Search

Aim: Structural valvular deterioration of xenogenic heart valve replacements is thought to be due to a chronic immune response. We sought to engineer porcine extracellular matrix that elicits minimal inflammatory immune response. Materials & methods: Whole blood, bone marrow and pericardium were collected from patients undergoing elective cardiac surgery. Porcine extracellular matrix was decellularized, reseeded with homologous mesenchymal stem cells and exposed to whole blood. Results: DAPI stain confirmed the absence of cells after decellularization, and presence of mesenchymal stem cells after recellularization. There was a significant reduction in IL-1β and TNF-α production in the recellularized matrix. Conclusion: Recellularization of porcine matrix is successful at attenuating the xenogenic immune response and may provide a suitable scaffold to address the current limitations of prosthetic heart valve replacements.

Background: Cardiac allograft vasculopathy (CAV) is the primary cause of late mortality after heart transplantation. We look to provide a comprehensive review of contemporary revascularization strategies in CAV. Methods: PubMed and Web of Science were systematically searched by 3 authors. 1,870 articles were initially screened and 24 were included in this review. Results: PCI is the main revascularization technique utilized in CAV. The pooled estimates for restenosis significantly favored DES over BMS (OR 4.26; 95% CI: 2.54–7.13; p < 0.00001; I2 = 4%). There were insufficient data to quantitatively compare mortality following DES versus BMS. There was no difference in short-term mortality between CABG and PCI. In-hospital mortality was 0.0% for CABG and ranged from 0.0 to 8.34% for PCI. One-year mortality was 8.0% for CABG and 5.0–25.0% for PCI. CABG had a potential advantage at 5 years. Five-year mortality was 17.0% for CABG and ranged from 14 to 40.4% following PCI. Select measures of postoperative morbidity trended toward superior outcomes for CABG. Conclusion: In CAV, PCI is the primary revascularization strategy utilized, with DES exhibiting superiority to BMS regarding postoperative morbidity. Further investigation into outcomes following CABG in CAV is required to conclusively elucidate the superior management strategy in CAV.

Acute kidney injury (AKI) is common after cardiac surgery. We quantified the mortality and costs of varying degrees of AKI using a population-based cohort in Alberta, Canada.A cohort of patients undergoing cardiac surgery from 2004 to 2009 was assembled from linked Alberta administrative databases. AKI was classified by Kidney Disease Improving Global Outcomes stages of severity. Our outcomes were in-hospital mortality, length of stay, and costs; among survivors, we also examined mortality and costs at 365 days. Estimates were adjusted for demographic characteristics, comorbidities, and other covariates.Ten thousand one hundred seventy participants were included, of whom 9771 patients were discharged to community. Overall in-hospital mortality, costs, and length of stay were 4%, 7 days, and Can $34,000, respectively. Postcardiac surgery, AKI occurred in 25%. Compared with those without AKI, AKI was independently associated with increased in-hospital mortality across severity categories, with the highest risk (adjusted odds ratio, 37.1; 95% confidence interval, 26.3-52.1; P .001) in patients who required acute dialysis. AKI severity was associated with increased hospital days and costs, with costs ranging from 1.21 for stage 1 AKI (95% confidence interval, 1.17-1.23) to 2.74 for acute dialysis (95% confidence interval, 2.49-3.00) (P .001) times higher than in patients without AKI, after covariate adjustment. Postdischarge to 365 days, patients with AKI continued to experience increased costs up to 1.35-fold, and patients who required dialysis acutely continued to experience a 2.86-fold increased mortality.AKI remains an important indicator of mortality and health care costs postcardiac surgery.

Background: The identification of frailty before complex and invasive procedures may have relevance for prognostic and recovery purposes, to optimally inform patients, caregivers and clinicians about perioperative risk and postoperative care needs. The aim of this study was to estimate the prevalence of frailty and describe the associated clinical course and outcomes of patients referred for nonemergent cardiac surgery. Methods: A prospective cohort of patients aged 50 years and older referred for nonemergent cardiac surgery in Alberta, Canada, from November 2011 to March 2014 were screened preoperatively for frailty, defined as a Clinical Frailty Scale (CFS) score of 5 or greater. Postoperatively, patients were followed by telephone to assess CFS score, health services use and vital status. The primary outcome was all-cause hospital mortality. Secondary outcomes included health services use, hospital discharge disposition, 1-year health-related quality of life and all-cause 5-year mortality. Results: The cohort (n = 529) had a mean age of 67 (standard deviation [SD] 9) years; 25.9% were female, and the prevalence of frailty was 9.6% (n = 51; 95% confidence interval [CI] 7.3%–12.5%). Frail patients were older (median age 75, interquartile range [IQR] 65–80 v. 67, IQR 60–73, yr; p < 0.001), were more likely to be female (51.0% v. 23.2%; p < 0.001), had a higher mean EuroSCORE II (8, SD 3 v. 5, SD 3; p < 0.001) and received combined coronary artery bypass grafting and valve procedures more frequently (29.4% v. 15.9%; p = 0.02) than nonfrail patients. Postoperatively, frail patients had a longer median duration of stay in the cardiovascular intensive care unit (median difference 2.2, 95% CI 1.60–2.79) and hospital (median difference 9.3, 95% CI 8.2–10.3). Hospital mortality was 9.8% among frail patients and 1.0% among nonfrail patients (adjusted hazard ratio 3.84, 95% CI 0.90–16.34). Interpretation: Preoperative frailty was present in 10% of patients and was associated with a higher risk of morbidity and greater health services use. Preoperative frailty has important implications for the postoperative clinical course and resource utilization of patients undergoing cardiac surgery.

Coronary artery disease (CAD) is common in candidates for lung transplantation (LTx) and has historically been considered a relative contraindication to transplantation. We look to review the outcomes of LTx in patients with CAD and determine the optimum revascularization strategy in LTx candidates. PubMed, Medline and Web of Science were systematically searched by three authors for articles comparing the outcomes of LTx in patients with CAD and receiving coronary revascularization. In total 1668 articles were screened and 12 were included in this review.Preexisting CAD in LTx recipients was not associated with significantly increased postoperative morbidity or mortality. The pooled estimates of mortality rate at 1, 3 and 5 years indicated significantly inferior survival in LTx recipients with a prior history of coronary artery bypass grafting (CABG) [odds ratio (OR), 1.84; 95% confidence interval (CI), 1.53-2.22; P 0.00001; I2 = 0%; OR, 1.52; 95% CI, 1.21-1.91; P = 0.0003; I2 = 0%; OR, 1.62; 95% CI, 1.13-2.33; P = 0.008; I2 = 71%, respectively). However, contemporary literature suggests that survival rates in LTx recipients with CAD that received revascularization either by percutaneous coronary intervention (PCI), previous or concomitant CABG, are similar to patients who did not receive revascularization. Trends in postoperative morbidity favored CABG in the rates of myocardial infarction and repeat revascularization, whereas rates of stroke favored PCI. The composite results of this study support the consideration of patients with CAD or previous coronary revascularization for LTx. Prospective, randomized controlled trials with consistent patient populations and outcomes reporting are required to fully elucidate the optimum revascularization strategy in LTx candidates.

Background Preoperative anemia is a common comorbidity that often necessitates allogeneic blood transfusion (ABT). As there is a risk associated with blood transfusions, preoperative intravenous iron (IV) has been proposed to increase the hemoglobin to reduce perioperative transfusion; however, randomized controlled trials (RCT) investigating this efficacy for IV iron are small, limited, and inconclusive. Consequently, a meta-analysis that pools these studies may provide new and clinically useful information. Methods/design Databases of MEDLINE, EMBASE, EBM Reviews; Cochrane-controlled trial registry; Scopus; registries of health technology assessment and clinical trials; Web of Science; ProQuest Dissertations and Theses; Clinicaltrials.gov; and Conference Proceedings Citation Index-Science (CPCI-S) were searched. Also, we screened all the retrieved reference lists. Selection criteria Titles and abstracts were screened for relevance (i.e., relevant, irrelevant, or potentially relevant). Then, we screened full texts of those citations identified as potentially applicable. Results Our search found 3195 citations and ten RCTs (1039 participants) that met our inclusion criteria. Preoperative IV iron supplementation significantly decreases ABT by 16% (risk ratio (RR): 0.84, 95% confidence interval [CI]: 0.71, 0.99, p = 0.04). In addition, preoperatively, hemoglobin levels increased after receiving IV iron (mean difference [MD] between the study groups: 7.15 g/L, 95% CI: 2.26, 12.04 g/L, p = 0.004) and at follow-up > 4 weeks postoperatively (MD: 6.46 g/L, 95% CI: 3.10, 9.81, p = 0.0002). Iron injection was not associated with increased incidence of non-serious or serious adverse effects across groups (RR: 1.13, 95% CI: 0.78, 1.65, p = 0.52) and (RR: 0.96, 95% CI: 0.44, 2.10, p = 0.92) respectively. Conclusions With moderate certainty, due to the high risk of bias in some studies in one or two domains, we found intravenous iron supplementation is associated with a significant decrease in the blood transfusions rate, and modest hemoglobin concentrations rise when injected pre-surgery compared with placebo or oral iron supplementation. However, further full-scale randomized controlled trials with robust methodology are required. In particular, the safety, quality of life, and cost-effectiveness of different intravenous iron preparations require further evaluation.

Objectives We aimed to evaluate the association between levosimendan treatment and acute kidney injury (AKI) as well as assess the clinical sequelae of AKI in cardiac surgery patients with depressed left ventricular function (ejection fraction Methods Patients in the LEVO-CTS trial undergoing on-pump coronary artery bypass grafting (CABG), valve, or CABG/valve surgery were stratified by occurrence and severity of postoperative AKI using the AKIN classification. The association between levosimendan infusion and AKI was modeled using multivariable regression. Results Among 854 LEVO-CTS patients, 231 (27.0%) experienced postoperative AKI, including 182 (21.3%) with stage 1, 35 (4.1%) with stage 2, and 14 (1.6%) with stage 3 AKI. The rate of AKI was similar between patients receiving levosimendan or placebo. The odds of 30-day mortality significantly increased by AKI stage compared to those without AKI (stage 1: adjusted odds ratio [aOR] 2.0, 95% confidence interval [CI] 0.8-4.9; stage 2: aOR 9.1, 95% CI 3.2-25.7; stage 3: aOR 12.4, 95% CI 3.0-50.4). No association was observed between levosimendan, AKI stage, and odds of 30-day mortality (interaction P = .69). Factors independently associated with AKI included increasing age, body mass index, diabetes, and increasing baseline systolic blood pressure. Increasing baseline eGFR and aldosterone antagonist use were associated with a lower risk of AKI. Conclusions Postoperative AKI is common among high-risk patients undergoing cardiac surgery and associated with significantly increased risk of 30-day death or dialysis. Levosimendan was not associated with the risk of AKI.

Azithromycin prophylaxis (AP) in lung transplant recipients has been shown to reduce the composite end-point of death or chronic lung allograft dysfunction (CLAD) onset but without a clear effect on overall survival. Our program began using AP in 2010. We sought to evaluate the association between AP and survival and the risk of CLAD and baseline lung allograft dysfunction (BLAD).We studied double lung recipients transplanted between 2004 and 2016. We defined AP as chronic use of azithromycin initiated before CLAD onset. We analyzed the association between AP and death or retransplant using Cox regression with adjustment for potential confounders. We further used Cox and logistic models to assess the relationship between AP and post-transplant CLAD onset and BLAD, respectively.A total of 445 patients were included, and 344 (77%) received AP (median time from transplant: 51 days). Patients receiving AP were more likely to receive induction with interleukin-2 receptor antagonists (57% vs 35%; p0.001). AP was associated with improved survival (hazard ratio [HR]: 0.59; 95% confidence interval [CI]: 0.42-0.82; p = 0.0020) in our fully adjusted model, with a reduced adjusted risk of BLAD (odds ratio: 0.53; 95% CI: 0.33-0.85; p = 0.0460) but no clear reduction in the adjusted risk of CLAD (HR: 0.69; 95% CI: 0.47-1.03; p = 0.0697).AP is associated with improved survival after lung transplantation, potentially through improved baseline function. These findings build on prior trial results and suggest that AP is beneficial for lung transplant recipients.

Case Presentation A 34-year-old previously healthy man of Korean descent (height, 174 cm; weight, 47.4 kg) demonstrated dyspnea with cough and chest tightness. The patient had no relevant occupational exposures and no history of illicit drug or tobacco use. His medical history was notable for chronic sinus tachycardia of undetermined cause, hypertension, gout, glaucoma of the right eye, and a remote history of an intracranial malignancy 24 years prior treated with unspecified chemotherapy, craniotomy, and ventriculoperitoneal shunt placement. His active medications included diltiazem, candesartan, and colchicine as needed.

Chronic mitral regurgitation (MR) remains a common cardiovascular condition resulting in significant morbidity and mortality. With an aging population, increasing trends for both primary (degenerative) and secondary (functional) MR have become apparent. Although the gold standard remains surgical intervention with mitral valve repair/replacement, comorbid conditions have steered the development of less invasive technologies to mitigate perioperative surgical risk. Transcatheter mitral valve repair using a percutaneous edge-to-edge technique is the most widely available choice at present. However, other transcatheter mitral valve repair techniques such as annuloplasty and chordal implantation are notable alternatives. Moreover, emerging technologies in transcatheter mitral valve replacement are rapidly establishing their roles in the field of chronic severe MR therapy. Hence, it is imperative to understand the indications and limitations of these various transcatheter mitral valve interventions to provide the best and most up-to-date clinical care for patients. This review will outline current evidence and patient selection criteria for such device-based therapies.

Transcatheter aortic valve replacement has transitioned from an experimental procedure to an important alternative therapy for patients with symptomatic aortic stenosis and high surgical risk. We present a case outlining an approach to deal with the issue of “failure to cross” the aortic valve in transcatheter aortic valve replacement from the transfemoral retrograde approach. Résumé: Le remplacement valvulaire aortique par cathéter est passé d’une intervention expérimentale à un traitement alternatif important pour les patients atteints d’une sténose aortique symptomatique et exposés à un risque opératoire élevé. Nous présentons un cas qui décrit une approche pour remédier au problème d’« échec à traverser » la valvule aortique lors du remplacement valvulaire aortique par cathéter selon une approche par voie rétrograde fémorale.

Background: Transcatheter aortic valve implantation (TAVI) is an effective alternative to surgical valve replacement in high-risk patients with severe aortic stenosis. Although measures of frailty have been used to attempt to predict outcomes in this population, few studies have demonstrated changes in these measures. Methods: We performed a prospective, observational study of 171 patients undergoing TAVI, of whom 44 had maximal follow-up of 1 month and 50 had maximal follow-up of 1 year. Quality of life was assessed using the Minnesota Living With Heart Failure Questionnaire, Katz Index of Independence in Activities of Daily Living questionnaire, and patient perception of overall well-being. Frailty was measured using the 10-m walk test and handgrip strength testing. Results: In the overall cohort, participants demonstrated improvements in quality of life metrics, but deterioration in 10-m walk test and handgrip at 1 month. These trends continued at 1 year. However, patients in the lowest quintile of handgrip and 10-m walk test demonstrated a trend of improvements in these metrics during follow-up. Conclusions: Despite improvements in quality of life after TAVI, no improvements in frailty were observed in patients at 1 year. Résumé: Contexte: Le remplacement valvulaire aortique par cathéter (TAVI) est une solution de rechange efficace à la chirurgie de remplacement valvulaire chez les patients atteints de sténose aortique grave et présentant un risque élevé. Les mesures de la fragilité sont utilisées pour tenter de prévoir les résultats au sein de cette population. Néanmoins, peu d’études ont permis d’objectiver les variations de ces mesures. Méthodologie: Nous avons réalisé une étude observationnelle prospective portant sur 171 patients ayant subi un TAVI, dont 44 suivis pendant un mois ou moins, et 50 durant un an ou moins. La qualité de vie a été évaluée au moyen de questionnaires – Minnesota Living With Heart Failure Questionnaire et Katz Index of Independence in Activities of Daily Living Questionnaire – et en fonction de la perception du patient relativement à son bien-être général. La fragilité a été mesurée à l’aide d’un test de marche sur dix mètres et d’un test de force de préhension. Résultats: Dans l’ensemble de la cohorte, une amélioration des mesures de la qualité de vie a été observée parallèlement à une détérioration des résultats au test de marche sur dix mètres et au test de force de préhension après un mois. Les tendances à cet égard se sont poursuivies au bout d’un an. Cependant, les résultats des patients du quintile inférieur au test de marche sur 10 m et au test de force de préhension ont eu tendance à s’améliorer au cours de la période de suivi. Conclusions: Malgré une amélioration de la qualité de vie après le TAVI, la fragilité des patients ne s’est nullement améliorée après un an.

Legionella community–acquired pneumonia necessitating veno-venous extracorporeal membrane oxygenation for severe acute respiratory distress syndrome has been reported in adults. However, few options remain in cases of refractory hypoxemia on veno-venous extracorporeal membrane oxygenation. Herein, we describe adjunctive extended therapeutic hypothermia for refractory hypoxemia despite veno-venous extracorporeal membrane oxygenation for successful management of severe acute respiratory distress syndrome secondary to Legionella.

Acute kidney injury after cardiac surgery is associated with adverse in-hospital and long-term outcomes. Novel risk factors for acute kidney injury have been identified, but it is unknown whether their incorporation into risk models substantially improves prediction of postoperative acute kidney injury requiring renal replacement therapy.We developed and validated a risk prediction model for acute kidney injury requiring renal replacement therapy within 14 days after cardiac surgery. We used demographic, and preoperative clinical and laboratory data from 2 independent cohorts of adults who underwent cardiac surgery (excluding transplantation) between Jan. 1, 2004, and Mar. 31, 2009. We developed the risk prediction model using multivariable logistic regression and compared it with existing models based on the C statistic, Hosmer-Lemeshow goodness-of-fit test and Net Reclassification Improvement index.We identified 8 independent predictors of acute kidney injury requiring renal replacement therapy in the derivation model (adjusted odds ratio, 95% confidence interval [CI]): congestive heart failure (3.03, 2.00-4.58), Canadian Cardiovascular Society angina class III or higher (1.66, 1.15-2.40), diabetes mellitus (1.61, 1.12-2.31), baseline estimated glomerular filtration rate (0.96, 0.95-0.97), increasing hemoglobin concentration (0.85, 0.77-0.93), proteinuria (1.65, 1.07-2.54), coronary artery bypass graft (CABG) plus valve surgery (v. CABG only, 1.25, 0.64-2.43), other cardiac procedure (v. CABG only, 3.11, 2.12-4.58) and emergent status for surgery booking (4.63, 2.61-8.21). The 8-variable risk prediction model had excellent performance characteristics in the validation cohort (C statistic 0.83, 95% CI 0.79-0.86). The net reclassification improvement with the prediction model was 13.9% (p0.001) compared with the best existing risk prediction model (Cleveland Clinic Score).We have developed and validated a practical and accurate risk prediction model for acute kidney injury requiring renal replacement therapy after cardiac surgery based on routinely available preoperative clinical and laboratory data. The prediction model can be easily applied at the bedside and provides a simple and interpretable estimation of risk.

Cardiac surgery waitlist recommendations, which were developed based on expert opinion, poorly predict preoperative mortality. Studies reporting risk factors for waitlist mortality have not evaluated the risks including nonadherence to waitlist benchmarks.In patients who underwent cardiac surgery or died on the waitlist between 2005 and 2015, we used a Fine and Gray competing risk model to identify independent predictors of waitlist mortality in 12,106 patients scheduled for urgent, semiurgent, or nonurgent surgery. The predictive variables were compared with Canadian Cardiovascular Society (CCS) waitlist recommendations using the Akaike information criterion.A total of 101 (0.8%) patients died awaiting surgery. The median wait times and frequency waitlist deaths among emergent, urgent, semi-urgent, and nonurgent surgery were 0.6, 7.4, 69.0, 55.5 days (P0.001) and 6.3%, 0.8%, 0.3%, 0.6% (P0.001), respectively. Adherence to CCS waitlist recommendations was higher in patients who died on the waitlist (51.6% vs 70.8%, P = 0.001) and was not predictive of waitlist mortality (hazard ratio 1.48, 95% confidence interval 0.62-0.56). Independent predictors of waitlist mortality were age, aortic surgery, ejection fraction35%, urgent surgery, prior myocardial infarction, haemodynamic instability during cardiac catheterization, hypertension, and dyslipidemia. These variables were superior to current CCS guidelines (Akaike information criterion 1251 vs 1317, likelihood ratio test P0.001).CCS waitlist recommendations were poorly predictive of waitlist mortality and the majority of waitlist deaths occur within recommended benchmarks. We identified variables associated with waitlist mortality with improved clinical performance. Our findings suggest a need to re-evaluate cardiac surgical triage criteria using evidence-based data.

Acute kidney injury (AKI) is a common occurrence after lung transplantation (LTx). Whether transient AKI or early recovery is associated with improved outcome is uncertain. Our aim was to describe the incidence, factors, and outcomes associated with transient AKI after LTx.We performed a retrospective cohort study of all adult recipients of LTx at the University of Alberta between 1990 and 2011. Our primary outcome transient AKI was defined as return of serum creatinine below Kidney Disease-Improving Global Outcome AKI stage I within 7days after LTx. Secondary outcomes included occurrence of postoperative complications, mortality, and long-term kidney function.Of 445 LTx patients enrolled, AKI occurred in 306 (68.8%) within the first week after LTx. Of these, transient AKI (or early recovery) occurred in 157 (51.3%). Transient AKI was associated with fewer complications including tracheostomy (17.2% vs 38.3%; P.001), reintubation (16.4% vs 41.9%; P.001), decreased duration of mechanical ventilation (median [interquartile range], 69 [41-142] vs 189 [63-403] hours; P.001), and lower rates of chronic kidney disease at 3 months (28.5% vs 51.1%, P.001) and 1 year (49.6% vs 66.7%, P=.01) compared with persistent AKI. Factors independently associated with persistent AKI were higher body mass index (per unit; odds ratio [OR], 0.91; 95% confidence interval, 0.85-0.98; P=.01), cyclosporine use (OR, 0.29; 0.12-0.67; P=.01), longer duration of mechanical ventilation (per hour [log transformed]; OR, 0.42; 0.21-0.81; P=.01), and AKI stages II to III (OR, 0.16; 0.08-0.29; P.001). Persistent AKI was associated with higher adjusted hazard of death (hazard ratio, 1.77 [1.08-2.93]; P=.02) when compared with transient AKI (1.44 [0.93-2.19], P=.09) and no AKI (reference category), respectively.Transient AKI after LTx is associated with fewer complications and improved survival. Among survivors, persistent AKI portends an increased risk for long-term chronic kidney disease.

This position statement addresses issues in revascularization for multivessel coronary artery disease (CAD) from the perspective of both cardiologists and cardiac surgeons. Recommendations are made based on evidence from clinical trials and observational studies, with an emphasis on the increasing number of individuals with significant comorbid disease burden and functional debilitation who are being referred for definitive management of their multivessel CAD in the context of routine clinical practice. These types of individuals have traditionally not been included in the many clinical trials that have been the basis for guidelines and recommendations, and the objective of the proposed medical intervention or revascularization (or both) would not necessarily be to improve prognosis but to improve quality of life. One purpose of this document is to propose practical multidisciplinary approaches to the management of these patients. Recommendations are made for revascularization in acute coronary syndromes and stable CAD, with specific considerations for individuals with left ventricular dysfunction and heart failure, chronic renal failure, and chronic obstructive pulmonary disease. We also consider the use of various risk scores, including the Society of Thoracic Surgeons score, the EuroSCORE, and the SYNTAX II score. The importance of a heart team approach is also emphasized. The complementary role of coronary bypass surgery and percutaneous coronary intervention is highlighted, along with the importance of optimal medical therapy.

Background Available cardiac surgery risk scores have not been validated in octogenarians. Our objective was to compare the predictive ability of the Society of Thoracic Surgeons (STS) score, EuroSCORE I, and EuroSCORE II in elderly patients undergoing isolated coronary artery bypass grafting surgery (CABG). Methods All patients who underwent isolated CABG (2002 – 2008) were identified from the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH) registry. All patients aged 80 and older (n = 304) were then matched 1:2 with a randomly selected control group of patients under age 80 (n = 608 of 4732). Risk scores were calculated. Discriminatory accuracy of the risk models was assessed by plotting the areas under the receiver operator characteristic (AUC) and comparing the observed to predicted operative mortality. Results Octogenarians had a significantly higher predicted mortality by STS Score (3 ± 2% vs. 1 ± 1%; p

Background The efficacy of coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) in patients with coronary artery disease has been well defined by randomized controlled trials. However, patients with severe left ventricular dysfunction (ejection fraction Methods The Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH), a clinical data collection and outcome monitoring initiative for the province of Alberta, Canada, was used to identify 2925 patients with coronary artery disease and left ventricular dysfunction undergoing CABG (n = 1,326) or PCI (n = 1,599) between 1995 and 2008. Patients were propensity matched to obtain comparable subgroups among left ventricular dysfunction patients. Results Cox proportional hazard analysis of the propensity-matched subgroups identified that CABG was significantly associated with lower rates of repeat revascularization and better survival compared with PCI at 1, 5, 10, and 15 years. Other significant independent predictors of poor long-term survival included age, renal failure, heart failure, diabetes mellitus, peripheral vascular disease, prior myocardial infarction, left main coronary artery disease, and prior CABG. Conclusions For patients with coronary artery disease and left ventricular dysfunction, CABG was associated with lower rates of repeat revascularization and improved survival over PCI, after adjustment for baseline risk profile differences. Further research exploring the factors leading to use of a particular revascularization modality in this patient population is required.

Background Evidence suggests that metabolic syndrome (MbS) is associated with early senescence of bioprosthetic aortic valve prostheses. The purpose of this study was to determine whether MbS is also associated with accelerated failure of bioprosthetic valves prostheses in the mitral position. Methods Records of all patients undergoing bioprosthetic mitral valve replacement (MVR) from 1993 to 2000 were reviewed. Results Of 114 patients undergoing bioprosthetic MVR, 48 (42%) had MbS. Mean age was 73 years (vs. 74 years for no MbS). Patients underwent MVR for regurgitation (n = 97; 85%), stenosis (n = 12; 11%), or mixed lesions (n = 4; 4%). Etiology was degenerative (n = 35; 32%), rheumatic (n = 26; 24%), ischemic (n = 30; 28%), calcific (n = 9; 8%), and endocarditis (n = 8; 8%). Mean follow-up was 4.5 years. Overall survival at 5 and 10 years was 56% and 26%, respectively. Survival was similar between groups (p = 0.15). Five patients (2 MbS; 4% vs. 3 no MbS; 5%) required mitral reoperation at a mean of 3.8 years after initial MVR. The risk of prosthetic valve failure was not different between groups (p = 0.66). Despite no initial difference in transmitral gradients, gradients beyond five-year follow-up were greater for those with MbS (6.8 mmHg MbS vs. 4.7 mmHg no MbS, p = 0.007). Independent predictors of gradient progression beyond two years were MbS (p = 0.027) and female gender (p = 0.012). There were no significant differences in valve area, regurgitation, or ejection fraction. Conclusions Although overall survival following bioprosthetic MVR is challenging, MbS did not predict diminished survival or excess reoperative risk compared to non-MbS patients. The trend toward more rapid progression of transprosthetic gradients in MbS patients warrants further investigation.

Transcatheter aortic valve replacement (TAVR) by valve-in-valve (VIV) implantation is an alternative treatment for high-risk patients with a degenerating aortic bioprosthesis. We present a case of transapical TAVR VIV with a 29-mm Edwards SAPIEN XT (ESV) (Edwards Lifesciences, Irvine, CA) into a 29-mm Medtronic Freestyle stentless bioprosthesis (Medtronic Inc, Minneapolis, MN) in which unanticipated dilatation of the Freestyle bioprosthesis resulted in intraprocedural embolization of the TAVR valve, necessitating urgent conversion to a conventional surgical aortic valve replacement (AVR). Our experience suggests that TAVR VIV with the 29-mm ESV in the setting of a degenerated 29-mm Freestyle stentless bioprosthesis must be undertaken with caution.

Objective Cryopreserved allograft tissue used in the Norwood procedure for infants with hypoplastic left heart syndrome causes a marked immunologic sensitization that may complicate future heart transplantation. Treatment of the allograft tissue before implantation may prevent this sensitization. The purpose of this study was to assess the anti-human leukocyte antigen antibody response to glutaraldehyde-treated allograft tissue used in the repair of hypoplastic left heart syndrome. Methods Since June 2005, the University of Alberta has subjected allograft vascular tissue used in the Norwood procedure to glutaraldehyde treatment. An observational study was designed to assess whether glutaraldehyde treatment of the allograft tissue affected subsequent panel reactive antibody after patch implantation. Panel reactive antibodies for class I (human leukocyte antigen-A, B, C) and class II (human leukocyte antigen-DR, DQ) antibodies were measured 4 months postoperatively using flow cytometry. Results Fourteen patients underwent a Norwood procedure using glutaraldehyde-treated allograft tissue. Historical controls consisted of 12 patients who underwent a Norwood procedure using untreated allograft tissue. At 4 months, infants who had received glutaraldehyde-treated allograft tissue had lower class I panel reactive antibody (7.3% ± 17.4% [median, 0%] vs 61.9% [median, 73%] ± 39.9%; P = .0005) and class II panel reactive antibody (6.1% [median, 0%] ± 22.7% vs 49.3% [median, 63%] ± 41.9%, P = .001) compared with the historical controls. Conclusion Intraoperative glutaraldehyde treatment of allograft tissue used in hypoplastic left heart syndrome repair prevents the profound immunologic sensitization that occurs in the majority of infants undergoing surgical palliation. In patients requiring subsequent heart transplantation, this decreases the risk of antibody-mediated rejection and increases the likelihood of finding a suitable donor, thus improving access to transplantation.

Specific B-cell tolerance toward donor blood group antigens develops in infants after ABO-incompatible heart transplantation, whereas their immune response toward protein antigens such as HLA has not been investigated. We assessed de novo HLA-antibodies in 122 patients after pediatric thoracic transplantation (28 ABO-incompatible) and 36 controls. Median age at transplantation was 1.7 years (1 day to 17.8 year) and samples were collected at median 3.48 years after transplantation. Antibodies were detected against HLA-class I in 21 patients (17.2%), class II in 18 (14.8%) and against both classes in 10 (8.2%). Using single-antigen beads, donor-specific antibodies (DSAs) were identified in six patients (all class II, one additional class I). Patients with DSAs were significantly older at time of transplantation. In patients who had undergone pretransplant cardiac surgeries, class II antibodies were more frequent, although use of homografts or mechanical heart support had no influence. DSAs were absent in ABO-incompatible recipients and class II antibodies were significantly less frequent than in children with ABO-compatible transplants. This difference was present also when comparing only children transplanted below 2 years of age. Therefore, tolerance toward the donor blood group appears to be associated with an altered response to HLA beyond age-related effects.

Background Reoperative mitral valve (MV) surgery through sternotomy can be technically challenging. Limited exposure and injury to the right ventricle or patent grafts (previous coronary artery bypass graft surgery [CABG]) are potential complications upon sternal reentry. The purpose of this study was to examine the results of port access MV surgery through right minithoracotomy in patients with previous cardiac surgery performed through median sternotomy. Methods From 1998 through July 2007, 651 port access MV procedures were performed. In 107 patients (16.4%), previous cardiac surgery had been performed through midline sternotomy. Mean age was 67.5 ± 11.2 years, and 60.7% (n = 65) were male. Previous surgery included CABG (n = 45, 42.1%), aortic valve replacement (n = 9, 8.4%), aortic valve replacement/MV repair (n = 2, 1.9%), MV repair (n = 21, 19.6%), MV replacement (n = 5, 4.7%), CABG/MV replacement (n = 1, 0.9%), CABG/MV repair (n = 8, 7.5%), CABG/aortic valve replacement (n = 2, 1.9%), and others (n = 14, 13.1%). New York Heart Association functional classes were I (n = 2, 1.9%), II (n = 28, 26.2%), III (n = 50, 46.7%), and IV (n = 27, 25.2%). The endoaortic balloon was used in 75 patients (70.1%) and the Chitwood clamp in 11 patients (10.2%). In the remaining patients (n = 21, 19.6%), fibrillatory arrest was employed. Results Mitral valve repair and MV replacement were performed in 60 patients (56.1%) and 47 patients (43.9%), respectively. The 30-day mortality was 4.7% (n = 5). The mean cardiopulmonary bypass and aortic cross-clamp times were 140.8 ± 43.7 minutes and 77.0 ± 49.7 minutes, respectively. Complications included 6 reoperations for bleeding (5.6%), 1 stroke (0.9%), and 2 wound infections (1.9%). Conversion to sternotomy was required in 1 patient (0.9%) because of an acute type A dissection secondary to aortic occlusion with Chitwood clamp. The mean hospital stay was 9.6 days. During follow-up, reoperation for failure of MV repair was performed in 4 patients (3.7%). Conclusions Reoperative port access MV surgery can be performed with minimal morbidity and mortality. This approach may be the preferred technique for patients who require MV procedures after previous cardiac surgery performed through median sternotomy.

Objective Cryopreserved allograft tissue used in the Norwood procedure for infants with hypoplastic left heart syndrome causes profound immunologic sensitization, which may complicate future transplantation. Intravenous immunoglobulin has been shown to reduce sensitization after it has developed, allowing successful transplantation. The purpose of this pilot trial was to determine whether intravenous immunoglobulin given before and after the procedure could prevent sensitization to cryopreserved allograft patches used in the initial repair of hypoplastic left heart syndrome. Methods Intravenous immunoglobulin (2 g/kg) was given preoperatively, 3 weeks postoperatively, and 4 months postoperatively to 7 infants undergoing the Norwood procedure. Panel-reactive antibodies were measured with flow cytometry preoperatively and at 1, 4, 6, and 12 months postoperatively and compared with values from a contemporary cohort of 12 infants undergoing the Norwood procedure who did not receive intravenous immunoglobulin. Results The groups were well matched for length and weight at time of surgery. Control infants were somewhat younger than the cohort receiving intravenous immunoglobulin (8 ± 5 vs 17 ± 14 days, P = .021). There were no differences in transfusion requirements. There was no difference in the degree of sensitization between control and intravenous immunoglobulin groups at 1 month (class I panel-reactive antibodies 20% ± 30% vs 4% ± 9%, P = .443, class II panel-reactive antibodies 17% ± 27% vs 20% ± 17%, P = .400), 4 months (class I panel-reactive antibodies 62% ± 40% vs 73% ± 41%, P = .813, class II panel-reactive antibodies 49% ± 42% vs 54% ± 41%, P = .706), and 12 months (class I panel-reactive antibodies 49% ± 42% vs 58% ± 39%, P = .686, class II panel-reactive antibodies 44% ± 36% vs 49% ± 42%, P = .651). Conclusion Despite studies showing intravenous immunoglobulin to reduce sensitization, we were unable to demonstrate that intravenous immunoglobulin prevented sensitization after exposure to allograft tissue in neonates undergoing congenital cardiac surgery.

Background Preoperative anemia is a common and potentially serious hematological problem in elective surgery and increases the risk for perioperative red blood cell (RBC) transfusion. Transfusion is associated with postoperative morbidity and mortality. Preoperative intravenous (IV) iron therapy has been proposed as an intervention to reduce perioperative transfusion; however, studies are generally small, limited, and inconclusive. Methods/Design We propose performing a systematic review and meta-analysis. We will search MEDLINE, EMBASE, EBM Reviews, Cochrane-controlled trial registry, Scopus, registries of health technology assessment and clinical trials, Web of Science, ProQuest Dissertations and Theses, and conference proceedings in transfusion, hematology, and surgery. We will contact our study drug manufacturer for unpublished trials. Titles and abstracts will be identified and assessed by two reviewers for potential relevance. Eligible studies are: randomized or quasi-randomized clinical trials comparing preoperative administration of IV iron with placebo or standard of care to reduce perioperative blood transfusion in anemic patients undergoing major surgery. Screening, data extraction, and quality appraisal will be conducted independently by two authors. Data will be presented in evidence tables and in meta-analytic forest plots. Primary efficacy outcomes are change in hemoglobin concentration and proportion of patients requiring RBC transfusion. Secondary outcomes include number of units of blood or blood products transfused perioperatively, transfusion-related acute lung injury, neurologic complications, adverse events, postoperative infections, cardiopulmonary complications, intensive care unit (ICU) admission/readmission, length of hospital stay, acute kidney injury, and mortality. Dichotomous outcomes will be reported as pooled relative risks and 95% confidence intervals. Continuous outcomes will be reported using calculated weighted mean differences. Meta-regression will be performed to evaluate the impact of potential confounding variables on study effect estimates. Discussion Reducing unnecessary RBC transfusions in perioperative medicine is a clinical priority. This involves the identification of patients at risk of receiving transfusions along with blood conservation strategies. Of potential pharmacological blood conservation strategies, IV iron is a compelling intervention to treat preoperative anemia; however, existing data are uncertain. We propose performing a systematic review and meta-analysis evaluating the efficacy and safety of IV iron administration to anemic patients undergoing major surgery to reduce transfusion and perioperative morbidity and mortality. Systematic review registration PROSPERO CRD42015016771 Electronic supplementary material The online version of this article (doi:10.1186/s13643-015-0016-4) contains supplementary material, which is available to authorized users.

Background and Aim: Accepting donors of advanced age may increase the number of hearts available for transplantation. Objectives were to review the outcomes of using cardiac donors 50 years of age and older and to identify predictors of outcome at a single institution. Methods: A retrospective analysis of all adult cardiac transplants (n = 338) performed at our institution between 1988 and 2002 was conducted. Results: Of these, 284 patients received hearts from donors

Decellularization of allograft heart valves has been proposed as a method to reduce the alloreactive immune response, which limits the durability of these tissues. Rat models are essential for prel...

ObjectivesCryopreserved valve allografts used in congenital cardiac surgery are associated with a significant cellular and humoral immune response. This might be reduced by removal of antigenic cellular elements (decellularization). The aim of this study was to determine the immunologic effect of decellularization in a rat allograft valve model.MethodsBrown Norway and Lewis rat aortic valves were decellularized with a series of hypotonic and hypertonic buffers, protease inhibitors, gentle detergents (Triton X-100), and phosphate-buffered saline. Valves were implanted into Lewis rats in syngeneic and allogeneic combinations. Cellular (CD3 and CD8) infiltrates were assessed with morphometric analysis, and the humoral response was assessed with flow cytometry.ResultsMorphometric analysis identified a significant reduction in CD3+ cell infiltrates (cells per square millimeter of leaflet tissue) in decellularized allografts compared with that seen in nondecellularized allografts at 1 (79 ± 29 vs 3310 ± 223, P < .001), 2 (26 ± 11 vs 109 ± 20, P = .004), and 4 weeks (283 ± 122 vs 984 ± 145, P < .001). Anti-CD8 staining confirmed the majority of infiltrates were cytotoxic T cells. Flow cytometric mean channel fluorescence intensity identified a negative shift (abrogated antibody formation) for decellularized allografts compared with nondecellularized allografts at 2 (19 ± 1 vs 27 ± 3, P = .033), 4 (35 ± 2 vs 133 ± 29, P = .001), and 16 weeks (28 ± 2 vs 166 ± 54, P = .017).ConclusionsDecellularization significantly reduces the cellular and humoral immune response to allograft tissue. This could prolong the durability of valve allografts and might prevent immunologic sensitization of allograft recipients.

Objective: Cryopreserved allograft tissue used in the Norwood procedure for infants with hypoplastic left heart syndrome (HLHS) has the potential to cause marked immunologic sensitization which may complicate potential future heart transplantation, if required. The purpose of this study was to assess the anti-HLA antibody response to allograft patches used in the initial repair of HLHS. Methods: A prospective cohort study was conducted comparing the panel-reactive antibody levels (PRA) in 12 infants undergoing repair of HLHS with cryopreserved allograft patch to 10 infants undergoing arterial switch for transposition of the great arteries (no allograft tissue used). PRA for Class I (HLA-A, B, C) and Class II (HLA-DR, DQ) antibodies were assessed preoperatively and postoperatively using flow cytometry. Results: The two groups were well matched at the time of surgery (age, weight, gender). Infants in both groups received blood from multiple donors; however, the allograft group received significantly more (12G10 vs. 5G1 units; P!0.001). By 4 months, most infants receiving allograft tissue had become highly sensitized for both Class I PRA (62G40 vs. 0; PZ0.002) and Class II PRA (49G42 vs. 2G3; PZ0.022). This response continued to increase at 12 months: Class I PRA (79G21 vs. 0; PZ0.008) and Class II PRA (66G27 vs. 5G6; PZ0.008). Specificity analysis confirmed antibodies were specific for the donor allograft HLA type. In addition, infants who were coincidently HLA-matched with their allograft did not develop an elevated PRA. Conclusions: Allograft tissue used in the repair of HLHS is associated with profound donor specific immunologic sensitization in the majority of recipients and may complicate or jeopardize future transplantation. Methods to reduce the immunogenicity of cryopreserved allograft tissue used for arch reconstruction requires further investigation. q 2005 Elsevier B.V. All rights reserved.

Transcatheter aortic valve implantation (TAVI) has been recognized as an alternative treatment for high-risk surgical patients with symptomatic severe aortic stenosis (AS). Valve migration is a potentially life-threatening complication of TAVI that usually occurs during implantation. Late (>24 h) ([

BACKGROUND: Acute kidney injury (AKI) is a serious complication following lung transplantation (LTx). We aimed to describe the incidence and outcomes associated with AKI following LTx. METHODS: A retrospective population-based cohort study of all adult recipients of LTx at the University of Alberta between 1990 and 2011. The primary outcome was AKI, defined and classified according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria, in the first 7 post-operative days. Secondary outcomes included risk factors, utilization of renal replacement therapy (RRT), occurrence of post-operative complications, mortality and kidney recovery. RESULTS: Of 445 LTx recipients included, AKI occurred in 306 (68.8%), with severity classified as Stage I in 38.9% (n = 173), Stage II in 17.5% (n = 78) and Stage III in 12.4% (n = 55). RRT was received by 36 (8.1%). Factors associated with AKI included longer duration of cardiopulmonary bypass [per minute, odds ratio (OR) 1.003; 95% confidence interval (CI), 1.001-1.006; P = 0.02], and mechanical ventilation [per hour (log-transformed), OR 5.30; 95% CI, 3.04-9.24; P < 0.001], and use of cyclosporine (OR 2.03; 95% CI, 1.13-3.64; P = 0.02). In-hospital and 1-year mortality were significantly higher in those with AKI compared with no AKI (7.2 versus 0%; adjusted P = 0.001; 14.4 versus 5.0%; adjusted P = 0.02, respectively). At 3 months, those with AKI had greater sustained loss of kidney function compared with no AKI [estimated glomerular filtration rate, mean (SD): 68.9 (25.7) versus 75.3 (22.1) mL/min/1.73 m(2), P = 0.01]. CONCLUSIONS: By the KDIGO definition, AKI occurred in two-thirds of patients following LTx. AKI portended greater risk of death and loss of kidney function.

Occlusion of the left atrial appendage (LAA) is a promising approach to stroke prevention in atrial fibrillation (AF). However, evidence of its efficacy and safety to date is lacking. We herein describe the rationale and design of a definitive LAA occlusion trial in cardiac surgical patients with AF.We plan to randomize 4,700 patients with AF in whom on-pump cardiac surgical procedure is planned to undergo LAA occlusion or no LAA occlusion. The primary outcome is the first occurrence of stroke or systemic arterial embolism over a mean follow-up of four years. Other outcomes include total mortality, operative safety outcomes (chest tube output in the first post-operative 24 hours, rate of post-operative re-exploration for bleeding in the first 48 hours post-surgery and 30-day mortality), re-hospitalization for heart failure, major bleed, and myocardial infarction.Left Atrial Appendage Occlusion Study (LAAOS) III is funded in a vanguard phase by the Canadian Institutes for Health Research (CIHR), the Canadian Network and Centre for Trials Internationally, and the McMaster University Surgical Associates. As of September 9, 2013, 162 patients have been recruited into the study.LAAOS III will be the largest trial to explore the efficacy of LAA occlusion for stroke prevention. Its results will lead to a better understanding of stroke in AF and the safety and efficacy of surgical LAA occlusion.

Procedural outcomes for transcatheter aortic valve implantation (TAVI) are well described. However, limited information exists regarding patient screening and selection. Thus, the purpose of the study was to review consecutive patients referred for TAVI from an inclusive-defined population. The Mazankowski Alberta Heart Institute TAVI program has maintained a prospective database on all referred patients. Patients are reviewed in outpatient clinic attended by a nurse, cardiologist, cardiac surgeon, and administrative assistant. After workup is complete, a TAVI Heart Team conference occurs to accept or reject each patient. Since November 2009, 276 patients (145 men and 131 women) have been referred with a steady increase in the number of referrals annually. Mean age was 82.2 years (men 81.6 and women 82.8), with 13% aged70 years. Mean EuroSCORE was 13.8 and mean STS score was 5.7. Of the referred patients, 34% received TAVI, 17% were rejected, 12% underwent open AVR, 10% refused TAVI, and 27% are currently being assessed or followed. There were no differences in the mean EuroSCORE (13.4 vs 14.3; p = 0.64) or STS scores (5.2 vs 6.4; p = 0.13) of those accepted for TAVI versus those who were not. In conclusion, a team-based approach to assess this complex patient population is essential to ensure efficient and comprehensive evaluation, in turn determining appropriate care allocation. With expansion of clinical experience and the evidence supporting TAVI, the Heart Teams defined to assess this patient population will be burdened with increased clinical commitment and require appropriate support.

Background: The efficacy of coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) in patients with multivessel coronary artery disease (CAD) has been well-defined by randomized controlled trials. However, patients with severe left ventricular dysfunction (ejection fraction Methods: We used APPROACH, a clinical data collection initiative, capturing all patients undergoing cardiac catheterization and revascularization in the province of Alberta, Canada, to identify 2477 patients with multivessel CAD and EF Results: Patients undergoing CABG were slightly older (65.8 vs. 65.3 years; p=0.269), more likely to have three vessel CAD (62% vs. 56%; p Conclusion: In patients with multivessel CAD and left ventricular dysfunction, CABG was associated with better survival than PCI after adjustment for baseline risk profile differences. Further research exploring the factors leading to use of a particular revascularization modality is required.

The very low risk of mitral valve repair performed through median sternotomy must be reproducible when using a port-access approach to justify early repair employing minimally invasive platforms. We compared the outcomes of mitral valve repair performed through port access using thoracoscopic assistance (port) versus median sternotomy (open).The early results after mitral valve repair performed by two different surgeons at two separate institutions were analyzed. Between January 1999 and December 2006, isolated mitral valve repair was performed with a port approach in 350 patients and an open approach in 365 patients.The mean age was similar between the two groups; however, port patients were more frequently female (148 [42%] versus 119 [33%], p = 0.007), and had a higher likelihood of having New York Heart Association class III to IV symptoms (100 [29%] versus 48 [13%], p0.001), diabetes mellitus (19 [5%] versus 8 [2%], p = 0.023), congestive heart failure (90 [26%] versus 26 [7%], p0.001), and a lower ejection fraction (53% versus 64%, p0.001) preoperatively. Cross-clamp time (104 versus 24 minutes, p0.001) and bypass time (140 versus 33 minutes, p = 0.001) were significantly lower for the open group. On univariate analysis, the duration of postoperative ventilatory support was significantly lower in the port group (5.0 versus 11.0 hours, p0.001); however, the length of hospital stay was longer (6.95 versus 6.19 days, p0.001). There were 2 early deaths (2 port versus 0 open). A propensity score factor was calculated and utilized to account for differences between groups. After adjusting for propensity score and significant factors identified in multivariate models, port mitral repair independently predicted a diminished duration of postoperative ventilatory support (p = 0.045), but there were no significant differences in other outcomes including postoperative blood transfusion, reoperation for hemorrhage, or length of stay in hospital.Despite longer cross-clamp and bypass times, early outcomes using a thoracoscopic port-access approach were similar to those for mitral valve repair performed through median sternotomy. Minimally invasive mitral valve repair was associated with a shorter time to extubation, but that did not translate into a diminished duration of postoperative hospitalization.

Rodent models have been essential to under- standing the immune-mediated failure of aortic valve allo- grafts (AVAs). Decellularization has been proposed to re- duce the immunogenicity of AVAs. The objective of this study was to determine the most effective method to decel- lularize AVAs for use in a rat model. Three different decel- lularization techniques were compared in Lewis aortic valves. Detergent decellularization involved a series of hy- potonic and hypertonic Tris buffers at 4°C for 48 h/buffer containing 0.5% Triton X-100 followed by a 72 h washout in phosphate-buffered saline. Osmotic decellularization was performed in similar manner to the detergent-based tech- nique except without the addition of Triton X-100. Enzy- matic decellularization consisted of trypsin/EDTA at 37°C for 48 h. Assessment was performed with light microscopy (H&E, Movat's pentachrome), immunohistochemistry for residual cellular elements, and hydroxyproline assays. De- tergent-based methodology effected near-complete decellu- larization of both the leaflets and aortic wall in addition to preservation of the extracellular matrix (ECM). Osmotic lysis was associated with preservation of ECM and moderate decellularization. Enzymatic decellularization resulted in complete decellularization but extensive degeneration and fragmentation of the ECM. When implanted into the infra- renal aorta of allogeneic rats for 1 week, valves decellular- ized with detergent-based and osmotic methodology failed to stimulate an allogeneic immune response as evidenced by an absence of T cell infiltrates. Osmotic lysis protocols with low dose detergent appear to be most effective at both removing antigenic cellular elements and preserving ECM. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res 79A: 254 -262, 2006

The bicaval technique of orthotopic heart transplantation, in contrast to the standard biatrial technique, may better preserve right atrial anatomy and, thus, may be associated with less sinus node dysfunction and less atrioventricular valve dysfunction.To compare the requirement for permanent pacemaker insertion and the incidence of atrioventricular valve dysfunction following heart transplantation with either the standard or the bicaval technique.A retrospective analysis was conducted of a consecutive cohort of 105 patients, older than 18 years of age, undergoing heart transplantation with either the standard (n=48) or the bicaval (n=57) technique from December 1998 to December 2001.Cross-clamp (100 min versus 112 min; P=0.012) and donor ischemic (222 min versus 276 min; P=0.005) times were significantly prolonged in the bicaval group. Perioperative morbidity and mortality were statistically similar between the groups. Bicaval transplantation resulted in a significant decrease in the requirement for permanent pacemaker insertion at 30 days (13% versus 0%; P=0.008) and 90 days (17% versus 1.8%; P=0.01) after transplantation. There was a nonsignificant trend toward a decreased degree of tricuspid valve regurgitation (mean 1.81 versus 1.36; P=0.141) and mitral valve regurgitation (mean 1.04 versus 0.79; P=0.348) with the bicaval technique.Although associated with longer cross-clamp and donor ischemic times, the data demonstrated a significant reduction in the need for permanent pacemaker insertion at 30 and 90 days post-transplantation with the bicaval technique. There was no statistically significant difference in the degree of mitral and tricuspid valve regurgitation between the two groups.