A formalized shared decision-making process with individualized decision aids for older patients referred for cardiac surgery.

BACKGROUND: Comprehension of risks, benefits and alternative treatment options is poor among patients referred for cardiac surgery interventions. We sought to explore the impact of a formalized shared decision-making (SDM) process on patient comprehension and decisional quality among older patients referred for cardiac surgery. METHODS: We developed and evaluated a paper-based decision aid for cardiac surgery within the context of a prospective SDM design. Surgeons were trained in SDM through a Web-based program. We acted as decisional coaches, going through the decision aids with the patients and their families, and remaining available for consultation. Patients (aged ≥ 65 yr) undergoing isolated valve, coronary artery bypass graft (CABG) or CABG and valve surgery were eligible. Participants in the non-SDM phase followed standard care. Participants in the SDM group received a decision aid following cardiac catheterization, populated with individualized risk assessment, personal profile and comorbidity status. Both groups were assessed before surgery on comprehension, decisional conflict, decisional quality, anxiety and depression. RESULTS: We included 98 patients in the SDM group and 97 in the non-SDM group. Patients who received decision aids through a formalized SDM approach scored higher in comprehension (median 15.0, interquartile range [IQR] 12.0-18.0) than those who did not (median 9.0, IQR 7.0-12.0, p < 0.001). Decisional quality was greater in the SDM group (median 82.0, IQR 73.0-91.0) than in the non-SDM group (median 76.0, IQR 62.0-82.0, p < 0.05). Decisional conflict scores were lower in the SDM group (mean 1.76, standard deviation [SD] 1.14) than in the non-SDM group (mean 5.26, SD 1.02, p < 0.05). Anxiety and depression scores showed no significant difference between groups. CONCLUSION: Institution of a formalized SDM process including individualized decision aids improved comprehension of risks, benefits and alternatives to cardiac surgery, as well as decisional quality, and did not result in increased levels of anxiety.

Six-year follow-up of aortic valve reoperation rates: Carpentier-Edwards Perimount versus St. Jude Medical Trifecta.

BACKGROUND: The Carpentier-Edwards Perimount valves have a proven track record in aortic valve replacement: good durability, hemodynamic performance, rates of survival, and low rates of valve-related complications and prosthesis-patient mismatch. The St. Jude Medical Trifecta is a newer valve that has shown comparable early and midterm outcomes. Studies show reoperation rates of Trifecta are comparable with Perimount valves, with a few recent studies bringing into focus early structural valve deterioration (SVD), and increased midterm SVD in younger patients. Given that midterm data for Trifecta is still sparse, we wanted to confirm the early low reoperation rates of Trifecta persist over time compared with Perimount. METHODS: The Maritime Heart Centre Database was searched for AVR between 2011 and 2016, inclusive. The primary endpoint of the study was all-cause reoperation rate. RESULTS: In total, 711 Perimount and 453 Trifecta implantations were included. The reoperation hazards were determined for age: 0.96 (0.92-0.99; p = .02), female (vs. male): 0.35 (0.08-1.53; p = .16), smoker (vs. nonsmoker): 2.44 (0.85-7.02; p = .1), and Trifecta (vs. Perimount): 2.68 (0.97-7.39; p = .06). Kaplan-Meier survival analysis in subgroups-age <60, age ≥60, male, female, smoker, and nonsmoker-showed Perimount having lower reoperation rates than Trifecta in patients younger than 60 (p = .02) and current smokers (p < .01). CONCLUSIONS: The rates of reoperation of Perimount and Trifecta were comparable, with Trifecta showing higher rates in patients younger than 60 years, and current smokers. Continued diligence and further independent reporting of midterm reoperation and SVD rates of the Trifecta, including detailed echocardiographic follow-up, are needed to confirm these findings.

The use of extracorporeal membrane oxygenation in the anticipated difficult airway: a case report and systematic review.

While extracorporeal membrane oxygenation (ECMO) is an effective method of oxygenation for patients with respiratory failure, further refinement of its incorporation into airway guidelines is needed. We present a case of severe glottic stenosis from advanced thyroid carcinoma in which gas exchange was facilitated by veno-arterial ECMO prior to achieving a definitive airway. We also conducted a systematic review of the MEDLINE, EMBASE, CINAHL, and Web of Science databases, using the keywords "airway/ tracheal obstruction", "anesthesia", "extracorporeal", and "cardiopulmonary bypass" to identify reports where ECMO was initiated as the a priori method of oxygenation during difficult airway management.Thirty-six papers were retrieved discussing the use of ECMO or cardiopulmonary bypass (CPB) for the management of critical airway obstruction. Forty-five patients underwent pre-induction of anesthesia institution of CPB or ECMO for airway obstruction. The patients presenting with critical airway obstruction had a range of airway pathologies with tracheal tumours (31%), tracheal stenosis (20%), and head and neck cancers (20%) being the most common. All cases reported a favourable patient outcome with all patients surviving to hospital discharge without significant complications.While most practitioners are familiar with the fundamental airway techniques of bag-mask ventilation, supraglottic airway use, tracheal intubation, and front-of-neck airway access for oxygenation, these techniques have limitations in managing patients with pre-existing severe airway obstruction. The use of ECMO should be considered in patients with severe (or near-complete) airway obstruction secondary to anterior neck or tracheal disease. This approach can provide essential tissue oxygenation while attempts to secure a definitive airway are carried out in a controlled environment.

Does more than a single chest tube for mediastinal drainage affect outcomes after cardiac surgery?

BACKGROUND: The use of 1 or more mediastinal chest tubes has traditionally been routine for all cardiac surgery procedures to deal with bleeding. However, it remains unproven whether multiple chest tubes offer a benefit over a single chest tube. METHODS: All consecutive patients undergoing cardiac surgery (2005-2010) received at least 1 chest tube at the time of surgery based on surgeon preference. Patients were grouped into those receiving a single chest tube (SCT) and those receiving multiple chest tubes (MCT). The primary outcome was return to the operating room for bleeding or tamponade. RESULTS: A total of 5698 consecutive patients were assigned to 2 groups: 3045 to the SCT and 2653 to the MCT group. Patients in the SCT group were older, more often female and less likely to undergo isolated coronary artery bypass graft than those in the MCT group. Unadjusted outcomes for SCT and MCT, respectively, were return to the operating room for bleeding or tamponade (4.7% v. 5.0%; p = 0.50), intensive care unit stay longer than 48 hours (25.5% v. 27.9%; p = 0.041, postoperative stay > 9 days (31.5% v. 33.1%; p = 0.20) and mortality (3.8% v. 4.6%; p = 0.16). Logistic regression analysis, adjusted for clinical differences between groups, showed that the number of chest tubes was not associated with return to the operating room for bleeding or tamponade. CONCLUSION: The use of multiple mediastinal chest tubes after cardiac surgery confers no advantage over a single chest tube in preventing return to the operating room for bleeding or tamponade.

Impact of Clopidogrel Stop Interval on Major Adverse Bleeding Events in Cardiac Surgery.

BACKGROUND: Major societal guidelines recommend a 5-day stop interval before cardiac surgery for patients with acute coronary syndrome receiving clopidogrel. Yet, many such patients present with high acuity, generating surgeon inclination toward use of shorter stop intervals. Thus, this study aimed to determine the impact of the duration and timing of the interval of clopidogrel cessation on adverse bleeding events. METHODS: Patients who underwent cardiac surgery between 2009 and 2016 at a tertiary-care centre were included in this retrospective cohort study. Multivariable logistic regression models adjusted for clopidogrel stop interval, age, urgency of procedure, and procedure type were used to quantify the effect of clinically relevant baseline demographic characteristics on incidence of massive transfusion as well as hemorrhagic complication outcomes. RESULTS: A total of 5748 patients underwent cardiac surgery. In this cohort, 1743 patients (30.3%) received clopidogrel preoperatively, and 884 (50.7%) of these patients discontinued clopidogrel 5 days before presenting to the operating room. The administration of clopidogrel 1-2 days before surgery (odds ratio 1.97; 95% confidence interval: 1.18 to 3.29) was an independent predictor for massive transfusions and hemorrhagic complications (odds ratio 1.85; 95% confidence interval: 1.01 to 3.37). The 3-4 day group did not have an increased risk of major bleeding complications. The risk for both massive transfusions and hemorrhagic complications also increased with the urgency and complexity of surgery. CONCLUSION: A clopidogrel stop interval of 3-4 days preoperatively was not associated with an increased risk for major bleeding complications.

INTRODUCTION: Les grandes lignes directrices sociétales recommandent une interruption de cinq jours avant l'intervention chirurgicale du cœur des patients atteints d'un syndrome coronarien aigu qui prennent du clopidogrel. Toutefois, comme il s'agit pour plusieurs d'entre eux de patients de haute acuité, le chirurgien penche vers l'utilisation d'une interruption plus courte. Par conséquent, la présente étude avait pour objectif de déterminer les conséquences de la durée et du moment de la cessation du clopidogrel sur les événements hémorragiques indésirables. MÉTHODES: La présente étude de cohorte rétrospective portait sur les patients qui avaient subi une intervention chirurgicale au cœur entre 2009 et 2016 dans un centre de soins tertiaires. Nous avons utilisé les modèles multivariés de régression logistique ajustés à l'interruption du clopidogrel, à l'âge, à l'urgence de l'intervention chirurgicale et au type d'intervention chirurgicale pour quantifier les effets des caractéristiques démographiques initiales cliniquement pertinentes sur la fréquence des transfusions massives ainsi que sur les issues des complications hémorragiques. RÉSULTATS: Un total de 5 748 patients ont subi une intervention chirurgicale au cœur. Dans cette cohorte, parmi les 1 743 patients (30,3 %) qui avaient reçu du clopidogrel avant l'opération, 884 (50,7 %) avaient cessé le clopidogrel cinq jours avant leur admission à la salle d'opération. L'administration du clopidogrel un à deux jours avant l'intervention chirurgicale (ratio d'incidence approché 1,97; intervalle de confiance [IC] à 95 % : de 1,18 à 3,29) était un prédicteur indépendant des transfusions massives et des complications hémorragiques (ratio d'incidence approché 1,85; [IC] à 95 % : de 1,01 à 3,37). Le groupe de l'interruption de trois à quatre jours n'a pas montré de risque accru de complications hémorragiques graves. Le risque de transfusions massives et de complications hémorragiques a aussi contribué à l'augmentation de l'urgence et de la complexité de l'intervention chirurgicale. CONCLUSION: Une interruption du clopidogrel de trois à quatre jours avant l'opération n'a pas été associée à un risque accru de complications hémorragiques graves.

Frail patients are at increased risk for mortality and prolonged institutional care after cardiac surgery.

BACKGROUND: Frailty is an emerging concept in medicine yet to be explored as a risk factor in cardiac surgery. Where elderly patients are increasingly referred for cardiac surgery, the prevalence of a frail group among these is also on the rise. We assessed frailty as a risk factor for adverse outcomes after cardiac surgery. METHODS AND RESULTS: Functional measures of frailty and clinical data were collected prospectively for all cardiac surgery patients at a single center. Frailty was defined as any impairment in activities of daily living (Katz index), ambulation, or a documented history of dementia. Of 3826 patients, 157 (4.1%) were frail. Frail patients were older, were more likely to be female, and had risk factors for adverse surgical outcomes. By logistic regression, frailty was an independent predictor of in-hospital mortality (odds ratio 1.8, 95% CI 1.1 to 3.0), as well as institutional discharge (odds ratio 6.3, 95% CI 4.2 to 9.4). Frailty was an independent predictor of reduced midterm survival (hazard ratio 1.5, 95% CI 1.1 to 2.2). CONCLUSIONS: Frailty is a risk for postoperative complications and an independent predictor of in-hospital mortality, institutional discharge, and reduced midterm survival. Frailty screening improves risk assessment in cardiac surgery patients and may identify a subgroup of patients who may benefit from innovative processes of care.

Hemodynamic performance of the St. Jude Medical Epic Supra aortic stented valve.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate the hemodynamic performance of the St. Jude Medical Epic Supra bioprosthesis during the early six-month follow up period, and to confirm the safety and efficacy of the valve by collecting details of adverse events and NYHA functional classification. METHODS: Fifty-seven patients undergoing aortic valve replacement (AVR) with the Epic Supra valve between September 2007 and January 2009 at three centers in Canada were evaluated for the study. The subjects were monitored preoperatively, at discharge, and at six months postoperatively. Echocardiographic data were available from 50 subjects at the six-month follow up. In order to prevent observer variability, all echocardiograms were sent to an independent Echocardiography Core Laboratory (ECL) for interpretation of the data. RESULTS: The mean subject age was 74 years. Concomitant coronary artery bypass grafting (CABG) was performed in 44% of the procedures. The mean pressure gradients were 11.2, 12.5, 10.8, 8.4 and 11.3 mmHg, respectively, for valves sized 19 mm (n = 2), 21 mm (n = 20), 23 mm (n = 22), 25 mm (n = 5) and 27 mm (n = 1). The average effective orifice areas (EOAs) were 1.44, 1.57, 1.69, 1.93 and 1.81 cm2 for the .valves sized 19, 21, 23, 25 and 27 mm, respectively. CONCLUSION: The results of the six-month echocardiographic follow up indicated that the Epic Supra valve offered excellent hemodynamic performance in the 21, 23 and 25 mm sizes. However, additional data are still required for the 19 and 27 mm valves to characterize their performance. The mean gradients and EOA-values were comparable to those of other supra-annular stented tissue valves. The EOA index indicated an absence of prosthesis-patient mismatch, with values in all subjects at or near 0.85 cm2/m2. The percentage of subjects without aortic insufficiency (AI) at follow up was 92%; only four subjects showed trivial AI.

Long-term results of heart operations performed by surgeons-in-training.

BACKGROUND: We investigated the association between trainees performing supervised operations and late outcomes of patients undergoing cardiac surgery. METHODS AND RESULTS: Data were prospectively collected on patients who underwent coronary artery bypass graft surgery, aortic valve replacement, or a combination of these between 1998 and 2005 at the Maritime Heart Center, Halifax, Canada. In-hospital mortality and a composite outcome of in-hospital mortality, stroke, bleeding, intra-aortic balloon pump insertion, renal failure, and sternal infection was compared between teaching (n=1054) and nonteaching cases (n=5877). Late survival and cardiovascular hospital readmissions were also examined. To adjust for baseline risk disparities, we used logistic regression for dichotomous in-hospital outcomes and Cox proportional hazards regression for survival data. Resident cases were significantly more likely to have high-risk features such as depressed ventricular function, redo operation, and urgent or emergent procedure. Resident as primary operator was not independently associated with in-hospital mortality (OR, 1.09; 95% CI, 0.75 to 1.58; P=0.66) or with the composite outcome (OR, 1.01; 95%, CI 0.82 to 1.26; P=0.90). The Kaplan-Meier event-free survival of the 2 groups was equivalent at 1, 3, and 5 years (log-rank P=0.06). By Cox regression, resident cases were not associated with late death or cardiovascular rehospitalization (hazard ratio, 1.05; 95% CI, 0.94 to 1.17; P=0.42). CONCLUSIONS: Cases performed by senior-level cardiac surgery residents were more likely to have greater acuity and complexity than staff surgeon-performed cases. However, clinical outcomes were similar in the short- and long-term. Allowing residents to perform cardiac surgery is not associated with adverse patient outcomes.

CD8(+) T cells mediate aortic allograft vasculopathy under conditions of calcineurin immunosuppression: role of IFN-gamma and CTL mediators.

We have developed a model of aortic allograft vasculopathy (AV) that uses mouse strains that are fully disparate at Class I, Class II and minor histocompatibility antigens. Acute rejection is ablated with therapeutic doses of the calcineurin inhibitor Cyclosporine A (CyA). In this way we successfully mimic human disease. Using this model we have demonstrated, with cell transfer models using highly purified T cell populations, that calcineurin inhibitors ablate CD4(+) T cell effector mechanisms. As such, in the presence of calcineurin inhibition, graft vasculopathy is dependent on CD8(+) T cell effector mechanisms. In this study we examine the etiology of graft vasculopathy by these CD8(+) T cells in the presence of calcineurin inhibition. We transferred CD8(+) T cells from CyA treated IFN-gamma deficient mice into immunodeficient mouse recipients of aortic allografts to demonstrate that IFN-gamma production by CD8(+) T cells is essential for the development of AV in the presence of calcineurin inhibition. Using two models of CTL ablation we also demonstrated that CTL activity by CD8(+) T cells is essential for the development of AV in the presence of calcineurin inhibition. This is in contrast to models without calcineurin inhibitor immunosuppression where either pathway is capable, by itself, of inducing AV. These data indicate that although calcineurin inhibition ablates CD4(+) T cell effects and weakens CD8(+) T cell pathways, the antigenic challenge of the graft is enough to induce sufficient responsiveness from CD8(+) T cells to induce robust AV.

Immunologic targets in the etiology of allograft vasculopathy: endothelium versus media.

The respective roles of the endothelium and the media as allo-immune targets in the generation of allograft vasculopathy (AV) have yet to be clearly defined. Although endothelial damage has been implicated in the progression of AV, evidence from mechanical vascular injury models suggests that medial injury may play a more dominant role. The overall objective of this research was to determine the relative importance of the endothelium versus the media as a target for immune injury and induction of AV. To investigate this we developed a novel model which involved the creation of chimeric aortic segments. To accomplish this we removed aortic segments from C3H/HeJ (C3H) mice and stripped them of endothelium by a short pulse with EDTA. The stripped C3H grafts were implanted into immunodeficient C57BL/6 (B6) RAG1(-/-) mice for a period of 21 days. As the immunodeficient mice did not mount an allo-immune response to the grafts, the endothelium was renewed by normal repair mechanisms. The new endothelium was recipient in origin, resulting in a chimeric graft with C3H media and B6 endothelium. We confirmed complete denudement by immunocytochemistry for endothelial specific markers, as well as by transmission and scanning electron microscopy. Replacement of endothelium with recipient endothelial cells was confirmed by immunocytochemistry, electron microscopy and by using a green fluorescent protein mouse transplant combination. Subsequent re-transplantation of the chimeric grafts into either B6 or C3H recipients demonstrated that an allogeneic media is more important than an allogeneic endothelium in inducing robust AV.

Mitral insufficiency and morbidity and mortality in left ventricular dysfunction.

BACKGROUND: Mitral insufficiency is known to occur in a substantial proportion of patients with heart failure. Its relationship with morbidity and mortality is poorly described. METHODS: The mortality and hospitalization for heart failure were retrospectively examined in patients who underwent baseline echocardiography in the Studies Of Left Ventricular Dysfunction (SOLVD) treatment and prevention trials. The presence and grade of mitral insufficiency was assessed, and patients with and without mitral insufficiency were compared. RESULTS: Patients with left ventricular dysfunction and mitral insufficiency had greater than twofold increased risk of death or admission for heart failure over two years (RR 2.38, 95% CI 1.43 to 3.97). This excess risk persisted after adjustment for the severity of heart failure, etiology and differences in treatment (RR 1.82, 95% CI 1.04 to 3.17; P=0.04). The presence of moderate mitral insufficiency versus no insufficiency was associated with even greater independent risk (RR 2.20, 95% CI 1.01 to 4.80; P=0.05). Results were consistent with binary and ordinal analysis of mitral insufficiency. CONCLUSION: The presence of mitral insufficiency in patients with left ventricular dysfunction is independently associated with adverse outcomes, including death and hospitalization for heart failure. This has potentially important clinical implications for the assessment and management of patients with heart failure.

Perioperative prediction of agitated (hyperactive) delirium after cardiac surgery in adults - The development of a practical scorecard.

BACKGROUND: Delirium is a temporary mental disorder that occurs frequently among hospitalized patients. In this study we sought to develop a user-friendly scorecard based on perioperative features to identify patients at risk of developing agitated delirium after cardiac surgery. METHODS: Retrospective analysis was performed on adult patients undergoing cardiac surgery in a single center. A parsimonious predictive model was created, with subsequent internal validation. Then a simple scorecard was developed that can be used to predict the probability of agitated delirium. RESULTS: Among the 5584 patients who met the study criteria, 614 (11.4%) developed postoperative agitated delirium. Independent predictors of postoperative agitated delirium were age, male gender, history of cerebrovascular disease, procedure other than isolated Coronary Arteries Bypass Surgery, transfusion of blood products within the first 48h, mechanical ventilation for >24h, length of stay in the Intensive Care Unit. The scorecard stratified patients into 4 categories at risk of postoperative agitated delirium ranging from <5% to >30%. CONCLUSION: Using a large cohort of adult patient's undergoing cardiac surgery, a user-friendly scorecard was developed and validated, which will facilitate the implementation of timely interventions to mitigate adverse effects of agitated delirium in this high risk population.

Toward Optimal Decision Making among Vulnerable Patients Referred for Cardiac Surgery: A Qualitative Analysis of Patient and Provider Perspectives.

OBJECTIVES: Comprehension of risks, benefits, and alternative treatment options has been shown to be poor among patients referred for cardiac interventions. Patients' values and preferences are rarely explicitly sought. An increasing proportion of frail and older patients are undergoing complex cardiac surgical procedures with increased risk of both mortality and prolonged institutional care. We sought input from patients and caregivers to determine the optimal approach to decision making in this vulnerable patient population. METHODS: Focus groups were held with both providers and former patients. Three focus groups were convened for Coronary Artery Bypass Graft (CABG), Valve, or CABG +Valve patients ≥ 70 y old (2-y post-op, ≤ 8-wk post-op, complicated post-op course) (n = 15). Three focus groups were convened for Intermediate Medical Care Unit (IMCU) nurses, Intensive Care Unit (ICU) nurses, surgeons, anesthesiologists and cardiac intensivists (n = 20). We used a semi-structured interview format to ask questions surrounding the informed consent process. Transcribed audio data was analyzed to develop consistent and comprehensive themes. RESULTS: We identified 5 main themes that influence the decision making process: educational barriers, educational facilitators, patient autonomy and perceived autonomy, patient and family expectations of care, and decision making advocates. All themes were influenced by time constraints experienced in the current consent process. Patient groups expressed a desire to receive information earlier in their care to allow time to identify personal values and preferences in developing plans for treatment. Both groups strongly supported a formal approach for shared decision making with a decisional coach to provide information and facilitate communication with the care team. CONCLUSIONS: Identifying the barriers and facilitators to patient and caretaker engagement in decision making is a key step in the development of a structured, patient-centered SDM approach. Intervention early in the decision process, the use of individualized decision aids that employ graphic risk presentations, and a dedicated decisional coach were identified by patients and providers as approaches with a high potential for success. The impact of such a formalized shared decision making process in cardiac surgery on decisional quality will need to be formally assessed. Given the trend toward older and frail patients referred for complex cardiac procedures, the need for an effective shared decision making process is compelling.

CD8+ T cells mediate aortic allograft vasculopathy by direct killing and an interferon-gamma-dependent indirect pathway.

OBJECTIVE: Allograft vasculopathy (AV) has emerged as the major obstacle to long-term survival in clinical heart transplantation. Immune events are implicated in the development of AV, but the cellular and molecular mechanisms involved remain unclear. We sought to determine whether and by what mechanism CD8(+) T lymphocytes are able to generate AV in a murine aortic allograft model. METHODS: Allo-primed CD8(+) T lymphocytes were transferred into immunodeficient (RAG-1(-/-)) mouse recipients of aortic allografts. We also transferred primed CD8(+) T cells with targeted deletions of effector molecules (perforin, Fas-ligand) to determine the role of direct cytolysis (CTL) in CD8(+) T-cell-mediated AV. We determined the role of non-CTL effector mechanisms through the transfer of either wildtype or interferon-gamma (IFN-gamma)-deficient CD8(+) T cells into RAG-1(-/-) recipients of MHC class I-deficient allografts. RESULTS: Adoptive transfer of primed wildtype CD8(+) T lymphocytes into immunodeficient recipients of aortic allografts resulted in the development of robust AV lesions. Transfer of CD8(+) T lymphocytes with targeted deletions in CTL effector molecules resulted in reduction of AV lesion size but not abrogation. Transfer of wildtype CD8(+) T cells into recipients of MHC class I-deficient grafts resulted in a reduction in AV lesion size, while transfer of interferon-gamma-deficient CD8(+) T cells into MHC class I-deficient grafts abrogated AV. CONCLUSIONS: These data indicate that CD8(+) T cells mediate AV through direct cytolysis and a distinct interferon-gamma-dependent non-CTL effector pathway. Given the resistance of this cell type to conventional immunosuppression, these results may have important therapeutic implications.

Coronary bypass surgery performed off pump does not result in lower in-hospital morbidity than coronary artery bypass grafting performed on pump.

BACKGROUND: There is increasing evidence that cardiopulmonary bypass (CPB) may be responsible for the morbidity associated with coronary artery bypass grafting (CABG) surgery. Recent developments in cardiac stabilization devices have made CABG without CPB feasible. However, there is conflicting evidence to date from published trials comparing outcomes between CABG performed with and without CPB, with some trials indicating an advantage to the avoidance of CPB and others showing little benefit. METHODS AND RESULTS: In a single-center randomized trial, 300 patients requiring CABG surgery at a single institution were prospectively randomized to have the procedure performed with CPB (n=150) or on the beating heart (n=150). Exclusion criteria for the trial included emergency procedure, concomitant major cardiac procedures, ejection fraction <30%, and reoperation. In-hospital outcomes were analyzed on an intention-to-treat basis. A mean of 3.0+/-0.9 grafts were performed in the CPB group compared with 2.8+/-0.9 grafts in the beating-heart group (P=0.06). There were no significant differences between the CPB group and the beating-heart group in mortality (0.7% versus 1.3%; P=1.0), transfusion (8.7% versus 9.3%), perioperative myocardial infarction (0.7% versus 2.7%; P=0.37), permanent stroke (0% versus 1.3%; P=0.50), new atrial fibrillation (32% versus 25%; P=0.20), and deep sternal wound infection (0.7% versus 0%; P=1.0). The mean time to extubation was 4 hours, the mean stay in the intensive care unit was 22 hours, and the median length of hospitalization was 5 days in both groups (P=NS). CONCLUSIONS: In contrast to published trials, we were unable to demonstrate any advantage with CABG performed without CPB in terms of patient morbidity. Excellent results can be obtained with either surgical approach.

The association between prior percutaneous coronary intervention and short-term outcomes after coronary artery bypass grafting.

BACKGROUND: Increasingly, patients are being referred for coronary artery bypass grafting (CABG) for management of symptoms after prior percutaneous coronary intervention (PCI). In this study, we assessed the impact of prior PCI on inhospital mortality after CABG. METHODS: Perioperative data were collected on patients who underwent first-time CABG at 2 surgical centers. Patients who underwent PCI and CABG during the same admission were excluded. Patients with prior PCI were compared with patients with no prior PCI, and the risk-adjusted impact of prior PCI on inhospital mortality after CABG was determined using both multivariate techniques and propensity score matching techniques. RESULTS: Six thousand thirty-two patients met inclusion criteria. Patients with prior PCI were less likely to be between the ages of 70 and 80 (P < .0001), to have an ejection fraction <0.40 (P < .0001), and to have 3-vessel/left main disease (P < .0001). They were, however, more likely to have Canadian Cardiovascular Society class IV symptoms (P < .0001) and to have an urgent status (P = .02). Rates of inhospital mortality after CABG were higher in patients with prior PCI (3.6% vs 2.3%, P = .02). Using multivariate techniques, prior PCI emerged as an independent predictor of postoperative inhospital mortality (odds ratio 1.93, P = .003). When patients with prior PCI were matched to patients with no prior PCI using propensity scores, inhospital mortality remained higher among patients with prior PCI (3.6% vs 1.7%, P = .01). CONCLUSION: Patients with prior PCI presented for CABG with less comorbidity and diminished coronary disease; yet, they had more advanced symptoms and greater urgency. After adjusting for these differences, prior PCI emerged as an independent predictor of inhospital mortality after CABG.

The preoperative intraaortic balloon pump in coronary bypass surgery: a lack of evidence of effectiveness.

BACKGROUND: There is limited evidence demonstrating the effectiveness of preoperative intraaortic balloon pump (IABP) use in isolated coronary artery bypass graft (CABG) surgery. A single-center randomized trial demonstrated its benefit. We undertook a multicenter observational study to verify this finding. METHODS: In 29,950 consecutive patients undergoing isolated CABG between 1995 and 2000 at 10 centers, we compared patients with and without a preoperative IABP. We also compared the effect of preoperative IABP use within 7 high-risk clinical subgroups. To validate the previous randomized trial, patients with any 2 of the following were also analyzed: left main > 70%, ejection fraction < 40%, redo CABG, or preoperative intravenous nitroglycerin. RESULTS: Preoperative IABPs were used in 1896 patients (6.3%). These patients had more comorbid conditions and a higher crude mortality than those who did not have preoperative IABPs (9.5% vs 2.3%, P < .0001). Preoperative IABP patients were caliper matched to non-preoperative IABP patients using a propensity score. Excess mortality associated with preoperative IABP persisted (9.2% vs 5.8%, P = .0004). In 7 high-risk subgroups, mortality was significantly higher with preoperative IABP. We used propensity caliper matching to compare preoperative IABP with non-preoperative IABP patients who met trial criteria (n = 4332). Preoperative IABP was associated with higher mortality (11.0% vs 6.5%, P = .0009). Removing emergency patients did not alter results. CONCLUSIONS: Use of preoperative IABPs was consistently associated with higher mortality. Despite detailed statistical analysis, we were unable to show benefit from preoperative IABP use or confirm the results of a single-center trial that demonstrated its benefit. Assessment of preoperative IABP efficacy will require a randomized trial.

Aortic allograft vasculopathy is mediated by CD8(+) T cells in Cyclosporin A immunosuppressed mice.

We investigated the role of CD4(+) T cells and CD8(+) T cells in mediating allograft vasculopathy in Cyclosporin A (CyA) immunosuppressed mice. We first established that a dose of 50 mg/kg/d CyA was required to prevent acute rejection in C57BL/6 mice. CyA given at 50 mg/kg/d did not prevent allograft vasculopathy in either cardiac or aortic transplants in these mice. Using CD4(-/-) and CD8(-/-) mice, we established that CyA immunosuppression at this dose was only effective at preventing allograft vasculopathy in mice lacking CD8(+) T cells. This implicates CD8(+) T cells in the development of AV in situations of clinical cardiac transplantation where CyA is still the mainstay of immunosuppressive therapy. We confirmed the important role for CD8(+) T cells in AV in the face of CyA immunosuppression by allopriming mice in the presence of CyA and transferring alloprimed T cells into RAG1(-/-) immunodeficient mice. The RAG1(-/-) mice were also treated with CyA. In this situation (CyA present during the allopriming and in the recipient), only primed CD8(+) T cells could mediate AV, primed CD4(+) T cells could not. Alloprimed CD8(+) T cells raised in the presence of CyA exhibited markedly reduced direct recognition responses (as measured by MLR) and effector responses (as measured by cytotoxic activity). In contrast indirect activation was retained. We interpret these data to suggest that in the face of CyA immunosuppression CD4(+) T cell effector function is ablated while CD8(+) T cell function remains partially intact. The in vitro data suggest that the indirect pathway remains intact in this population of CyA resistant CD8(+) T cells.

Impairment of recipient cytolytic activity attenuates allograft vasculopathy.

We investigated the role of CD4+ and CD8+ T subsets as well as T cell cytolytic effector mechanisms in the aortic allograft model of allograft vasculopathy using CD4 and CD8 gene knockout mice (CD4(-/-), CD8(-/-)) and mice deficient in cytolytic effector pathways. Medial apoptosis at 2 weeks was reduced in CD8(-/-) mice and in mice where cytotoxic T cell activity was compromised. At 8 weeks, substantial medial damage was observed in wild-type (WT) and CD4(-/-) recipients but medial preservation was evident in CD8(-/-) mice and in mice with impaired cytotoxic T cell activity. The intima/media ratio, a comprehensive measure of allograft vasculopathy, was similar in WT and CD4(-/-) recipients but was significantly reduced in CD8(-/-) mice and mice with impaired cytotoxic T cell activity. These data indicate that CD8+ T cells contribute to the vascular remodeling that is characteristic of allograft vasculopathy. They also show that CD8+ T cells participate in allograft vasculopathy in the absence of CD4+ T cell help. We further demonstrated that WT mice exhibited robust allograft vasculopathy in the presence of cyclosporin A immunosuppression but that allograft vasculopathy was ablated in cyclosporin-treated CD8(-/-) mice. This supports the hypothesis that non-CD8+ T cell effector mechanisms are sensitive to calcineurin inhibitor therapy but that CD8+ T cell-mediated allograft vasculopathy is refractory to such treatment. Taken together, our data suggest that CD8+ T cells contribute to the induction of vascular remodeling in allograft vasculopathy and provide evidence that novel therapies which target CD8+ T cell effector function might be effective in mitigating AV in the clinical setting.

Conversion to on pump from OPCAB is associated with increased mortality: results from a randomized controlled trial.

OBJECTIVE: Recent developments in cardiac stabilization devices, have made OPCAB feasible. However, there is conflicting evidence to date regarding the rate and adverse events associated with conversion from OPCAB to CABG with CPB. The objective of the present study was to review all conversions in the setting of a randomized controlled trial comparing CABG with or without CPB. METHODS: Three hundred patients requiring CABG surgery at a single institution were prospectively randomized to have the procedure performed with CPB (n=150) or OPCAB (n=150). Patients that could not be performed OPCAB were defined as conversion group (cross over). RESULTS: Twenty patients were converted from OPCAB to CABG with CPB because of hemodynamic instability (14/20), small target vessel (5/20), or inadequate visualization (1/20). Seventeen were converted during attempts at coronary anastomosis: LAD/diagonal (7/20), circumflex (8/20), or right coronary (2/20). The overall in hospital mortality rate for the trial was 1% but was significantly higher in converted patients (10 vs. 0%; P=0.01). Converted patients required significantly more inotropes (P=0.001) and blood transfusions (P=0.05). An elevated BMI was the only pre-operative variable that appeared to be associated with conversion. CONCLUSIONS: In the setting of a randomized controlled trial the overall conversion rate associated with OPCAB reached 13% and was associated with an increased risk of mortality.