Cost of an emerging epidemic: an economic analysis of atrial fibrillation in the UK

OBJECTIVE

To evaluate the cost of atrial fibrillation (AF) to health and social services in the UK in 1995 and, based on epidemiological trends, to project this estimate to 2000. DESIGN, SETTING, AND MAIN OUTCOME MEASURES: Contemporary estimates of health care activity related to AF were applied to the whole population of the UK on an age and sex specific basis for the year 1995. The activities considered (and costs calculated) were hospital admissions, outpatient consultations, general practice consultations, and drug treatment (including the cost of monitoring anticoagulant treatment). By adjusting for the progressive aging of the British population and related increases in hospital admissions, the cost of AF was also projected to the year 2000.

RESULTS

There were 534 000 people with AF in the UK during 1995. The "direct" cost of health care for these patients was 244 million pounds sterling (approximately 350 million euros) or 0.62% of total National Health Service (NHS) expenditure. Hospitalisations and drug prescriptions accounted for 50% and 20% of this expenditure, respectively. Long term nursing home care after hospital admission cost an additional 46.4 million pounds sterling (approximately 66 million euros). The direct cost of AF rose to 459 million pounds sterling (approximately 655 million euros) in 2000, equivalent to 0.97% of total NHS expenditure based on 1995 figures. Nursing home costs rose to 111 million pounds sterling (approximately 160 million euros).

CONCLUSIONS

AF is an extremely costly public health problem.

Agricultural environmental management; case studies from theory to practice

Six farms were examined, each from a different sector of Scottish agriculture. Surveys were carried out to identify both diffuse pollution risks and options for habitat conservation and enhancement. Financial data were also gathered to determine the current sources of farm income, both from sale of produce and from grants. Whole farm plans were produced aimed at bringing about reductions in diffuse pollution to water, soil and air and also habitat improvements. The assembled information was used to devise a possible agri-environment grant scheme to aid the implementation of the whole farm plans.

The current cost of angina pectoris to the National Health Service in the UK

OBJECTIVE

To calculate the cost of angina pectoris to the UK National Health Service (NHS) in the year 2000.

METHODS

Calculation of the cost of hospital admissions, revascularisation procedures, hospital outpatient consultations, general practice (GP) consultations, and prescribed drug treatment.

RESULTS

634 000 individuals (1.1% of the UK population) consulted GPs 2.35 million times, costing pound 60.5 million. They required 16.0 million prescriptions (cost pound 80.7 million) and 254 000 hospital outpatient referrals (cost pound 30.4 million). There were 149 000 hospital admissions, 117 000 coronary angiograms, 21 400 coronary artery bypass operations, 17 700 percutaneous coronary interventions, and 516 000 outpatient visits, at a cost of pound 208.4 million, pound 69.9 million, pound 106.2 million, pound 60.7 million, and pound 52.2 million, respectively. The direct cost of angina was therefore pound 669 million (1.3% of total NHS expenditure), with hospital bed occupancy and procedures accounting for 32% and 35% of this total, respectively.

CONCLUSIONS

Angina is a common and costly public health problem. It consumed over 1% of all NHS expenditure in the year 2000, mainly because of hospital bed occupancy and revascularisation procedures. This is likely to be a conservative estimate of its true cost.

Can a busy abortion service cope with a screen-and-treat policy for Chlamydia trachomatis infection?

In order to determine the effectiveness of a screen-and-treat policy for Chlamydia trachomatis within a busy medical and surgical abortion service, a retrospective audit was conducted of 2058 women undergoing induced abortion over 12 months. The prevalence of C. trachomatis was 6%. Although most positive results were available before a surgical abortion (97%), only 76% were available before a medical abortion (P = 0.007). This resulted in more treatment delays in the medical group (P = 0.04). Although the majority of women (94% surgical and 84% medical) were seen by genitourinary medicine, only one-quarter of partners attended for contact tracing. The current screen-and-treat policy has been shown to be deficient in several areas. Of most concern are the treatment delays with medical abortion, which may be due to the faster 'processing' of women since this method is only available at < or = 9 weeks' gestation. Such challenges to a screen-and-treat policy, are likely to become more common as medical abortion becomes more widely adopted.

Heart failure and the aging population: an increasing burden in the 21st century?

BACKGROUND

Despite an overall decline in age adjusted mortality from coronary heart disease in developed countries, the number of patients with heart failure may be increasing.

OBJECTIVE

To project the future burden of heart failure in Scotland from contemporary epidemiological data.

METHODS

Scotland, like many industrialised countries, has an aging though numerically stable population (5.1 million). Current estimates of prevalence, general practice (GP) consultation rates, and hospital admission rates related to heart failure were applied to the whole Scottish population. These estimates were then projected over the period 2000 to 2020, on an age and sex specific basis, using expected changes in the age structure of the Scottish population.

RESULTS

There are currently estimated to be 40 000 men and 45 000 women aged > or = 45 years with heart failure in Scotland. On the basis of population changes alone, these figures will rise in men and women by 2300 (6%) and 1500 (3%) by year 2005, and by 12 300 (31%) and 7800 (17%) in the longer term (2020), respectively. On the same basis, the annual number of male and female GP visits is likely to rise by 6400 (6%) and 2500 (2%) by year 2005, and by 35 200 (40%) and 17 300 (16%) in the longer term (124 000 and 126 000 visits), respectively. In the year 2000 about 3500 men and 4300 women in Scotland had an incident hospital admission for heart failure. By the year 2020 these figures are likely to increase by 52% (1800 more) and 16% (717 more) in men and women, respectively. If recent trends in short term case fatality rates continue to improve, the number of men who survive this event will increase by 59% (1700 more). Overall, by 2020 the annual number of male and female hospital admissions associated with a principal diagnosis of heart failure is expected to increase by 34% (from 5500 to 7500) and by 12% (from 7800 to 8500), respectively.

CONCLUSIONS

Unless rapid and major changes occur in the incidence of heart failure, the burden of this disorder will continue to increase in both primary and secondary care over the next two decades. The greatest increase is likely to occur in men. Future health service planning must take this into account.

Beneficial clinical effects of perhexiline in patients with stable angina pectoris and acute coronary syndromes are associated with potentiation of platelet responsiveness to nitric oxide

AIMS

To examine whether the prophylactic antianginal agent perhexiline potentiates platelet responsiveness to nitric oxide (NO) in patients with stable angina pectoris (SAP) and acute coronary syndromes (ACS: unstable angina pectoris or non-Q-wave myocardial infarction).

METHODS AND RESULTS

Blood samples were obtained from patients before and after initiation of treatment with perhexiline. ADP-induced platelet aggregation and its inhibition by the NO donor sodium nitroprusside (SNP) were determined via impedance aggregometry in whole blood (WB) and platelet-rich plasma (PRP). Intraplatelet cGMP content was assayed by RIA, and superoxide (O(2)(-)) level by lucigenin-derived chemiluminescence. In patients with ACS not receiving perhexiline (n=12), platelet responsiveness to SNP did not vary significantly over the first 3 days post admission to hospital. Therapy with perhexiline for 3 days was associated with increases in SNP-induced inhibition of aggregation from 29+/-2% to 43+/-4% (n=50,P <0.001) in WB and from 20+/-5% to 42+/-7% (n=12, P<0.01) in PRP. Resolution of symptomatic ischaemia (n=39) was associated with significantly greater (P<0.01) increases than non-resolution (n=11). Similar increases in SNP responsiveness (P<0.001) occurred following institution of perhexiline therapy in patients with SAP (n=30), associated with a 85% decrease in anginal frequency. Treatment with perhexiline potentiated the cGMP-elevating effects of SNP in platelets (n=9,P =0.03). Although perhexiline did not alter whole blood O(2)(-) concentration ex vivo, it inhibited (P<0.01) O(2)(-) release from neutrophils in vitro.

CONCLUSION

Perhexiline potentiates platelet responsiveness to NO both in SAP and ACS patients; in the latter group this improvement was predictive of resolution of ischaemic symptoms. The predominant mechanism of perhexiline effect is an increase in platelet cGMP responsiveness. Perhexiline also may reduce the potential for NO clearance by neutrophil-derived O(2)(-).

Evaluation of health-care worker vaccination in a tertiary Australian hospital

BACKGROUND

Maintaining a complete vaccination status for health-care workers (HCWs) is important to minimize morbidity among staff and patients. Despite recommendations from public-health authorities to support this process, not all hospitals have adequate policy and practice in place.

AIMS

To independently assess the implementation and impact of a new policy aimed at improving HCW vaccination coverage in a tertiary Victorian hospital.

METHODS

Two cross-sectional surveys were conducted by telephone in July and October 2000 for a random sample of HCWs, before and after the introduction of the policy. These surveys examined knowledge, attitudes and practices surrounding vaccination and self-reported vaccination status. Policy implementation was assessed by ascertaining completion of compulsory vaccination status forms and attendance at suggested appointments to review vaccination status.

RESULTS

Only 19% of 269 HCWs reported a complete vaccination status at baseline. Most (76%) had not heard of or seen vaccination guidelines and 39% kept written vaccination records. This was despite a belief in the importance of vaccination (94%) and a willingness to update if necessary (96%). At follow up there was no improvement in any outcome. Only 11/26 (42%) newly employed HCWs surveyed received and returned compulsory vaccination status forms. Of the few HCWs who attended recommended vaccination appointments, all received vaccinations.

CONCLUSIONS

HCW vaccination coverage and knowledge of vaccination requirements were poor. Although attending a physician to discuss vaccination status did result in vaccination, few HCWs made such an appointment. While policy development is an important first step towards improving vaccination coverage, effective implementation requires ongoing evaluation, adequate resources and HCW education.

AZT myopathy and HIV-1 polymyositis: one disease or two?

PURPOSE

This paper discusses the association between inflammatory and mitochondrial pathologies in patients with HIV-1/AIDS treated with zidovudine (AZT).

METHODS

We present the clinical and pathological details of a 52-year-old HIV-1 positive male who presented with progressive muscle weakness. We also review the current literature and address the debated pathogenesis of the inflammatory pathology.

RESULTS

Muscle biopsy revealed evidence of both HIV-1 polymyositis and AZT myopathy. Six months after initiation of corticosteroid therapy and discontinuation of AZT, the patient's symptoms had greatly improved. The biopsy was repeated to show that both pathologies had resolved.

CONCLUSIONS

The perceived overlap in the pathological spectra of HIV-1 polymyositis and AZT myopathy has produced some debate on causation and treatment. Unfortunately, there have been very few reports where a repeat biopsy following a drug washout period confirmed resolution of the pathology. Furthermore, affected patients have not been treated in a uniform fashion. Whether this represents one disease or two remains uncertain. The clinical relevance of this issue lies in the potential for harm from the unnecessary use of corticosteroids. This question may be best addressed by a randomized clinical trial.

Characterising doctor-parent communication in counselling for impending preterm delivery

OBJECTIVE

To examine the counselling of women admitted to hospital in preterm labour. Such women and their partners are often asked to participate in difficult decisions including mode of delivery, fetal monitoring, and resuscitation.

STUDY DESIGN

Questionnaire based descriptive study.

STUDY SETTING

A tertiary level perinatal referral centre.

PATIENTS

Forty-nine women in preterm labour at 22-30 weeks gestation, admitted in two separate periods between March 1997 and May 1999. INTERVENTION AND OUTCOME MEASURE: Within 24 hours of counselling, parents were asked to complete a questionnaire assessing recall of the management plan, desire for involvement in decision making, anxiety, and feelings of control over their health. A parallel questionnaire was completed by the clinicians.

RESULTS

Parents and clinicians on recall agreed well about obstetric issues but poorly about neonatal issues. Overall 27% of parents felt: "I would prefer to have the doctors advise me, rather than asking me to decide". In 79% of cases, clinicians believed parents preferred advice rather than to make decisions, but in 45% of these, they misidentified those who wished to make their decisions. Anxiety levels for one third of the mothers were high, and associated with poorer concordance of recall between parents and clinicians.

CONCLUSIONS

Serious deficiencies exist in parent-clinician encounters during extremely preterm labour. Concordance between parents and clinicians is poor and anxiety very high. A quarter of parents appear to prefer to relinquish decision making autonomy, but clinicians cannot correctly identify this subgroup. Standardised counselling in the perinatal period, using formal decision aids, should be investigated.

An economic analysis of specialist heart failure nurse management in the UK; can we afford not to implement it?

AIMS

Hospital activity represents the major component of health care expenditure related to heart failure. This study evaluated the economic impact of applying specialist nurse management programmes that limit heart failure-related hospital readmissions within a whole population.

METHODS

Using a reliable and validated estimate of the current level and cost of heart failure-related hospital activity in the U.K., we determined the thresholds at which the actual cost of establishing and applying a national service based on three different models of specialist nurse management would be equal to the 'cost' of bed utilization associated with preventable hospital readmissions in the year 2000. The three models of care examined were home-based, clinic-based or a combination of home plus clinic-based, post-discharge follow-up. The potential impact of this service was based on a U.K.-wide caseload of 122,000 patients discharged to home with a discharge diagnosis of congestive heart failure in that year.

RESULTS

Based on heart failure-specific patterns of hospital activity, we estimate that 47,000 of these 122,000 patients would normally accumulate a total of 594000 days of associated hospital stay from 49,000 readmissions (for any reason) within 1 year of hospital discharge. The cost of these admissions to the National Health Service was calculated at 166.2 million pounds sterling. Taking into account other costs associated with such hospital activity (e.g. general practice and hospital outpatient visits) each 10% reduction in recurrent bed utilization would be associated with 18.0 million ponds sterling in cost savings. Alternatively, the cost of applying a U.K.-wide programme of home-, clinic- or home plus clinic-based follow-up was calculated to be 69.4 pounds sterling, 73.1 pounds sterling and 72.5 million pounds sterling per annum, respectively. The relative thresholds at which generated 'cost-savings' would equal the cost of applying these programmes of care would therefore be a 38.5%, 40.6% and 40.3% reduction in recurrent bed utilization, respectively. If, as expected, a home-based programme of specialist nurse management reduced recurrent bed utilization by 50% or more, annual savings equivalent to 169,000 pounds sterling per 1000 patients treated would be generated.

CONCLUSIONS

This is the first study to examine the economic consequences of applying a specialist nurse-mediated, post-discharge management service for heart failure within a whole population. Our findings suggest that such a service will not only improve quality of life and reduce readmissions in patients with congestive heart failure, but also reduce costs and improve the efficiency of the health care system in doing so.

CT characterization of "indeterminate" renal masses: targeted or comprehensive scanning?

PURPOSE

A comprehensive renal mass evaluation CT protocol is usually performed for simultaneous characterization and staging of incidentally discovered renal masses considered indeterminate on ultrasound (US). The purpose of the study was to determine if a comprehensive examination is appropriate in these patients.

MATERIALS AND METHODS

The authors performed a retrospective review of 100 patients (mean age, 61 years) with 102 sonographically indeterminate renal masses and who were referred to undergo CT for lesion characterization. Lesions were classified according to surgical histology or imaging follow-up evaluation. Statistical analysis was performed.

RESULTS

Thirteen lesions (12.7%) in 11 (11%) patients (mean age, 59 years) were malignant. Eighty-seven lesions (85.3%) in 87 patients (87%; mean age, 62 years) were benign. Two lesions (1.96%) in two patients (2%) remained indeterminate.

CONCLUSION

Although comprehensive renal mass evaluation protocol provides a more thorough patient evaluation, only a small fraction of indeterminate renal masses seen on US are malignant. The authors' results suggest a targeted renal CT imaging protocol for evaluation of indeterminate renal masses incidentally discovered on US.

Retrofitting of a satellite repeat DNA-based murine artificial chromosome (ACes) to contain loxP recombination sites

A satellite DNA-based mammalian artificial chromosome (ACes) was generated and subsequently modified by targeting of a loxP-red fluorescent protein (RFP) expression cassette via homologous recombination into a ribosomal DNA (rDNA)-containing locus. Clones containing correctly targeted ACes were identified by PCR from populations of RFP-expressing cells enriched by FACS sorting and were further characterized by fluorescent in situ hybridization. The targeted ACes maintained its ability to be purified to near homogeneity. Studies are currently underway to further characterize the functionality, carrying capacity, stability and transfectability of this modified ACes.

Effects of automatic cluster remover settings on average milking duration, milk flow, and milk yield

A crossover study design was used in five commercial dairy herds to study the effect of altering the switch point settings for automatic cluster remover units on the average duration of unit attachment, milk flow, and milk yield. Automatic cluster remover switch point settings were alternated, for 1-wk periods, between 0.50 and 0.64 kg/min (1.1 and 1.4 lb/min) in one herd and between 0.73 and 0.82 kg/min (1.6 and 1.8 lb/min) in the four remaining herds. Parlor data were captured at 329 separate milking sessions (range 39 to 92 per herd), representing 239,393 individual cow milkings. While increasing the automatic cluster remover switch point setting was not associated with a change in average milking duration in one herd, it had the effect of significantly reducing the average milking duration by between 10.2 and 15.6 s per cow in the remaining four herds. Milk flow was significantly increased at higher switch point settings for all five herds. Higher automatic cluster remover switch point settings did not have a negative effect on milk yield in any of the herds studied and, in fact, were associated with increased milk yield in two of the five herds. Decreasing milking duration while either maintaining or increasing the volume of milk harvested should ultimately lead to improved milking efficiency and parlor performance. Modifying systems to increase automatic cluster remover switch point settings offers an important potential opportunity to increase parlor efficiency in commercial dairy herds.

Substantial between-hospital variation in outcome following first emergency admission for heart failure

BACKGROUND

Following hospitalization with a range of cardiovascular disorders, substantial variation has been noted in clinical outcome, both between and within countries.

OBJECTIVES

To examine the variation, between hospitals, in the clinical outcomes of death and readmission following hospitalization with heart failure in Scotland. Setting All 29 acute hospitals in Scotland with more than 200 beds.

PATIENTS

All 31 452 patients discharged from these hospitals between January 1990 and December 1995 with a first-ever, primary, diagnosis at discharge/death of heart failure.

ANALYSIS

An analysis of the Scottish database of discharge summaries linking index admissions with subsequent admissions and deaths. Death rates and readmission rates were adjusted for baseline age, co-morbidity and socio-economic status and were calculated at different time periods (inpatient, 30 days, 1 year). Rates were calculated separately for large teaching hospitals (n=6, category A), large general hospitals with specialist units (n=8, category B) and medium sized general hospitals with limited specialist units (n=15 category C).

RESULTS

A total of 31 452 patients were discharged between 1990-1995 - 10 219 (33%), 9735 (31%) and 11 498 (37%) to category A, B and C hospitals, respectively. The national, average, inpatient case fatality rate was 15.3%, ranging, in individual hospitals, from the lowest rate of 8.5% to the highest rate of 23.4%. The average 1 year case fatality rate was 42.4%, ranging between 35.3% and 50.8%. A similar two- to threefold variation was found in hospital readmission rates - thus the average 30 day readmission rate was 5.3% (lowest 3.3%, highest 7.3%). This variation, in both case-fatality and readmission rates, was apparent within all three groups of hospitals and persisted after adjustment for the baseline factors outlined above.

CONCLUSIONS

A patient admitted to one Scottish hospital with heart failure may be two to three times more likely to die or be readmitted, both in the short and longer term, compared to a patient admitted to another hospital. Although we may not have accounted for some sources of variation, it is both surprising and disturbing that large, statistically significant, differences in adjusted death and readmission rates can apparently exist for such an important condition in a relatively small country with generally homogenous health care provision. Further, detailed investigation of this apparent variation is required.

Trends in case-fatality in 22968 patients admitted for the first time with atrial fibrillation in Scotland, 1986-1995

BACKGROUND

Although atrial fibrillation (AF) is an important cause of cardiovascular morbidity and mortality there is a paucity of data describing hospitalisation rates and case-fatality associated with this common arrhythmia. This study examines recent trends in first-ever hospitalisations for AF in Scotland.

METHODS

Using the linked Scottish Morbidity Record Scheme, we identified all 22968 patients admitted to Scottish hospitals for the first time with a principal diagnosis of AF between 1986 and 1995. For each calendar year we calculated short (30-day) and medium (31 day to 2 years) case-fatality rates. Adjusting for each patient's age, sex, deprivation status, concurrent diagnoses and prior hospitalisation status, we examined whether case-fatality rates had significantly improved during this 10-year period.

RESULTS

Between 1986 and 1995 the number of men hospitalised for the first time with AF increased by 926 (125%) to 1730 per annum and the number of women and by 875 (105%) to 1712 (both P<0.001). Hospitalisation rates increased from 0.31 to 0.70/1000 men and from 0.32 to 0.65/1000 women (both P<0.001). By the end of this period the proportion of men had increased from 48 to 50%. In both sexes, the median age of patients rose--in men from 66 to 68 years and in women from 74 to 75 years (both P<0.01). Despite the increasing age of patients and greater comorbidity, short-term (30-day) case-fatality declined from 4.0 to 3.1% in men (P<0.001) and 4.1 to 3.8% (P<0.01) in women. Similarly, medium-term (31-day to 2-year) case-fatality fell from 25 to 22% in men and 27 to 25% (both P<0.001) in women. Adjusting for the age, sex, extent of deprivation, secondary diagnoses and prior hospitalisation of hospitalised patients, we found that the risk of short-term case-fatality in the 1995 male and female cohort significantly declined by 21% (P<0.05) and 24% (P<0.05), respectively, in comparison to the 1986 cohort. The adjusted risk of case-fatality in the medium term also declined significantly in men by 30% (P<0.05) over this period and by 20% (P<0.05) in women relative to 1986.

CONCLUSION

The number of first-ever hospitalisations for AF has increased twofold during the 10-year period 1986-1995. Although the age of patients has progressively increased during this period, short and medium case-fatality rates have declined, especially in men. This may partly reflect better treatment of AF. However, changing admission thresholds and other factors could also have led to an apparent improvement in prognosis. Nevertheless, medium-term case fatality remains substantial after a first ever admission to hospital with AF.

Geological Sequestration of Anthropogenic Carbon Dioxide in the Western Canada Sedimentary Basin: Suitability Analysis

Abstract

Geological sequestration of anthropogenic carbon dioxide is a potential solution to the release into the atmosphere of CO2, a greenhouse gas thought of as significantly contributing to the global warming trend observed since the beginning of the industrial revolution. Basically, CO2 can be sequestered in geological media:through enhanced oil recovery (EOR),by storage in depleted oil and gas reservoirs,through replacement by CO2 of methane in deep coal beds (ECBMR),by injection into deep saline aquifers, and

by storage in salt caverns. Criteria in assessing the suitability of a sedimentary basin for CO2 sequestration are:tectonism and geology,the flow of formation waters and geothermal regime, andthe existence of storage media (hydrocarbon reservoirs, coal seams, deep aquifers and salt structures).

Generally, the Western Canada Sedimentary Basin is suitable for CO2 sequestration by all means because it is tectonically stable, it has regional-scale aquifers confined by aquitards or aquicludes, and it has oil and gas reservoirs in various stages of depletion, uneconomic coal seams, and extensive salt beds. However, various regions in the basin have different degrees of suitability, ranging from not suitable along the eastern edge of the basin, to extremely suitable in southwestern and central Alberta. Most major CO2 producers, such as power plants and refineries around Edmonton, are found in regions that are unsuitable for CO2 sequestration in geological media; however, some, such as the oil sands plants in the Athabasca area, are in regions that are not suitable. This analysis of the suitability of the Western Canada Sedimentary Basin for CO2 sequestration in geological media should provide industry and governments with essential information needed for developing plans and policies in response to climate change effects of anthropogenic greenhouse gas emissions into the atmosphere.

Introduction

Human activity since the industrial revolution had the effect of increasing atmospheric concentrations of gases with a greenhouse effect, such as carbon dioxide (CO2) and methane (CH4), leading to climate warming and weather changes(1, 2). Because of its relative abundance compared with the other greenhouse gases, CO2 is by far the most important, being responsible for about 64% of the enhanced "greenhouse effect"(1). On a sectoral basis, the energy sector contributes globally the most (45%) to anthropogenic (produced by human activity) effects on climate change(3). The high use of fossil fuels (85% of the world's energy needs), foreseen to continue well into the future(2, 4), is the major contributor to increased emissions of CO2 into the atmosphere. Thus, a major challenge in mitigating anthropogenic (man-made) effects on climate change is the reduction of these emissions.

Figure 1 shows Canada's profile in CO2 emissions by sector and by province. The profile of CO2 emissions in the Western Canada Sedimentary Basin is different from the national and other regions' profile because the basin is a major North American producer of fossil fuels.

Expression of a reporter gene after microinjection of mammalian artificial chromosomes into pronuclei of bovine zygotes

The introduction of mammalian artificial chromosomes (ACs) into zygotes represents an alternative, more predictive technology for the production of recombinant proteins in transgenic animals. The aim of these experiments was to examine the effects of artificial chromosome microinjection into bovine pronuclei on embryo development and reporter gene expression. Bovine oocytes aspirated from 2-5 mm size follicles were matured in vitro for 22 hr. Mature oocytes were fertilized in vitro with frozen- thawed bull spermatozoa. Artificial chromosome carrying either beta-galactosidase (Lac-Z) gene or green fluorescence protein (GFP) gene were isolated by flow cytometry. A single chromosome was microinjected into one of the two pronuclei of bovine zygotes. Sham injected zygotes served as controls. Injected zygotes were cultured in G 1.2 medium for 7 days. Hatched blastocysts were cultured on blocked STO cell feeder layer for attachment and outgrowth of ICM and trophectoderm cells. The results showed a high zygote survival rate following LacZ-ACs microinjection (74%). However, the blastocyst development rate after 7 days of culture was significantly lower than that of sham injected zygotes (7.5 vs. 22%). Embryonic cells positive for Lac-Z gene were detected by PCR in three of nine outgrowth colonies. In addition, GFP gene expression was observed in 15 out of 85 (18%) embryos at the arrested 2-cell stage to blastocyst stage. Six blastocysts successfully outgrew, three outgrowths were GFP positive for up to 3 weeks in culture. We conclude that the methodology for artificial chromosome delivery into bovine zygotes could lead to viable blastocyst development, and reporter gene expression could be sustained during pre-implantation development.

Electrical cardioversion for atrial fibrillation: outcomes in "real-life" clinical practice

BACKGROUND

There is currently considerable debate with regard to the optimal management of atrial fibrillation/flutter (AF), including the long-term success of electrical cardioversion and the duration of anti-coagulation thereafter. The aim of this study was to investigate the current management and outcomes of electrical cardioversion in unselected patients in ordinary clinical practice.

METHODS

A prospective, observational study of 111 consecutive patients with AF who had been referred for electrical cardioversion was undertaken in a large teaching hospital. After cardioversion, patients were followed-up for 12 months or until death if this occurred earlier.

RESULTS

Sinus rhythm was restored immediately in 96 of 111 (86%) patients. Only 54 of 88 (61%) patients in sinus rhythm at discharge remained in this rhythm at 1 month. Of these 54, a further 21 (39%) had relapsed into AF by 12 months. Independent predictors of sinus rhythm at discharge were younger age (for a difference of 5 years, odds ratio=1.54; 95% confidence interval 1.04 to 1.16; P=0.002) and absence of hypertension (1.73, 1.22-1.91; P=0.015). The presence of sinus rhythm at discharge (6.4, 1.6-25.3; P=0.007) was an independent predictor of sinus rhythm at 1 month, whereas older age was a negative predictor (0.96, 0.92-1.0; P=0.05). Health-related quality of life improved at 1 and 12 months in those patients who remained in sinus rhythm compared to those who remained in AF.

CONCLUSIONS

Though electrical cardioversion for AF has a high initial success rate only a minority of patients remained in sinus rhythm 1 year. The common practice of discontinuing anticoagulant treatment in patients in sinus rhythm at 1 month may be unsafe. Long-term maintenance of sinus rhythm is, however, associated with better health-related quality of life.