A Systems-Based Morbidity and Mortality Conference Was Associated With a Transient Reduction in ECG Completion Times

BACKGROUND AND OBJECTIVES

During its monthly morbidity and mortality conference (MMC), the University of Colorado Division of Cardiology reviewed a "near-miss" patient safety event involving the delayed completion of a Stat-priority (ie, statim, meaning high priority) electrocardiogram (ECG). Because critical and interprofessional stakeholders participated in the conference, we hypothesized that the MMC would be associated with reduced ECG completion times.

METHODS

Data were collected for in-hospital ECGs performed at the University of Colorado Hospital between January 1, 2017, and June 30, 2018. An interrupted time series analysis was used to estimate the immediate and ongoing impact of the MMC (held on February 28, 2018) on ECG completion times, stratified by order priority (Stat, Now, or Routine). The percentage of delayed Stat-priority ECGs was analyzed as a secondary outcome.

RESULTS

Before the MMC, ECG completion times were stable for all order priorities ( P > .2), but the proportion of delayed Stat-priority ECGs increased from 5% in January 2017 to 20% in February 2018 ( P < .01). The MMC was associated with an immediate reduction in average daily ECG completion times for Routine (-18.4 minutes, P = .03) and Now (-8 minutes, P = .024) priority ECGs. No reduction was seen for Stat ECGs ( P = .97), though the percentage of delayed Stat ECGs stopped increasing ( P = .63). In the post-MMC period, completion times for Routine-priority ECGs increased and approached pre-MMC levels.

CONCLUSIONS

The MMC was associated with an immediate, but temporary, improvement in ECG completion times. Although the observed clinical benefit of the MMC is novel, these data support the need for more durable reforms to sustain initial improvements.

Medication adherence in cardiovascular medicine

Cardiovascular disease is the leading cause of death globally. While pharmacological advancements have improved the morbidity and mortality associated with cardiovascular disease, non-adherence to prescribed treatment remains a significant barrier to improved patient outcomes. A variety of strategies to improve medication adherence have been tested in clinical trials, and include the following categories: improving patient education, implementing medication reminders, testing cognitive behavioral interventions, reducing medication costs, utilizing healthcare team members, and streamlining medication dosing regimens. In this review, we describe specific trials within each of these categories and highlight the impact of each on medication adherence. We also examine ongoing trials and future lines of inquiry for improving medication adherence in patients with cardiovascular diseases.

Acute Myocardial Infarction Cohorts Defined by International Classification of Diseases, Tenth Revision Versus Diagnosis-Related Groups: Analysis of Diagnostic Agreement and Quality Measures in an Integrated Health System

BACKGROUND

Among Medicare value-based payment programs for acute myocardial infarction (AMI), the Hospital Readmissions Reduction Program uses International Classification of Diseases, Tenth Revision (ICD-10) codes to identify the program denominator, while the Bundled Payments for Care Improvement Advanced program uses diagnosis-related groups (DRGs). The extent to which these programs target similar patients, whether they target the intended population (type 1 myocardial infarction), and whether outcomes are comparable between cohorts is not known.

METHODS

In a retrospective study of 2176 patients hospitalized in an integrated health system, a cohort of patients assigned a principal ICD-10 diagnosis of AMI and a cohort of patients assigned an AMI DRG were compared according to patient-level agreement and outcomes such as mortality and readmission.

RESULTS

One thousand nine hundred thirty-five patients were included in the ICD-10 cohort compared with 662 patients in the DRG cohort. Only 421 patients were included in both AMI cohorts (19.3% agreement). DRG cohort patients were older (70 versus 65 years, P<0.001), more often female (48% versus 30%, P<0.001), and had higher rates of heart failure (52% versus 33%, P<0.001) and kidney disease (42% versus 25%, P<0.001). Comparing outcomes, the DRG cohort had significantly higher unadjusted rates of 30-day mortality (6.6% versus 2.5%, P<0.001), 1-year mortality (21% versus 8%, P<0.001), and 90-day readmission (26% versus 19%, P=0.006) than the ICD-10 cohort. Two observations help explain these differences: 61% of ICD-10 cohort patients were assigned procedural DRGs for revascularization instead of an AMI DRG, and type 1 myocardial infarction patients made up a smaller proportion of the DRG cohort (34%) than the ICD-10 cohort (78%).

CONCLUSIONS

The method used to identify denominators for value-based payment programs has important implications for the patient characteristics and outcomes of the populations. As national and local quality initiatives mature, an emphasis on ICD-10 codes to define AMI cohorts would better represent type 1 myocardial infarction patients.

The Cardiovascular Quality Improvement and Care Innovation Consortium: Inception of a Multicenter Collaborative to Improve Cardiovascular Care

Despite decades of improvement in the quality and outcomes of cardiovascular care, significant gaps remain. Existing quality improvement strategies are often limited in scope to specific clinical conditions and episodic care. Health services and outcomes research is essential to inform gaps in care but rarely results in the development and implementation of care delivery solutions. Although individual health systems are engaged in projects to improve the quality of care delivery, these efforts often lack a robust study design or implementation evaluation that can inform generalizability and further dissemination. Aligning the work of health care systems and health services and outcomes researchers could serve as a strategy to overcome persisting gaps in cardiovascular quality and outcomes. We describe the inception of the Cardiovascular Quality Improvement and Care Innovation Consortium that seeks to rapidly improve cardiovascular care by (1) developing, implementing, and evaluating multicenter quality improvement projects using innovative care designs; (2) serving as a resource for quality improvement and care innovation partners; and (3) establishing a presence within existing quality improvement and care innovation structures. Success of the collaborative will be defined by projects that result in changes to care delivery with demonstrable impacts on the quality and outcomes of care across multiple health systems. Furthermore, insights gained from implementation of these projects across sites in Cardiovascular Quality Improvement and Care Innovation Consortium will inform and promote broad dissemination for greater impact.

Expanding Training in Quality Improvement and Patient Safety Through a Multispecialty Graduate Medical Education Curriculum Designed for Fellows

INTRODUCTION

Although the Accreditation Council for Graduate Medical Education requires quality improvement and patient safety (QIPS) training for fellow-level trainees, this experience is often insufficient due to lack of faculty time and expertise within fellowship training programs. We developed a centralized GME curriculum targeted to an integrated, multispecialty audience of fellow-level trainees with the goal of promoting leadership and scholarship in QIPS.

METHODS

The University of Colorado implemented the Fellows' Quality and Safety Academy, a three-seminar curriculum in patient safety and health systems improvement. As most participants had prior training in QIPS during medical school or residency, educational strategies emphasized application of QIPS concepts through focused didactic content review paired with small-group case-based exercises and coaching of experiential project work to promote content mastery as well as practice of leadership and scholarship strategies.

RESULTS

Since the curriculum's inception in 2017, there have been 106 participants in the Foundations in Patient Safety seminar, 49 participants in the Adverse Events Into Quality Improvement seminar, and 48 participants in the Quality in Academics seminar. These participants represented 44 separate fellowship disciplines from both adult and pediatric subspecialties. Learners reported improved attitudes and confidence and demonstrated objective knowledge acquisition across QIPS content domains.

DISCUSSION

Our pedagogical approach of centralizing QIPS training and harnessing faculty expertise to teach fellow-level trainees across specialties through interdisciplinary collaboration and interactive project-based work is an effective strategy to promote development of QIPS competencies during fellowship training.

Abstract 380: S.T.A.T. ECGs: Supporting Technicians in Acquiring Timely ECGs

Introduction/Background: A quality improvement project at the University of Colorado Hospital (UCH) was initiated to better understand perceived delays in the completion of STAT priority electrocardiograms (ECGs). The project team obtained ECG acquisition time data from the electronic health record in order to describe delays and evaluate potential solutions.

Methods: Analysis of 25,159 completed, time-stamped inpatient ECGs completed at UCH between 1/1/2018 and 10/30/2018 were completed. Descriptive statistics for ECG volume, ECG completion delays and total AHT staffing levels were calculated and correlations between ECG characteristics and delays were examined. Between February and April 2019, a trained qualitative researcher completed interviews and observations with UCH staff involved in ECG completion, focusing on work processes and the workplace environment. Based on these initial quantitative and qualitative analyses, a simulation model was developed to evaluate changes in 1) technician shifts and staffing ratios; 2) the proportion of STAT orders; and 3) nurse training to help perform ECGs.

Results: ECGs were ordered with a STAT priority in 40% of cases and, among individual providers, use of the STAT priority varied from 7% to 95%. ECG completion was delayed (>15 minutes) for 35% of STAT ECGs, compared to less than 10% of non-stat ECGs. In qualitative interviews, technicians described a “cascade” effect to delays resulting from a compounding effect of a series of late ECGs and supported by the quantitative observation that delays are strongly correlated with STAT ECG volume. Technicians also described spikes in ECG ordering during hours in which staffing levels are low and for non-emergency reasons (such as discharge), a finding again supported by quantitative analysis. Results of discrete event simulation suggest: adding technician staffing hours during the day outperforms reducing the proportion of STAT ECGs; short shifts (4-8 hours) may be a cost effective way to add personnel; ECG training for Cardiology nurses, who expressed a desire to help with ECG completion, could additionally offload technicians and reduce delays; the negative effect of technician “attrition” - e.g. a technician calls in sick and is not replaced - is more powerful than the positive effect of any intervention. That technicians described a hectic and unforgiving work environment suggests workplace interventions to manage the volume of ECGs per technician may improve satisfaction and avoid technician attrition.

Conclusions: In light of the above findings, UCH operations leadership trained charge nurses on Cardiology units to perform STAT ECGs and are evaluating processes by which technician breaks are more structured, a feedback process is more formalized and staffing hours are more reflective of hourly fluctuations in ECG volume. Results of these interventions will be the subject of future analyses.

Abstract 350: Assessment of Clinicians’ Attitudes and Knowledge About Cardiac Troponin Testing

In the United States, the positive predictive value (PPV) of cardiac troponin for type 1 myocardial infarction is substantially lower than in Europe (15% vs. 50%). Further, even with publication of the 4 th Universal Definition of Myocardial Infarction, recent studies have shown that inaccurate classification of myocardial injury is common among clinicians in the United States. These findings are at least partly attributable to clinicians’ knowledge and attitudes about cardiac troponin testing; a survey of these parameters has never been conducted.

Clinicians at the University of Colorado completed a brief 8-question multiple-choice survey related to troponin use, definitions of myocardial infarction and clinical assessment of elevated troponin levels. The survey was distributed via secure email and administered electronically using the Qualtrics™ platform. Responses were anonymous, completion was estimated to take 3 minutes and a lottery award system was used as an incentive for participation. Respondents included trainees, advanced practice providers and attending physicians from internal medicine, emergency medicine and medical subspecialties. We plan to obtain a total of 300 responses with descriptive findings of preliminary results included below.

The survey was completed by 114 clinicians: 37 interns (32%), 45 residents (39%), 9 advanced practice providers (8%), 11 fellows (10%), and 12 attending physicians (11%). Regarding indications for troponin testing, 93% (106/114) indicated that they “usually” or “always” check troponin levels in patients with chest pain. More interestingly, 46% (52/112) reported checking troponin on “undifferentiated patients” at least half the time. For troponin interpretation, 97% (110/114) of participants identified that troponin levels alone cannot rule in or rule out coronary artery disease. In contrast, only 36% (41/114) and 55% (63/114), respectively, identified the NPV and PPV of a contemporary troponin assay for type 1 MI. Further, only 50% (57/114) of respondents identified that the likelihood of type 1 MI increases as troponin levels increase. Three brief clinical vignettes revealed that, while 78% (89/114) and 74% (45/61) of participants, respectively, identified type 1 MI and type 2 MI presentations, only 40% (21/53) of respondents correctly identified a vignette for non-ischemic myocardial injury. Concordant with this finding, 54% (61/114) of clinicians correctly identified the 4 th Universal Definition of Myocardial Infarction.

These preliminary findings highlight important facets of clinician attitudes and knowledge about troponin testing that help explain the poor PPV for troponin and diagnostic misclassification observed among U.S. clinicians. These results could help guide curricular and clinical decision support interventions designed to improve the use and interpretation of cardiac troponin testing.

Abstract 221: How an ICD-10 Code for Type 2 Myocardial Infarction Impacts Patient Inclusion in Acute MI Cohorts for Value-based Programs

Background: The Center for Medicare and Medicaid Services uses primary discharge ICD-10 codes for Acute Myocardial Infarction (AMI) to define inclusion in value-based payment programs such as the hospital readmissions reduction program. Prior studies have shown that a significant number of hospitalizations with an ICD-10 code for AMI actually represent a Type 2 MI (T2MI) or non-ischemic myocardial injury (NIMI). Yet, the care of such patients may differ from those with AMI, and their inclusion in value-based payment programs risks inaccurately assessing hospital care and even unwarranted financial penalties. In October 2018, a new ICD-10 code for T2MI was introduced (I21.A1). It is unclear what effect, if any, this new code has had on Type 1 MI (T1MI) representation among discharges assigned an ICD-10 code for AMI.

Methods: We screened all discharges from 8 UCHealth hospitals between January 1, 2017 and June 30, 2019 for a primary discharge ICD-10 code of AMI (n=3,445). Hospitalizations occurring during a six month period prior to the introduction of I21.A1 (January 1, 2017 to June 30, 2017) and a six-month period after the introduction of I21.A1 (January 1, 2019 to June 30, 2019) were selected for chart review. Using the 4th Universal Definition of MI, hospitalizations were assigned a gold-standard clinical diagnosis of T1MI, T2MI, or NIMI. The cohorts were compared according to the primary outcomes of readmission and mortality at 30 and 90 days.

Results: Of 1,364 discharges reviewed, 676 occurred in the pre-I21.A1 period and 667 occurred in the post-I21.A1 period. In the pre-I21.A1 cohort, 86% (585 of 676) of discharges met clinical criteria for T1MI, 10% (67 of 676) were deemed T2MI and 4% (24 of 676) represented NIMI. In the post-I21.A1 group, 93% (626 of 676) were deemed T1MI, while 5% (33 of 667) were deemed T2MI and 2% (12 of 667) met criteria for NIMI. The post-I21.A1 cohort had significantly fewer readmissions at 30 and 90 days when compared to the pre-I21.A1 cohort, but had similar rates of mortality.

Conclusions: After the introduction of an ICD-10 code for T2MI, fewer patients with T2MIs and NIMIs were eligible for inclusion in value-based programs. Concomitantly, we observed lower readmission rates among patients with an ICD-10 code for AMI after the T2MI code was introduced.

Applications of machine learning in decision analysis for dose management for dofetilide

Background

Initiation of the antiarrhythmic medication dofetilide requires an FDA-mandated 3 days of telemetry monitoring due to heightened risk of toxicity within this time period. Although a recommended dose management algorithm for dofetilide exists, there is a range of real-world approaches to dosing the medication.

Methods and results

In this multicenter investigation, clinical data from the Antiarrhythmic Drug Genetic (AADGEN) study was examined for 354 patients undergoing dofetilide initiation. Univariate logistic regression identified a starting dofetilide dose of 500 mcg (OR 5.0, 95%CI 2.5–10.0, p<0.001) and sinus rhythm at the start of dofetilide loading (OR 2.8, 95%CI 1.8–4.2, p<0.001) as strong positive predictors of successful loading. Any dose-adjustment during loading (OR 0.19, 95%CI 0.12–0.31, p<0.001) and a history coronary artery disease (OR 0.33, 95%CI 0.19–0.59, p<0.001) were strong negative predictors of successful dofetilide loading. Based on the observation that any dose adjustment was a significant negative predictor of successful initiation, we applied multiple supervised approaches to attempt to predict the dose adjustment decision, but none of these approaches identified dose adjustments better than a probabilistic guess. Principal component analysis and cluster analysis identified 8 clusters as a reasonable data reduction method. These 8 clusters were then used to define patient states in a tabular reinforcement learning model trained on 80% of dosing decisions. Testing of this model on the remaining 20% of dosing decisions revealed good accuracy of the reinforcement learning model, with only 16/410 (3.9%) instances of disagreement.

Conclusions

Dose adjustments are a strong determinant of whether patients are able to successfully initiate dofetilide. A reinforcement learning algorithm informed by unsupervised learning was able to predict dosing decisions with 96.1% accuracy. Future studies will apply this algorithm prospectively as a data-driven decision aid.

Determining post-test risk in a national sample of stress nuclear myocardial perfusion imaging reports: Implications for natural language processing tools

BACKGROUND

Reporting standards promote clarity and consistency of stress myocardial perfusion imaging (MPI) reports, but do not require an assessment of post-test risk. Natural Language Processing (NLP) tools could potentially help estimate this risk, yet it is unknown whether reports contain adequate descriptive data to use NLP.

METHODS

Among VA patients who underwent stress MPI and coronary angiography between January 1, 2009 and December 31, 2011, 99 stress test reports were randomly selected for analysis. Two reviewers independently categorized each report for the presence of critical data elements essential to describing post-test ischemic risk.

RESULTS

Few stress MPI reports provided a formal assessment of post-test risk within the impression section (3%) or the entire document (4%). In most cases, risk was determinable by combining critical data elements (74% impression, 98% whole). If ischemic risk was not determinable (25% impression, 2% whole), inadequate description of systolic function (9% impression, 1% whole) and inadequate description of ischemia (5% impression, 1% whole) were most commonly implicated.

CONCLUSIONS

Post-test ischemic risk was determinable but rarely reported in this sample of stress MPI reports. This supports the potential use of NLP to help clarify risk. Further study of NLP in this context is needed.

When a Short-Term Outlook Is the Best Long-Term Strategy: Time-Varying Risk of Readmission After Acute Myocardial Infarction

See Article by Khot et al

Supporting Parents During Cardiology Fellowship: Because Life Happens

See Article Mwakyanjala et al.

Abstract 20: Are We Ready for High(er) Sensitivity Troponin Assays? The Positive Predictive Value of a Contemporary Troponin Assay for Acute Myocardial Infarction

Background: Patients with elevated troponin (cTn) in the absence of Acute Myocardial Infarction (AMI) present a diagnostic dilemma: they at high risk of adverse cardiac events, yet there is little evidence on how they should be managed clinically. In recent years, greater sensitivity of cTn assays and less selective use of cTn in clinical practice have led to a greater number of non-AMI patients with elevated troponin. The exact scope of the problem in routine clinical practice is not known, as published estimates of troponin’s positive predictive value (PPV) for AMI range from 15% to 70%. We sought to define troponin’s PPV for AMI at our institution and examine both process and outcome measures for AMI and non-AMI patients.

Methods: In a retrospective cohort analysis of patients evaluated at the University of Colorado Hospital, we identified 5,903 hospital encounters between January 1, 2017 and October 6, 2018 in which patients were found to have an elevated serum troponin level (>0.04 ng/mL, Siemens Advia Centaur Tnl-Ultra). We used ICD-10 codes, billing diagnosis related groups (DRGs), or inclusion in the NCDR® ACTION Registry® to identify patients with a diagnosis of AMI. Patients not captured by one of these diagnoses were categorized as non-AMI. We then compared AMI and non-AMI patients according to the primary outcome of 100-day mortality. Secondary outcomes and process measures were also examined.

Results: Out of 5,903 hospital encounters in which elevated cTn was detected, 730 were associated with any diagnosis of AMI (PPV 12.4%). The PPV was lower for individual AMI diagnosis groups. The primary outcome of 100-day mortality was observed in 10.3% of AMI patients versus 20.5% of non-AMI patients (p < 0.001). AMI patients also had significantly shorter hospitalizations, higher rates of inpatient echocardiography and higher rates of P2Y12 inhibitor therapy (Table 1).

Conclusion: The PPV of a contemporary troponin assay for AMI was 12.4% in routine clinical practice at a tertiary care academic hospital. Concordant with prior studies, non-AMI patients had worse outcomes. With high-sensitivity troponin (hsTn) assays poised to increase the prevalence of non-AMI troponin elevation, guidance is needed regarding the appropriate use of hsTn as well as the evaluation and treatment of non-ACS patients.

Recent Approaches to Improve Medication Adherence in Patients with Coronary Heart Disease: Progress Towards a Learning Healthcare System

PURPOSE OF REVIEW

Non-adherence to medications for the secondary prevention of myocardial infarction (MI) is a major contributor to morbidity and mortality in these patients. This review describes recent advances in promoting adherence to therapies for coronary artery disease (CAD).

RECENT FINDINGS

Two large randomized controlled trials to "incentivize" adherence were somewhat disappointing; neither financial incentives nor "peer pressure" successfully increased rates of adherence in the post-MI population. Patient education and provider engagement appear to be critical aspects of improving adherence to CAD therapies, where the provider is a physician, pharmacist, or nurse and follow-up is performed in person or by telephone. Fixed-dose combinations of CAD medications, formulated as a so-called "polypill," have shown some early efficacy in increasing adherence. Technological advances that automate monitoring and/or encouragement of adherence are promising but seem universally dependent on patient engagement. For example, medication reminders via text message perform better if patients are required to respond. Multifaceted interventions, in which these and other interventions are combined together, appear to be most effective. There are several available types of proven interventions through which providers, and the health system at large, can advance patient adherence to CAD therapies. No single intervention to promote adherence will be successful in all patients. Further study of multifaceted interventions and the interactions between different interventions will be important to advancing the field. The goal is a learning healthcare system in which a network of interventions responds and adapts to patients' needs over time.

Wisdom of the crowd: bright ideas and innovations from the teaching value and choosing wisely challenge

PROBLEM

Medical education has been cited as both part of the problems facing, and part of the solution to reforming, the increasingly challenging U.S. health care system which is fraught with concerns regarding the quality and affordability of care. To teach value in ways that are impactful, sustainable, and scalable, the best and brightest ideas need to be shared such that educators can build on successful existing innovations.

APPROACH

To identify the most promising innovations and bright ideas for teaching value to clinical trainees, the authors hosted the "Teaching Value and Choosing Wisely Challenge." The challenge used crowdsourcing methods to solicit scalable, pedagogical approaches from across North America, and then draw generalizable lessons.

OUTCOMES

The authors received 74 submissions (28 innovations; 46 bright ideas) from 14 students, 20 residents/fellows, 38 faculty members (ranging from instructors to full professors), and 2 nonclinical administrators. Submissions represented 14 clinical disciplines including internal medicine, emergency medicine, surgery, pediatrics, obstetrics-gynecology, laboratory medicine, and pharmacy. Thirty-nine abstracts focused on graduate medical education, 15 addressed undergraduate medical education, and 20 applied to both.

NEXT STEPS

The authors have solicited, shared, and described solutions for teaching high-value care to medical trainees. Challenge participants demonstrated commitment to improving value and ingenuity in addressing professional barriers to change. Further success requires strong local faculty champions and willing trainee participants. Additionally, the use of data to demonstrate the collective positive impact of these ideas and programs will be critical for sustaining pedagogical changes in the health professions.

Connexin40 abnormalities and atrial fibrillation in the human heart

Normal atrial conduction requires similar abundances and homogeneous/overlapping distributions of two connexins (Cx40 and Cx43). The remodeling of myocyte connections and altered electrical conduction associated with atrial fibrillation (AF) likely involves perturbations of these connexins. We conducted a comprehensive series of experiments to examine the abundances and distributions of Cx40 and Cx43 in the atria of AF patients. Atrial appendage tissues were obtained from patients with lone AF (paroxysmal or chronic) or normal controls. Connexins were localized by double label immunofluorescence confocal microscopy, and their overlap was quantified. Connexin proteins and mRNAs were quantified by immunoblotting and qRT-PCR. PCR amplified genomic DNA was sequenced to screen for connexin gene mutations or polymorphisms. Immunoblotting showed reductions of Cx40 protein (to 77% or 49% of control values in samples from patients with paroxysmal and chronic AF, respectively), but no significant changes of Cx43 protein levels in samples from AF patients. The extent of Cx43 immunostaining and its distribution relative to N-cadherin were preserved in the AF patient samples. Although there was variability of Cx40 staining among paroxysmal AF patients, all had some fields with substantial Cx40 heterogeneity and reduced overlap with Cx43. Cx40 immunostaining was severely reduced in all chronic AF patients. qRT-PCR showed no change in Cx43 mRNA levels, but reductions in total Cx40 mRNA (to <50%) and Cx40 transcripts A (to ~50%) and B (to <25%) as compared to controls. No Cx40 coding region mutations were identified. The frequency of promoter polymorphisms did not differ between AF patient samples and controls. Our data suggest that reduced Cx40 levels and heterogeneity of its distribution (relative to Cx43) are common in AF. Multiple mechanisms likely lead to reductions of functional Cx40 in atrial gap junctions and contribute to the pathogenesis of AF in different patients.

Outcomes with the selective use of enteric exocrine drainage in pancreas transplantation

BACKGROUND

Bladder drainage of the exocrine secretions of pancreas transplants has been the standard of practice as it affords the ability to monitor for rejection and is thought to be associated with decreased morbidity. Recently, there has been renewed interest in avoiding the urinary tract complications and metabolic derangements that accompany bladder drainage by draining pancreatic exocrine secretions into the jejunum (enteric drainage). We sought to determine whether enteric drainage of pancreas transplants is safe and offers advantages without compromise in graft function or longevity.

METHODS

We retrospectively reviewed all pancreas transplants performed at the University of Washington between 2000 and 2003. Selection of the exocrine drainage method was based on the length of cold ischemia time and whether the pancreas was transplanted alone or in combination with a kidney. Pearson's chi-square and Fisher's Exact tests were used for statistical comparisons in complications or rejections between the groups.

RESULTS

Thirty-four pancreas transplants were performed with exocrine drainage into the bladder used in 17 and enteric drainage in 17. The complication rate was 53% in the bladder-drained group and 41% (P=.49) in the enteric-drained group. The incidence of pancreas rejection was 24% in the bladder-drained versus 29% in the enteric-drained patients (P=.50). One graft failed, which was in the bladder cohort.

CONCLUSIONS

We found comparable rejection and complication rates between groups. We conclude that enteric drainage is safe when used selectively, and entails no increased risks compared with bladder drainage.

Rescue of acute portal vein thrombosis after liver transplantation using a cavoportal shunt at re-transplantation

BACKGROUND

Portal vein thrombosis is a rare but devastating complication following orthotopic liver transplantation. Fulminant liver failure ensues with acute portal vein thrombosis after transplantation limiting the treatment options.

METHODS

We successfully re-transplanted a 46-year-old female patient who developed acute portal vein thrombosis 19 d after orthotopic liver transplantation. Vascular reconstruction included a cavoportal shunt to augment portal blood flow.

RESULTS

Twelve months after re-transplantation this patient lives independently and enjoys excellent liver allograft function.

CONCLUSIONS

Cavoportal shunt can augment portal blood flow in adult recipients of orthotopic liver transplants. This technique can be successfully employed during re-transplantation when portal blood flow is inadequate to maintain patency.

Venous thrombosis and occlusion after pancreas transplantation: evaluation with breath-hold gadolinium-enhanced three-dimensional MR imaging

OBJECTIVE

We describe the imaging findings of venous thrombosis and occlusion after pancreatic transplantation in five patients who underwent multiphasic breath-hold gadolinium-enhanced three-dimensional MR imaging.

CONCLUSION

Venous thrombus appeared as serpetine voids within the graft parenchyma or at the venous anastomosis during the venous phase of MR imaging. Nonenhancement or heterogeneous enhancement of graft parenchyma corresponded to glandular necrosis at pancreatectomy in two patients. Initial sonographic evaluation was nondiagnostic of venous thrombosis in two of five patients. Multiphasic breath-hold gadolinium-enhanced three-dimensional MR imaging of pancreatic transplants can provide information to make the specific diagnosis of venous thrombosis or occlusion.

A strategy for generating consistent long-term donor-specific tolerance to solid organ allografts

Current triple drug immunosuppression while effective, increases the risk of opportunistic infection and lymphoproliferative disorders. An alternative strategy would be the generation of donor-specific tolerance with short-term treatment. The use of donor-specific transfusions (DST) with a single brief course of cyclosporine (CsA) and rapamycin (Rapa) has produced promising results in animal models, but falls short of uniform tolerance. It was hypothesized that a DST/CsA/Rapa protocol administered in the perioperative period and redosed at one month might improve on this success in the ACI to Lewis rat heterotopic cardiac transplant model. Recipients received no treatment (group 1), a 1 ml DST intravenously (i.v.) with CsA 10 mg/kg subcutaneously (s.c.) at D-1 and CsA 2.5 mg/kg DO6D+13 (group 2), DST/CsA as dosed above with intraperitoneally (i.p.) Rapa 1 mg/kg D+36D+7 (group 3), DST/CsA/Rapa as above with all components redosed at one month (group 4), DST/CsA/Rapa with only CsA and Rapa repeated (group 5), and DST/CsA/Rapa with CsA redosed and Rapa continued indefinitely (group 6). Comparison of permanent survival (longer than 200 days) between protocols revealed groups 4-6 were significantly greater than control groups 1-3. Donor specificity was verified in group 6, where three permanent survivors received a second cardiac allograft from a Buffalo rat donor and rejected these grafts almost as quickly as untreated strain pair matched controls 21 +/- 1 days vs 30.3 +/- 5 days. Animals from group 6 displayed a greatly reduced mixed lymphocyte response to ACI cells but not to third-party cells. The percentage of T cells producing cytokines was reduced and shifted toward Th-2 type cytokines (IL-4). Thus, a repeated cycle of this brief DST/CsA/Rapa treatment appears to generate consistent permanent graft survival (up to 91%) that exceeds previously studied tolerance inducation protocols and is donor specific.

An examination of tissue chimerism in the ACI to Lewis rat cardiac transplant model

While the existence of chimeric cells in host tissue following organ transplantation is well documented, its distribution, temporal evolution and relationship to allograft survival is less clear. To explore this phenomenon, Lewis recipients of ACI cardiac allografts representing a wide range of immunosuppressive protocols and graft survival times were examined for the presence of chimerism using a sensitive polymerase chain reaction assay. Four groups of animals were examined: untransplanted animals receiving donor specific transfusion (DST)/cyclosporine A (CsA); allograft recipients with no treatment; recipients treated with DST/CsA/supplementary immunosuppression with rejection at 21-183 days; and recipients sacrificed with functioning allografts, treated with DST/CsA/supplementary immunosuppression and surviving > 200 days. To elucidate variations in the tissue distribution of chimeric cells, bone marrow, skin, liver, spleen, and thymus were examined in each animal. Untransplanted animals receiving DST/CsA displayed no evidence of chimerism. In animals receiving a cardiac allograft but no treatment, there was extensive evidence of chimerism in four of five animals. Chimerism was also detected in seven of nine animals with intermediate graft survival at the time of rejection. In animals with long-term graft survival, only four of eight displayed chimerism. These results suggest that, without immunosuppression, early chimerism does not lead to prolonged graft survival and that, even when graft survival is moderately prolonged, these cells are not sufficient to prevent rejection. In conclusion, chimerism appears to be a common phenomenon following transplantation, is not a result of DST, and may not be necessary for maintenance of long-term graft survival.

The significance of timing of additional short-term immunosuppression in the donor-specific transfusion/cyclosporine-treated rat

It is hypothesized that the mechanism, or mechanisms, responsible for donor-specific transfusion (DST)/cyclosporine (CsA) immunosuppression is generated by an active immune response that is most dynamic in the immediate peritransplant period and thus might be at the peak of vulnerability to the influences of added immunosuppression. To better define this concept, four immunosuppressive drugs were combined with a d-1 DST and 14-day course of CsA in the ACl-to-Lewis cardiac transplant model. A 5-day course of antithymocyte globulin (ATG) initiated at d-1 or d+4 with DST/CsA reduced survival vs. DST/CsA alone (27.0 +/- 2.6 days and 24.6 +/- 5.7 days vs. 95.3 +/- 16.3 days, P<.05). Delay of initiation to d+7 improved survival to 39.5 +/- 8.9 days. A 5-day course of methylprednisolone (MP) begun at d-1 with DST/CsA decreased survival vs. DST/CsA alone, 59.2 +/- l0.0 days vs. 95.3 +/- 16.3 days, but delay to d+4 improved survival to 110 +/- l8 days, P<.05 vs d-1. A 3-day course of brequinar (Breq) begun at d-1 with DST/CsA increased survival to 244 +/- 48.6 days, while delay to d+4 reduced survival to 49.0 +/- 6.7 days, P<.05 vs. d-1. Finally, a 5-day course of rapamycin (Rapa), was given with d-1 DST/CsA treatment beginning on d-1, d0, d+l, d+3, d+5, and d+7. In this instance, no significant differences in survival were found between timing groups or DST/CsA control. Together, these data support the hypothesis that DST/CsA treatment generates an active immune response that is inhibited by early initiation of ATG or MP, enhanced by early administration of Breq, and unchanged by early administration of Rapa.

Nutritional immunomodulation enhances cardiac allograft survival in rats treated with donor-specific transfusion and cyclosporine

The aim of this study was to assess the efficacy of an enteral diet fortified with arginine, RNA, and fish oil (Impact), alone and in combination with cyclosporine (CsA) and donor-specific transfusion (DST) on allograft survival in the ACI:Lewis rat cardiac transplant model. Animals were fed ad libitum with either standard rat chow or Impact diet. Six groups were studied; these consisted of untreated recipients fed either standard diet or Impact diet; recipients treated with CsA 10 mg/kg on the day prior to engraftment (day-1) followed by 2.5 mg/kg/d, day 0-->day+13 and fed with either standard diet or Impact; and animals given a DST (1 ml) on day-1, CsA as described previously and fed either standard diet or Impact. Untreated animals standard diet (group 1, n = 8) rejected their allografts at 7.0 +/- 0.0 days, while those fed Impact (group 2, n = 9) had graft survival of 12.8 +/- 2.1 days, (P = .01 versus group 1). Animals treated with CsA alone and standard diet (group 3, n = 9) rejected at 30.3 +/- 4.8 days, while the combination of CsA and Impact diet (group 4, n = 8) rejected at 33.0 +/- 9.5 days--minimally improved survival compared with group 3. Animals treated with DST/CsA and standard diet (group 5, n = 7) rejected at 72.1 +/- 6.8 days, while the substitution of Impact for standard diet (group 6, n = 8) led to a significant graft prolongation to 275 +/- 53 days, n = 8 (P < .015 vs. groups 1-5). These data suggest that Impact diet alone can have potent immunomodulatory properties but may require the addition of DST/CsA to realize its potential. These findings underscore the potential of dietary immunomodulatory therapy to prevent rejection and promote tolerance to solid organ allografts.

Administration of intragraft interleukin-4 prolongs cardiac allograft survival in rats treated with donor-specific transfusion/cyclosporine

It has been hypothesized that immunoregulating cytokines produced by intragraft Th-2 cells may be important for prolonged allograft survival. ACI hearts transplanted into untreated Lewis rat recipients survived for 6.2 days, but they survived for 72.1 days in recipients treated with a donor-specific transfusion and low dose CsA for 14 days. In donor-specific transfusion/CsA-treated animals, intragraft infusion of IL-10 via a 14-day osmotic minipump had no effect on graft survival (75.6 days), but intragraft infusion of IL-4 prolonged graft survival to 149.2 days (P < 0.01). While the actual mechanism of this effect is unclear, it suggests that IL-4 may be important in the development of long-term graft survival.