Stress myocardial perfusion single-photon emission computed tomography is clinically effective and cost effective in risk stratification of patients with a high likelihood of coronary artery disease (CAD) but no known CAD

OBJECTIVES: We sought to evaluate the prognostic and cost implications of stress myocardial perfusion single-photon emission computed tomography (SPECT), or MPS, in patients with a high pretest likelihood (>0.85) of coronary artery disease (CAD) with no previous CAD. BACKGROUND: Sparse data are available regarding the prognostic performance characteristics of MPS in this patient group. METHOD: We followed up 1,270 consecutive patients with no previous revascularization or myocardial infarction (MI), with a pre-exercise tolerance test (ETT) likelihood of CAD > or =0.85, who underwent exercise or adenosine stress MPS (follow-up 94.4% complete; 2.2 +/- 1.2 years; 60 hard events [5.9%, 2.6%/year]). Risk adjustment of survival data was done using Cox proportional hazards analysis. Costs per reclassification of risk were calculated using assumed costs and threshold analyses. RESULTS: In patients treated medically after MPS, normal MPS had a low risk of cardiac death and hard events (0.6% and 1.3% per year, respectively). With increasing extent and severity of MPS defects, the risk of both cardiac death and hard events increased significantly (p < 0.05). Cox models indicated that the addition of MPS data resulted in incremental prognostic value over pre-MPS data (chi-square increase 48 to 87, p < 0.0001). Compared with strategies of initial referral to ETT in patients able to exercise, initial referral to MPS appeared to be a more cost-effective strategy. Similarly, compared with a strategy of direct referral to catheterization in patients with a high likelihood of CAD, initial referral to MPS is a cost-saving approach. CONCLUSIONS: In patients with a high likelihood of CAD but without known CAD, stress MPS yields incremental value and achieves risk stratification in a cost-effective manner. The current results support a strategy of initial stress imaging in this patient cohort, as a reasonable alternative to direct referral to catheterization or initial ETT.     

Cost effectiveness of interferon alpha or peginterferon alpha with ribavirin for histologically mild chronic hepatitis C

BACKGROUND: For patients with mild chronic hepatitis C the cost effectiveness of antiviral therapy is unknown. AIMS: To assess whether antiviral therapy (either interferon alpha or peginterferon alpha combined with ribavirin) is cost effective at a mild stage compared with waiting and only treating those cases who progress to moderate disease. PATIENTS: Cases with mild chronic hepatitis C. METHODS: A cost effectiveness model which estimates long term costs and outcomes for patients with mild chronic hepatitis C. The model uses effectiveness and cost data from the UK mild hepatitis C randomised controlled trial, combined with estimates of disease progression and cost from observational studies. RESULTS: Antiviral treatment at a mild rather than a moderate stage improved outcomes measured by quality adjusted life years (QALYS) gained. The mean cost per QALY gained from antiviral treatment with interferon alpha-2b and ribavirin, compared with no treatment at a mild stage, was 4535 pounds sterling (7108 dollars) for patients with genotype non-1 and 25,188 pounds sterling (39,480 dollars) for patients with genotype 1. Providing peginterferon alpha-2b and ribavirin at a mild rather than a moderate stage was also associated with a gain in QALYS; the costs per QALY gained were 7821 pounds sterling (12,259 dollars) for patients with genotype non-1 and 28,409 pounds sterling (44,528 dollars) for patients with genotype 1. CONCLUSIONS: For patients with chronic hepatitis C, it is generally more cost effective to provide antiviral treatment at a mild rather than a moderate disease stage. For older patients (aged 65 years or over) with genotype 1, antiviral treatment at a mild stage is not cost effective.     

Direct healthcare costs and predictors of costs in patients with primary Sjogren's syndrome

OBJECTIVES: To analyse the healthcare usage, direct healthcare costs and predictors of cost in primary Sj?gren's syndrome (PSS) in the UK and to compare the findings with the data from healthy control groups and rheumatoid arthritis (RA) patients. METHODS: A total of 129 patients with PSS (American-European criteria), 91 with RA and 92 controls, were included in the study. All groups were age-matched females and all completed questionnaires on health status (SF-36) and healthcare utilization (economic component of the Stanford Health Assessment Questionnaire). Annual direct healthcare costs were calculated (and expressed in 2004 UK pound sterling) and predictors of costs for each patient group were determined by regression analyses. Age, health status, disease duration and anti-Ro/La antibody positivity were used as potential predictor variables. RESULTS: Mean age was similar in the PSS (59.2 yrs, S.D. 11.6), RA (60.3 yrs, S.D. 10.5) and control groups (57.7 yrs, S.D. 12.5). The mean disease duration was 5.4 yrs (S.D. 4.8) in the PSS group and 13.4 yrs (S.D. 11.4) in the RA group. The mean annual total direct cost per patient [95% confidence interval (CI)] was 2188 pounds sterling (1831 and 2546 pounds sterling) in the PSS group, 2693 pounds sterling(2069 and 3428 pounds sterling) in the RA group and 949 pounds sterling (741 and 1156 pounds sterling) in the control group. The costs in the PSS group were greater than for the RA and control groups for visits to all healthcare professionals (total) as well as visits to the dentist, dental hospital and ophthalmologist. The costs in the PSS and RA groups were higher than in controls for diagnostic tests and visits to hospital and the accident and emergency (A&E) department. The PSS group also incurred higher costs than controls, but lower costs than the RA group, for visits to a rheumatologist, urine and blood tests, assistive devices and drug therapy. Regression analysis identified the SF-36 physical function subscale as the best predictor of costs in PSS patients as well as controls and the mental health subscale in RA patients. CONCLUSION: This is the first study to evaluate direct healthcare costs in patients with PSS. PSS has a significant impact on the healthcare system, similar to that of RA, by more than doubling costs compared with control patients.     

Patient self-management of anticoagulation therapy: a trial-based cost-effectiveness analysis

Demand for anticoagulation management is increasing due to an expansion of clinical indications for therapy. One possible model of care to meet demand is patient self-management (PSM), beneficial to patients who need control over their condition. This study aimed to determine the cost and cost-effectiveness of PSM of anticoagulation compared with routine clinic-based care for patients receiving long-term anticoagulation. A cost-utility analysis was conducted alongside a randomised controlled trial; 617 patients were recruited and followed up for 12 months. There was no significant difference in mean quality-adjusted life years (QALYs) between groups - after adjusting for baseline, the mean difference in QALYs was 0.009 (95% CI, -0.012 to 0.030). Overall mean healthcare costs in the PSM arm were significantly higher at pounds sterling 417 (CI pounds sterling 394- pounds sterling 442) compared with pounds sterling 122 (CI pounds sterling 103- pounds sterling 144) in the control arm. Therefore, using a formal cost-effectiveness analysis, PSM of anticoagulation does not appear to be cost-effective. However, PSM may have other benefits in relieving pressure on traditional clinic-based care, and the cost-effectiveness of this model of care for some subgroups of anticoagulation patients needs to be explored further.     

Evaluation of chest pain in patients with low to intermediate pretest probability of coronary artery disease by electron beam computed tomography

Despite its limited sensitivity and specificity in patients with low to intermediate probability of coronary artery disease (CAD), exercise treadmill testing (ETT) is frequently used as the initial test for investigation of chest pain. Although myocardial perfusion imaging is a significantly more accurate test, its added cost to ETT is considerable. The cost of a non-contrast electron beam computed tomography (EBCT) scan is comparable to that of ETT and the calcium score (CS) correlates closely with the volume of atherosclerotic plaque. Therefore, we tested the hypothesis that EBCT might be an effective and cost-beneficial technique for the identification of angiographically obstructive CAD (> or = 50% stenosis) in patients with low to intermediate pretest probability of disease. We calculated the theoretic cost of attaining a diagnosis of CAD based on a Bayesian model that utilizes published sensitivity and specificity levels for ETT, EBCT, and stress myocardial perfusion imaging. We then submitted a cohort of 207 patients with low to intermediate probability of disease both to EBCT and ETT in random order, and estimated the cost of achieving a correct diagnosis by either route based on the number of expected further tests. An EBCT calcium score of 150 was chosen as a cut-point with a sensitivity of 74% and a specificity of 89% for the presence of obstructive CAD. The theoretic Bayesian model predicted substantial cost savings when EBCT was used as the initial test instead of ETT, with decreasing benefit as the prevalence of disease increased (44% saving at 0% prevalence; 15% saving at 100% prevalence). In the patient cohort, the diagnostic pathway starting with EBCT provided a 45% to 65% cost saving over the ETT pathway. We conclude that in patients with low to intermediate pretest probability of disease, a pathway based on EBCT as the initial test to investigate presence of obstructive CAD provides a substantial cost benefit over a pathway based on ETT. Such cost advantages decrease as the prevalence of disease increases.     

Modelling the health benefits and economic implications of implanting dual-chamber vs. single-chamber ventricular pacemakers in the UK.

AIMS: To estimate the consequences of managing bradycardia due to sinoatrial node disease or atrioventricular block with dual-chamber vs. single-chamber ventricular pacemakers. METHODS AND RESULTS: A discrete-event simulation was conducted to predict outcomes over 5 years. Patients could develop post-operative complications, clinically relevant pacemaker syndrome leading to replacement of single-chamber with dual-chamber, atrial fibrillation (AF; which if chronic might require anticoagulants) or stroke. Survival, quality-adjusted life years (QALYs), complications, and associated direct medical costs were estimated (2003 British Pounds pounds sterling). Identical patients were simulated after receiving a single-chamber device or a more expensive dual-chamber pacemaker. Probabilities of conditions were obtained from clinical trials. Benefits were discounted at 1.5% and costs at 6%. Post-operative complications increased from 6.4% with single-chamber to 7.7% with dual-chamber but AF decreased (22 vs. 18%) as did clinically relevant pacemaker symptoms (16.8 vs. 0%). Approximately 4300 pounds sterling were accrued per patient over 5 years. Additional health benefits with dual-chamber are achieved at a mean net cost of 43 pounds sterling per patient, leading to 0.09 QALY with a cost-effectiveness ratio of 477 pounds sterling/QALY. CONCLUSION: Implanting the costlier device increases the cost of the initial operation; however, this is expected to be offset by a reduction in costs associated with re-operations and AF.     

The direct healthcare costs associated with ankylosing spondylitis patients attending a UK secondary care rheumatology unit

OBJECTIVES: To explore the direct healthcare resources associated with ankylosing spondylitis (AS) in the UK. A secondary objective was to establish if resources, and thus healthcare costs, vary by disease severity. METHODS: Medical records of 147 sequential AS patients attending a UK secondary care rheumatology unit were examined to assess the direct healthcare resources used over the previous 12 months. Starting with a detailed inventory and measurement of resources consumed, unit cost multipliers were applied to the quantity of each type of resource consumed. The mean cost per patient was estimated using the total cost divided by the number of patients included. RESULTS: The mean (median) annual cost per patient was 1852 pounds sterling (892 pounds sterling). The distribution of cost data was skewed, with 11% of patients incurring 50% of the total costs. The three most relevant cost domains were physiotherapy, hospitalization and medication costs at 32, 21 and 20% of the total costs, respectively. Twenty percent of the patients received physiotherapy, 13% received inpatient care and almost all incurred medication costs. Thirty-four percent of patients were prescribed disease-modifying anti-rheumatic drugs and 85% non-steroidal anti-inflammatory drugs. Over 50% of patients had at least one comorbidity. CONCLUSION: Direct costs accelerate steeply with disease activity (Bath Ankylosing Spondylitis Disease Activity Index >6.0) and increasing loss of function (Bath Ankylosing Spondylitis Functional Index >6.0) in patients with AS. The most severely affected patients incur 50% of the total costs, and physiotherapy accounts for 32% of the total healthcare costs in the UK.     

Safety, feasibility, and prognostic implications of pharmacologic stress echocardiography in 1482 patients evaluated in an ambulatory setting

BACKGROUND: The outpatient prognostic assessment of coronary artery disease (CAD) by exercise electrocardiography has limitations, including the feasibility of the test and its low positive predictive value in several clinical conditions. In the current study we investigated the safety, feasibility, and prognostic value of pharmacologic stress echocardiography in a large cohort of ambulatory patients. METHODS: The study group was made of 1482 ambulatory patients (969 men, aged 60 +/- 10 years) who underwent stress echocardiography with either dipyridamole (n = 846) or dobutamine (n = 636) for evaluation of suspected or known stable CAD.The pretest likelihood of CAD was intermediate (<70%) in 709 patients and high (> or =70%) in 773 patients. RESULTS: There was no complication during the dipyridamole test, whereas 2 ischemia-dependent, sustained ventricular tachycardias occurred during the dobutamine test. Limiting side effects were observed in 2% of dipyridamole and in 3% of dobutamine stresses. The echocardiogram was positive in 459 patients. During a mean follow-up of 28 +/- 24 months, 58 patients died, 33 had a nonfatal myocardial infarction, and 158 underwent early (< or =3 months) and 64 late (>3 months) revascularization. Multivariate predictors of hard events (death, infarction) were positive echocardiographic results (hazard ratio [HR] 2.9) and resting wall motion score index (WMSI) (HR 2.3). In considering major events (death, infarction, late revascularization) as end points, positive echocardiographic result (HR 4.3), scar (HR 2.2), and resting WMSI (HR 1.7) were independent prognostic predictors. The 5-year survival rates for the ischemic and nonischemic groups were, respectively, 80% and 91% (HR 3.6, 95% confidence interval [CI] 3.8-8.4; P <.0001) considering hard cardiac events and 65% and 88% (HR 2.6, 95% CI 2.1-5.9; P <.0001) considering major events. Multivariate predictors of major events were positive echocardiographic results (HR 8.2) and male sex (HR 2.5) for the intermediate-risk group and positive echocardiographic results (HR 2.9), resting WMSI (HR 1.8), and prior Q-wave myocardial infarction (HR 1.8) for the high-risk group. CONCLUSIONS: Pharmacologic stress echocardiography is safe, highly feasible, and effective in prognostic assessment of ambulatory patients when both a general population and groups selected on the basis of pretest likelihood of CAD are analyzed. It represents a valid complementary tool to exercise electrocardiography for prognostic purposes in outpatients.     

ECG Diagnosis of Coronary Artery Disease

Objective: In order to assess the diagnostic accuracy of ST depression in the diagnosis of coronary artery disease (CAD) in patients with suspected myocardial ischemia we compared ST depression in 3-lead ambulatory ECG (AECG) with that of exercise tolerance testing (ETT). Methods: Significant coronary artery stenosis in coronary angiography was used as a standard reference. ST analysis could be performed in 106 of the investigated 113 patients, all with suspected CAD. One person with left bundle branch block was excluded from the ST analysis, and six persons could not perform ETT. Results: Seventy-eight of the 106 patients had at least one significant stenosis (> 70% narrowing) and 28 had no stenosis according to coronary angiography. The sensitivity for AECG was 62% and for ETT it was 63%, the specificity for AECG was 79% and for ETT the specificity was 57%. The accuracy for AECG was 66%, and for ETT it was 61%. We also evaluated late potentials (LPs) from the AECG tapes in order to correlate LP to left ventricular function (LVF), myocardial infarction (Ml), and/or CAD. We found that LP correlates better to advanced CAD than to Ml or LVF. Conclusion: The accuracy of ST diagnosis of CAD in patients with suspected myocardial ischemia using AECG was equal to that of a maximal ETT. LP finding from an AECG tape may support the argument for CAD in patients with ST depressions at AECG.     

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.     

Real-time dobutamine stress myocardial perfusion echocardiography predicts outcome in the elderly.

AIMS: Although there is an increasing number of studies showing the value of perfusion imaging with real-time contrast echocardiography (RTCE) for detecting coronary artery disease (CAD), no data exist regarding the value of this technique for detecting CAD and predicting outcome in the elderly. METHODS AND RESULTS: We examined the outcome of 399 patients > or =70 years old who underwent dobutamine stress RTCE for known or suspected CAD. Myocardial perfusion imaging (MPI) was performed using low mechanical index pulse sequence schemes following intravenous small bolus injections of ultrasound contrast. Quantitative coronary angiography (QCA) was performed within 1 month of the stress test in 60 patients. Events were defined as cardiac death or non-fatal myocardial infarction (MI). Sensitivity of MPI for detecting CAD by QCA was 94% [confidence interval (CI) 91-99], specificity was 67% (CI 36-74), and accuracy was 90% (CI 82-95). During a median follow-up of 21 months, 46 events occurred (31 cardiac deaths, 15 non-fatal MI). Univariate predictors of outcome were diuretic use (P = 0.03), abnormal stress wall motion (P < 0.0001), and abnormal stress MPI (P < 0.0001). Abnormal stress MPI, however, was the most significant predictor of outcome (chi(2) 7.5; P = 0.006). CONCLUSION: Myocardial perfusion analysis during dobutamine stress RTCE provides incremental predictive value in determining the outcome of elderly patients being evaluated for the presence of CAD.     

Relationship between noninvasive coronary angiography with multi-slice computed tomography and myocardial perfusion imaging.

OBJECTIVES: The aim of this study was to perform a head-to-head comparison between multi-slice computed tomography (MSCT) and myocardial perfusion imaging (MPI) in patients with an intermediate likelihood of coronary artery disease (CAD) and to compare non-invasive findings to invasive coronary angiography. BACKGROUND: Multi-slice computed tomography detects atherosclerosis, whereas MPI detects ischemia; how these 2 techniques compare in patients with an intermediate likelihood of CAD is unknown. METHODS: A total of 114 patients, mainly with intermediate likelihood of CAD, underwent both MSCT and MPI. The MSCT studies were classified as having no CAD, nonobstructive (<50% luminal narrowing) CAD, or obstructive CAD. Myocardial perfusion imaging examinations were classified as showing normal or abnormal (reversible and/or fixed defects). In a subset of 58 patients, invasive coronary angiography was performed. RESULTS: On the basis of the MSCT data, 41 patients (36%) were classified as having no CAD, of whom 90% had normal MPI. A total of 33 patients (29%) showed non-obstructive CAD, whereas at least 1 significant (> or =50% luminal narrowing) lesion was observed in the remaining 40 patients (35%). Only 45% of patients with an abnormal MSCT had abnormal MPI; even in patients with obstructive CAD on MSCT, 50% still had a normal MPI. In the subset of patients undergoing invasive angiography, the agreement with MSCT was excellent (90%). CONCLUSIONS: Myocardial perfusion imaging and MSCT provide different and complementary information on CAD, namely, detection of atherosclerosis versus detection of ischemia. As compared to invasive angiography, MSCT has a high accuracy for detecting CAD in patients with an intermediate likelihood of CAD.     

Childhood asthma: healthcare resource utilisation in those with and without a diagnosis of the condition

AIM: To examine healthcare utilisation and the direct financial costs in providing medical care to a population of children aged 5-15 years with respiratory complaints. Secondarily, to assess whether these costs depended upon having specific asthma diagnosis or not. METHOD: A postal respiratory questionnaire was sent to the parents or guardians of all children registered with two general practices. A search of the general practice medical records over a 2-year reference period was made for a stratified random sample and results are presented for 488 children aged 5-15 years. RESULTS: The cost of primary care lower respiratory tract consultations in children with 4-5 symptoms/risk factors was pounds sterling 17.02 per patient per year for those with a previous diagnosis of asthma compared with pounds sterling 6.08 per patient per year for those with the same number of symptoms but no diagnosis (t = -4.446, P<0.001). The cost of primary care lower respiratory consultations in those with no GP diagnosis of asthma and no symptoms/risk factors was pounds sterling 2.25 per patient per year. CONCLUSIONS: Studies, which fail to include the costs associated with treating children with respiratory symptoms but without a formal diagnosis, will seriously underestimate the costs of treating asthmatic children.     

Myocardial perfusion imaging in patients with a recent,normal exercise test

AIM: To investigate the added value of myocardial perfusion scintigraphy imaging (MPI) in consecutive patients with suspected coronary artery disease (CAD) and a recent, normal exercise electrocardiography (ECG). METHODS: This study was a retrospective analysis of consecutive patients referred for MPI during a 2-year period from 2006-2007 at one clinic. All eligible patients were suspected of suffering from CAD, and had performed a satisfactory bicycle exercise test (i.e. , peak heart rate > 85% of the expected, age-predicted maximum) within 6 mo of referral, their exercise ECG was had no signs of ischemia, there was no exercise-limiting angina, and no cardiac events occurred between the exercise test and referral. The patients subsequently underwent a standard 2-d, stress-rest exercise MPI. Ischemia was defined based on visual scoring supported by quantitative segmental analysis (i.e. , sum of stress score > 3). The results of cardiac catheterizationwere analyzed, and clinical follow up was performed by review of electronic medical files. RESULTS: A total of 56 patients fulfilled the eligibility criteria. Most patients had a low or intermediate ATPⅢ pretest risk of CAD (6 patients had a high pre-test risk). The referral exercise test showed a mean Duke score of 5 (range: 2 to 11), which translated to a low postexercise risk in 66% and intermediate risk in 34%. A total of seven patients were reported with ischemia by MPI. Three of these patients had high ATPⅢ pre-test risk scores. Six of these seven patients underwent cardiac catheterization, which showed significant stenosis in one patient with a high pre-test risk of CAD, and indeterminate lesions in three patients (two of whom had high pre-test risk scores). With MPI as a gate keeper for catheterization, no significant, epicardial stenosis was observed in any of the 50 patients (0%, 95% confidence interval 0.0 to 7.1) with low to intermediate pre-test risk of CAD and a negative exercise test. No cardiac events occurred in any patients within a median follow up period of > 1200 d. CONCLUSION: The added diagnostic value of MPI in patients with low or intermediate risk of CAD and a recent, normal exercise test is marginal.     

平板运动试验时的QT离散度诊断冠心病的价值

为了解ＱＴ离散度（ＱＴｄ）在运动试验中的变化对冠心病心肌缺血的诊断价值，对３０例临床诊断或疑诊为冠心病的病人先后行平板运动试验（简称运动试验）及冠状动脉（简称冠脉）造影检查。１７例运动试验阳性者中１０例确诊为冠心病；１３例运动试验阴性者中１０例冠状动脉正常。运动试验诊断冠心病的敏感性７６．９％、特异性５８．８％、准确性６６．７％。冠心病组与冠脉正常组运动前、中、后ＱＴｄ分别为４６．２５±２０．１３ｍｓ、７１．９２±２０．３７ｍｓ、５１．２５±１４．４８ｍｓ及３２．３５±６．６４ｍｓ、３０．８８±９．２３ｍｓ、２９．３８±８．５４ｍｓ，两者比较，Ｐ均＜０．０１。冠心病组运动前、后与运动中ＱＴｄ比较，差异有显著性，Ｐ＜０．００５；而冠脉正常组ＱＴｄ变化无显著性。以运动中ＱＴｄ≥６０ｍｓ为异常，诊断冠心病的敏感性为９２．３％、特异性１００％、准确性９６．７％。提示运动试验中ＱＴｄ增加可作为诊断冠心病心肌缺血的敏感而特异的指标     

The cost-effectiveness of the use of clopidogrel in acute coronary syndromes in five countries based upon the CURE study.

BACKGROUND: The CURE study demonstrated that clopidogrel prevents a range of ischaemic cardiovascular events in patients with Acute Coronary Syndromes (unstable angina or non-ST-segment elevation MI). DESIGN: We undertook an economic analysis of the use of clopidogrel in the UK, USA, Sweden, France and Canada based on the CURE study. METHODS: The costs of hospitalization, study drug and other medications were calculated, based on resource utilization for all patients in CURE. Unit costs were obtained for all resource items for each country, and are reported in local currencies in 2001 prices. RESULTS: While hospitalization costs were lower in the clopidogrel group, when the acquisition cost of clopidogrel for 9 months is included, the average cost per patient is higher in the clopidogrel group than the placebo group in all countries [difference in costs (with 95% CI) 208 pounds sterling (119, 297), 451 US dollars (58, 845), SKr 2571 (728, 4412), 325 euros (85, 565), 161 Canadian dollars (-185, 506)]. The absolute reduction in the number of total primary events was 2.0%, resulting in an incremental cost-effectiveness ratio (ICER) of 10,366 pounds sterling in the UK, 22,484 US dollars in the USA, SKr 127,951 in Sweden, 16,186 euros in France, and 7973 Canadian dollars in Canada per primary event avoided with clopidogrel. CONCLUSIONS: Clopidogrel in CURE reduced hospitalization costs but the acquisition cost of clopidogrel creates an overall increase in direct health care costs over 9 months. Nevertheless, the cost-effectiveness is in a range comparable to other therapies currently utilized for acute coronary syndromes.     

Impact of clinical presentation and pretest likelihood on the relation between calcium score and computed tomographic coronary angiography

The purpose of the present study was to assess the impact of clinical presentation and pretest likelihood on the relation between coronary calcium score (CCS) and computed tomographic coronary angiography (CTA) to determine the role of CCS as a gatekeeper to CTA in patients presenting with chest pain. In 576 patients with suspected coronary artery disease (CAD), CCS and CTA were performed. CCS was categorized as 0, 1 to 400, and >400. On CT angiogram the presence of significant CAD (≥50% luminal narrowing) was determined. Significant CAD was observed in 14 of 242 patients (5.8%) with CCS 0, in 94 of 260 patients (36.2%) with CCS 1 to 400, and in 60 of 74 patients (81.1%) with CCS >400. In patients with CCS 0, prevalence of significant CAD increased from 3.9% to 4.1% and 14.3% in nonanginal, atypical, and typical chest pain, respectively, and from 3.4% to 3.9% and 27.3% with a low, intermediate, and high pretest likelihood, respectively. In patients with CCS 1 to 400, prevalence of significant CAD increased from 27.4% to 34.7% and 51.7% in nonanginal, atypical, and typical chest pain, respectively, and from 15.4% to 35.6% and 50% in low, intermediate, and high pretest likelihood, respectively. In patients with CCS >400, prevalence of significant CAD on CT angiogram remained high (>72%) regardless of clinical presentation and pretest likelihood. In conclusion, the relation between CCS and CTA is influenced by clinical presentation and pretest likelihood. These factors should be taken into account when using CCS as a gatekeeper for CTA.     

Cost effectiveness of expanded antenatal HIV testing in London

BACKGROUND: Recently the Department of Health announced the introduction in England of voluntary universal HIV screening in early pregnancy to prevent vertical transmission. New data have shown the importance of HIV infection in infants born to mothers who were HIV-negative in early pregnancy and who acquired HIV later in pregnancy or during lactation. This requires consideration of repeat testing in late pregnancy and testing of partners of pregnant women (expanded antenatal HIV testing). OBJECTIVE: To estimate cost effectiveness of expanded antenatal HIV testing in London (England) within the framework of universal voluntary HIV screening in early pregnancy. DESIGN: Incremental cost-effectiveness analysis. METHODS: Cost estimates of service provision for HIV-positive children and adults by stage of HIV infection were combined with estimates of health benefits for infants and parents and with costs of counselling and testing (testing costs). In a pharmacoeconomic model cost effectiveness was estimated for expanded antenatal HIV testing in London for universal and selective strategies. RESULTS: Testing costs in the plausible range of pounds sterling 4 to pounds sterling 40 translate into favourable incremental cost-effectiveness estimates for expanded antenatal HIV testing in London which is already at low numbers of vertical transmissions averted per 100000 pregnant women who test HIV-negative in early pregnancy. Favourable cost effectiveness for universal expanded testing would require testing costs in the lower range, whereas selective expanded testing may produce favourable cost effectiveness at testing costs close to pounds sterling 40. CONCLUSION: Based on pharmaco-economic considerations, the authors believe that implementation of expanded HIV testing in London should be considered.     

Stress echocardiography is superior to exercise ECG in the risk stratification of patients presenting with acute chest pain with negative Troponin.

OBJECTIVE: To compare exercise electrocardiography (ExECG) and stress echocardiography (SE) in the risk stratification of patients presenting to hospital with cardiac-sounding chest pain, non-diagnostic ECGs and negative cardiac Troponin. METHODS: Patients presenting with acute chest pain were prospectively randomised to early ExECG or SE. A post-test likelihood of CAD was determined by the pre-test likelihood and the result of the stress test. Patients with a low post-test likelihood of CAD were discharged; those with a high post-test probability were considered for coronary angiography. All others were managed according to standard hospital protocols. RESULTS: A total of 302 patients underwent either ExECG or SE. SE identified significantly more patients with a low post-test probability of CAD (80% vs 31%, p<0.0001) and significantly fewer patients with an intermediate post-test likelihood of CAD compared to ExECG (3% vs 47%; p<0.0001). Significantly fewer patients undergoing SE were referred for further tests to exclude or refute the diagnosis of CAD (16% vs 52%; p<0.0001). In total, 36 (12%) had flow limiting CAD demonstrated by coronary angiography. Significant CAD was seen in fewer patients with a positive ExECG than with a positive SE (56% vs 84% (p=0.12)). Event rates were low for both modalities in patients with low post-test probability (3.5% for SE vs 5.1% for ExECG; p=ns) though the number of patients identified as low risk was higher if SE was performed. CONCLUSION: Despite negative cardiac Troponin, 12% of patients with acute chest pain had significant CAD. SE is superior to ExECG in discriminating between those patients with a low and intermediate risk of CAD and correctly identified patients with significant CAD, as well as conferring an excellent prognosis in those considered low risk. SE significantly reduces the requirement for further tests to diagnose CAD compared to ExECG.     

Predictive values of Framingham risk and coronary artery calcium scores in the detection of obstructive CAD in patients with normal SPECT

A subgroup of patients with normal stress myocardial perfusion imaging (MPI) have obstructive coronary artery disease (CAD) on coronary computed tomographic angiography (CCTA). A retrospective study was performed to identify factors associated with obstructive CAD in patients with normal MPI. Bivariate differences between patients with obstructive (>50% stenosis) and nonobstructive (<50% stenosis) CAD were assessed. Of the 105 patients with normal MPI, 42 (40%) had obstructive CAD on CCTA. After a multivariable logistic regression analysis increased Framingham risk scores ([FRS] ≥10%) and coronary artery calcium scores ([CACS] >100 Agatston Units [AU]) were independently associated with obstructive CAD (P = .006 and P < .0001, respectively). Patients with normal MPI had 13 times and 98 times higher odds of having obstructive CAD if they had a FRS ≥10% versus <10% and CACS >100 AU versus ≤100 AU, respectively. Increased FRS and CACS may stratify patients who may benefit from further evaluation for significant CAD despite normal MPI.