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Recent diagnostic and therapeutic advances have been questioning the role of exercise electrocardiography (ECG) for risk stratification of patients recovering from an acute coronary syndrome. The aim of this review was to verify whether evidence still exists supporting the use of exercise ECG as first choice stress testing modality in this clinical setting in the light of the most recent prognostic data and of cost effectiveness considerations. It was concluded that a large body of evidence supports the use of exercise ECG as a cost-effective tool for prognostic purposes and for quality of life assessment following acute coronary syndromes.

Background: Patients with known or suspected coronary disease are often investigated to facilitate risk assessment. We sought to examine the cost-effectiveness of strategies based on exercise echocardiography and exercise electrocardiography., Methods and Results: We studied 7656 patients undergoing exercise testing; of whom half underwent exercise echocardiography. Risk was defined with the Duke treadmill score for those undergoing exercise electrocardiography alone, and by the extent of ischaemia by exercise echocardiography. Cox proportional hazards models, risk adjusted for pretest likelihood of coronary artery disease, were used to estimate time to cardiac death or myocardial infarction. Costs (including diagnostic and revascularisation procedures, hospitalisations, and events) were calculated, inflation-corrected to year 2000 using Medicare trust fund rates and discounted at a rate of 5%. A decision model was employed to assess the marginal cost effectiveness (cost/life year saved) of exercise echo compared with exercise electrocardiography. Exercise echocardiography identified more patients as low-risk (51% vs 24%, p<0.001), and fewer as intermediate- (27% vs 51%, p<0.001) and high-risk (22% vs 4%); survival was greater in low- and intermediate-risk and less in high-risk patients. Although initial procedural costs and revascularisation costs (in intermediate-high risk patients) were greater, exercise echocardiography was associated with a greater incremental life expectancy (0.2 years) and a lower use of additional diagnostic procedures when compared with exercise electrocardiography (especially in lower risk patients). Using decision analysis, exercise echocardiography ( in 2615/life year saved) was more cost effective than exercise electrocardiography., Conclusion: Exercise echocardiography may enhance cost-effectiveness for the detection and management of at risk patients with known or suspected coronary disease.

Objectives: The present study sought to determine the value of fractional flow reserve (FFR) compared with stress perfusion scintigraphy (SPS) in patients with recent unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI)., Background: Fractional flow reserve, an invasive index of stenosis severity, is a reliable surrogate for SPS in patients with normal left ventricular function. An FFR > or = 0.75 can distinguish patients after myocardial infarction (MI) with a positive SPS from those with a negative SPS. However, the use of FFR has not been investigated after UA/NSTEMI., Methods: Seventy patients who had recent UA/NSTEMI and an intermediate single-vessel stenosis were randomized to either SPS (n = 35) or FFR (n = 35). Patients in the SPS group were discharged if the SPS revealed no ischemia, whereas those in the FFR group were discharged if the FFR was > or = 0.75. Patients with a positive SPS and those with an FFR <0.75 underwent percutaneous transluminal coronary angioplasty. The use of FFR markedly reduced the duration and cost of hospitalization compared with SPS (11 +/- 2 h vs. 49 +/- 5 h [-77%], p < 0.001; and 1,329 US dollars +/- 44 US dollars vs. 2,113 US dollars +/- 120 US dollars, respectively, p < 0.05). There were no significant differences in procedure time, radiation exposure time, or event rates during follow-up, including death, MI, or revascularization., Conclusions: These data indicate that: 1) the use of FFR in patients with recent UA/NSTEMI markedly reduces the duration and cost of hospitalization compared with SPS; and 2) these benefits are not associated with an increase in procedure time, radiation exposure time, or clinical event rates.

Electron beam CT (EBCT) or ultrafast CT is a diagnostic imaging technique that can identify calcium deposits within coronary arteries. Intra-coronary calcium is associated with coronary artery atherosclerosis. EBCT imaging has been advocated as a "better" way to screen for coronary artery disease. By producing a measure of the amount of calcium present, it may provide a non-invasive risk assessment tool that can predict the risk of future coronary events and death. Medical literature concerning identification and assessment of coronary risk using EBCT in the clinical setting is reviewed. The primary purpose is to illustrate one approach to a simple "back of the envelope" cost-benefit analysis (protective value) comparing EBCT with exercise electrocardiography as a life insurance coronary disease risk assessment tool. The performance and results of this analysis are contingent on a number of critical assumptions that are outlined in the text. The analysis limitations, and the future research required to refine the results are reviewed. With optimum levels of EBCT test performance, favorable thresholds of test costs, and long-term mortality data useful for assessment of value preservation, EBCT might prove to be a valuable risk assessment tool from a cost-benefit perspective under certain circumstances. Answers to key clinical research questions from prospective studies in asymptomatic cohorts are essential for refinement of a cost-benefit estimate.

Unlabelled: In this study, we examined the utility of preoperative dobutamine stress echocardiograms (DSE) obtained for 85 patients in accordance with guidelines published by the American College of Cardiology (ACC) and the American Heart Association (AHA). The medical record of each patient was reviewed to identify the clinical criteria that indicated the need for a DSE, the DSE results, therapeutic interventions rendered as a result of the DSE, and any perioperative cardiac morbidity. The DSE was positive for inducible ischemia in 4 patients (4.7%), negative in 74 (87.1%), and nondiagnostic in 7 (8.2%). DSEs that were obtained for 48 patients because of a history of diabetes mellitus, mild angina, or "minor clinical predictors" produced only negative results. Of the four patients with positive DSE results, three underwent coronary angiography, and one of those three underwent bypass grafting before surgery. An additional 29 patients received a preoperative DSE but were excluded from the study because the criteria for ordering the DSE did not meet the ACC/AHA guidelines. No patient had any perioperative morbidity related to myocardial ischemia. The total patient charge for the 85 DSEs obtained at our institution was US$104,635. Use of the ACC/AHA guidelines for preoperative DSEs does not appear to be cost-effective. However, the current algorithm could be significantly improved by altering the criteria for obtaining preoperative DSEs., Implications: This study was a retrospective review of 85 patient charts that found a low cost-effectiveness of using American College of Cardiology/American Heart Association guidelines for obtaining preoperative dobutamine stress echocardiograms. Suggested modifications of these guidelines should improve their specificity with no loss in sensitivity.

Background: The prognoses of patients with false-negative test results by myocardial single photon emission computed tomography (SPECT) and by stress echocardiography are known to be different; the prognosis with false-negative SPECT is better in suspected and proven coronary artery disease (CAD)., Methods and Results: Three strategies by which to diagnose CAD were compared for their cost-effectiveness when considering the prognostic value of false-negative results: (1) stress myocardial SPECT by dipyridamole or adenosine followed by coronary angiography (CAG), (2) exercise stress echocardiography followed by CAG, and (3) dobutamine stress echocardiography followed by CAG. Delta quality-adjusted life-year (QALY) was calculated for the three strategies separately when annual mortality and infarction rates were 0.5% and 0.5% for myocardial SPECT and 2% and 2% for stress echocardiography, respectively. Costs were estimated and costs per DeltaQALY were calculated according to the pretest likelihood of CAD (pCAD). The myocardial SPECT followed by CAG strategy was the most cost-effective in the patients with a pCAD of 0.3 or greater, and the dobutamine echocardiography followed by CAG strategy was the most cost-effective in patients with a pCAD of 0.2 or lower. This was the case when we assumed that the nondiagnostic test rate of dobutamine echocardiography was 9% (in contrast to 0% by myocardial SPECT and 18% by exercise echocardiography). Sensitivity analysis showed that the cost-effectiveness of dobutamine echocardiography followed by CAG was best only if the prognosis of false-negative results of dobutamine echocardiography was better. The cost-effectiveness of exercise echocardiography was dubious because of the high nondiagnostic rate with inadequate exercise., Conclusions: When the lower event rates of (false) negative SPECT were considered, the relatively expensive myocardial SPECT strategy was more cost-effective than the cheaper stress echocardiography strategy in patients with a pCAD of 0.3 or greater. According to sensitivity analysis, the prognostic value of false-negative results and the nondiagnostic test rate were important determinants of stress myocardial study cost-effectiveness.

Objective: The objective of this study is to assess the cost/value tradeoff of a routine treadmill requirement for life insurance applicants. For this purpose, we are interested in the treadmill's ability to provide unique information on the mortality risk in a population of apparently healthy and asymptomatic individuals, as opposed to the treadmill done for diagnostic or confirmatory purposes., Materials and Methods: We performed a protective value study, solving for the face amount at which the mortality savings outweigh the various treadmill requirement costs. Multiple scenarios were evaluated, varying the following assumptions: percent of cases uniquely discovered through the treadmill, excess mortality associated with the treadmill, proportion of would-be applicants ending the process when confronted with a treadmill requirement, proportion of not-takens in the face of a positive treadmill, and various profitability requirements. While there is an array of information available from the treadmill, to avoid double counting effects we chose 2 representative and independent findings: abnormal ECG and low fitness (duration). Prevalence of findings and mortality associations were derived from published studies., Results and Conclusion: While many companies are moving to eliminate or restrict the use of treadmill testing, low break-even policy sizes were produced in virtually every iteration of our assumptions. In one variation, however, we ignored the possibility of any "fitness" findings. Under this assumption, results were roughly consistent with current industry practice. This suggests that some companies could enhance the value of their treadmill requirements by requesting Balke protocol treadmills and/or interpreting duration information. Others may want to reconsider current face amount thresholds for their treadmill requirement in light of this valuable risk-selection information.

Study Objective: Acute cardiac ischemia (ACI) encompasses the diagnoses of unstable angina pectoris and acute myocardial infarction (AMI). Accurate diagnosis and triage of patients with ACI in the emergency department should increase survival for these patients and reduce unnecessary hospital admissions., Methods: We conducted a systematic review of the English-language literature published between 1966 and December 1998 on the accuracy and clinical effect of diagnostic technologies for ACI. We evaluated prospective and retrospective studies of adult patients who presented to the ED with symptoms suggesting ACI. Outcomes were diagnostic performance (test sensitivity and specificity) and measures of clinical effect. Meta-analyses were performed when appropriate. A decision and cost-effectiveness analysis was conducted that investigated various diagnostic strategies used in the diagnosis of ACI in the ED., Results: We screened 6,667 abstracts, reviewed 407 full articles, and included 106 articles articles in the main analysis. Single measurements of biomarkers at presentation to the ED have low sensitivity for AMI, although they have high specificity. Serial measurements greatly increase the sensitivity for AMI while maintaining their excellent specificity. Diagnostic technologies to evaluate ACI in selected populations, such as electrocardiography, sestamibi perfusion imaging, and stress ECG, may have very good to excellent sensitivity; however, they have not been sufficiently studied. The Goldman Chest Pain Protocol has good sensitivity (about 90%) for AMI but has not been shown to result in any differences in hospitalization rate, length of stay, or estimated costs in the single clinical effect study performed. Its applicability to patients with unstable angina pectoris has not been evaluated. The use of an Acute Cardiac Ischemia-Time-Insensitive Predictive Instrument led to the appropriate triage of 97% of patients with ACI presenting to the ED and reduced unnecessary hospitalizations., Conclusion: Many of the current technologies remain underevaluated, especially regarding their clinical effect. The extent to which combinations of tests may provide better accuracy than any single test needs further study.

Physical fitness is a term describing maximal aerobic capacity adjusted for body size and composition, and is an integrated measure of cardiorespiratory and neuromusculo-skeletal function, oxygen transport and delivery, and psychological drive. Accordingly, high physical fitness requires that all these important body functions function normally, while low physical fitness suggests malfunction of one or more of them. High levels of physical fitness--maintained through heavy daily exercise--has probably been a necessary requirement for survival in the earlier history of humans. In modern, industrialised countries the demand for physical activity to sustain life is declining, and a decline in physical fitness is observed in many populations. Epidemiological studies over the past 50 years have unanimously shown that low physical activity and physical fitness is associated with high cardiovascular and total mortality. Recent data also suggest that low physical activity and physical fitness is followed by an increased incidence of diabetes mellitus and nonfatal cardiovascular diseases. A number of unfavourable biochemical and physiological aberrations following physical inactivity probably explain these observations. However, recent studies also indicate that changes in physical activity, and especially changes that bring increases in physical fitness, can reverse this rather pessimistic scenario. The Global Burden of Disease Study initiated by the World Health Organization included physical inactivity among the most important risk factors threatening global health. A sedentary life style may be as detrimental to health as smoking. Encouragement of physical activity is an important and difficult task, as society is becoming increasingly successful in reducing our need to move.

Background: In most centers, exercise testing (ET) is performed by one or two trained technologists during the weekdays (0800 hours-1600 hours), leaving a void during evenings and weekends. This leads to unnecessary increased costs due to delays in management of patients. Electrocardiography technologists (ECGT) are often available for extended hours. This project was undertaken to improve the efficiency of the ET laboratory by using ECGT to perform ET during these extended hours., Methods: Clinical utility and cost saving of a 7 day per week ET for management of patients with suspected and/or known coronary artery disease utilizing ECGT was assessed after adequate training. Of 4099 patients undergoing ET between January 1995 and December 1997, 810 tests performed by ECGT were reviewed retrospectively., Results: Of the 810 patients (age mean 58.4 +/- 0.44 yrs; range 16-88; males: 508, females: 302), 806 (99.5%) underwent the Bruce protocol. The indications were: diagnostic, 61.3%, predischarge acute myocardial infarction (AMI), 17.7%, evaluation of angina, 19.6%, other, 1.4%. Only 8 (0.1%) patients had complications (prolonged chest pain, 6; nonsustained ventricular tachycardia, 2) with no AMIs or deaths. This strategy resulted in a savings of 158 bed days (Can189,600 dollars) on inpatients and 15 bed days (Can18,000 dollars) on those presenting to the emergency department., Conclusions: This study demonstrates the feasibility and safety of utilizing ECGT for ET thus extending the hours of service. This resulted in efficient patient management, with a considerable cost-saving to the hospital.

Cost-effectiveness analysis is a method of comparing societal economic value of 2 different strategies. Ideally, it defines accurate test-related (direct and downstream) costs and appropriately converts differential patient outcomes into a dollar value. The likelihood that cost-effectiveness analysis translated into a policy-making tool will enhance health care and/or control costs is dependent on the validity of numerous assumptions about relative costs, patient outcomes, and generalizability of the literature to regional capabilities. The purpose of this report is to review the concept of cost-effectiveness analysis as it applies to stress echocardiography and stress myocardial perfusion imaging for selected patient subsets.

Myocardial perfusion imaging provides important prognostic information in patients with known or suspected coronary artery disease (CAD) and sustained myocardial infarction. The combination of several scintigraphic variables allows separation of patients at low and high risk for future events. In patients with known or suspected CAD, myocardial perfusion imaging has been demonstrated to provide incremental information over clinical, exercise ECG and angiographic data. Also, an increase in referral-rate for cardiac catheterization and revascularization, paralleling the increase in severity of abnormalities on myocardial perfusion imaging, was observed. Perfusion imaging results appear to be interpreted and implemented appropriately in the diagnostic work-up and subsequent treatment of patients with known or suspected CAD. Therefore, myocardial perfusion imaging may serve as a gatekeeper for more costly and invasive procedures. With the introduction of gated SPECT imaging, it is now possible to assess both perfusion and left ventricular function simultaneously. It is anticipated that gated SPECT imaging will provide very strong prognostic data.

In contrast to the often debated NYHA classification, the determination of peak oxygen uptake (peak VO2) by cardiopulmonary exercise testing allows an objective assessment of the exercise capacity of patients with congestive heart failure (CHF). However, cardiopulmonary exercise testing is a time consuming and costly diagnostic tool, which requires sophisticated equipment and specially trained personel. Exercise capacity can also be determined by the 6 minute walk test. This test simply measures the distance covered by strong walking on a hallway level within 6 minutes. The 6 minute walk test is a submaximal exercise test, which is associated with much smaller increments in heart rate, blood pressure and plasma catecholamines than cardiopulmonary exercise testing. It is characterized by a very small intraindividual variance. Furthermore, it can be easily performed and, due to low logistic and personal requirements, it is very cost effective. The results of the 6 minute walk test--as well as of cardiopulmonary exercise testing--are influenced by extracardial exercise-limiting disorders, such as pulmonary diseases. Independent from the etiology of CHF, the results of the 6 minute walk test are closely related to peak VO2. In serial exercise testing the distance covered within 6 minutes allow to predict the individual peak VO2. Like peak VO2 the 6 minute walk test has been shown to be a predictor of morbidity and mortality in CHF, with its predictive value being independent from left ventricular ejection fraction and other potential prognostic parameters. In CHF patients a walking distance < 300 m is associated with a one-year-mortality of up to 50%, whereas the one-year-mortality in patients reaching a walking distance > 450 m amounts to only a few percent. In addition, the hospitalization rate of patients reaching a walking distance of < 300 m is several fold higher than in those with a walking distance > or = 450 m. Like cardiopulmonary exercise testing, the 6 minute walk test allows to control the efficiency of specific treatments and to monitor the natural course of the disease. The 6 minute walk test is, thus, a cost effective alternative to cardiopulmonary exercise testing in CHF patients. However, neither the 6 minute walk test alone nor the results of cardiopulmonary exercise testing alone are sufficient for selecting patients, e.g., for cardiac transplantation, as each individual case requires a synopsis of all relevant facts and parameters.

Study Objective: Conventional emergency department testing strategies for patients with chest pain often do not provide unequivocal diagnosis of acute coronary syndromes. This study was conducted to determine whether the routine use of single photon emission computed tomography (SPECT) imaging at rest and early exercise stress testing to assess intermediate-risk patients with chest pain and no ECG evidence of acute ischemia will lead to earlier discharges, more discriminate use of coronary angiography, and an overall reduction in average costs of care with no adverse clinical outcomes., Methods: All patients in this study had technetium 99m tetrofosmin SPECT imaging at rest and were randomly assigned to either a conventional (results of the imaging test blinded to the physician) or perfusion imaging-guided (results of the imaging test unblinded to the physician) strategy. Patients in the conventional arm were treated at their physician's discretion. Patients in the perfusion imaging-guided arm were treated according to a predefined protocol based on SPECT imaging test results: coronary angiography after a positive scan result and exercise treadmill testing after a negative scan result. Study endpoints consisted of total in-hospital costs and length of stay. Hospital costs were calculated using hospital department-specific Medicare cost/charge ratios. Length of stay was calculated as total hospital room days billed (regular and intensive care)., Results: We enrolled 46 patients, 9 with acute myocardial infarctions. Patients randomly assigned to the perfusion imaging-guided arm had $1,843 (95% confidence interval [CI] $431 to $6,171) lower median in-hospital costs and 2.0-day (95% CI 1.0 to 3.0 days) shorter median lengths of stay but similar rates of in-hospital and 30-day follow up events as patients in the conventional arm., Conclusion: An ED chest pain diagnostic strategy incorporating acute resting (99m)Tc tetrofosmin SPECT imaging and early exercise stress testing may lead to reduced in-hospital costs and decreased length of stay for patients with acute chest pain and nondiagnostic ECGs., (Copyright © 2000 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.)

Most attempts to identify qualitative and quantitative techniques for assessing myocardial viability and the likelihood of improved function after revascularization in patients with healed myocardial infarcts have focused on treatment strategies and prognosis. This review examines the true value of the electrocardiographic phenomenon of exercise-induced ST segment elevation (EISTE) in Q wave leads as a diagnostic tool for the assessment of myocardial viability. The prognostic potential and clinical utility of the EISTE phenomenon are inhibited both by the heart's electrophysiologic response to exercise-induced metabolic and hemodynamic changes, and by the ECG's limited facility in assessing myocardial preservation. The use of EISTE as an independent indicator for surgical intervention is proscribed by these limitations. The EISTE phenomenon could serve as a useful tool in the first line of discrimination in patients with healed Q wave myocardial infarction, and may justify further diagnostic work-up in patients under consideration for a revascularization procedure. In the era of sophisticated nuclear and echo techniques, accurate imaging studies should not be replaced by ECG analysis alone in the search for viable tissue, except when financial costs are of major importance., (Copyright 2000 S. Karger AG, Basel)

Clinical, economical, organizative, and medico-legal issues raised by management of citizens who come to Emergency Department with acute chest pain and non diagnostic electrocardiogram are well known. Data from the Italian Health Ministry show that, in 1996, 37,444 patients had been discharged from Italian hospitals with the main diagnosis of chest pain. To obtain this "non-diagnosis", it was needed a mean hospital stay of 4.2 days with estimated costs close to $57,000,000. The ASSENCE study is a randomized, multicenter, international trial aimed at comparing three strategies of handling citizens presenting to emergency department for unexplained chest pain in terms of cost/effectiveness ratio and quality of patients' life. The three strategies that will be compared are: 1. current clinical protocols, prescribing an in-hospital observation period and discharge after several hours/days; 2. performing a dobutamine-atropine stress echocardiography between 0 and 18 hours after randomization (at 6 hours after index chest pain onset) and discharging the patients (if negative) immediately thereafter; 3. performing an electrocardiographic exercise stress test between 0 and 18 hours after randomization and discharging the patients (if negative) immediately thereafter. The main ASSENCE study end-point will be assessment of cost/effectiveness of the 3 strategies tested. Costs will be assessed taking into account: hospital stay length, performed diagnostic procedures and treatments during index admission, in-hospital and 2-month follow-up events (cardiac death, myocardial infarction, definite unstable angina, coronary angioplasty, by-pass surgery, re-admission to hospital for chest-pain). A secondary ASSENCE study end-point will be to assess the effect on patient quality of life of the use of the 3 strategies tested. Sample size estimation calculated in order to detect an absolute difference of at least 10% and based on a 30% expected rate of events, was of 186 patients for each strategy tested.

Background: The diagnostic value of exercise electrocardiography (ECG) in patients with complete right bundle block (cRBBB) remains controversial. The aim of this study was to investigate the diagnostic accuracy of exercise ECG for predicting ischemia in the presence of cRBBB., Methods: From a series of 1300 consecutive patients attending for exercise ECG and 99mTc-tetrofosmin single photon emission computed tomography (SPECT), we identified 38 male patients with cRBBB and 38 matched controls with normal intraventricular conduction. Patients with left ventricular hypertrophy or previous revascularization were excluded. Exercise ECG (modified Bruce protocol) was considered positive at > or = 1 mm ST horizontal or downsloping depression in > or = 2 adjacent leads. SPECT imaging at rest and post-exercise was performed at least 48 hours apart., Results: The odds ratio for ischemia comparing patients with positive and negative exercise ECGs was 11.0 (95% confidence interval 2.49-48.64, p = 0.002) in controls and 2.49 (95% confidence interval 0.64-9.08, p = 0.32) in cRBBB. The prior probability of ischemia was 0.37 in controls and 0.58 with cRBBB. The posterior probability after a positive test was 0.65 in controls and 0.68 in cRBBB. Thus, the utility of the test (posterior probability minus prior probability) was greater in controls (+0.28) than in cRBBB (+0.1). This difference was most pronounced in the anterior leads V1-V4 (controls +0.63 vs cRBBB +0.01) but less significant in the lateral leads V5-V6 (controls +0.26 vs cRBBB +0.21). Similar analysis also indicated reduced diagnostic value of negative exercise ECGs in cRBBB patients., Conclusions: The diagnostic value of exercise ECG is reduced in patients with cRBBB, although ST-segment changes in the lateral ECG territory provide superior predictive accuracy to those in the anterior leads. The use of SPECT as a first-line investigation may be justified in patients with cRBBB.

Because of constraints on the costs of providing medical care, cardiologists in the future will find themselves challenged to provide care for their patients in the most cost-effective manner possible. Although stress-echocardiography has been shown to compare favorably with other tests in diagnostic accuracy, data on cost-effectiveness are scarce. In this article, general concepts of cost-effectiveness as they relate to stress-echocardiography are reviewed and the available literature is summarized. Although definitive data are lacking, there is evidence to suggest that stress-echocardiography may prove to be cost-effective in several clinical situations.

Background: Many noninvasive tests exist to determine whether patients should undergo coronary angiography. The routine use of coronary angiography without previous noninvasive testing is typically not advocated., Objective: To determine the cost-effectiveness of diagnostic strategies for patients with chest pain., Design: Cost-effectiveness analysis., Data Sources: Published data., Target Population: Patients who present with chest pain, have no history of myocardial infarction, and are able to perform an exercise stress test., Time Horizon: Lifetime., Perspective: Societal., Interventions: No testing, exercise electrocardiography, exercise echocardiography, exercise single-photon emission computed tomography (SPECT), and coronary angiography alone., Outcome Measures: Quality-adjusted life expectancy, lifetime cost, and incremental cost-effectiveness., Results of Base-Case Analysis: The incremental cost-effectiveness ratio of routine coronary angiography compared with exercise echocardiography was $36,400 per quality-adjusted life-year (QALY) saved for 55-year-old men with typical angina. For 55-year-old men with atypical angina, exercise echocardiography compared with exercise electrocardiography cost $41,900 per QALY saved. If adequate exercise echocardiography was not available, exercise SPECT cost $54,800 per QALY saved compared with exercise electrocardiography for these patients. For 55-year-old men with nonspecific chest pain, the incremental cost-effectiveness ratio of exercise electrocardiography compared with no testing was $57,700 per QALY saved., Results of Sensitivity Analysis: On the basis of a probabilistic sensitivity analysis, there is a 75% chance that exercise echocardiography costs less than $50,900 per QALY saved for 55-year-old men with atypical angina., Conclusions: Exercise electrocardiography or exercise echocardiography resulted in reasonable cost-effectiveness ratios for patients at mild to moderate risk for coronary artery disease in terms of age, sex, and type of chest pain. Coronary angiography without previous noninvasive testing resulted in reasonable cost-effectiveness ratios for patients with a high pretest probability of coronary artery disease.

Background: The appropriate roles for several diagnostic tests for coronary disease are uncertain., Objective: To evaluate the cost-effectiveness of alternative approaches to diagnosis of coronary disease., Design: Meta-analysis of the accuracy of alternative diagnostic tests plus decision analysis to assess the health outcomes and costs of alternative diagnostic strategies for patients at intermediate pretest risk for coronary disease., Data Sources: Studies of test accuracy that met inclusion criteria; published information on treatment effectiveness and disease prevalence., Target Population: Men and women 45, 55, and 65 years of age with a 25% to 75% pretest risk for coronary disease., Time Horizon: 30 years., Perspective: Societal., Interventions: Diagnostic strategies were initial angiography and initial testing with one of five noninvasive tests--exercise treadmill testing, planar thallium imaging, single-photon emission computed tomography (SPECT), stress echocardiography, and positron emission tomography (PET)--followed by coronary angiography if noninvasive test results were positive. Testing was followed by observation, medical treatment, or revascularization., Outcome Measures: Life-years, quality-adjusted life-years (QALYs), costs, and costs per QALY., Results of Base-Case Analysis: Life expectancy varied little with the initial diagnostic test; for a 55-year-old man, the best-performing test increased life expectancy by 7 more days than the worst-performing test. More sensitive tests increased QALYs more. Echocardiography improved health outcomes and reduced costs relative to stress testing and planar thallium imaging. The incremental cost-effectiveness ratio was $75,000/QALY for SPECT relative to echocardiography and was greater than $640,000 for PET relative to SPECT. Compared with SPECT, immediate angiography had an incremental cost-effectiveness ratio of $94,000/QALY., Results of Sensitivity Analysis: Qualitative findings varied little with age, sex, pretest probability of disease, or the test indeterminancy rate. Results varied most with sensitivity to severe coronary disease., Conclusions: Echocardiography, SPECT, and immediate angiography are cost-effective alternatives to PET and other diagnostic approaches. Test selection should reflect local variation in test accuracy.

Objectives: The study aim was to determine observational differences in costs of care by the coronary disease diagnostic test modality., Background: A number of diagnostic strategies are available with few data to compare the cost implications of the initial test choice., Methods: We prospectively enrolled 11,372 consecutive stable angina patients who were referred for stress myocardial perfusion tomography or cardiac catheterization. Stress imaging patients were matched by their pretest clinical risk of coronary disease to a series of patients referred to cardiac catheterization. Composite 3-year costs of care were compared for two patients management strategies: 1) direct cardiac catheterization (aggressive) and 2) initial stress myocardial perfusion tomography and selective catheterization of high risk patients (conservative). Analysis of variance techniques were used to compare costs, adjusting for treatment propensity and pretest risk., Results: Observational comparisons of aggressive as compared with conservative testing strategies reveal that costs of care were higher for direct cardiac catheterization in all clinical risk subsets (range: $2,878 to $4,579), as compared with stress myocardial perfusion imaging plus selective catheterization (range: $2,387 to $3,010, p < 0.0001). Coronary revascularization rates were higher for low, intermediate and high risk direct catheterization patients as compared with the initial stress perfusion imaging cohort (13% to 50%, p < 0.0001); cardiac death or myocardial infarction rates were similar (p > 0.20)., Conclusions: Observational assessments reveal that stable chest pain patients who undergo a more aggressive diagnostic strategy have higher diagnostic costs and greater rates of intervention and follow-up costs. Cost differences may reflect a diminished necessity for resource consumption for patients with normal test results.

Unlabelled: Rehabilitation patients who will undergo noncardiac surgery or strenuous rehabilitation programs often cannot exercise to greater than 85% of predicted maximal heart rate as required for valid treadmill testing. Because many patients have known or suspected coronary artery disease, greatly increasing their risk for a cardiac event, dipyridamole thallium scans are usually performed, despite a cost of approximately $1400, patient radiation exposure, and the need for a gamma camera. Instead, arm-leg cycle stress testing can be continued to an appropriately high heart rate, is done in the physician's office with an electrocardiograph machine and a blood pressure cuff, and costs $250. This study describes nine patients who had both dipyridamole thallium scans and arm-leg cycle ergometry. Four awaited peripheral vascular surgery, one needed bilateral knee replacements, one was an amputee, and three had claudication. Six had documented and three had suspected coronary disease., Results: In eight of nine patients, the electrocardiograms during both dipyridamole thallium imaging and ergometry were in agreement as to the presence or absence of ischemia (kappa statistic, 0.7273; P = 0.0117). In seven of nine patients, thallium images and ergometry agreed (78% concurrence). To achieve 90% agreement between dipyridamole thallium scans and cycle results, however, 68 patients would have to be studied., Conclusion: In this preliminary study, arm-leg ergometry was feasible in all patients and seemed cost-effective and useful for detecting myocardial ischemia. Clinically, if the ergometry were inconclusive, dipyridamole thallium scans could be performed subsequently to obtain the needed information.

Objectives: The purpose of this study was to determine if electron beam computed tomography (EBCT) has potential as a cost-effective approach to diagnosis of obstructive coronary disease., Background: Coronary calcification quantified by EBCT is closely related to the extent of atherosclerosis., Methods: A model based upon published sensitivities (Se)/specificities (Sp) for diagnosis in an ambulatory patient of obstructive coronary disease (> or =50% stenosis) and population prevalence was tested for angiography alone, or treadmill exercise, stress echocardiography, stress thallium or predetermined EBCT calcium score outpoints, followed by angiography if indicated., Results: Total direct testing costs increased in proportion to disease prevalence whereas cost-effectiveness, direct costs/patient diagnosed correctly with disease, decreased as a function of prevalence. Using an EBCT calcium score of 168 (Se/Sp = 71%/90%) provided for the least costly and most cost-effective noninvasive pathway. Calcium scores of 80 (Se/Sp = 84%/84%) and 37 (Se/Sp = 90%/77%) were also cost-effective when prevalence of disease was < or =70%; but results for a >0 calcium score (Se/Sp = 95%/46%) cutpoint were not superior to conventional methods. Calcium score cutpoints of 37, 80 or 168 provided similar or superior overall negative and positive predictive values to conventional noninvasive testing pathways across all prevalence subgroups., Conclusions: In ambulatory patients evaluated for obstructive coronary disease, a testing pathway utilizing quantification of coronary calcium by EBCT as an initial noninvasive testing approach minimized direct costs, and maximized cost-effectiveness in population groups with low/ moderate disease prevalence (< or =70%); as expected, direct angiography as the first and only test proved most cost-effective in patients with a high prevalence (>70%) of disease.

Objective: To determine the outcome, safety, and possible cost savings of patients undergoing weekend or holiday exercise treadmill testing., Design: Medical records of all 195 patients scheduled for weekend and holiday exercise testing were reviewed, and 77.9% of patients were contacted by telephone to ascertain medical outcomes and need for further emergency department or inpatient care. Costs were calculated from estimates of days of hospitalization saved and incremental costs incurred in conjunction with weekend or holiday testing., Setting: Urban tertiary care academic medical center., Patients: A total of 195 patients were scheduled for testing, and 181 tests were performed. Over three quarters (75.1%) of patients underwent testing for assessment of chest pain. Other indications included risk stratification after myocardial infarction or coronary angioplasty or prior to noncardiac surgery, or evaluation for arrhythmias, dyspnea, or syncope., Measurements and Main Results: Outcomes included results and complications of testing, hospital course after testing, subsequent emergency department visits and readmissions, myocardial infarction, need for cardiac catheterization or revascularization, and mortality. No complications were noted during testing. In 136 patients tested for the indication of chest pain, 90 (66.2%) had negative tests, 39 (28. 7%) were intermediate, and 6 (4.4%) were positive for ischemia. Same day discharge occurred in 115 (84.6%) of the patients, saving an estimated 185 days of hospitalization ($316.83 per patient tested). Event rates over the 6 months following discharge were low., Conclusions: Weekend and holiday exercise testing is a safe and effective means of risk stratification prior to hospital discharge for patients with chest pain. It also reduces length of stay and is cost saving.

Background: It has been suggested that in patients with a normal resting electrocardiogram (ECG), exercise radionuclide myocardial perfusion imaging (MPI) does not add significant incremental diagnostic information to exercise ECG., Methods and Results: Of 840 consecutive patients referred for physical exercise MPI, 313 (37%) had normal resting ECGs. There were 189 men and 124 women with a mean age of 54+/-11.9 years. Exercise MPI was performed with either TI-201 or 99mTc-labeled sestamibi. Overall concordance between exercise ECG result and MPI result was 79% (kappa agreement = .54). One hundred eighty-four patients had normal exercise ECG; 181 (98.4%) of these also had normal exercise MPI. In 271 patients with low (< or =20%) to intermediate (21% to 70%) pre-exercise likelihood of coronary artery disease (CAD), concordance between normal exercise ECG and normal MPI was 100%. In the high likelihood (> or =71%) group 3 (15 %) patients with normal exercise ECG had abnormal exercise MPI. Of 129 patients with abnormal exercise ECG, 67 (52%) patients also had abnormal MPI, but 62 (48%) patients had normal MPI. Complete follow-up was obtained in 89% of patients at 9 months. Only 1 hard cardiac event occurred: nonfatal myocardial infarction. Twenty-one (8%) patients had subsequent coronary revascularization or admission with unstable angina. Although both abnormal stress ECG and abnormal exercise MPI were significantly (P < .0001) associated with hard and "soft" events, the association of abnormal exercise MPI was significantly stronger. Because all patients with a low and intermediate likelihood of CAD who had normal exercise ECG also had normal exercise MPI, we propose a stepwise diagnostic testing strategy whereby exercise MPI imaging is performed only in patients with a low to intermediate likelihood of CAD when the exercise ECG is abnormal. When the exercise ECG is performed first, and exercise MPI is performed only when the exercise ECG is abnormal, substantial (38%) cost savings can be achieved. In patients with a high likelihood of CAD, the exercise ECG may be falsely negative, and exercise MPI is preferred., Conclusion: In patients with normal resting ECGs a stepwise diagnostic strategy can reduce costs of exercise testing without compromising diagnostic yield when pretest likelihood of coronary artery disease is taken into consideration.

Background: The role of myocardial-perfusion imaging in calculating risk in symptom-free patients who have had coronary-artery-bypass grafting (CABG) is unclear. Practice guidelines have argued against routine screening of these patients. We sought to find out the independent and incremental prognostic value of exercise thallium-201 single-photon-emission computed tomography (SPECT) for prediction of death and non-fatal myocardial infarction (MI) in these patients., Methods: Analyses were based on 873 symptom-free patients undergoing symptom-limited exercise thallium-201 SPECT between September, 1990, and December, 1993. All had undergone CABG and none had recurrent angina or other major intercurrent coronary events. Exercise and thallium-perfusion variables were analysed to determine their prognostic importance during 3 years of follow-up., Findings: Myocardial-perfusion defects were noted in 508 (58%) patients. There were 57 deaths and 72 patients had major events (death or non-fatal MI). Patients with thallium-perfusion defects were more likely to die (9% vs 3%, p=0.0004) or suffer a major event (11% vs 4%, p=0.0002). Reversible defects were also predictive of death (12% vs 5%, p=0.002) and major events (13% vs 7%, p=0.004). The exercise variable with the strongest predictive power was an impaired (< or = 6 METs [measure of oxygen consumption equal to 3.5 mL/kg/min]) exercise capacity; poor exercise capacity was predictive of death (18% vs 4%, p<0.0001) and death or non-fatal MI (19% vs 5%, p<.00001). After adjusting for baseline clinical variables, surgical variables, time elapsed since CABG, and standard cardiovascular risk factors, thallium-perfusion defects remained predictive of death (adjusted relative risk 2.78, 95% CI 1.44-5.39) and major events (2.63, 1.49-4.66). Similarly, impaired exercise remained strongly predictive of death (4.16, 2.38-7.29) and major events (3.61, 2.22-5.87) after adjusting for confounders., Interpretation: In this group of patients who were symptom-free after CABG, thallium-perfusion defects and impaired exercise capacity were strong and independent predictors of subsequent death or non-fatal MI. Recommendations against routine screening exercise myocardial-perfusion studies in this setting should be reconsidered.

Exercise treadmill testing is frequently performed to screen for coronary artery disease (CAD) in asymptomatic individuals; however, its clinical value is unclear. We examined a consecutive cohort of asymptomatic adults undergoing exercise treadmill testing at the Cleveland Clinic Foundation between September 1990 and December 1993. End points included (1) identification of subjects with severe CAD and (2) performance of any second diagnostic study within 90 days of the index exercise treadmill test. Screening exercise treadmill testing was performed in 4,334 adults (median age 51, 89% men); only 34% had > or = 1 cardiac risk factor and 15% exhibited an abnormal response to exercise. A second test after treadmill testing was performed in 215 patients (in 110, coronary angiography; in 105, stress thallium scintigraphy, followed by coronary angiography in 16). The strongest predictor of referral for a second test was an ischemic ST-segment response (adjusted odds ratio [OR] 34, 95% confidence intervals [Cl] 24 to 47, p < 0.0001). The only clinical variable independently associated with referral for a second test was female gender (adjusted OR 0.35, 95% CI 0.21 to 0.60, p <0.0001). Of the 126 patients who underwent coronary angiography, severe CAD was identified in only 19 individuals (10.44% of the original cohort, 95% CI 0.26% to 0.62%); coronary artery bypass grafting was performed in 14 of these patients. The estimated cost of exercise treadmill testing to identify 1 case of severe CAD for which surgical revascularization may provide a survival benefit was $39,623. The estimated cost per year of life saved was at least $55,274. Thus, as used in actual practice in 1 center, screening exercise treadmill testing has a low yield and is costly. This is perhaps in part because of the low-risk population that was selected and the failure to incorporate pretest variables, increasing probability of disease into post-test clinical decision making.

Mitral valve prolapse is sometimes associated with chest pain, but this symptom may also be caused by coexisting coronary disease. The accuracy of exercise echocardiography in diagnosing coronary disease in these patients and the most cost-efficient diagnostic approach are unclear. We studied 96 patients (aged 59 +/- 12 years; 70 men) with mitral valve prolapse who underwent exercise electrocardiography, exercise echocardiography, and coronary angiography. The accuracies of seven diagnostic strategies based on the current and expected use of exercise electrocardiography and exercise echocardiography in patients with mitral valve prolapse were examined, with the costs calculated based on Medicare reimbursement. Thirteen (13.5%) patients had significant coronary artery disease. The sensitivity and specificity of exercise electrocardiography in the 71 patients with interpretable electrocardiograms were 50% and 72%, respectively. For the 73 patients who achieved >85% of maximal heart rate, 52 had interpretable exercise electrocardiograms (sensitivity 50%; specificity 69%). Exercise echocardiography had a sensitivity of 69% and a specificity of 98% in the 96 patients and a sensitivity of 82% and a specificity of 96% in patients who achieved >85% of maximal heart rate. Approaches adopting Bayes' theorem and restricting further investigation to patients with at least intermediate pretest probability of coronary disease were the least costly. When combined with exercise echocardiography as the initial test, clinical stratification was associated with a false-negative rate of 21%. The utility of exercise electrocardiography is limited by the high prevalence of resting electrocardiographic abnormalities and suboptimal sensitivity and specificity. The best balance of cost and diagnostic accuracy is to perform exercise echocardiography in patients with at least intermediate probability of coronary artery disease.

Objective: To conduct a cost-minimization analysis of intravenous adenosine and intravenous dipyridamole in thallous chloride TI 201 single-photon emission computed tomography (SPECT) myocardial perfusion imaging., Design: A retrospective, open-label, cost-minimization analysis., Setting: University hospital, outpatient nuclear medicine department., Patients: Eighty-three patients undergoing dipyridamole TI 201 SPECT and 166 patients undergoing adenosine TI 201 SPECT., Main Outcome Measures: A cost-minimization analysis was conducted using a direct cost accounting approach estimating institutional costs. For the purpose of this study, sensitivity and specificity between adenosine SPECT and dipyridamole SPECT were assumed to be identical. Key costs evaluated included acquisition, administration, monitoring, treatment of adverse effects, follow-up care, and repeat tests., Results: Adenosine increased heart rate and lowered blood pressure to a significantly greater extent than dipyridamole. The frequency of adverse reactions was not significantly different (p = 0.103) between adenosine (1.64 +/- 1.32 per patient) and dipyridamole (1.36 +/- 1.23 per patient). The frequency of prolonged and late-onset adverse effects was significantly greater for dipyridamole than for adenosine (p < 0.001). The frequency of adverse events requiring medical intervention was statistically greater for dipyridamole (24%) compared with adenosine (5%) (p < 0.00001). Total cost was significantly less for adenosine ($378.50 +/- $128.20 per patient) compared with dipyridamole ($485.60 +/- $230.40). Although adenosine had a significantly greater acquisition cost than dipyridamole (p < 0.0001), administration, monitoring, and adverse reaction costs were significantly less for adenosine than for dipyridamole., Conclusions: The cost of using dipyridamole is significantly greater than the cost of using adenosine despite adenosine's high acquisition cost. Adenosine is less expensive to use because of lower administration costs, monitoring costs, and adverse effect costs. Adenosine should be the agent of choice for pharmacologic vasodilation in the setting of myocardial perfusion imaging.

The purpose was to determine whether physicians receive substantially less compensation from patient groups (women, older patients, and nonwhite patients) that are reported to have low rates of utilization of cardiovascular services. Over an 18-month period we collected information on payments to physicians by 3,194 consecutive patients who underwent stress testing an 833 consecutive patients who underwent percutaneous coronary angioplasty at the Yale University Cardiology Practice. Although the charges for procedures were not related to patient characteristics, there were large and significant differences in payment to physicians based on age, sex, and race. For example, physicians who performed percutaneous transluminal coronary angioplasty received at least $2,500 from, or on behalf of, 72% of the patients 40 to 64 years old, 22% of the patients 65 to 74 years old, and 3% of the patients 75 years and older (P < 0.001); from 49% of the men and 28% of the women (P < 0.001); and 42% of the whites and 31% of the nonwhites (P < 0.001). Similar differences were observed for stress testing. These associations were largely explained by differences in insurance status.

Study Objective: To determine whether emergency patients with acute chest pain and low suspicion of acute myocardial infarction (AMI) can be managed cost-effectively and safely in a dedicated chest pain center (CPC) that incorporates mandatory stress testing., Methods: We assembled a prospective observational case series of consecutive adult patients transferred from the emergency department to a nine-bed, 23-hour CPC in a 564-bed community hospital from January 13 through May 31, 1994. In our institution, all emergency patients with acute nontraumatic chest pain of unclear origin, suggestive of myocardial ischemia but with a low probability of AMI, are transferred to the CPC for further evaluation. All patients in whom AMI is ruled out undergo individually appropriate cardiac diagnostic testing in accordance with CPC clinical guidelines. Patients with end-stage coronary artery disease transferred to the CPC for a "rule-out" protocol only did not undergo further diagnostic testing. Admitted and discharged patients were followed through chart review and telephone survey, respectively., Results: Of the 502 patients transferred to the CPC, 477 (95%) completed follow-up at 14 days. Four hundred ten (86%) were discharged home. Those discharged after diagnostic evaluation yielded negative findings had 100% survival and zero diagnosis of AMI at 5-month follow-up. Overall mortality and incidence of AMI on long-term follow-up for all patients transferred to the CPC were .4% and .2%, respectively. Sixty-seven patients (13%) were admitted from the CPC, of whom 44 (66%) had a final diagnosis of ischemic heart disease (IHD) or AMI. Twenty-four patients with IHD (55%; 6% of stress-tested group) were identified only on further stress testing. Of these patients, seven underwent percutaneous transluminal coronary angioplasty or coronary artery bypass grafting during hospitalization. All were discharged home without major morbidity. Four hundred twenty-four patients (84%) underwent stress testing. The cost of mandatory stress testing to identify one patient with IHD after AMI was ruled out was $3,125. An average cost-per-case savings of 62% was achieved for each patient transferred to the CPC who would have been hospitalized before the inception of the CPC., Conclusion: Mandatory stress testing is a safe, cost-effective, and valuable diagnostic and prognostic tool in CPC patients.

The role of different instruments in evaluation of disturbance in the lower urinary tract has been discussed briefly, emphasizing simplicity and the power of the contact between the physician and the patient. A good history based on clear and descriptive language is still the milestone in making the correct diagnosis. Combined with a proper physical examination and simple inexpensive and time-saving clinical examination this may leave only few patients requiring sophisticated multichannel urodynamic equipment before the adequate treatment can be offered. One should bear in mind that the world is facing diminishing medical resources at the same time as there are more and more women seeking help for their incontinence. Therefore the measurements must be cost effective and patient friendly.

P. carinii pneumonia is one of the most frequent opportunistic infections in HIV-infected patients. Clinical and radiological manifestations are non-specific and reference diagnostic procedure remains broncho-alveolar lavage which is costly and invasive. Alternative diagnostic strategies have been proposed. We report here our experience as well as literature date in this field with the purpose to show the usefulness of decision analysis techniques in choosing an optimal cost-effective strategy.

The Electrophysiologic Study Versus Electrocardiographic Monitoring (ESVEM) trial was completed in 1992 and the primary results were reported in 1993. Since then, considerable discussion about this trial has taken place and new trial results have been reported. Trial analysis has yielded seven principal findings to date concerning treatment of patients with ventricular tachyarrhythmias, ie: (1) similar accuracy of electrophysiologic study (EPS), Holter monitoring (HM), and EPS combined with HM for predicting antiarrhythmic drug efficacy; (2) greater efficiency and lower cost of HM; (3) improved survival associated with predicted drug efficacy; (4) predictors of response to EPS and HM; (5) greater efficacy and lower cost of therapy with sotalol compared with drugs with class-l effects; (6) lack of a relationship between presenting and recurring arrhythmia; and (7) preponderance of nonarrhythmic deaths in trial participants. A number of additional specific findings of the trial are reviewed in this symposium. Several criticisms of the trial's enrollment, methods, and efficacy criteria are reviewed and discussed. Some criticisms are valid. Many are related to misunderstandings of ESVEM trial methodology and to bias of the individual critics. Some are simply incorrect. The importance of the ESVEM trial in the present day may be limited by the growing use of implanted devices rather than drugs for treatment of ventricular tachyarrhythmias. If clinical trials ultimately prove devices to be no more effective than drugs, the findings of the ESVEM investigators will grow in importance.

The hypothesis that a diagnostic evaluation performed by a generalist is less expensive than that performed by a specialist is untested. We retrospectively evaluated the indications and financial ramifications of radionuclide exercise stress testing by cardiologists and noncardiologists in 1,902 consecutive adults with normal resting electrocardiograms. Subjects completed radionuclide exercise tests for the diagnosis or management of coronary artery disease during a 14-month period. Tests were considered "indicated" or "not indicated" based on criteria determined from published reports and established practice guidelines. Savings in costs and charges were determined for a strategy of referral to a cardiologist before ordering tests. Non-cardiologists ordered more tests that were not indicated than cardiologists (69.6% vs 36.2%, chi-square = 209.07, p < 0.00001). Non-cardiologists also ordered tests that were not indicated in patients with (chi-square = 110.02, p < 0.00001) and without (chi-square = 110.02, p < 0.00001) and without (chi-square = 45.44, p < 0.00001) chest pain. Tests that were not indicated resulted in excess costs of $591,384 and excess charges of $1,082,400. Referral to a cardiologist before ordering tests could have saved $63,257 in costs and $169,800 in charges. Both cardiologists and non-cardiologists overutilized radionuclide exercise stress test; however, non-cardiologists were more likely to order tests that were not indicated. A strategy of referral to a cardiologist before ordering tests may be cost-effective in this population.

The aim of this study was to analyse the cost-effectiveness ratio of four diagnostic strategies for Pneumocystis carinii pneumonia (PCP) in patients infected with human immunodeficiency virus (HIV). Two hundred and ten HIV-infected patients with suspected PCP underwent induced-sputum (IS) followed, if negative, by bronchoalveolar lavage (BAL); 85 of these patients were able to undergo an exercise test (ET), prior to induced sputum and BAL. The following strategies were analysed: BAL strategy (BAL whenever PCP is suspected); IS strategy (induced sputum followed by BAL if negative); exercise test (ET) strategy, (ET followed by BAL if the results are abnormal); and the ES (exercise sputum) strategy (i.e. BAL only after abnormal ET and negative IS). The cost of each strategy was calculated by taking into account only direct costs; the conditions in which two given strategies would be cost-equivalent were also evaluated. The prevalence of PCP in this population was 31%; IS had 100% specificity and 71% sensitivity, whilst ET had 100% sensitivity and 77% specificity. The costs of BAL, IS, ET and ES strategies were 210,000, 191,940, 140,700 and 112,700 FF, respectively. The ES strategy is, thus, most suitable for our unit. The most economic strategy depends not only on the cost and characteristics of the procedures, but also on the prevalence of PCP in the test population. In conclusion, we developed a model for use by diagnostic centres in choosing the most suitable strategy, on the basis of the local prevalence of PCP.

Objectives: This study assessed the incremental prognostic implications of normal and equivocal exercise technetium-99m (Tc-99m) sestamibi single-photon emission computed tomography (SPECT) and sought to determine its incremental prognostic value, impact on patient management and cost implications., Background: The prognostic implications of Tc-99m sestamibi SPECT are not well defined, and risk stratification using this test has not been explored., Methods: We studied 1,702 patients referred for exercise Tc-99m sestamibi SPECT who were followed up for a mean (+/- SD) of 20 +/- 5 months. Patients with previous percutaneous transluminal coronary angioplasty or coronary artery bypass surgery were excluded. The SPECT studies were assessed using semiquantitative visual analysis. Cardiac death and myocardial infarction were considered "hard" events, and coronary angioplasty and bypass surgery > 60 days after testing were considered "soft" events., Results: Of the 1,702 patients studied, 1,131 had normal or equivocal scan results. A total of 10 events occurred in this group (1 cardiac death and 1 myocardial infarction [0.2% hard events]; 4 coronary angioplasty and 4 bypass surgery procedures [0.7% soft events]). The rates of hard events and referral to catheterization after SPECT were similarly low in patients with a low (< 0.15), intermediate (0.15 to 0.85) and high (> 0.85) post-exercise treadmill test (ETT) likelihood of coronary artery disease. With respect to scan type, patients with normal, probably normal or equivocal scan results had similarly low hard event rates. In the 571 patients with abnormal scan results, there were 43 hard events (7.5%) and 42 soft events (7.4%) (p < 0.001 vs. 1,131 patients with normal scan results for both). When the complete spectrum of scan responses was considered, SPECT provided incremental prognostic value in all patient subgroups analyzed. However, the nuclear scan was cost-effective only in patients with interpretable exercise ECG responses and an intermediate to high post-ETT likelihood of coronary artery disease and in those with uninterpretable exercise ECG responses and an intermediate to high pre-ETT likelihood of coronary artery disease., Conclusions: Normal or equivocal exercise Tc-99m sestamibi study results are associated with a benign prognosis, even in patients with a high likelihood of coronary artery disease. Although incremental prognostic value is added by nuclear testing in all patient subgroups, a testing strategy incorporating nuclear testing proved to be cost-effective only in the groups with an intermediate to high likelihood of coronary artery disease before scanning.