Impact of Visit Volume on the Effectiveness of Electronic Tools to Improve Heart Failure Care

BACKGROUND

Electronic health record (EHR) tools can improve prescribing of guideline-recommended therapies for heart failure with reduced ejection fraction (HFrEF), but their effectiveness may vary by physician workload.

OBJECTIVES

This paper aims to assess whether physician workload modifies the effectiveness of EHR tools for HFrEF.

METHODS

This was a prespecified subgroup analysis of the BETTER CARE-HF (Building Electronic Tools to Enhance and Reinforce Cardiovascular Recommendations for Heart Failure) cluster-randomized trial, which compared effectiveness of an alert vs message vs usual care on prescribing of mineralocorticoid antagonists (MRAs). The trial included adults with HFrEF seen in cardiology offices who were eligible for and not prescribed MRAs. Visit volume was defined at the cardiologist-level as number of visits per 6-month study period (high = upper tertile vs non-high = remaining). Analysis at the patient-level used likelihood ratio test for interaction with log-binomial models.

RESULTS

Among 2,211 patients seen by 174 cardiologists, 932 (42.2%) were seen by high-volume cardiologists (median: 1,853; Q1-Q3: 1,637-2,225 visits/6 mo; and median: 10; Q1-Q3: 9-12 visits/half-day). MRA was prescribed to 5.5% in the high-volume vs 14.8% in the non-high-volume groups in the usual care arm, 10.3% vs 19.6% in the message arm, and 31.2% vs 28.2% in the alert arm, respectively. Visit volume modified treatment effect (P for interaction = 0.02) such that the alert was more effective in the high-volume group (relative risk: 5.16; 95% CI: 2.57-10.4) than the non-high-volume group (relative risk: 1.93; 95% CI: 1.29-2.90).

CONCLUSIONS

An EHR-embedded alert increased prescribing by >5-fold among patients seen by high-volume cardiologists. Our findings support use of EHR alerts, especially in busy practice settings. (Building Electronic Tools to Enhance and Reinforce Cardiovascular Recommendations for Heart Failure [BETTER CARE-HF]; NCT05275920).

Cluster-Randomized Trial Comparing Ambulatory Decision Support Tools to Improve Heart Failure Care

BACKGROUND

Mineralocorticoid receptor antagonists (MRAs) are underprescribed for patients with heart failure with reduced ejection fraction (HFrEF).

OBJECTIVES

This study sought to compare effectiveness of 2 automated, electronic health record-embedded tools vs usual care on MRA prescribing in eligible patients with HFrEF.

METHODS

BETTER CARE-HF (Building Electronic Tools to Enhance and Reinforce Cardiovascular Recommendations for Heart Failure) was a 3-arm, pragmatic, cluster-randomized trial comparing the effectiveness of an alert during individual patient encounters vs a message about multiple patients between encounters vs usual care on MRA prescribing. This study included adult patients with HFrEF, no active MRA prescription, no contraindication to MRAs, and an outpatient cardiologist in a large health system. Patients were cluster-randomized by cardiologist (60 per arm).

RESULTS

The study included 2,211 patients (alert: 755, message: 812, usual care [control]: 644), with average age 72.2 years, average ejection fraction 33%, who were predominantly male (71.4%) and White (68.9%). New MRA prescribing occurred in 29.6% of patients in the alert arm, 15.6% in the message arm, and 11.7% in the control arm. The alert more than doubled MRA prescribing compared to usual care (relative risk: 2.53; 95% CI: 1.77-3.62; P < 0.0001) and improved MRA prescribing compared to the message (relative risk: 1.67; 95% CI: 1.21-2.29; P = 0.002). The number of patients with alert needed to result in an additional MRA prescription was 5.6.

CONCLUSIONS

An automated, patient-specific, electronic health record-embedded alert increased MRA prescribing compared to both a message and usual care. These findings highlight the potential for electronic health record-embedded tools to substantially increase prescription of life-saving therapies for HFrEF. (Building Electronic Tools to Enhance and Reinforce Cardiovascular Recommendations-Heart Failure [BETTER CARE-HF]; NCT05275920).

Design and pilot implementation for the BETTER CARE-HF trial: A pragmatic cluster-randomized controlled trial comparing two targeted approaches to ambulatory clinical decision support for cardiologists

BACKGROUND

Beart failure with reduced ejection fraction (HFrEF) is a leading cause of morbidity and mortality. However, shortfalls in prescribing of proven therapies, particularly mineralocorticoid receptor antagonist (MRA) therapy, account for several thousand preventable deaths per year nationwide. Electronic clinical decision support (CDS) is a potential low-cost and scalable solution to improve prescribing of therapies. However, the optimal timing and format of CDS tools is unknown.

METHODS AND RESULTS

We developed two targeted CDS tools to inform cardiologists of gaps in MRA therapy for patients with HFrEF and without contraindication to MRA therapy: (1) an alert that notifies cardiologists at the time of patient visit, and (2) an automated electronic message that allows for review between visits. We designed these tools using an established CDS framework and findings from semistructured interviews with cardiologists. We then pilot tested both CDS tools (n = 596 patients) and further enhanced them based on additional semistructured interviews (n = 11 cardiologists). The message was modified to reduce the number of patients listed, include future visits, and list date of next visit. The alert was modified to improve noticeability, reduce extraneous information on guidelines, and include key information on contraindications.

CONCLUSIONS

The BETTER CARE-HF (Building Electronic Tools to Enhance and Reinforce CArdiovascular REcommendations for Heart Failure) trial aims to compare the effectiveness of the alert vs. the automated message vs. usual care on the primary outcome of MRA prescribing. To our knowledge, no study has directly compared the efficacy of these two different types of electronic CDS interventions. If effective, our findings can be rapidly disseminated to improve morbidity and mortality for patients with HFrEF, and can also inform the development of future CDS interventions for other disease states. (Trial registration: Clinicaltrials.gov NCT05275920).

Missed opportunities in medical therapy for patients with heart failure in an electronically-identified cohort

BACKGROUND

National registries reveal significant gaps in medical therapy for patients with heart failure and reduced ejection fraction (HFrEF), but may not accurately (or fully) characterize the population eligible for therapy.

OBJECTIVE

We developed an automated, electronic health record-based algorithm to identify HFrEF patients eligible for evidence-based therapy, and extracted treatment data to assess gaps in therapy in a large, diverse health system.

METHODS

In this cross-sectional study of all NYU Langone Health outpatients with EF ≤ 40% on echocardiogram and an outpatient visit from 3/1/2019 to 2/29/2020, we assessed prescription of the following therapies: beta-blocker (BB), angiotensin converting enzyme inhibitor (ACE-I)/angiotensin receptor blocker (ARB)/angiotensin receptor neprilysin inhibitor (ARNI), and mineralocorticoid receptor antagonist (MRA). Our algorithm accounted for contraindications such as medication allergy, bradycardia, hypotension, renal dysfunction, and hyperkalemia.

RESULTS

We electronically identified 2732 patients meeting inclusion criteria. Among those eligible for each medication class, 84.8% and 79.7% were appropriately prescribed BB and ACE-I/ARB/ARNI, respectively, while only 23.9% and 22.7% were appropriately prescribed MRA and ARNI, respectively. In adjusted models, younger age, cardiology visit and lower EF were associated with increased prescribing of medications. Private insurance and Medicaid were associated with increased prescribing of ARNI (OR = 1.40, 95% CI = 1.02-2.00; and OR = 1.70, 95% CI = 1.07-2.67).

CONCLUSIONS

We observed substantial shortfalls in prescribing of MRA and ARNI therapy to ambulatory HFrEF patients. Subspecialty care setting, and Medicaid insurance were associated with higher rates of ARNI prescribing. Further studies are warranted to prospectively evaluate provider- and policy-level interventions to improve prescribing of these evidence-based therapies.

A preliminary assessment of mercury in the feathers of migratory songbirds breeding in the North American subarctic

Passerines appear to have a greater sensitivity to mercury than other avian orders, and little data exists for mercury exposure in songbirds breeding at high latitudes. In this preliminary study, we examined mercury exposure in 12 migratory songbird species breeding in Denali National Park & Preserve, in subarctic interior Alaska. Overall, we analyzed 343 feather samples collected in 2015-2017 for their total mercury content. Mercury levels found in feathers indicates exposure during the period of feather growth, which we assume largely took place on the breeding ground. In this limited sample of songbird feathers, mercury concentrations ranged from near zero to 6.34 μg/g. Most species sampled showed relatively low mercury, but some individuals had high enough concentrations to be subject to adverse physiological and behavioral effects. There was an indication that mercury concentrations of breeding songbirds may vary by diet composition, with non-invertivorous species possibly tending towards lower mercury concentrations. Overall, however, the degree of mercury exposure observed was low for songbirds breeding in the subarctic. Further examination would prove useful in clarifying mercury exposure and ecological relationships in this under-studied region.

Multimodality imaging: Bird's eye view from the 2019 American College of Cardiology Scientific Sessions

The 2019 American College of Cardiology Scientific Sessions displayed innovation in many areas for the evaluation and management of cardiovascular disease from preventive evaluation and care to advanced interventions. Imaging played a central role in these developments with a highlight of the conference being the imaging research presented. This review will summarize key imaging studies which were presented at this scientific meeting which will lead to innovation in the evaluation and management of cardiovascular disease. Experts in nuclear imaging (DW/MA), echocardiography (MS), cardiac magnetic resonance (SL), and cardiac computed tomography (RB) selected abstracts which they found to be of particular interest to the multimodality imaging audience and were integrated into this review (LP).

Value of gated-SPECT MPI for ischemia-guided PCI of non-culprit vessels in STEMI patients with multivessel disease after primary PCI

There remains a clinical question of which patients benefit from revascularization of non-culprit coronary artery stenosis in the setting of acute ST-segment elevation myocardial infraction (STEMI). This is a large population of patients with prior studies showing 40 to 70% of patients with STEMI having non-culprit stenosis. This article reviews the current state of the literature evaluating outcomes of those previously randomized to revascularization of non-culprit stenosis around the time of the STEMI. We propose a new study design to utilize gated-SPECT in the decision process by using an ischemic burden of > 5% as a cut-off for revascularization vs. complete revascularization without ischemia assessment.

The elusive role of myocardial perfusion imaging in stable ischemic heart disease: Is ISCHEMIA the answer?

The assessment of ischemia through myocardial perfusion imaging (MPI) is widely accepted as an index step in the diagnostic evaluation of stable ischemic heart disease (SIHD). Numerous observational studies have characterized the prognostic significance of ischemia extent and severity. However, the role of ischemia in directing downstream SIHD care including coronary revascularization has remained elusive as reductions in ischemic burden have not translated to improved clinical outcomes in randomized trials. Importantly, selection bias leading to the inclusion of many low risk patients with minimal ischemia have narrowed the generalizability of prior studies along with other limitations. Accordingly, an ongoing randomized controlled trial entitled ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) will compare an invasive coronary revascularization strategy vs a conservative medical therapy approach among stable patients with moderate to severe ischemia. The results of ISCHEMIA may have a substantial impact on the management of SIHD and better define the role of MPI in current SIHD pathways of care.

Myocardial perfusion imaging in women for the evaluation of stable ischemic heart disease-state-of-the-evidence and clinical recommendations

This document from the American Society of Nuclear Cardiology represents an updated consensus statement on the evidence base of stress myocardial perfusion imaging (MPI), emphasizing new developments in single-photon emission tomography (SPECT) and positron emission tomography (PET) in the clinical evaluation of women presenting with symptoms of stable ischemic heart disease (SIHD). The clinical evaluation of symptomatic women is challenging due to their varying clinical presentation, clinical risk factor burden, high degree of comorbidity, and increased risk of major ischemic heart disease events. Evidence is substantial that both SPECT and PET MPI effectively risk stratify women with SIHD. The addition of coronary flow reserve (CFR) with PET improves risk detection, including for women with nonobstructive coronary artery disease and coronary microvascular dysfunction. With the advent of PET with computed tomography (CT), multiparametric imaging approaches may enable integration of MPI and CFR with CT visualization of anatomical atherosclerotic plaque to uniquely identify at-risk women. Radiation dose-reduction strategies, including the use of ultra-low-dose protocols involving stress-only imaging, solid-state detector SPECT, and PET, should be uniformly applied whenever possible to all women undergoing MPI. Appropriate candidate selection for stress MPI and for post-MPI indications for guideline-directed medical therapy and/or invasive coronary angiography are discussed in this statement. The critical need for randomized and comparative trial data in female patients is also emphasized.

Optimising diagnostic accuracy with the exercise ECG: opportunities for women and men with stable ischaemic heart disease

The exercise ECG is an integral part within the evaluation algorithm for diagnosis and risk stratification of patients with stable ischaemic heart disease (SIHD). There is evidence, both older and new, that the exercise ECG can be an effective and cost-efficient option for patients capable of performing at maximal levels of exercise with suitable resting ECG findings. In this review, we will highlight the major dilemmas in interpreting suspected coronary artery disease symptoms in women and identify optimal strategies for employing exercise ECG as a first-line diagnostic test in the SIHD evaluation algorithm. We will highlight current evidence as well as recent guideline statements on this subject.

TRIAL REGISTRATION NUMBER

NCT01471522; Pre-results.

Ankle-Brachial Index Testing at the Time of Stress Testing in Patients Without Known Atherosclerosis

BACKGROUND

Individuals referred for stress testing to identify coronary artery disease may have nonobstructive atherosclerosis, which is not detected by stress tests. Identification of increased risk despite a negative stress test could inform prevention efforts. Abnormal ankle-brachial index (ABI) is associated with increased cardiovascular risk.

HYPOTHESIS

Routine ABI testing in the stress laboratory will identify unrecognized peripheral arterial disease in some patients.

METHODS

Participants referred for stress testing without known history of atherosclerotic disease underwent ABI testing (n = 451). Ankle-brachial index was assessed via simultaneous arm and leg pressure using standard measurement, automated blood-pressure cuffs at rest. Ankle-brachial index was measured after exercise in 296 patients and 30 healthy controls. Abnormal postexercise ABI was defined as a >20% drop in ABI or fall in ankle pressure by >30 mm Hg.

RESULTS

Overall, 2.0% of participants had resting ABI ≤0.90, 3.1% had ABI ≥1.40, and 5.5% had borderline ABI. No patient with abnormal or borderline ABI had an abnormal stress test. Participants who met peripheral arterial disease screening criteria (age ≥65 or 50-64 with diabetes or smoking) tended toward greater frequency of low ABI (2.9% vs 1.0%; P = 0.06) and were more likely to have borderline ABI (0.91 to 0.99; 7.8% vs 2.9%; P = 0.006). Postexercise ABI was abnormal in 29.4% of patients and 30.0% of controls (P not significant).

CONCLUSIONS

Ankle-brachial index screening at rest just before stress testing detected low ABI in 2.0% of participants, all of whom had negative stress tests.

Comparative definitions for moderate-severe ischemia in stress nuclear, echocardiography, and magnetic resonance imaging

The lack of standardized reporting of the magnitude of ischemia on noninvasive imaging contributes to variability in translating the severity of ischemia across stress imaging modalities. We identified the risk of coronary artery disease (CAD) death or myocardial infarction (MI) associated with ≥10% ischemic myocardium on stress nuclear imaging as the risk threshold for stress echocardiography and cardiac magnetic resonance. A narrative review revealed that ≥10% ischemic myocardium on stress nuclear imaging was associated with a median rate of CAD death or MI of 4.9%/year (interquartile range: 3.75% to 5.3%). For stress echocardiography, ≥3 newly dysfunctional segments portend a median rate of CAD death or MI of 4.5%/year (interquartile range: 3.8% to 5.9%). Although imprecisely delineated, moderate-severe ischemia on cardiac magnetic resonance may be indicated by ≥4 of 32 stress perfusion defects or ≥3 dobutamine-induced dysfunctional segments. Risk-based thresholds can define equivalent amounts of ischemia across the stress imaging modalities, which will help to translate a common understanding of patient risk on which to guide subsequent management decisions.

Lessons learned from MPI and physiologic testing in randomized trials of stable ischemic heart disease: COURAGE, BARI 2D, FAME, and ISCHEMIA

There is a preponderance of evidence that, in the setting of an acute coronary syndrome, an invasive approach using coronary revascularization has a morbidity and mortality benefit. However, recent stable ischemic heart disease (SIHD) randomized clinical trials testing whether the addition of coronary revascularization to guideline-directed medical therapy (GDMT) reduces death or major cardiovascular events have been negative. Based on the evidence from these trials, the primary role of GDMT as a front line medical management approach has been clearly defined in the recent SIHD clinical practice guideline; the role of prompt revascularization is less precisely defined. Based on data from observational studies, it has been hypothesized that there is a level of ischemia above which a revascularization strategy might result in benefit regarding cardiovascular events. However, eligibility for recent negative trials in SIHD has mandated at most minimal standards for ischemia. An ongoing randomized trial evaluating the effectiveness of randomization of patients to coronary angiography and revascularization as compared to no coronary angiography and GDMT in patients with moderate-severe ischemia will formally test this hypothesis. The current review will highlight the available evidence including a review of the published and ongoing SIHD trials.

Noninvasive assessment of coronary artery disease in women: What's next?

Significant progress in research has been made in the areas of sex-specific aspects of cardiovascular disease. Despite these advances, coronary artery disease (CAD) is the leading cause of death of women in the Western world. Over the past decade, the focused research on women at risk for ischemic heart disease has helped to clarify our understanding of some of the sex-specific factors, which are important in detecting CAD. In women, the detection and evaluation of physiologically significant CAD is challenging, especially given that traditional tests designed to detect focal areas of coronary artery stenosis are less sensitive and specific in female patients who have a lower prevalence of obstructive coronary disease, greater burden of symptoms, and a high atherosclerotic burden. In this article, we review the available evidence on the role of contemporary cardiovascular imaging techniques in evaluating ischemic heart disease in women.

Clinical evaluation of the appropriateness use criteria for single-photon emission-computed tomography: differences by patient population, physician specialty, and patient outcomes

Objectives. Determine outcome of the 2005 appropriateness use criteria (AUC) for SPECT in a diverse population of patients and physicians. Background. AUC for SPECT were the first cardiology document to identify 52 clinical indications for imaging, 49 of them for stress SPECT. AUC have been proposed as cornerstone of responsible use of perfusion imaging. Methods. 585 consecutive patients undergoing SPECT were evaluated prospectively. Appropriateness was examined for demographic variables, clinical variables, and for physician and patient subgroups. Combined end-point of total mortality, cardiac revascularization, and cardiac admissions at 1 year post SPECT was evaluated. Results. SPECT indications were: appropriate, 63%; uncertain, 20%; inappropriate, 14%; not assigned, 3%. Most appropriate SPECT were observed in patients with known coronary disease (72%), chest pain syndrome (89%), high pre-test likelihood of disease (100%), men (70%), inpatients (72%), and cardiovascular physicians' referrals (69%). End-point was reached in 53 patients (97.4% follow up). Unadjusted event rates were: appropriate (12%), uncertain (7.1%), inappropriate (2.4%) SPECT (P = .01). Conclusion. Appropriateness of SPECT differs in subgroups of patients and physicians. Clinically significant outcomes occur more frequently in the appropriate stress SPECT group. Focused efforts are need for outpatients, asymptomatic patients, women, and non-cardiovascular physicians.

Wide-beam reconstruction half-time SPECT improves diagnostic certainty and preserves normalcy and accuracy: a quantitative perfusion analysis

BACKGROUND

Filtered back-projection (FBP) has been a standard in SPECT imaging. Newer iterative reconstruction algorithms have been shown to improve image quality and shorten acquisition time by taking into account statistical nature of raw data and using resolution recovery (RR). Wide-beam reconstruction (WBR) is an iterative algorithm with RR and adaptive noise control. We prospectively investigated outcome of WBR half-time SPECT on diagnostic certainty, accuracy and normalcy by quantitative perfusion analysis in comparison to full-time FBP images.

METHODS

434 patients underwent rest (201)Tl/stress (99m)Tc-sestamibi full-time (20 s/stop, FBP) followed by a half-time (10 s/stop, WBR) SPECT. 34 patients underwent an angiogram within 90 days of SPECT. Diagnostic certainty was based on summed stress scores (SSS, 5-point/17 segments): normal if SSS ≤ 1, equivocal if SSS = 2-3, and abnormal if SSS ≥ 4. Perfusion defects were normalized to a percent of total myocardium, and expressed as %LV = defect SSS/maximal SSS × 100% with maximal SSS of 28 for left anterior descending (LAD), and of 20 for right coronary (RCA) and left circumflex (LCX). Change in %LV (Δ%LV = %LV FBP - %LV WBR) was evaluated for diagnostically discordant versus concordant scans.

RESULTS

SSS and %LV demonstrated very good correlation. There were significantly fewer equivocal scans with WBR (38 vs 151 FBP, P < .0001). Most discordant scans were equivocal FBP SPECT becoming normal with WBR (123/151). Δ%LV(LAD) for discordant studies was greater for women (5.4% ± 4.2%, P < .001), while Δ%LV(RCA,LCX) (4.4% ± 5.1%, P < .001; 1.2% ± 5.0%, P = .04) were greater for men. Normalcy rate was 91.4% for FBP and WBR with more definitely normal WBR studies (84.5% vs 43.9% for FBP, P < .0001). There were no differences in sensitivity (FBP 84.2%, WBR 81.6%), specificity (FBP 54.6%, WBR 63.6%), and accuracy (FBP, WBR 77.6%).

CONCLUSION

Quantitative perfusion analysis suggests that adaptive noise control with WBR improves uniformity of myocardium comparing to FBP techniques, and results in improved diagnostic certainty while preserving normalcy and accuracy.

Mandatory diagnostic angiography for carotid artery stenosis prior to carotid artery intervention

INTRODUCTION

Revascularization is an important strategy for reducing stroke risk in patients with severe carotid atherosclerosis. Magnetic resonance angiography (MRA) and/or carotid ultrasound have traditionally been used as the only diagnostic modalities prior to revascularization. Patients undergoing CEA frequently have no further assessments of carotid anatomy prior to surgery. Evaluation with carotid ultrasound and MRA can often overestimate the degree of stenosis. We sought to determine if noninvasive imaging was sufficient for determining whether a patient should be referred for carotid intervention.

METHODS

We performed an analysis of 101 patients referred for carotid artery stenting (CAS). All patients had previously been evaluated with carotid ultrasound and 94% had undergone MRA as well. We sought to determine if noninvasive diagnostic imaging for carotid stenosis was sufficient to determine the necessity for endovascular intervention.

RESULTS

Of the 101 patients referred for carotid intervention, 36 (36%) were shown to have <70% stenoses and did not require intervention. Of those who had significant disease, 49 (75%) underwent successful CAS, 15 (23%) underwent CEA, and 1 patient was treated medically for a total occlusion. Three of the 36 patients not requiring carotid intervention were found to have subclavian stenosis. Two (4%) of the patients undergoing CAS and 4 (27%) of the patients undergoing CEA had minor complications. No patients suffered a major stroke, MI, or death at follow-up.

CONCLUSION

This analysis demonstrates that 36% of patients referred for endovascular intervention based on noninvasive imaging did not meet criteria by angiography. This emphasizes the need for carotid angiography prior to carotid intervention.

Leukocyte adhesion deficiency (LAD) II

The occurrence of recurrent bacterial infections, neutrophil motility dysfunction and normal expression of beta 2 integrins (CD18) in two unrelated children suggested an as yet undescribed adhesion deficiency. The fact that both children exhibited the rare Bombay blood group and were Lewis negative, each involving carbohydrates with different fucose linkages, suggested a possible defect in the fucose-containing ligand for E- and P-selectin, sialyl Lewis X (SLe(x)). Using a monoclonal anti-SLe(x) antibody, we did not detect expression of SLe(x) on the neutrophils of the patients. Adhesion of neutrophils to endothelial cells activated with interleukin-1 beta or histamine was markedly decreased ( < 5% of control). The observation that the neutrophils did not bind to recombinant E-selectin and purified P-selectin confirmed the SLe(x) deficiency as the basis for adhesion deficiency. Using several in vivo techniques, we were able to show that neutrophil rolling, the first step in their adhesion, is markedly decreased, and therefore neutrophil emigration through the endothelium and arrival at site of inflammation is significantly diminished (1-2% of normal). Low binding of fucose-specific lectins to the patients' B lymphocytes transformed with Epstein-Barr virus was observed, while the binding of mannose-specific lectins was normal, providing further evidence for a general fucose deficiency as the primary defect. The existence of the patients and their deficiency emphasizes the essential role of the endothelial cell selectins and their ligand, SLe(x), in recruitment of neutrophils to sites of infection.

Coronary Artery Dissection During Pregnancy Treated With Medical Therapy

Spontaneous coronary artery dissection is a rare etiology of myocardial infarction with a higher noted incidence in pregnancy. The recognition and proper treatment of this condition affects patient outcomes. We report the case of a coronary artery dissection during a twin pregnancy involving the left anterior descending artery. Successful treatment with medical management was possible once spontaneous reperfusion had been achieved.

Theoretical studies of mechanisms and kinetic isotope effects on the decarboxylation of orotic acid and derivatives

The mechanism of orotidine 5'-monophosphate decarboxylase was studied computationally by using the decarboxylation of orotic acid analogues as model systems. These calculations indicate that mechanisms involving proton transfer to the 2-oxygen or the 4-oxygen are energetically favorable, as compared to direct decarboxylation without proton transfer, for a series of model compounds where N1 is substituted with respectively H, CH(3), and a tetrahydrofuran moiety. Proton transfer to the 4-oxygen during decarboxylation is found to be energetically more favorable than 2-protonation, which is attributable to both the 4-oxygen site being more basic and an apparent intrinsic preference for the 4-protonation pathway. (15)N isotope effect calculations were also conducted, and compared to experimental (15)N isotope effects previously measured at N1 by Rishavy and Cleland (Biochemistry 2000, 39, 4569-4574). The theoretical isotope effects establish, for the first time, that the experimental (15)N isotope effect is consistent with decarboxylation without protonation, as well as with decarboxylation with protonation, at either O2 or at O4. Furthermore, we propose herein an isotope measurement that could potentially distinguish among mechanisms involving protonation from those that do not involve proton transfer.

Site-specific control of T cell traffic in the brain: T cell entry to brainstem vs. hippocampus after local injection of IFN-gamma

Although it is known that neurotransmitters and neuropeptides can affect immune function in vitro, less is understood about how the neural environment affects immune function in the brain. Previously, we showed that regulation of parenchymal class II MHC after local injection of IFN-gamma is site-specific. In this companion study, we defined the effect of local IFN-gamma on the entry of class II-restricted T cells to the brain parenchyma. To activate endogenous T cells, adult CDF rats were immunized with a normal neural antigen (MBP). Two weeks later, the proinflammatory cytokine IFN-gamma (100 to 10,000 U/site) was injected stereotaxically into two neurochemically and anatomically distinct sites, the hippocampus (area CAI) and brainstem (nucleus of the solitary tract). Monoclonal R73 was used to detect T cells on cryostat sections. The greatest difference was seen 48 h after 300 U IFN-gamma was injected at each site, when there were several-fold more parenchymal T cells in the brainstem than in the hippocampus. Most parenchymal T cells were CD4+ /class II-restricted. Thus, parenchymal T cell entry and parenchymal class II up-regulation show the same hierarchy (brainstem >> hippocampus) after local IFN-gamma injection, although T cell entry was more sensitive to the IFN-gamma dose. We suggest that the local regulatory environment contributes to site-specific immune regulation, and discuss implications for the distribution of MS plaques and other aspects of local immune control. Further, in interpreting the many previous studies of cytokine-mediated immune changes in the CNS, the possibility of site-specific differences should be considered.

Site-specific immune regulation in the brain: differential modulation of major histocompatibility complex (MHC) proteins in brainstem vs. hippocampus

Although neurotransmitters and neuropeptides are known to affect immune function in vitro and in non-neural tissues, little is known about how the local mix of neurochemicals affects immune function in the brain. Here, we study local modulation of the class II major histocompatibility complex (MHC) proteins, which present antigen to T cells in a key pathway for cell-mediated immune activity. Two sites that are well-separated anatomically and have very different neuroregulatory environments, the brainstem and hippocampus, were compared. The class II-upregulating cytokine, gamma interferon (IFN-gamma, 0.1 to 10,000 U/site), was injected stereotaxically into the hippocampus and contralateral brainstem of adult Charles-derived Fischer rats. Four days later, monoclonal antibody staining was used to detect class II MHC proteins on cryostat sections, followed by computer-assisted image analysis. As compared to hippocampus, the brainstem showed enhanced class II expression at lower IFN-gamma doses, and reached a higher plateau. Site-specific class II modulation was also seen within the layers of the hippocampus, and among other brain sites. Injection of marker protein to visualize the spread of injected protein, plus injection of IFN-gamma into alternative sites, suggested that preferential flow cannot explain all of the site-specific effects. We suggest that the local neuroregulatory environment and/or intrinsic differences among target microglia are likely to play a role. Implications for the distribution of pathological changes, such as multiple sclerosis plaques, and for local immunotherapy are discussed.

Impact of anti-vaccine movements on pertussis control: the untold story

To assess the impact of anti-vaccine movements that targeted pertussis whole-cell vaccines, we compared pertussis incidence in countries where high coverage with diphtheria-tetanus-pertussis vaccines (DTP) was maintained (Hungary, the former East Germany, Poland, and the USA) with countries where immunisation was disrupted by anti-vaccine movements (Sweden, Japan, UK, The Russian Federation, Ireland, Italy, the former West Germany, and Australia). Pertussis incidence was 10 to 100 times lower in countries where high vaccine coverage was maintained than in countries where immunisation programs were compromised by anti-vaccine movements. Comparisons of neighbouring countries with high and low vaccine coverage further underscore the efficacy of these vaccines. Given the safety and cost-effectiveness of whole-cell pertussis vaccines, our study shows that, far from being obsolete, these vaccines continue to have an important role in global immunisation.

Sialyl Lewis(x) analog improves liver function by decreasing neutrophil migration after hemorrhagic shock

BACKGROUND

Little is known about the changes in the hepatic microcirculation and the leukocyte-endothelial adhesion processes during the early reperfusion period after resuscitation in hemorrhagic shock. P-selectin and its natural ligand Sialyl Lewis(x) (SLe(x)) are involved in the early stages of reperfusion events leading to neutrophil migration. Therefore, the aim of this study was to investigate the effect of the administration of CY-1503 [corrected], a synthetic SLe(x) analog, in the liver inflammatory response and neutrophil migration after hemorrhagic shock.

MATERIALS AND METHODS

Rats, each weighing 275 to 300 grams, were subjected to 60 minutes of pressure controlled hemorrhagic shock. After this period, animals were resuscitated according to the following protocol: shed blood was reinfused to equal 50% of the total volume bled, and the other 50% was replaced with 3x volume of Ringer's lactated solution. Animals were divided into sham and two study groups to receive vehicle (controls) and CY-1503 [corrected] (10 mg/kg intravenously) diluted in 1 mL of normal saline 45 minutes after initiating hemorrhagic shock. The following parameters were analyzed: 7-day survival, liver injury tests, liver tissue myeloperoxidase as an index of neutrophil infiltration, and liver histology.

RESULTS

Survival was significantly increased from 48% in the controls to 90% in the CY-1503 [corrected] treated group. Animals treated with the SLe(x) analog showed significantly better mean arterial blood pressure after 15 minutes after resuscitation. Also, the treated group showed a marked decrease in liver enzymes levels at 5 minutes and 4 hours after reperfusion. Neutrophil migration was significantly ameliorated as reflected by decreased myeloperoxidase levels in the SLe(x) analog treated group. Furthermore, we observed improved histologic damage scores in the treated group when compared with controls.

CONCLUSIONS

The SLe(x) analog, CY-1503 [corrected], had a protective effect in ischemic livers by decreasing neutrophil migration after hemorrhagic shock and resuscitation. This protective effect also resulted in improved survival and mean arterial blood pressure after resuscitation.

Micropropagation of flowering dogwood (Cornus florida) from seedlings

A method for regenerating whole plants from nodal (axillary bud) cultures of seedlings was developed for flowering dogwood (Cornus florida L.). The seed source significantly influenced the rate of proliferation, although cultures initiated from each of the seven mother trees produced some shoots. Woody plant medium (WPM) was superior to either Murashige and Skoog or Schenk and Hildebrandt basal medium. 6-Benzyladenine (BA) at 2.2 or 4.4 μM stimulated the generation of significantly more useable shoots (≥1 cm) compared to all other concentrations (0.5-22.5 μM tested. Thidiazuron (TDZ) at 0.6 and 1.1 μM supported proliferation, but strongly inhibited shoot elongation. TDZ initiated cultures transferred to medium containing 4.4 μM BA produced usable shoots after five additional subcultures. Shoots generated adventitious roots when exposed to either a 12-h pulse of relatively high concentrations (246-1230 μM or continuous lower concentrations (0.5-49.0 μM of indolebutyric acid (IBA) for longer periods. Microshoots produced the significantly greatest number of roots when subjected to 4.9 μM IBA in WPM over a 4-week period. Whole plants were acclimatized to the laboratory conditions and subsequently to the greenhouse. The methodology described here should be useful in a breeding program by supplying multiple copies of unique, recombinant genotypes.

The development and evaluation of the role of an advanced nurse practitioner in dementia--an action research project

This action research project developed a new role of Advanced Nurse Practitioner (ANP) in dementia from first principles in response to the needs and requirements of the healthcare professionals already working in the service. In Phase 1 of the project, 42 workers were interviewed to determine their needs, hopes and fears of the role, from which a preliminary job description was constructed. In Phase 2, this role was implemented and continuously modified through regular reflective interviews with the ANP, resulting in some major changes to the original job description. In the final phase, the impact of the role was evaluated through interviews with patients who had used the new service, and questionnaires to the healthcare workers interviewed in Phase 1. The role that emerged from the project was therefore grounded in practice and proved to be an attractive proposition to the local healthcare trust.

Novel regulation of peripheral gustatory function by the immune system

Soon after adult rats receive unilateral chorda tympani nerve section in combination with dietary sodium restriction, neural taste responses recorded from the intact, contralateral chorda tympani nerve are substantially reduced. We hypothesized that the immune system is compromised in sodium-restricted rats, which leads to functional alterations in the peripheral taste system after neural injury. Here, immune function was stimulated with a systemic injection of lipopolysaccharide (LPS), and neurophysiological responses were recorded from the uncut chorda tympani 4-10 days after nerve section to determine if normal sodium sensitivity was restored. Rats receiving nerve section, dietary sodium restriction, and LPS exhibited normal sodium responses. In intact rats, injection of LPS alone or LPS injection combined with sodium restriction had no effect on taste responses to sodium stimuli. Surprisingly, combining nerve section, LPS injection, and maintenance of rats on a normal diet induced supersensitive responses to sodium. These findings are the first to demonstrate that the immune system can regulate peripheral gustatory function.

Cardioprotection by liposome-conjugated sialyl Lewisx-oligosaccharide in myocardial ischaemia and reperfusion injury

OBJECTIVES

Selectins are important adhesion molecules which utilize a carbohydrate ligand such as sialyl Lewisx (SLex). Our objective was to study the effects of a liposome-conjugated SLex (Lipo-SLex) in myocardial ischaemia (MI) and reperfusion (R) injury in order to further clarify the actions of this carbohydrate.

METHODS

We studied the efficacy of Lipo-SLex in a feline model of MI (90 min) and R (270 min) injury in vivo. Lipo-SLex (400 micrograms SLex/kg, iv) was administered intravenously 10 min prior to R. We also utilized an in vitro system of neutrophil adherence to thrombin-stimulated coronary endothelium to validate the efficacy of Lipo-SLex.

RESULTS

Lipo-SLex significantly attenuated myocardial necrosis (8.6 +/- 1.2 vs. 29.5 +/- 3.1% of area-at-risk, P < 0.01) and plasma creatine kinase activities (P < 0.01) compared to vehicle (liposome alone). Moreover, endothelium-dependent relaxation to acetylcholine and A23187 in ischaemic-reperfused coronary rings obtained from cats treated with Lipo-SLex was significantly preserved compared to cats given liposomes without SLex (P < 0.01). After reperfusion, ex vivo PMN adherence to ischaemic-reperfused coronary endothelium was significantly increased in vehicle-treated cats, however, this was significantly attenuated in Lipo-SLex-treated cats (82 +/- 7 vs. 28 +/- 3 PMNs/mm2, P < 0.01). Myeloperoxidase activity in the ischaemic myocardium, a marker of PMN accumulation, was also significantly attenuated in Lipo-SLex-treated cats compared to liposomes without SLex (P < 0.01).

CONCLUSIONS

Liposome-conjugated SLex-oligosaccharide attenuates myocardial necrosis and preserves coronary endothelial function following MI/R in vivo. The mechanism appears to be mediated by inhibition of the initial PMN-endothelial interaction and eventual accumulation into the ischaemic cardiac tissue. The liposome-SLex complex may be an efficient drug formulation for acute inflammatory diseases.

An action research project to develop and evaluate the role of an advanced nurse practitioner in dementia

This paper outlines the first phase of a project to generate and evaluate the role of an advanced nurse practitioner inductively from first principles. The role was developed by interviewing a wide range of health-care professionals, careers and patients. The resulting role is responsive to perceived need at grassroots level rather than to the needs of managers with no clinical experience. Although the role might not be generalizable to other settings, the method can be applied to any role in any clinical area.