclear. We sought to quantify the change in the probability of good neurological outcome with ECLS rewarming rate and identify the optimal rewarming rate threshold. METHODS: We performed a secondary analysis of the International ACcidental Hypothermia Extracorporeal Life Support Collaborators, an individual patient data data set (n = 658) for ECLS-assisted rewarming for accidental hypothermia. The independent variable of interest was rewarming rate. The primary outcome was survival with good neurological status. We applied an adjusted marginal effects model to quantify the probability of good neurological outcome over clinically observed rewarming rates. We examined strata defined by sex, initial potassium level and history of asphyxiation. RESULTS: Of 658 cases, the median age and initial core temperature were 36 years (22-55) and 24.5°C (22.1-26.2) respectively; 190 (29%) were female, and 547 (83%) had a non-perfusing initial cardiac rhythm. The mean rewarming rate was 7.0°C/h. The median ECLS duration was 5.8 h (range: 0.5-158 h). The overall survival was 46% (n = 303/658), and good neurological outcome was 40% (n = 265/658). The median intensive care unit and hospital length of stay was 5 days (range: 1-35 days) and 18 days (range: 1-106 days), respectively. Marginal effects analysis demonstrated a 1.9% decrease in the probability of survival with good neurological outcome for each 1°C/h increase in rewarming. Across the reported range of rewarming rates (0.05-30.8°C/h), the probability of good neurological outcome declined from 49.6% to 4.1% for an average patient. The relationship was similar within various subgroups. The optimal cut-off threshold for the rate of rewarming to distinguish between a good and poor neurological outcome was ≤5.0°C/h. CONCLUSIONS: Among cases with severe accidental hypothermia treated with ECLS, slower rewarming rates are associated with improved survival with good neurological outcomes. Slow rewarming, at rates ≤5.0°C/h, may improve clinical outcomes.

Traumatic and hemorrhagic complications after extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest.

INTRODUCTION: Extracorporeal cardiopulmonary resuscitation (ECPR) is an emerging invasive rescue therapy for treatment of refractory out-of-hospital cardiac arrests (OHCA). We aim to describe the incidence of traumatic and hemorrhagic complications among patients undergoing ECPR for OHCA and examine the association between CPR duration and ECPR-related injuries or bleeding. METHODS: We examined prospectively collected data from the Extracorporeal Resuscitation Outcomes Database (EROD), which includes ECPR-treated OHCAs from participating hospitals (October 2014 to August 2019). The primary outcome was traumatic or hemorrhagic complications, defined any of the following: pneumothorax, pulmonary hemorrhage, major bleeding, cannula site bleeding, gastrointestinal bleeding, thoracotomy, cardiac tamponade, aortic dissection, or vascular injury during hospitalization. The primary exposure was the cardiac arrest to ECPR initiation interval (CA-ECPR interval), measured as the time from arrest to initiation of ECPR. Descriptive statistics were used to compare demographic, cardiac arrest, and ECPR characteristics among patients with and without CPR-related traumatic or bleeding complications. Multivariable logistic regression was used to examine the association between CA-ECPR interval and traumatic or bleeding complications. RESULTS: A total of 68 patients from 4 hospitals receiving ECPR for OHCA were entered into EROD and met inclusion criteria. Median age was 51 (interquartile range 38-58), 81% were male, 40% had body mass index > 30, and 70% had pre-existing medical comorbidities. A total of 65% had an initial shockable cardiac rhythm, mechanical CPR was utilized in at least 29% of patients, and 27% were discharged alive. The median time from arrest to ECPR initiation was 73 min (IQR 60-104). A total of 37% experienced a traumatic or bleeding complication, with major bleeding (32%), vascular injury (18%), and cannula site bleeding (15%) being the most common. Compared to patients with shorter CPR times, patients with a longer CA-ECPR interval had 18% (95% confidence interval - 2-42%) higher odds of suffering a mechanical or bleeding complication, but this did not reach statistical significance (p = 0.08). CONCLUSIONS: Traumatic injuries and bleeding complications are common among patients undergoing ECPR. Further study is needed to investigate the relation between arrest duration and complications. Clinicians performing ECPR should anticipate and assess for injuries and bleeding in this high-risk population.

Prediction and risk stratification of survival in accidental hypothermia requiring extracorporeal life support: An individual patient data meta-analysis.

BACKGROUND: Extra-corporeal life support (ECLS) is a life-saving intervention for patients with hypothermia induced cardiac arrest or severe cardiovascular instability. However, its application is highly variable due to a paucity of data in the literature to guide practice. Current guidelines and recommendations are based on expert opinion, single case reports, and small case series. Combining all of the published data in a patient-level analysis can provide a robust assessment of the influence of patient characteristics on survival with ECLS. OBJECTIVE: To develop a prediction model of survival with good neurologic outcome for accidental hypothermia treated with ECLS. METHODS: Electronic searches of PubMed, EMBASE, CINAHL were conducted with a hand search of reference lists and major surgical and critical care conference abstracts. Studies had to report the use of ECLS configured with a circuit, blood pump and oxygenator with an integrated heat exchanger. Randomized and observational studies were eligible for inclusion. Non-human, non-English and review manuscripts were deemed ineligible. Study authors were requested to submit patient level data when aggregate or incomplete individual patient data was provided in a study. Survival with good neurologic outcome was categorized for patients to last follow-up based on the reported scores on the Cerebral Performance Category (1 or 2), Glasgow Outcome Scale (4 or 5) and Pediatric Overall Performance Category (1 or 2). A one-stage, individual patient data meta-analysis was performed with a mixed-effects multi-level logistic regression model reporting odds ratio (OR) with a 95% confidence interval (CI). RESULTS: Data from 44 observational studies and 40 case reports (n = 658) were combined and analyzed to identify independent predictors of survival with good neurologic outcome. The survival rate with good neurologic outcome of the entire cohort was 40.3% (265 of 658). ECLS rewarming rate (OR: 0.93; 95% CI: 0.88, 0.98; p = .007), female gender (OR: 2.78; 95% CI: 1.69, 4.58; p < 0.001), asphyxiation (OR: 0.19; 95% CI: 0.11, 0.35; p < 0.001) and serum potassium (OR: 0.62; 95% CI: 0.53, 0.73; p < 0.001) were associated with survival with a good neurologic outcome. The logistic regression model demonstrated excellent discrimination (c-statistic: 0.849; 95% CI: 0.823, 0.875). CONCLUSIONS: The use of extracorporeal life support in the treatment of hypothermic cardiac arrest provides a favourable chance of survival with good neurologic outcome. When used in a weighted scoring system, asphyxiation, serum potassium and gender can help clinicians prognosticate the benefit of resuscitating hypothermic patients with ECLS.

Association of Mortality and Acute Aortic Events With Ascending Aortic Aneurysm: A Systematic Review and Meta-analysis.

Importance: The natural history of ascending aortic aneurysm (AsAA) is currently not well characterized. Objective: To summarize and analyze existing literature on the natural history of AsAA. Data Sources: A search of Ovid MEDLINE (January 1, 1946, to May 31, 2017) and Embase (January 1, 1974, to May 31, 2017) was conducted. Study Selection: Studies including patients with AsAA were considered for inclusion; studies were excluded if they considered AsAA, arch, and descending thoracic aneurysm as 1 entity or only included descending aneurysms, patients with heritable or genetic-related aneurysms, patients with replaced bicuspid aortic valves, patients with acute aortic syndrome, or those with mean age less than 16 years. Two independent reviewers identified 20 studies from 7198 unique studies screened. Data Extraction and Synthesis: Data extraction was performed according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline; 2 reviewers independently extracted the relevant data. Summary effect measures of the primary outcomes were obtained by logarithmically pooling the data with an inverse variance-weighted random-effects model. Metaregression was performed to assess the relationship between initial aneurysm size, etiology, and the primary outcomes. Main Outcomes and Measures: The primary composite outcome was incidence of all-cause mortality, aortic dissection, and aortic rupture. Secondary outcomes were growth rate, incidence of proximal aortic dissection or rupture, elective ascending aortic repair, and all-cause mortality. Results: Twenty studies consisting of 8800 patients (mean [SD] age, 57.75 [9.47] years; 6653 [75.6%] male) with a total follow-up time of 31 823 patient-years were included. The mean AsAA size at enrollment was 42.6 mm (range, 35.5-56.0 mm). The combined effect estimate of annual aneurysm growth rate was 0.61 mm/y (95% CI, 0.23-0.99 mm/y). The pooled incidence of elective aortic surgery was 13.82% (95% CI, 6.45%-21.41%) over a median (interquartile range) follow-up of 4.2 (2.9-15.0) years. The linearized mortality rate was 1.99% per patient-year (95% CI, 0.83%-3.15% per patient-year), and the linearized rate of the composite outcome of all-cause mortality, aortic dissection, and aortic rupture was 2.16% per patient-year (95% CI, 0.79%-3.55% per patient year). There was no significant relationship between year of study completion and the initial aneurysm size and primary outcomes. Conclusions and Relevance: The growth rate of AsAA is slow and has implications for the interval of imaging follow-up. The data on the risk of dissection, rupture, and death of ascending aortic aneurysm are limited. A randomized clinical trial may be required to understand the benefit of surgical intervention compared with surveillance for patients with moderately dilated ascending aorta.

Classification and outcomes of extended arch repair for acute Type A aortic dissection: a systematic review and meta-analysis.

Objectives: Distal extent of repair in patients undergoing surgery for acute Type A aortic dissection (ATAAD) is controversial. Emerging hybrid techniques involving open and endovascular surgery have been reported in small numbers by select individual centres. A systematic review and meta-analysis was performed to investigate the outcomes following extended arch repair for ATAAD. A classification system is proposed of the different techniques to facilitate discussion and further investigation. Methods: Using Ovid MEDLINE, 38 studies were identified reporting outcomes for 2140 patients. Studies were categorized into four groups on the basis of extent of surgical aortic resection and the method of descending thoracic aortic stent graft deployment; during circulatory arrest (frozen stented elephant trunk) or with normothermic perfusion and use of fluoroscopy (warm stent graft): (I) surgical total arch replacement, (II) total arch and frozen stented elephant trunk, (III) hemiarch and frozen stented elephant trunk and (IV) total arch and warm stent graft. Perioperative event rates were obtained for each of the four groups and the entire cohort using pooled summary estimates. Linearized rates of late mortality and reoperation were calculated. Results: Overall pooled hospital mortality for extended arch techniques was 8.6% (95% CI 7.2-10.0). Pooled data categorized by surgical technique resulted in hospital mortality of 11.9% for total arch, 8.6% total arch and frozen stented elephant trunk, 6.3% hemiarch and frozen stented elephant trunk and 5.5% total arch and 'warm stent graft'. Overall incidence of stroke for the entire cohort was 5.7% (95% CI 3.6-8.2). Rate of spinal cord ischaemia was 2.0% (95% CI 1.2-3.0). Pooled linearized rate of late mortality was 1.66%/pt-yr (95% CI 1.34-2.07) with linearized rate of re-operation of 1.62%/pt-yr (95% CI 1.24-2.05). Conclusions: Perioperative results of extended arch procedures are encouraging. Further follow-up is required to see if long-term complications are reduced with these emerging techniques. The proposed classification system will facilitate future comparison of short- and long-term results of different techniques of extended arch repair for ATAAD.

Is Aortic Valve Repair Reproducible? Analysis of the Learning Curve for Aortic Valve Repair.

BACKGROUND: Aortic valve (AV) preservation and repair, although effective, is performed in a limited number of centres. Lack of wider application might be due to challenges in dissemination of tacit surgical knowledge. We examined the learning curve in 2 centres that initiated dedicated programs in AV repair. METHODS: Prospectively collected data on the first 100 (cohort A) and 150 consecutive patients (cohort B) who underwent AV repair surgery were analyzed. Safety end points included mortality, myocardial infarction or stroke, early AV repeat surgery, re-exploration for bleeding, or pacemaker implantation. Efficiency was assessed according to aortic crossclamp and cardiopulmonary bypass times. Efficacy parameters included residual aortic insufficiency or stenosis. Indices of case complexity included presence of severe aortic insufficiency, nontrileaflet AV, and associated cardiac procedures. Each cohort was divided into 3 equal tertiles (T1, T2, and T3). RESULTS: Early mortality was ≤ 1% in both cohorts. In cohort A, a total of 12 safety events occurred with a significant reduction in incidence over the tertiles (18%, 15%, and 3%, in T1, T2, and T3, respectively; P = 0.05). In cohort B, 20 safety events occurred in 18 patients with a trend toward reduction of incidence over tertiles (20%, 12%, and 8%, in T1, T2, and T3, respectively; P = 0.14). aortic crossclamp and cardiopulmonary bypass times decreased significantly after T2 in cohort A and T1 in cohort B (P < 0.01). Intraoperative procedural efficacy was similar across tertiles in both cohorts. CONCLUSIONS: Procedural safety and efficiency improves with experience whereas efficacy is consistent over time. AV repair is reproducible and appears to have a learning curve of approximately 40-60 cases.

Aortic valve preservation and repair in acute Type A aortic dissection.

OBJECTIVES: Repair and preservation of the aortic valve in Type A aortic dissection (AAD) remains controversial. We performed a meta-analysis of outcomes for aortic valve (AV) repair and preservation in AAD focusing on long-term valve-related events. METHODS: Structured searches were performed in Embase (1980-2013) and PubMed (1966-2013) for studies reporting AV repair or preservation in AAD. Early mortality and linearized rates for late mortality and valve-related events were derived. Outcome data were pooled with an inverse-variance-weighted random-effects model. RESULTS: Of 5325 screened articles, 19 observational studies met the eligibility criteria consisting of 2402 patients with a median follow-up of 4.1 [range: 3.1-12.6 years, total 13 733 patient-years (pt-yr)]. The cohort was principally male (median = 68.1%, range: 39-89) with a median age of 59 (range: 55-68) years and Marfan's syndrome was present in 2.5%. AV resuspension was performed in 95% of the patients and the remainder underwent valve-sparing root replacement (reimplantation = 2.5% and remodelling = 2.5%). Pooled early mortality rate was 18.7% [95% confidence interval (95% CI): 12.2-26.2%], and linearized late mortality rate was 4.7%/pt-yr (95% CI: 3.4-6.3). Linearized rate for AV reintervention was 2.1%/pt-yr (95% CI: 1.0-3.6), recurrent aortic insufficiency (>2+) was 0.9%/pt-yr (95% CI: 0.3-2.2) and endocarditis was 0.2%/pt-yr (95% CI: 0.1-0.5). The composite rate of thromboembolism and bleeding was 1.4%/pt-yr (95% CI: 0.7-2.2). CONCLUSIONS: Patients surviving an AAD have a limited long-term survival. Preservation and repair of the aortic valve is associated with a moderate risk of reoperation, but a low risk of thromboembolism, bleeding and endocarditis.

Systematic review of aortic valve preservation and repair.

BACKGROUND: Aortic valve repair has emerged as a feasible alternative to replacement in the surgical treatment of selected patients with aortic valve (AV) pathology. In order to provide a synopsis of the current literature, we preformed a systematic review with a focus on valve-related events following AV repair. METHODS: Structured keyword searches of Embase and PubMed were performed in January 2012. A study was eligible for inclusion if it reported early mortality, late mortality, or valve-related morbidity in the adult population. RESULTS: Initial search results identified 3,507 unique studies. After applying inclusion and exclusion criteria, 111 studies remained for full-text review. Of these, 17 studies involving 2,891 patients were included for quantitative assessment. No randomized trials were identified. Tricuspid and bicuspid AV pathologies were present in 65% (range, 21-100%) and 13.5% (range, 5-100%) of the population, respectively. Cusp repair techniques were applied in a median of 46% (range, 5-100%) of patients. The median requirement for early reoperation for post-operative bleeding and early reintervention for primary AV repair failure was 3% (range, 0-10%) and 2% (range, 0-16%), respectively. Pooled early mortality was 2.6% (95% CI: 1.4-4.4%, I(2) =0%). Late mortality and valve-related events were linearized [(number of events/number of patient-years) ×100] (%/pt-yr) for each study. Late operated valve endocarditis was reported at median event rate of 0.23%/pt-yr (range, 0-0.78%/pt-yr), while a composite outcome of neurological events and thromboembolism occurred at a median rate of 0.52%/pt-yr (0-0.95%/pt-yr). Late AV re-intervention requiring AV replacement or re-repair occurred at a rate of 2.4%/pt-yr (range, 0-4.2%/pt-yr). The median 5-year freedom from AV re-intervention and late recurrent aortic insufficiency >2+ estimated from survival curves was 92% (range, 87-98%) and 88% (range, 87-100%), respectively. Pooled late mortality produced summary estimate of 1.3%/pt-yr (95% CI: 0.9-2.1%, I(2) =0%). CONCLUSIONS: The present systematic review confirmed the low operative risk of patients who underwent aortic valve preservation and repair. There is a need for long-term follow-up studies with meticulous reporting of outcomes following AV repair, as well as comparative studies with aortic valve replacement.

Centrifugal pump and roller pump in adult cardiac surgery: a meta-analysis of randomized controlled trials.

Centrifugal pump (CP) and roller pump (RP) designs are the dominant main arterial pumps used in cardiopulmonary bypass (CPB). Trials reporting clinical outcome measures comparing CP and RP are controversial. Therefore, a meta-analysis was undertaken to evaluate clinical variables from randomized controlled trials (RCTs). Keyword searches were performed on Medline (1966-2011), EmBase (1980-2011), and CINAHL (1981-2011) for studies comparing RP and CP as the main arterial pump in adult CPB. Pooled fixed-effects estimates for dichotomous and continuous data were calculated as an odds ratio and weighted-mean difference, respectively. The P value was utilized to assess statistical significance (P < 0.05) between CP and RP groups. Eighteen RCTs met inclusion criteria, which represented 1868 patients (CP = 961, RP = 907). The prevailing operation was isolated coronary artery bypass graft surgery (CP = 88%, RP = 87%). Fixed-effects pooled estimates were performed for end-of-CPB (ECP) and postoperative day one (PDO) for platelet count (ECP: P = 0.51, PDO: P = 0.16), plasma free hemoglobin (ECP: P = 0.36, PDO: P = 0.24), white blood cell count (ECP: P = 0.21, PDO: P = 0.66), and hematocrit (ECP: P = 0.06, PDO: P = 0.51). No difference was demonstrated for postoperative blood loss (P = 0.65) or red blood cell transfusion (P = 0.71). Intensive care unit length of stay (P = 0.30), hospital length of stay (P = 0.33), and mortality (P = 0.91) were similar between the CP and RP groups. Neurologic outcomes were not amenable to pooled analysis; nevertheless, the results were inconclusive. There was no reported pump-related malfunction or mishap. The meta-analysis of RCTs comparing CP and RP in adult cardiac surgery suggests no significant difference for hematological variables, postoperative blood loss, transfusions, neurological outcomes, or mortality.

Does ABO-incompatible and ABO-compatible neonatal heart transplant have equivalent survival?

A best evidence topic (BET) in cardiac surgery was written according to a structured protocol. The question addressed was whether ABO-incompatible (ABO-I) heart transplant recipients have a similar survival rate as an ABO-compatible (ABO-C) transplant in the pediatric population <1 year of age. Altogether more than 112 papers were found using the reported search, of which 10 represented the best evidence to answer the clinical question. Generally, ABO-I transplantation has been associated with the neonatal population because of the relative immaturity of the immune system for the first year of life. In the BET the search-term 'pediatric' was used as a method to ensure retrieval all relevant papers. However, the vast majority of the patients reviewed were <1 year of age with specific techniques undertaken to modulate preoperative, intraoperative and postoperative isohemagglutinin titer levels with rejection monitoring. Therefore, the BET conclusions should not be applied to the pediatric group as a broad age classification. Two large series are of particular interest. Patel et al. reviewed all primary heart transplantation recipients < or =1 year of age in the United Network for Organ Sharing/Organ Procurement and Transplantation Network (UNOS/OPTN) registry (ABO-I=35 vs. ABO-C=556). There was no difference in 30-day mortality (ABO-I=5.9% vs. ABO-C=8.8%; P=0.55); one-year mortality (ABO-I=16.6% vs. ABO-C=14.7%; P=0.77); graft rejection (ABO-I=1 vs. ABO-C=0); and graft failure (ABO-I=24% vs. ABO-C=24%; P>0.99). Three-year Kaplan-Meier survival was 70% (P=0.85). Propensity score adjusted analysis did not implicate ABO-I as a predictor of mortality [hazard ratio (HR)=3.6, confidence interval (CI): 0.2-49.0; P=0.33]. The ABO-I group demonstrated an increased need for pacemaker (ABO-I=3.1% vs. ABO-C=0.4%; P=0.03) and higher stroke rate (ABO-I=12.9% vs. ABO-C=1.3%; P<0.0001). Dipchand et al. published the results of the Toronto cohort from 1992 to 2006 (ABO-I=16 vs. ABO-C=38). The median age at transplantation (ABO-I=88 days vs. ABO-C=84 days; P=0.82) and the number of neonatal transplant recipients (ABO-I=17% vs. ABO-C=22%; P=0.59) was similar. The freedom from post-transplantation death or retransplantation was equivalent at one year (ABO-I=77% vs. ABO-C=84%) and seven years (ABO-I=74% vs. ABO-C=74%; P=0.87). No significant difference was observed for the five-year freedom from: rejection (ABO-I=60% vs. ABO-C=45%; P=0.41); renal dysfunction (ABO-I=67% vs. ABO-C=72%; P=0.70); allograft vasculopathy (ABO-I=87% vs. ABO-C=78%; P=0.45); and post-transplantation lymphoproliferative disorder (PTLD) (ABO-I=87% vs. ABO-C=86%; P=0.93). We conclude that ABO-I transplantation is comparable to ABO-C transplantation, with several retrospective papers concluding there is no difference in mortality, morbidity or graft failure in the pediatric population <1 year of age.

A small post-operative rise in serum creatinine predicts acute kidney injury in children undergoing cardiac surgery.

To predict development of acute kidney injury and its outcome we retrospectively studied children having cardiac surgery. Acute kidney injury (AKI) was defined using the serum creatinine criteria of the pediatric Risk Injury Failure Loss End-Stage (pRIFLE) kidney disease definition. We tested whether a small rise (less than 50%) in creatinine on post-operative days 1 or 2 could predict a greater than 50% increase in serum creatinine within 48 h in 390 children. AKI occurred in 36% of patients, mostly in the first 4 post-operative days. Using logistic regression, significant independent risk factors for AKI were bypass time, longer vasopressor use, and a tendency for younger age. Using Cox regression, AKI was independently associated with longer intensive care unit stay and duration of ventilation. Patients whose serum creatinine did not increase on post-operative days 1 or 2 were unlikely to develop AKI (negative predictive values of 87 and 98%, respectively). Percentage serum creatinine rise on post-operative day 1 predicted AKI within 48 h (area under the curve=0.65). Our study shows that AKI after pediatric heart surgery is common and is a risk factor for poorer outcome. Small post-operative increases in serum creatinine may assist in the early prediction of AKI.

Retrograde autologous priming and allogeneic blood transfusions: a meta-analysis.

A literature review and meta-analysis were undertaken to assess the clinical effectiveness of retrograde autologous priming of the cardiopulmonary bypass circuit to reduce allogeneic packed red blood transfusions in adult cardiac surgery. Structured searches of Medline, Embase, Cochrane Collaboration Library, Scopus, Cumulative Index to Nursing and Allied Health Literature and Science Direct were performed to identify randomized trials comparing retrograde autologous priming to a prospective control group. A total of 21,643 studies were identified and eighteen trials were retrieved for full-text review. Six trials met eligibility criteria. Pooled estimates demonstrated that retrograde autologous priming significantly reduced the number of patients receiving intraoperative packed red cell transfusions (OR=0.36; 95% CI: 0.13, 0.94; P=0.04, I(2)=47.5%), total hospital stay packed red cell transfusions (OR=0.26; 95% CI: 0.13, 0.52; P=0.0001, I(2)=0%), and the number of units transfused of total hospital stay packed red blood cells (WMD=-0.60; 95% CI: -0.90, -0.31; P=0.0001, I(2)=0%). Retrograde autologous priming, however, did not provide a clinical benefit in reducing the number of units transfused of intraoperative packed red blood cells (WMD=-0.29; 95% CI: -0.59, 0.01; P=0.05). The combined patient population studied in the six trials was mainly primary isolated coronary artery bypass surgery. Assessing the safety of retrograde autologous priming was not possible due to limited data.