Is Porcine Small Intestinal Submucosal Extracellular Matrix (ECM) a Suitable Material for Right Ventricular Outflow Tract Reconstruction in Association With Pulmonary Valve Replacement?

Pulmonary valve replacement (PVR) with right ventricular outflow tract (RVOT) reconstruction is a common congenital cardiac operation. Porcine submucosal intestinal-derived extracellular matrix (ECM) patches have been used for RVOT reconstruction. We present 2 adult patients with Tetralogy of Fallot who underwent PVR with RVOT reconstruction utilizing ECM. Both cases required reoperation due to patch dehiscence causing a large paravalvular leak. One patient also had a pseudoaneurysm associated with ECM dehiscence. There may be a propensity for ECM dehiscence in this application and, based on these cases, we recommend avoidance of ECM in RVOT reconstruction with PVR. PVR patients repaired with ECM should be monitored for this complication.

Flipping the Classroom: How to Optimize Learning in the Didactic Setting

Classic classroom education emphasizes the teacher imparting knowledge, experience, or wisdom (pedagogy). Adult educational theory indicates learning is optimized in an experiential setting, where the learner prepares, the session is case based, and the responsibility of the educator is to teach what the learner does not know. This is referred to as "flipping the classroom." Flipping the classroom is not simple, as the historical educational culture often changes; and, at least early in the transition process, different expectations, preparation, or training are essential for both the learner and educator for this approach to be effective.

Individual Variations in the Fibrinolytic Response During and After Cardiopulmonary Bypass

The purpose of this study was to determine whether individual patients show different patterns of fibrinolytic response to cardiopulmonary bypass (CPB) and whether preoperative or intraoperative parameters were predictive of these different patterns. Active t-PA, active PAI-1 and total t-PA antigen were measured in plasma samples obtained from 38 subjects, age 32 to 85 (median 69 years), before, during and after CPB. Four patterns of fibrinolytic response were noted: 1) 40% of patients showed the “typical” response, a rapid rise in active and total t-PA during CPB followed postoperatively by elevated PAI-I and reduced t-PA, 2) 10% showed no change in t-PA or PAI-1 during or after CPB, 3) 24% showed no change in t-PA with an increase in PAI-1 postoperatively, and 4) 26% showed an increase in t-PA during CPB with no change in PAI-1 postoperatively. When present, the t-PA response was rapid, occurring within the first 30 min of CPB and was more common in patients undergoing valve surgery than in coronary artery bypass grafting (p <0.005). Increased levels of PAI-1 postoperatively were associated with ischemic times greater than 70 min (p = 0.003) but not with the total length of CPB. Age, sex, CPB temperature, total CPB time and preoperative levels of t-PA and PAI-1 were not associated in the intra- or postoperative fibrinolytic response pattern. We conclude that the fibrinolytic response to CPB is heterogeneous. Further studies will be needed to determine whether different response patterns are clinically significant.

The Joint Council on Thoracic Surgery Education (JCTSE) "Educate the Educators" Faculty Development Course: Analysis of the First 5 Years

BACKGROUND

Since 2010, the Joint Council on Thoracic Surgery Education, Inc (JCTSE) has sponsored an annual "Educate the Educators" (EtE) course. The goal is to provide United States academic cardiothoracic surgeons (CTS) the fundamentals of teaching skills, educational curriculum development, and using education for academic advancement. This report describes the course development and evaluation along with attendee's self-assessment of skills through the first 5 years of the program.

METHODS

The content of this 2½-day course was based on needs assessment surveys of CTS and residents attending annual meetings in 2009. From 2010 to 2014, EtE was offered to all CTS at training programs approved by the Accreditation Council for Graduate Medical Education. Course content was evaluated by using end-of-course evaluation forms. A 5-point Likert scale (1 = poor, 5 = excellent) was used to obtain composite assessment mean scores for the 5 years on course variables, session presentations, and self-assessments.

RESULTS

With 963 known academic CTS in the United States, 156 (16.3%) have attended, representing 70 of 72 training programs (97%), and 1 international surgeon attended. There were also 7 program coordinators. Ratings of core course contents ranged from 4.4 to 4.8, accompanied with highly complementary comments. Through self-assessment, skills and knowledge in all content areas statistically improved significantly. The effect of the course was evaluated with a follow-up survey in which responders rated the program 4.3 on the usefulness of the information for their career and 3.9 for educational productivity.

CONCLUSIONS

The EtE program offers an excellent opportunity for academic CTS to enhance their teaching skills, develop educational activities, and prepare for academic promotion. With its unique networking and mentorship environment, the EtE program is an important resource in the evolution of cardiothoracic surgical training in the United States.

Gunshot-Induced Aorto-Left Atrial Fistula Diagnosed by Intraoperative Transesophageal Echocardiography

Aorto-left atrial fistula (AAF) is rarely encountered in clinical practice, and the early diagnosis can be very challenging. This report describes a unique case of AAF caused by a gunshot injury and the pivotal role of transesophageal echocardiography for diagnosis and assessment.

Gamification in thoracic surgical education: Using competition to fuel performance

OBJECTIVES

In an effort to stimulate residents and trainers to increase their use of simulation training and the Thoracic Surgery Curriculum, a gamification strategy was developed in a friendly but competitive environment.

METHODS

"Top Gun." Low-fidelity simulators distributed annually were used for the technical competition. Baseline and final video assessments were performed, and 5 finalists were invited to compete in a live setting from 2013 to 2015. "Jeopardy." A screening examination was devised to test knowledge contained in the Thoracic Surgery Curriculum. The top 6 2-member teams were invited to compete in a live setting structured around the popular game show Jeopardy.

RESULTS

"Top Gun." Over 3 years, there were 43 baseline and 34 final submissions. In all areas of assessment, there was demonstrable improvement. There was increasing evidence of simulation as seen by practice and ritualistic behavior. "Jeopardy." Sixty-eight individuals completed the screening examination, and 30 teams were formed. The largest representation came from the second-year residents in traditional programs. Contestants reported an average in-training examination percentile of 72.9. Finalists reported increased use of the Thoracic Surgery Curriculum by an average of 10 hours per week in preparation. The live competition was friendly, engaging, and spirited.

CONCLUSIONS

This gamification approach focused on technical and cognitive skills, has been successfully implemented, and has encouraged the use of simulators and the Thoracic Surgery Curriculum. This framework may capitalize on the competitive nature of our trainees and can provide recognition of their achievements.

Accreditation Council for Graduate Medical Education case log: general surgery resident thoracic surgery experience

BACKGROUND

General surgery resident training has changed dramatically over the past 2 decades, with likely impact on specialty exposure. We sought to assess trends in general surgery resident exposure to thoracic surgery using the Accreditation Council for Graduate Medical Education (ACGME) case logs over time.

METHODS

The ACGME case logs for graduating general surgery residents were reviewed from academic year (AY) 1989-1990 to 2011-2012 for defined thoracic surgery cases. Data were divided into 5 eras of training for comparison: I, AY89 to 93; II, AY93 to 98; III, AY98 to 03; IV, AY03 to 08; V, AY08 to 12. We analyzed quantity and types of cases per time period. Student t tests compared averages among the time periods with significance at a p values less than 0.05.

RESULTS

A total of 21,803,843 general surgery cases were reviewed over the 23-year period. Residents averaged 33.6 thoracic cases each in period I and 39.7 in period V. Thoracic cases accounted for nearly 4% of total cases performed annually (period I 3.7% [134,550 of 3,598,574]; period V 4.1% [167,957 of 4,077,939]). For the 3 most frequently performed procedures there was a statistically significant increase in thoracoscopic approach from period II to period V.

CONCLUSIONS

General surgery trainees today have the same volume of thoracic surgery exposure as their counterparts over the last 2 decades. This maintenance in caseload has occurred in spite of work-hour restrictions. However, general surgery graduates have a different thoracic surgery skill set at the end of their training, due to the predominance of minimally invasive techniques. Thoracic surgery educators should take into account these differences when training future cardiothoracic surgeons.

Novel use of an apical-femoral wire rail to assist with transfemoral transcatheter aortic valve replacement

The inability to reposition or retrieve balloon-expandable transcatheter aortic valves once they have been deployed requires implantation of the valve in the descending aorta or open surgical procedures to extract the valve. We describe the challenging transfemoral delivery of an Edwards Lifesciences Sapien valve wherein we had difficulty crossing the aortic valve and the guidewire position was compromised. We performed a transapical puncture to snare the guidewire and create a left ventricular to femoral wire rail, allowing us to deliver the transfemoral transcatheter valve, salvaging a situation where we would have been required to implant the valve in the descending aorta. We believe this is the first time this technique has been reported and represents an important method to facilitate delivery of transcatheter valves where guidewire support is insufficient or lost.

Role of cytokine hemoadsorption in cardiopulmonary bypass-induced ventricular dysfunction in a porcine model

Little is known about the effect of cardiopulmonary bypass alone on cardiac function; in an attempt to illuminate this relationship and test a possible mechanism, we used Cytosorb, a device capable of removing virtually all types of circulating cytokines to test the hypothesis that hemoadsorption of cytokines during bypass attenuates bypass-induced acute organ dysfunction. Twelve Yorkshire pigs (50-65 kg) were instrumented with a left ventricular conductance catheter. Baseline mechanics and cytokine expression (tumor necrosis factor [TNF], interleukin-6 [IL-6], and interleukin-10) were measured before and hourly after 1 hour of normothermic cardiopulmonary bypass. Animals underwent bypass without (cardiopulmonary bypass [CPB], n = 6) or with (CPB+HA, n = 6) the CytosorbTM device. Data were compared with "historical" controls (n = 6) that were similarly instrumented but underwent observation instead of bypass. Five hours after separation from bypass (or observation), animals were euthanized. Myocardial water content was determined postmortem. Neither TNF nor IL-6 was significantly elevated in either experimental group versus controls at any time point. Preload recruitable stroke work and dP/dtmax were significantly depressed immediately after separation from bypass in both CPB+HA and CPB and remained depressed for the duration of the experiment. Although Tau remained unchanged, dP/dTmin was significantly diminished in both bypass groups at all time points after separation from bypass. Cytokine hemoadsorption had no effect on any measurable index of function. Differences in postmortem data were not evident between groups. One hour of normothermic CPB results in a significant and sustained decline in left ventricular function that appears unrelated to changes in cytokine expression. Because we did not appreciate a significant change in cytokine concentrations postbypass, the capacity of cytokine hemoadsorption to attenuate CPB-induced ventricular dysfunction could not be assessed.

Long-term outcome for the surgical treatment of infective endocarditis with a focus on intravenous drug users

BACKGROUND

We reviewed our experience with surgical procedures for infective endocarditis (IE) in order to evaluate modern outcomes and objectively examine our institutional preferences, including the use of bioprostheses in intravenous drug users (IVDUs) regardless of age and prompt surgical intervention in patients with either septic cerebral emboli or active infection.

METHODS

Review of medical records was conducted from February 1999 to November 2010. The Social Security Death Index was used to determine death from any cause in the postoperative period. Hospital records were used to identify infectious complications, recurrent endocarditis, and reoperation.

RESULTS

Sixty-four patients were identified as IVDUs and 133 patients as non-IVDUs. Survival at 30 days, 1 year, 5 years, and 10 years for IVDUs and non-IVDUs was 91.2% versus 93.6%, 77.5% versus 83.0%, 46.7% versus 71.1%, and 41.1% versus 52.0%, respectively. Cox regression analysis identified intravenous drug use as an independent risk factor for diminished survival (p=0.03), although not for reoperation (p=0.95) despite 95.3% of IVDUs receiving bioprostheses versus 73.7% of non-IVDUs (p=0.0002, Fisher's exact test). Forty-three patients were identified as having preoperative septic cerebral emboli; none had a perioperative hemorrhagic event. Active infection approached significance as an independent risk factor for the composite end point of recurrent IE and perioperative infection (odds ratio 2.8; 95% confidence interval, 0.777 to 10.9; p=0.12, Fisher's exact test).

CONCLUSIONS

Bioprostheses are reasonable for IVDUs undergoing valve replacement for IE regardless of age. Prompt surgical intervention in the setting of septic cerebral emboli is justified; in the setting of active infection it is less clear.

Management of acute regurgitation in left-sided cardiac valves

The management of acute, severe cardiac valvular regurgitation requires expeditious multidisciplinary care. Although acute, severe valvular regurgitation can be a true surgical emergency, accurate diagnosis and subsequent treatment decisions require clinical acumen, appropriate imaging, and sound judgment. An accurate and timely diagnosis is essential for successful outcomes and requires appropriate expertise and a sufficiently high degree of suspicion in a variety of settings. Whereas cardiovascular collapse is the most obvious and common presentation of acute cardiac valvular regurgitation, findings may be subtle, and the clinical presentation can often be nonspecific. Consequently, other acute conditions such as sepsis, pneumonia, or nonvalvular heart failure may be mistaken for acute valvular regurgitation. In comparison with that of the right-sided valves, regurgitation of the left-sided valves is more common and has greater clinical impact. Therefore, this review focuses on acute regurgitation of the aortic and mitral valves.

Consensus statement: minimal criteria for reporting the systemic inflammatory response to cardiopulmonary bypass

The lack of established cause and effect between putative mediators of inflammation and adverse clinical outcomes has been responsible for many failed anti-inflammatory interventions in cardiopulmonary bypass (CPB). Candidate interventions that impress in preclinical trials by suppressing a given inflammation marker might fail at the clinical trial stage because the marker of interest is not linked causally to an adverse outcome. Alternatively, there exist examples in which pharmaceutical agents or other interventions improve clinical outcomes but for which we are uncertain of any antiinflammatory mechanism. The Outcomes consensus panel made 3 recommendations in 2009 for the conduct of clinical trials focused on the systemic inflammatory response. This panel was tasked with updating, as well as simplifying, a previous consensus statement. The present recommendations for investigators are the following: (1) Measure at least 1 inflammation marker, defined in broad terms; (2) measure at least 1clinical end point, drawn from a list of practical yet clinically meaningful end points suggested by the consensus panel; and(3) report a core set of CPB and perfusion criteria that maybe linked to outcomes. Our collective belief is that adhering to these simple consensus recommendations will help define the influence of CPB practice on the systemic inflammatory response, advance our understanding of causal inflammatory mechanisms, and standardize the reporting of research findings in the peer-reviewed literature.

Protease-activated receptor 2 deficiency reduces cardiac ischemia/reperfusion injury

OBJECTIVE

To investigate the effect of protease-activated receptor (PAR) 2 deficiency on ischemia/reperfusion (I/R) injury-induced infarct size, inflammation, heart remodeling, and cardiac function.

METHODS AND RESULTS

PAR-2 signaling enhances inflammation in different diseases. The effect of PAR-2 deficiency in cardiac I/R injury is unknown. PAR-2(-/-) mice and wild-type littermates were subjected to 30 minutes of ischemia and up to 4 weeks of reperfusion. Infarct size, oxidative/nitrative stress, phosphorylation of mitogen-activated protein kinases, and inflammatory gene expression were assessed 2 hours after reperfusion. Changes in heart size and function were measured by echocardiography up to 4 weeks after reperfusion. Infarct size was significantly reduced in hearts of PAR-2(-/-) mice compared with wild-type littermates. In addition, oxidative/nitrative stress, phosphorylation of mitogen-activated protein kinase, and expression of proinflammatory genes were significantly attenuated in injured hearts of PAR-2(-/-) mice. Finally, PAR-2(-/-) mice were protected from postinfarction remodeling and showed less impairment in heart function compared with wild-type littermates up to 4 weeks after I/R injury.

CONCLUSIONS

PAR-2 deficiency reduces myocardial infarction and heart remodeling after I/R injury.

Characteristics of extracoronary vascular disease in heart transplant recipient

BACKGROUND

Heart transplant candidates carry many of risk factors for vascular disease, and in addition, recipients continue to accumulate them following heart transplantation (HTx). However, very limited information is available on this entity. This study was designed to address characteristics of extracoronary vascular disease in heart transplant recipients.

METHODS

This is a nonconcurrent cohort study of 402 patients who received HTx at the University of Washington between 1985 and 2004. Pretransplant arterial evaluation included carotid, lower extremity, and renal artery duplex studies. CT angiogram was obtained when indicated. Patients with severe arterial disease were excluded from the transplant list. Posttransplant vascular evaluation was done with the patient's history and physical examination.

RESULTS

Median follow-up was 5.5 years. Seventy vascular diseases were detected in 49 patients (12% of study population). Patients with pretransplant vascular disease, compared to those without, were older at the HTx, carried the diagnosis of ischemic cardiomyopathy more commonly, and had more comorbidities including history of smoking, alcohol drinking, chronic obstructive pulmonary disease, and prior heart operations. The prevalence of vascular disease was 6% prior to HTx and it cumulatively increased up to 17% at 17 years after HTx. Nineteen percent of these diseases were the result of arterial traumas mostly caused by medical interventions. Fourteen patients developed abdominal aortic aneurysm (AAA) with two deaths.

CONCLUSIONS

It is important for care providers to be aware of the high probability of vascular disease, to be familiar with vascular disease, and to provide appropriate prophylactic and therapeutic measures when evaluating this patient population.

Protease-activated receptor-1 contributes to cardiac remodeling and hypertrophy

BACKGROUND

Protease-activated receptor-1 (PAR-1) is the high-affinity receptor for the coagulation protease thrombin. It is expressed by a variety of cell types in the heart, including cardiomyocytes and cardiac fibroblasts. We have shown that tissue factor (TF) and thrombin contribute to infarct size after cardiac ischemia-reperfusion (I/R) injury. Moreover, in vitro studies have shown that PAR-1 signaling induces hypertrophy of cardiomyocytes and proliferation of cardiac fibroblasts. The purpose of the present study was to investigate the role of PAR-1 in infarction, cardiac remodeling, and hypertrophy after I/R injury. In addition, we analyzed the effect of overexpression of PAR-1 on cardiomyocytes.

METHODS AND RESULTS

We found that PAR-1 deficiency reduced dilation of the left ventricle and reduced impairment of left ventricular function 2 weeks after I/R injury. Activation of ERK1/2 was increased in injured PAR-1(-/-) mice compared with wild-type mice; however, PAR-1 deficiency did not affect infarct size. Cardiomyocyte-specific overexpression of PAR-1 in mice induced eccentric hypertrophy (increased left ventricular dimension and normal left ventricular wall thickness) and dilated cardiomyopathy. Deletion of the TF gene in cardiomyocytes reduced the eccentric hypertrophy in mice overexpressing PAR-1.

CONCLUSIONS

Our results demonstrate that PAR-1 contributes to cardiac remodeling and hypertrophy. Moreover, overexpression of PAR-1 on cardiomyocytes induced eccentric hypertrophy. Inhibition of PAR-1 after myocardial infarction may represent a novel therapy to reduce hypertrophy and heart failure in humans.

Myocardial infarction following coronary artery bypass graft surgery increases healthcare resource utilization

OBJECTIVE

To assess the health economic impact of perioperative myocardial infarction in a cohort of patients undergoing coronary artery bypass graft surgery.

DESIGN

Retrospective cohort analysis using data from hospital bills and uniform billing forms.

SETTING

A total of 147 geographically diverse hospitals in the United States.

PATIENTS

The study population consisted of 2,102 coronary artery bypass graft surgery patients enrolled in the PRIMO-CABG trial at U.S. sites between January 2002 and February 2003.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Resource utilization and costs during the index hospitalization and during a 6-month follow-up period were compared between patients who had a myocardial infarction by postoperative day 4 and those who did not. Linear regression was used to examine whether myocardial infarction by day 4 was associated with index hospitalization costs, after adjusting for baseline characteristics. Myocardial infarction occurred in 191 (9.1%) patients undergoing coronary artery bypass graft surgery. Myocardial infarction was associated with a doubling of intensive care unit time (3.5 days among patients with no myocardial infarction and 7.1 days among patients with myocardial infarction, p < .01) and a 48% increase in hospital length of stay. Myocardial infarction by day 4 was associated with a 43% increase in hospital costs, a 29% increase in physician service costs, a 41% increase in total costs during the index hospitalization, and a 38% increase in cumulative 6-month costs. After baseline adjustment, myocardial infarction continued to be associated with higher index hospitalization costs.

CONCLUSIONS

Myocardial infarction following coronary artery bypass graft surgery was associated with a significant increase in intensive care unit time, hospital length of stay, and overall costs, which contributed to greater hospital and physician service costs. Healthcare resource utilization is increased in patients sustaining a myocardial infarction following coronary artery bypass graft surgery.

Is pre-transplant vascular disease a risk factor for mortality and morbidity after heart transplantation?☆

BACKGROUND

Severe vascular disease is a relative contraindication to heart transplantation (HTx). We addressed the effect of vascular disease on HTx outcomes.

METHODS

This is a nonconcurrent cohort study of 402 patients who received HTx at our institution between 1985 and 2004. Pre-transplant vascular evaluation included carotid, lower extremity, and renal artery duplex studies, and CT angiogram when indicated. Patients with severe and nontreatable vascular disease were excluded. Patients were divided into Group 1: those with pre-transplant vasculopathy, and Group 2: those without pre-transplant vasculopathy. Group 1 had 24 patients with 25 vascular lesions: 1 aortic dissection, 2 abdominal aortic aneurysm (AAA)'s, 5 carotid artery stenoses, 1 renal artery stenosis, and 16 peripheral vascular lesions. Interventions were performed to 15 lesions prior to HTx and to 2 lesions after HTx.

RESULTS

Median follow-up was 5.5 years. Group 1 had higher incidence of ischemic cardiomyopathy (p<0.001), hypertension (p=0.028), chronic obstructive pulmonary disease (COPD) (p=0.004), and smoking history (p<0.001). There were no differences in sex, hyperlipidemia, diabetes, stroke, or renal dysfunction. Multivariate analysis revealed odds of post-transplant death in Group 1 was 1.4 (95% CI: 0.48-4.1, p=0.54) times greater than that in Group 2. Cox proportional hazards model for survival showed a 50% increase in the hazard of death in patients with pre-transplant vasculopathy, but without statistical significance. Group 1 had higher incidence of post-transplant stroke (p=0.001) but no difference in allograft coronary atherosclerosis.

CONCLUSIONS

Pre-transplant vascular disease seems to have negative effect on outcomes after HTx. Larger scale study is needed for further evaluation.

Pexelizumab -- a C5 complement inhibitor for use in both acute myocardial infarction and cardiac surgery with cardiopulmonary bypass

Myocardial injury and dysfunction in acute infarction and during cardiac surgery with cardiopulmonary bypass (CPB) are associated with an undesirable systemic inflammatory response, in which the complement cascade plays a major role. In animal models C5 inhibition has been found to significantly reduce myocardial infarct size and decrease cellular necrosis and apoptosis. Pexelizumab (Alexion Pharmaceuticals, Inc., Cheshire, CT, USA) is a humanized, monoclonal, single-chain antibody fragment that inhibits C5, thereby blocking its cleavage into active forms. Prospective, randomised, double-blind, placebo-controlled trials using pexelizumab during percutaneous coronary intervention following acute myocardial infarction (AMI), or in patients undergoing coronary artery bypass graft (CABG) with CPB, have demonstrated a reduction in morbidity and mortality. Thus, pexelizumab represents a promising therapeutic option with sustained benefit both in AMI and during CABG with CPB.

Evaluation of web-based learning tools: lessons learned from the thoracic surgery directors association curriculum project three-year experience

BACKGROUND

In 2001 the Thoracic Surgery Directors Association implemented a web-based curriculum for prematriculated TS residents containing 75 learning modules organized into 13 sections Each module contains an audio/video presentation, a summary, frequently asked questions, references, a self-assessment, and a critique. Curriculum content was provided as a randomized prospective trial one year prior to matriculation to residents matching into a TS program from 2001 to 2004.

METHODS

Over 3 years the utilization and impact of this curriculum was evaluated by 8 different methods including resident surveys, faculty surveys, web tracking, examination scores, and individual online learning module critiques. Each completed critique evaluated the resident's perception of the relevance, content quality and presentation quality of the module on a scale corresponding to low, average and high.

RESULTS

A total of 11,117 learning modules were used through the end of 2004 with complete critiques available on 1458 (13%). Utilization and measured quality continue to increase over the 3-year interval. The average rating scores for relevance, content and presentation tracked together and were overall rated as good or excellent (92%). There were large variations in utilization and perceived quality by section subject. As the average module rating score improved, the utilization increased and the variability of the rating decreased substantially.

CONCLUSIONS

Module specific learner evaluation of educational content is one of several important feedback tools for monitoring ongoing curricular development and refinement. These studies, based upon web tracking, demonstrate increasing resident use and strong resident satisfaction. This educational format will hopefully lend itself to many important improvements in web-based Thoracic Surgery education.

Inhibition of Toll-like receptor 4 with eritoran attenuates myocardial ischemia-reperfusion injury

BACKGROUND

We previously reported that the functional mutation of Toll-like receptor 4 (TLR4) in C3H/HeJ mice subjected to myocardial ischemia-reperfusion (MI/R) injury resulted in an attenuation of myocardial infarction size. To investigate the ligand-activating TLR4 during MI/R injury, we evaluated the effect of eritoran, a specific TLR4 antagonist, on MI/R injury, with the goal of defining better therapeutic options for MI/R injury.

METHODS AND RESULTS

C57BL/6 mice received eritoran (5 mg/kg) intravenously 10 minutes before 30 minutes of in situ of transient occlusion of the left anterior descending artery, followed by 120 minutes of reperfusion. Infarct size was measured using triphenyltetrazoliumchloride staining. A c-Jun NH(2)-terminal kinase (JNK) activation was determined by Western blotting, nuclear factor (NF)-kappaB activity was detected by gel-shift assay, and cytokine expression was measured by ribonuclease protection assay. Mice treated with eritoran developed significantly smaller infarcts when compared with mice treated with vehicle alone (21.0+/-6.4% versus 30.9+/-13.9%; P=0.041). Eritoran pretreatment resulted in a reduction in JNK phosphorylation (eritoran versus vehicle: 3.98+/-0.81 versus 7.01+/-2.21-fold increase; P=0.020), less nuclear NF-kappaB translocation (2.70+/-0.35 versus 7.75+/-0.60-fold increase; P=0.00007), and a decrease in cytokine expression (P<0.05).

CONCLUSIONS

We conclude that inhibition of TLR4 with eritoran in an in situ murine model significantly reduces MI/R injury and markers of an inflammatory response.

Pexelizumab reduces death and myocardial infarction in higher risk cardiac surgical patients

BACKGROUND

Morbidity and mortality after coronary artery bypass graft surgery are directly related to specific preoperative risk factors. We assessed the influence of preoperative risk factors on the effect of pexelizumab, a C5 complement inhibitor, to reduce postoperative morbidity and mortality in this post hoc analysis of the Pexelizumab for Reduction in Myocardial Infarction and MOrtality in Coronary Artery Bypass Graft surgery (PRIMO-CABG) trial, a phase III double-blind, placebo-controlled study of 3,099 patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass.

METHODS

The composite endpoint of death or myocardial infarction or both through postoperative day 30 was examined in subpopulations of patients with pre-specified risk factors, which included diabetes mellitus, prior coronary artery bypass graft, urgent intervention, female sex, history of neurologic event, history of congestive heart failure, and two or more previous myocardial infarctions or a recent myocardial infarction. Stratified post hoc analyses were also performed on patients presenting with two or more and three or more of those risk factors.

RESULTS

Pexelizumab significantly reduced the incidence of the composite endpoint of death or myocardial infarction through postoperative day 30 by 28% in patients with two or more risk factors (p = 0.004) and 44% in patients with three or more risk factors (p < 0.001).

CONCLUSIONS

The C5 complement inhibitor, pexelizumab, reduced morbidity and mortality among high-risk patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.

Effect of pexelizumab on mortality in patients with acute myocardial infarction or undergoing coronary artery bypass surgery: a systematic overview

BACKGROUND

Recent trials evaluating the C5 complement inhibitor, pexelizumab, have shown that modulation of inflammation during ischemia/reperfusion in patients with acute myocardial infarction (MI) or undergoing coronary artery bypass graft (CABG) surgery may improve clinical outcomes.

METHODS

We performed a systematic overview of individual patient data from all completed randomized controlled trials of pexelizumab to evaluate the effect on all-cause mortality at 30 and 180 days after treatment. We used a random effects model and included all 5916 patients randomized in 4 clinical trials. Patients received placebo, pexelizumab bolus only or pexelizumab bolus followed by a 24-hour infusion.

RESULTS

A significant reduction in mortality at 30 days was observed in patients treated with bolus plus infusion (n = 2476) compared with placebo (n = 2492) (2.9% vs 4.2%; relative risk [RR], 0.70; 95% confidence interval [CI], 0.52-0.95; P = .02), with no interaction according to disease state of CABG or acute MI (P for interaction .33). A trend toward a reduction in mortality was observed in patients who received bolus plus infusion or bolus only (n = 3429) compared with placebo (n = 2476) (3.5% vs 4.2%; RR, 0.85; 95% CI, 0.66-1.0975; P = .215), but not in patients who received bolus only (n = 937) compared with placebo (n = 937) (5.2% vs 5.4%; RR, 0.96; 95% CI, 0.66-1.41; P = .918). The mortality benefit with bolus plus infusion compared with placebo persisted through 180 days (P = .05).

CONCLUSIONS

Pexelizumab reduced 30-day mortality in this systematic evaluation. Bolus plus infusion dose is being studied in ongoing trials in acute MI and CABG populations.

Expectant management is safe for cholelithiasis after heart transplant

BACKGROUND

The optimal management of cholelithiasis after heart transplant remains unclear. We use expectant management based on symptoms, without screening studies or prophylactic treatment. We hypothesized that expectant management for cholelithiasis after heart transplant does not result in significant mortality or morbidity from gallstone-associated disease.

METHODS

Between November 1985 and August 2004, 409 heart transplants were performed in 402 recipients at the University of Washington. This is a non-concurrent cohort study of these recipients.

RESULTS

Among recipients, 24 underwent cholecystectomy before heart transplant. After transplant, in the remaining 378 patients, 34 were found to have gallstones during the observation period. There was no mortality from gallstone-associated disease. Thirty patients developed morbidity from gallstones, including 25 cases of biliary colic, 3 of acute cholecystitis and 2 of pancreatitis, and there was 1 abnormal liver function test. Acute cholecystitis and pancreatitis were treated with conservative management followed by cholecystectomy. Cholecystectomy was performed in 32 patients after transplant. Indications included symptomatic cholelithiasis in 31, and prophylactic cholecystectomy prior to kidney transplant in 1. The laparoscopic approach was performed in 25 of these 32 patients. There was no mortality from cholecystectomy, but there were 4 complications: surgical site infections (n = 2); wound dehiscence (n = 1); and bile duct injury (n = 1). Median hospital stay was 1 day.

CONCLUSIONS

Our expectant management for cholelithiasis after heart transplant resulted in no mortality or significant morbidity related to delay in treatment. Symptomatic cholelithiasis was successfully treated with cholecystectomy, mostly with the laparoscopic approach. We believe expectant management is safe for patients after heart transplant.