Cessation of Smoking Trial in the Emergency Department (COSTED): a multicentre randomised controlled trial

BACKGROUND

Supporting people to quit smoking is one of the most powerful interventions to improve health. The Emergency Department (ED) represents a potentially valuable opportunity to deliver a smoking cessation intervention if it is sufficiently resourced. The objective of this trial was to determine whether an opportunistic ED-based smoking cessation intervention can help people to quit smoking.

METHODS

In this multicentre, parallel-group, randomised controlled superiority trial conducted between January and August 2022, adults who smoked daily and attended one of six UK EDs were randomised to intervention (brief advice, e-cigarette starter kit and referral to stop smoking services) or control (written information on stop smoking services). The primary outcome was biochemically validated abstinence at 6 months.

RESULTS

An intention-to-treat analysis included 972 of 1443 people screened for inclusion (484 in the intervention group, 488 in the control group). Of 975 participants randomised, 3 were subsequently excluded, 17 withdrew and 287 were lost to follow-up. The 6-month biochemically-verified abstinence rate was 7.2% in the intervention group and 4.1% in the control group (relative risk 1.76; 95% CI 1.03 to 3.01; p=0.038). Self-reported 7-day abstinence at 6 months was 23.3% in the intervention group and 12.9% in the control group (relative risk 1.80; 95% CI 1.36 to 2.38; p<0.001). No serious adverse events related to taking part in the trial were reported.

CONCLUSIONS

An opportunistic smoking cessation intervention comprising brief advice, an e-cigarette starter kit and referral to stop smoking services is effective for sustained smoking abstinence with few reported adverse events.

TRIAL REGISTRATION NUMBER

NCT04854616.

Guided graded exercise self-help for chronic fatigue syndrome: Long term follow up and cost-effectiveness following the GETSET trial

OBJECTIVE

The GETSET trial found that guided graded exercise self-help (GES) improved fatigue and physical functioning more than specialist medical care (SMC) alone in adults with chronic fatigue syndrome (CFS) 12 weeks after randomisation. In this paper, we assess the longer-term clinical and health economic outcomes.

METHODS

GETSET was a randomised controlled trial of 211 UK secondary care patients with CFS. Primary outcomes were the Chalder fatigue questionnaire and the physical functioning subscale of the short-form-36 survey. Postal questionnaires assessed the primary outcomes and cost-effectiveness of the intervention 12 months after randomisation. Service costs and quality-adjusted life years (QALYs) were combined in a cost-effectiveness analysis.

RESULTS

Between January 2014 and March 2016, 164 (78%) participants returned questionnaires 15 months after randomisation. Results showed no main effect of intervention arm on fatigue (chi²(1) = 4.8, p = 0.03) or physical functioning (chi²(1) = 1.3, p = 0.25), adjusting for multiplicity. No other intervention arm or time*arm effect was significant. The short-term fatigue reduction was maintained at long-term follow-up for participants assigned to GES, with improved fatigue from short- to long-term follow up after SMC, such that the groups no longer differed. Healthcare costs were £85 higher for GES and produced more QALYs. The incremental cost-effectiveness ratio was £4802 per QALY.

CONCLUSIONS

The short-term improvements after GES were maintained at long-term follow-up, with further improvement in the SMC group such that the groups no longer differed at long-term follow-up. The cost per QALY for GES compared to SMC alone was below the usual threshold indicating cost-effectiveness, but with uncertainty around the result.

Mental health, well-being and support interventions for UK ambulance services staff: an evidence map, 2000 to 2020

Background:

Prior to COVID-19 there had been a renewed policy focus in the National Health Service on the health and well-being of the healthcare workforce, with the ambulance sector identified as a priority area. This focus is more important than ever as the sector deals with the acute and longer-term consequences of a pandemic.

Aim:

To systematically identify, summarise and map the evidence regarding mental health, well-being and support interventions for United Kingdom ambulance services staff and to identify evidence gaps.

Method:

Evidence mapping methodology of published and grey original research published in English from 1 January 2000 to 23 May 2020 describing the health risk, mental health and/or well-being of UK ambulance services staff including retired staff, volunteers and students. MEDLINE, EMBASE, PsychINFO, CINAHL and AMED databases, plus EThOS, Zetoc, OpenGrey and Google, were searched, alongside hand-searching of grey literature and bibliographies. Information was extracted on study aims, sample, design and methodology, funding source, country and key findings. Included studies were categorised into seven a priori theme areas.

Results:

Of 1862 identified articles, 45 peer-reviewed studies are included as well as 24 grey literature documents. Peer-reviewed research was largely observational and focused on prevalence studies, post-traumatic stress disorder or organisational and individual social factors related to health and well-being. Most grey literature reported the development and testing of interventions. Across all study types, underpinning theory was often not cited.

Conclusion:

To date, intervention research has largely been funded by charities and published in the grey literature. Few studies were identified on self-harm, bullying, sleep and fatigue or alcohol and substance use. Theoretically informed intervention development and testing, including adaptation of innovations from other countries and 24-hour workforces, is needed. This evidence map provides important context for planning of staff well-being provision and research as the sector responds to and recovers from the pandemic.

PROSPERO registration number:

CRD42018104659.

Sick of the Sick Role: Narratives of What "Recovery" Means to People With CFS/ME

Little is known about what recovery means to those with chronic fatigue syndrome/myalgic encephalomyelitis, a poorly understood, disabling chronic health condition. To explore this issue, semi-structured interviews were conducted with patients reporting improvement (n = 9) and deterioration (n = 10) after a guided self-help intervention, and analyzed via "constant comparison." The meaning of recovery differed between participants-expectations for improvement and deployment of the sick role (and associated stigma) were key influences. While some saw recovery as complete freedom from symptoms, many defined it as freedom from the "sick role," with functionality prioritized. Others redefined recovery, reluctant to return to the lifestyle that may have contributed to their illness, or rejected the concept as unhelpful. Recovery is not always about eliminating all symptoms. Rather, it is a nexus between the reality of limited opportunities for full recovery, yet a strong desire to leave the illness behind and regain a sense of "normality."

Cytokine responses to exercise and activity in patients with chronic fatigue syndrome: case-control study

Chronic fatigue syndrome (CFS) is characterized by fatigue after exertion. A systematic review suggested that transforming growth factor (TGF)-β concentrations are often elevated in cases of CFS when compared to healthy controls. This study attempted to replicate this finding and investigate whether post-exertional symptoms were associated with altered cytokine protein concentrations and their RNA in CFS patients. Twenty-four patients fulfilling Centers for Disease Control criteria for CFS, but with no comorbid psychiatric disorders, were recruited from two CFS clinics in London, UK. Twenty-one healthy, sedentary controls were matched by gender, age and other variables. Circulating proteins and RNA were measured for TGF-β, tumour necrosis factor (TNF), interleukin (IL)-8, IL-6 and IL-1β. We measured six further cytokine protein concentrations (IL-2, IL-4, IL-5, IL-10, IL-12p70, and interferon (IFN)-γ). Measures were taken at rest, and before and after both commuting and aerobic exercise. CFS cases had higher TGF-β protein levels compared to controls at rest (median (quartiles) = 43·9 (19·2, 61·8) versus 18·9 (16·1, 30·0) ng/ml) (P = 0·003), and consistently so over a 9-day period. However, this was a spurious finding due to variation between different assay batches. There were no differences between groups in changes to TGF-β protein concentrations after either commuting or exercise. All other cytokine protein and RNA levels were similar between cases and controls. Post-exertional symptoms and perceived effort were not associated with any increased cytokines. We were unable to replicate previously found elevations in circulating cytokine concentrations, suggesting that elevated circulating cytokines are not important in the pathophysiology of CFS.

Guided graded exercise self-help plus specialist medical care versus specialist medical care alone for chronic fatigue syndrome (GETSET): a pragmatic randomised controlled trial

BACKGROUND

Graded exercise therapy is an effective and safe treatment for chronic fatigue syndrome, but it is therapist intensive and availability is limited. We aimed to test the efficacy and safety of graded exercise delivered as guided self-help.

METHODS

In this pragmatic randomised controlled trial, we recruited adult patients (18 years and older) who met the UK National Institute for Health and Care Excellence criteria for chronic fatigue syndrome from two secondary-care clinics in the UK. Patients were randomly assigned to receive specialist medical care (SMC) alone (control group) or SMC with additional guided graded exercise self-help (GES). Block randomisation (randomly varying block sizes) was done at the level of the individual with a computer-generated sequence and was stratified by centre, depression score, and severity of physical disability. Patients and physiotherapists were necessarily unmasked from intervention assignment; the statistician was masked from intervention assignment. SMC was delivered by specialist doctors but was not standardised; GES consisted of a self-help booklet describing a six-step graded exercise programme that would take roughly 12 weeks to complete, and up to four guidance sessions with a physiotherapist over 8 weeks (maximum 90 min in total). Primary outcomes were fatigue (measured by the Chalder Fatigue Questionnaire) and physical function (assessed by the Short Form-36 physical function subscale); both were self-rated by patients at 12 weeks after randomisation and analysed in all randomised patients with outcome data at follow-up (ie, by modified intention to treat). We recorded adverse events, including serious adverse reactions to trial interventions. We used multiple linear regression analysis to compare SMC with GES, adjusting for baseline and stratification factors. This trial is registered at ISRCTN, number ISRCTN22975026.

FINDINGS

Between May 15, 2012, and Dec 24, 2014, we recruited 211 eligible patients, of whom 107 were assigned to the GES group and 104 to the control group. At 12 weeks, compared with the control group, mean fatigue score was 19·1 (SD 7·6) in the GES group and 22·9 (6·9) in the control group (adjusted difference -4·2 points, 95% CI -6·1 to -2·3, p<0·0001; effect size 0·53) and mean physical function score was 55·7 (23·3) in the GES group and 50·8 (25·3) in the control group (adjusted difference 6·3 points, 1·8 to 10·8, p=0·006; 0·20). No serious adverse reactions were recorded and other safety measures did not differ between the groups, after allowing for missing data.

INTERPRETATION

GES is a safe intervention that might reduce fatigue and, to a lesser extent, physical disability for patients with chronic fatigue syndrome. These findings need confirmation and extension to other health-care settings.

FUNDING

UK National Institute for Health Research Research for Patient Benefit Programme and the Sue Estermann Fund.

Response to the editorial by Dr Geraghty

This article is written in response to the linked editorial by Dr Geraghty about the adaptive Pacing, graded Activity and Cognitive behaviour therapy; a randomised Evaluation (PACE) trial, which we led, implemented and published. The PACE trial compared four treatments for people diagnosed with chronic fatigue syndrome. All participants in the trial received specialist medical care. The trial found that adding cognitive behaviour therapy or graded exercise therapy to specialist medical care was as safe as, and more effective than, adding adaptive pacing therapy or specialist medical care alone. Dr Geraghty has challenged these findings. In this article, we suggest that Dr Geraghty’s views are based on misunderstandings and misrepresentations of the PACE trial; these are corrected.

Graded Exercise Therapy Guided Self-Help Trial for Patients with Chronic Fatigue Syndrome (GETSET): Protocol for a Randomized Controlled Trial and Interview Study

Background

Chronic fatigue syndrome, also known as myalgic encephalomyelitis (CFS/ME), is characterized by chronic disabling fatigue and other symptoms, which are not explained by an alternative diagnosis. Previous trials have suggested that graded exercise therapy (GET) is an effective and safe treatment. GET itself is therapist-intensive with limited availability.

Objective

While guided self-help based on cognitive behavior therapy appears helpful to patients, Guided graded Exercise Self-help (GES) is yet to be tested.

Methods

This pragmatic randomized controlled trial is set within 2 specialist CFS/ME services in the South of England. Adults attending secondary care clinics with National Institute for Health and Clinical Excellence (NICE)-defined CFS/ME (N=218) will be randomly allocated to specialist medical care (SMC) or SMC plus GES while on a waiting list for therapist-delivered rehabilitation. GES will consist of a structured booklet describing a 6-step graded exercise program, supported by up to 4 face-to-face/telephone/Skype™ consultations with a GES-trained physiotherapist (no more than 90 minutes in total) over 8 weeks. The primary outcomes at 12-weeks after randomization will be physical function (SF-36 physical functioning subscale) and fatigue (Chalder Fatigue Questionnaire). Secondary outcomes will include healthcare costs, adverse outcomes, and self-rated global impression change scores. We will follow up all participants until 1 year after randomization. We will also undertake qualitative interviews of a sample of participants who received GES, looking at perceptions and experiences of those who improved and worsened.

Results

The project was funded in 2011 and enrolment was completed in December 2014, with follow-up completed in March 2016. Data analysis is currently underway and the first results are expected to be submitted soon.

Conclusions

This study will indicate whether adding GES to SMC will benefit patients who often spend many months waiting for rehabilitative therapy with little or no improvement being made during that time. The study will indicate whether this type of guided self-management is cost-effective and safe. If this trial shows GES to be acceptable, safe, and comparatively effective, the GES booklet could be made available on the Internet as a practitioner and therapist resource for clinics to recommend, with the caveat that patients also be supported with guidance from a trained physiotherapist. The pragmatic approach in this trial means that GES findings will be generalizable to usual National Health Service (NHS) practice.

Trial Registration

International Standard Randomized Controlled Trial Number (ISRTCTN): 22975026; http://www.isrctn.com/ISRCTN22975026 (Archived by WebCite at http://www.webcitation.org/6gBK00CUX)

Spontaneous hybrids between native and exotic Rubus in the Western United States produce offspring both by apomixis and by sexual recombination

Facultative asexual reproduction is a trait commonly found in invasive species. With a combination of sexual and asexual reproductive modes, such species may adapt to new environments via sexual recombination during range expansion, while at the same time having the benefits of asexuality such as the maintenance of fitness effects that depend upon heterozygosity. In the Western United States, native species of Rubus (Rosaceae) reproduce sexually whereas exotic naturalized Rubus species reproduce by pseudogamous apomixis. We hypothesized that new asexual lineages of Rubus could arise from hybridization in this range. To detect hybridization between native and exotic Rubus, we genotyped 579 individuals collected across California, Oregon and Washington with eight nuclear microsatellites and two chloroplast markers. Principal Coordinate Analysis and Bayesian clustering revealed a limited amount of hybridization of the native R. ursinus with the exotic R. armeniacus and R. pensilvanicus, as well as cultivated varieties. Genetic distances between these hybrids and their offspring indicated that both R. ursinus × R. armeniacus and R. ursinus × R. pensilvanicus produced a mix of apomictic and sexual seeds, with sexual seeds being more viable. Although neither of these hybrid types is currently considered invasive, they model the early stages of evolution of new invasive lineages, given the potential for fixed heterosis and the generation of novel genotypes. The hybrids also retain the ability to increase their fitness via sexual recombination and natural selection. Mixed reproductive systems such as those described here may be an important step in the evolution of asexual invasive species.

Service use and costs for people with headache: a UK primary care study

This paper aims to estimate the service and social costs of headache presenting in primary care and to identify predictors of headache costs. Patients were recruited from GP practices in England and service use and lost employment recorded. Predictors of cost were identified using regression models. Service and social costs were available on 288 and 282 patients, respectively. Average service costs over 3 months were £117 whilst total costs (including lost production) were £582. Patients referred to neurologists had service costs that were £82 higher than those not referred (90% CI £36–£128). Costs including lost employment were higher by £150, but this was not significant (90% CI -£139–£439). The annual mean service and social costs, weighted to represent population rates of referral, were £468 and £2328, respectively. Higher costs were significantly related to pain. Age was linked to higher service costs and lower social costs. The figures extrapolated to the whole of the UK suggest £956 million due to service use and £4.8 billion including lost employment. These are likely to be underestimates because many people experiencing headaches do not consult their GP.

Predictors of outcome in patients consulting their general practitioners for headache: a prospective study

Headache is the most common neurological symptom presenting to general practitioners (GPs). Identifying factors predicting outcome in patients consulting their GPs for headache may help GPs with prognosis and choose management strategies which would improve patient care. We followed up a cohort of patients receiving standard medical care, recruited from 18 general practices in the South Thames region of England, approximately 9 months after their initial participation in the study. Of the baseline sample (N=255), 134 provided both full baseline and follow-up data on measures of interest. We determined associations between patients' follow-up scores on the Headache Impact Test-6 and baseline characteristics (including headache impact and frequency scores, mood, attributions about psychological/medical causes of their headaches, satisfaction with GP care and illness perceptions). Greater impact and stronger beliefs about the negative consequences of headaches at baseline were the strongest predictors of poor outcome at follow-up.

Comparison of adaptive pacing therapy, cognitive behaviour therapy, graded exercise therapy, and specialist medical care for chronic fatigue syndrome (PACE): a randomised trial

BACKGROUND

Trial findings show cognitive behaviour therapy (CBT) and graded exercise therapy (GET) can be effective treatments for chronic fatigue syndrome, but patients' organisations have reported that these treatments can be harmful and favour pacing and specialist health care. We aimed to assess effectiveness and safety of all four treatments.

METHODS

In our parallel-group randomised trial, patients meeting Oxford criteria for chronic fatigue syndrome were recruited from six secondary-care clinics in the UK and randomly allocated by computer-generated sequence to receive specialist medical care (SMC) alone or with adaptive pacing therapy (APT), CBT, or GET. Primary outcomes were fatigue (measured by Chalder fatigue questionnaire score) and physical function (measured by short form-36 subscale score) up to 52 weeks after randomisation, and safety was assessed primarily by recording all serious adverse events, including serious adverse reactions to trial treatments. Primary outcomes were rated by participants, who were necessarily unmasked to treatment assignment; the statistician was masked to treatment assignment for the analysis of primary outcomes. We used longitudinal regression models to compare SMC alone with other treatments, APT with CBT, and APT with GET. The final analysis included all participants for whom we had data for primary outcomes. This trial is registered at http://isrctn.org, number ISRCTN54285094.

FINDINGS

We recruited 641 eligible patients, of whom 160 were assigned to the APT group, 161 to the CBT group, 160 to the GET group, and 160 to the SMC-alone group. Compared with SMC alone, mean fatigue scores at 52 weeks were 3·4 (95% CI 1·8 to 5·0) points lower for CBT (p = 0·0001) and 3·2 (1·7 to 4·8) points lower for GET (p = 0·0003), but did not differ for APT (0·7 [-0·9 to 2·3] points lower; p = 0·38). Compared with SMC alone, mean physical function scores were 7·1 (2·0 to 12·1) points higher for CBT (p = 0·0068) and 9·4 (4·4 to 14·4) points higher for GET (p = 0·0005), but did not differ for APT (3·4 [-1·6 to 8·4] points lower; p=0·18). Compared with APT, CBT and GET were associated with less fatigue (CBT p = 0·0027; GET p = 0·0059) and better physical function (CBT p=0·0002; GET p<0·0001). Subgroup analysis of 427 participants meeting international criteria for chronic fatigue syndrome and 329 participants meeting London criteria for myalgic encephalomyelitis yielded equivalent results. Serious adverse reactions were recorded in two (1%) of 159 participants in the APT group, three (2%) of 161 in the CBT group, two (1%) of 160 in the GET group, and two (1%) of 160 in the SMC-alone group.

INTERPRETATION

CBT and GET can safely be added to SMC to moderately improve outcomes for chronic fatigue syndrome, but APT is not an effective addition.

FUNDING

UK Medical Research Council, Department of Health for England, Scottish Chief Scientist Office, Department for Work and Pensions.

How do patients referred to neurologists for headache differ from those managed in primary care?

BACKGROUND

Headache is the neurological symptom most frequently presented to GPs and referred to neurologists, but little is known about how referred patients differ from patients managed by GPs.

AIM

To describe and compare headache patients managed in primary care with those referred to neurologists.

DESIGN OF STUDY

Prospective study.

SETTING

Eighteen general practices in south-east England.

METHOD

This study examined 488 eligible patients consulting GPs with primary headache over 7 weeks and 81 patients referred to neurologists over 1 year. Headache disability was measured by the Migraine Disability Assessment Score, headache impact by the Headache Impact Test, emotional distress by the Hospital Anxiety and Depression Scale and illness perception was assessed using the Illness Perception Questionnaire.

RESULTS

Participants were 303 patients who agreed to participate. Both groups reported severe disability and very severe impact on functioning. Referred patients consulted more frequently than those not referred in the 3 months before referral (P = 0.003). There was no significant difference between GP-managed and referred groups in mean headache disability, impact, anxiety, depression, or satisfaction with care. The referred group were more likely to link an increased number of symptoms to their headaches (P = 0.01), to have stronger emotional representations of their headaches (P = 0.006), to worry more (P = 0.001), and were made anxious by their headache symptoms (P = 0.044).

CONCLUSION

Patients who consult for headache experience severe disability and impact, and up to a third report anxiety and/or depression. Referral is not related to clinical severity of headaches, but is associated with higher consultation frequency and patients' anxiety and concern about their headache symptoms.

Headache: a 'suitable case' for behavioural treatment in primary care?

Headache is a health problem with considerable impact at personal, social, and financial levels in terms of distress, disability, and cost. In the past, many studies have investigated the use of various behavioural treatment modalities for headache. Literature reviews consistently support the effectiveness of behavioural therapeutic approaches for the treatment of the most common primary headaches, namely migraine and tension-type headache. This article recommends that behavioural headache therapies should be developed, tested, and integrated into primary care practice, where most patients with headache are seen and treated. The large population seen in general practice, most of whom have uncomplicated primary headaches, could represent the ideal target for testing behavioural therapies.

Application of in vivo and ex vivo magnetic resonance imaging for evaluation of tranilast on neointima formation following balloon angioplasty of the rat carotid artery

OBJECTIVE

Recent studies suggest that tranilast inhibits a variety of agents implicated in neointimal growth and restenosis in experimental animal models and humans. We report here a study evaluating the efficacy of tranilast in the rat carotid artery balloon angioplasty model, a model that mimics many aspects of the percutaneous transluminal angioplasty procedure in humans. Efficacy was determined based on in vivo and ex vivo magnetic resonance imaging (MRI) as well as by histomorphometry. The utility of this study, using a reverse paradigm, is to investigate if agents successful in the clinic can demonstrate efficacy in this animal model primary screen as measured by MRI and histomorphometry.

METHODS

Tranilast (300 mg/kg/day, p.o.) was administered to Sprague-Dawley rats 3 days prior to balloon injury and continued for 14 days after injury. Three methods of measuring the vascular injury that occurs in this model were employed: (1) in vivo MRI, used to measure in vivo lumen volumes for the carotid artery once at baseline (pre-surgery) and again at 14 days post angioplasty; (2) ex vivo MRI (and histomorphometry), used to evaluate the total arterial wall thickness and the intima-to-media ratio; and (3) analysis of collagen density, used to evaluate the efficacy of tranilast to abrogate collagen synthesis and deposition following vascular injury.

RESULTS

Tranilast provided 33% protection (P<0.05) from angioplasty-induced lumen narrowing as measured by MRI in vivo. The results of the ex vivo MR analysis of total wall thickness showed a 14% protection of angioplasty-induced narrowing (P<0.05), and the mean intima-to-media ratio showed a 39% (P<0.006) protection for the tranilast-treated rats. Histological analysis of the mean intima-to-media ratio demonstrated that tranilast provided 36% (P<0. 01) protection in the intima-to-media ratio. Further, treatment with tranilast showed a 52% reduction in collagen density of the intimal layer and a 70% reduction in collagen density of the medial layer of the injured arteries.

CONCLUSION

The data obtained by in vivo MRI, ex vivo MRI, histology and collagen analysis demonstrate that tranilast provided significant beneficial effects in inhibiting neointimal formation in the rat carotid artery model. Also this study, to the best of our knowledge, is the first to harness complimentary information from various technologies, including lumen patency by in vivo MRI, neointimal formation by ex vivo MRI and conventional histomorphometry, and histological analysis for collagen density, to provide a comprehensive understanding of the pathology in this disease model.

Application of serial in vivo magnetic resonance imaging to evaluate the efficacy of endothelin receptor antagonist SB 217242 in the rat carotid artery model of neointima formation

BACKGROUND

Alleviating vascular restenosis after percutaneous transluminal angioplasty remains a formidable challenge. Although multiple factors have been implicated in the pathophysiology of this vascular remodeling disorder, only limited therapeutic success has been achieved. Endothelin (ET)-1 has recently been implicated in the pathogenesis of neointimal growth. We report the in vivo efficacy of SB 217242, a nonpeptide dual ET(A)/ET(B) receptor antagonist with high oral bioavailability, in the rat carotid artery balloon angioplasty model.

METHODS AND RESULTS

The lumen volumes of carotid arteries were estimated serially with magnetic resonance imaging (MRI) at baseline and at day 7 and day 14 after balloon catheter-induced denudation of the carotid arterial wall in the rat. Histomorphometric analysis was performed at day 14 after surgery to quantitate intimal hyperplasia. Statistical analysis was performed with ANOVA followed by post hoc Newman-Keuls multiple comparison test. In comparison to vehicle-treated animals, a 20% protection (P<0.05) from reduction was shown in the estimated lumen volume with long-term administration of SB 217242 (15 mg/kg BID p.o.). Histologic analyses indicated a 42% decrease (P<0.05) in neointimal growth. The MRI lumen volumes had a significant correlation with the corresponding histologic indices.

CONCLUSIONS

Serial MRI provides the opportunity to assess the progression of vascular lumen volume in vivo after balloon angioplasty. MRI measurements can, in conjunction with in vitro histologic measurements, contribute to the understanding of the actions of pharmacologic agents in experimental models of neointima formation. With the use of serial MRI and histologic measurements, it is demonstrated that protection from both lumen volume reduction and neointima formation is obtained in this model by use of a potent, nonpeptide dual ET(A)/ET(B) receptor antagonist, SB 217242. Furthermore, this study provides additional support to the implication of ET-1 in the pathophysiology of neointima formation.