Utility of stress testing and coronary calcification measurement for detection of coronary artery disease in women

Accurate and safe diagnostic testing provides the crucial link between detection and optimal management of coronary artery disease (CAD). Noninvasive diagnostic testing for CAD may be less accurate in women than in men. Many noninvasive diagnostic modalities are available for this purpose. An exercise tolerance test provides an assessment of functional capacity and has the advantages of wide availability and low initial cost. However, exercise echocardiography may be the most cost-effective method for the initial assessment of coronary artery disease in intermediate-risk women owing to its higher sensitivity and specificity. Recent studies with electron-beam computed tomography reveal that women with no coronary calcification are very unlikely to have obstructive CAD. In symptomatic women with an intermediate likelihood of CAD, either an exercise treadmill test or exercise echocardiography is appropriate for initial screening and can provide useful prognostic information. Alternatively, an electron-beam computed tomographic scan with a 0 calcium score may spare many women with atypical chest pain or equivocal findings on an exercise tolerance test from undergoing more expensive stress imaging studies or coronary angiography. For high-risk symptomatic women, a more aggressive approach involving coronary angiography appears to be the preferred initial diagnostic strategy.     

Cost-effectiveness of diagnostic strategies for patients with chest pain.

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.     

The Role of Noninvasive Imaging in Coronary Artery Disease Detection,Prognosis, and Clinical Decision Making

A vast array of noninvasive imaging modalities is available for the evaluation of the presence and severity of coronary artery disease (CAD). Choosing the right test can be challenging but is critical for proper patient diagnosis and management. Presently available imaging tests for CAD include: (1) nuclear myocardial perfusion imaging procedures (single-photon emission tomography) and positron emission tomography, (2) stress echocardiography, (3) computed tomography coronary angiography, and (4) cardiac magnetic resonance imaging. Exercise treadmill testing electrocardiography is another alternative that we will discuss briefly. Selection of the most appropriate imaging modality requires knowledge of the clinical question being addressed, patient characteristics (pretest probability and prevalence of disease), the strengths, limitations, risks, costs, and availability of each procedure. To assist with test selection, we review the relevant literature in detail to consider the relative merits of cardiac imaging modalities for: (1) detection of CAD, (2) risk stratification and prognostication, and (3) guiding clinical decision making.     

Diagnosis of suspected coronary artery disease in women: a cost-effectiveness analysis.

BACKGROUND: The optimal strategy for the diagnosis of coronary artery disease (CAD) in women is not well defined. We compared the cost-effectiveness of several strategies for diagnosing CAD in women with chest pain. METHODS: We performed decision and cost-effectiveness analyses with simulations of 55-year-old ambulatory women with chest pain. With a Markov model, simulations of patients underwent exercise electrocardiography, exercise testing with thallium scintigraphy, exercise echocardiography, angiography, or no workup. RESULTS: Diagnosis with angiography cost less than $17, 000 per quality-adjusted life-year compared with exercise echocardiography if the patient had definite angina and less than $76,000 per life-year if she had probable angina. If she had nonspecific chest pain, diagnosis with exercise echocardiography increased life-years compared with no testing. CONCLUSIONS: Cost-effectiveness of first-line diagnostic strategy for diagnosis of CAD in women varies mostly according to pretest probability of CAD. Diagnosis of coronary artery disease with angiography is cost-effective in 55-year-old women with definite angina. In 55-year-old women with probable angina, diagnosis with angiography would increase quality-adjusted life-years but significantly increase costs. Use of exercise echocardiography as a first-line diagnosis for CAD is cost effective in 55-year-old women with probable angina and nonspecific chest pain.     

Cardiac Imaging in the Diagnosis of Coronary Artery Disease

Coronary artery disease (CAD) continues to be a leading cause of morbidity and mortality worldwide. Although invasive coronary angiography has previously been the gold standard in establishing the diagnosis of CAD, there is a growing shift to more appropriately use the cardiac catheterization laboratory to perform interventional procedures once a diagnosis of CAD has been established by noninvasive imaging modalities rather than using it primarily as a diagnostic facility to confirm or refute CAD. With ongoing technological advancements, noninvasive imaging plays a pre-eminent role in not only diagnosing CAD but also informing the choice of appropriate therapies, establishing prognosis, all while containing costs and providing value-based care. Multiple imaging modalities are available to evaluate patients suspected of having coronary ischemia, such as stress electrocardiography, stress echocardiography, single-photon emission computed tomography myocardial perfusion imaging, positron emission tomography, coronary computed tomography (CT) angiography, and magnetic resonance imaging. These imaging modalities can variably provide functional and anatomical delineation of coronary stenoses and help guide appropriate therapy. This review will discuss their advantages and limitations and their usage in the diagnostic pathway for patients with CAD. We also discuss newer technologies such as CT fractional flow reserve, CT angiography with perfusion, whole-heart coronary magnetic resonance angiography with perfusion, which can provide both anatomical as well as functional information in the same test, thus obviating the need for multiple diagnostic tests to obtain a comprehensive assessment of both, plaque burden and downstream ischemia. Recognizing that clinicians have a multitude of tests to choose from, we provide an underpinning of the principles of ischemia detection by these various modalities, focusing on anatomy vs physiology, the database justifying their use, their prognostic capabilities and lastly, their appropriate and judicious use in this era of patient-centered, cost-effective imaging.     

Evaluation of Suspected Ischemic Heart Disease in Symptomatic Women

There is a wealth of evidence about the role of a variety of diagnostic testing modalities to define coronary artery disease (CAD) risk in women presenting for evaluation of suspected myocardial ischemia. The exercise electrocardiogram (ECG) is the core index procedure, which can define risk in women capable of performing maximal exercise. Stress imaging, using echocardiography or myocardial perfusion single-photon emission computed tomography/positron emission tomography, is useful for symptomatic women with an abnormal resting ECG or for those who are functionally disabled. For women with low-risk stress imaging findings, there is a very low risk of CAD events, usually < 1%. There is a gradient relationship between the extent and severity of inducible abnormalities and CAD event risk. Women at high risk are those defined as having moderate to severely abnormal wall motion or abnormal perfusion imaging findings. In addition to stress imaging, the evidence of the relationship between CAD extent and severity and prognosis has been clearly defined with coronary computed tomographic angiography. In women, prognosis for those with mild but nonobstructive CAD is higher when compared with those without any CAD. The current evidence base clearly supports that women presenting with chest pain can benefit from one of the commonly applied diagnostic testing modalities.     

Stress echocardiography in women.

The diagnosis of coronary heart disease in women has been thought to be more difficult than in men, owing to the overall lower prevalence and severity of disease in women, as well as more subtle clinical presentations. Exercise electrocardiography is associated with a high rate of false-positive results. In contrast, exercise and pharmacologic stress echocardiography have been shown to have high sensitivity, specificity, and prognostic value in women, comparable to that obtained in a male population. Although exercise thallium provides high f disease accuracy, due to its cost, availability, and radiation exposure, it may not be the ideal initial test in women. Thus, compared with other modalities, the advantages of stress echocardiography include its lower cost, availability, and high diagnostic accuracy. In the evaluation of women with chest pain, the initial step should involve clinical stratification into low, moderate, or high-probability groups based on symptoms, age, and cardiovascular risk factors. In women with atypical chest pain and a low probability of coronary heart disease, further testing should be avoided because any positive result is likely to be falsely positive. In those women with a moderate likelihood of disease, the most efficient and cost-effective strategy includes stress echocardiography as the initial test. This approach avoids the high rate of false-positive results with subsequent unnecessary angiography generated by exercise electrocardiography, as well as minimalizing false-negative results, which would lead to delays and potential increase in morbidity and mortality from untreated coronary heart disease. The optimal strategy for women at high clinical risk may be either exercise echocardiography or cardiac catheterization as the initial test. Although the diagnosis of CAD in women is different than in men, it is not necessarily more difficult. Astute clinical evaluation, in conjunction with judicious use of diagnostic testing, yields excellent results.     

Coronary computed tomography angiography in patients with stable coronary artery disease

The treatment of coronary artery disease (CAD), which is defined by stable anatomical atherosclerotic and functional alterations of epicardial vessels or microcirculation, focuses on managing intermittent angina symptoms and preventing major adverse cardiovascular events with optimal medical therapy. When patients with known CAD present with angina and no acute coronary syndrome, they have historically been evaluated with a variety of noninvasive stress tests that utilize electrocardiography, radionuclide scintigraphy, echocardiography, or magnetic resonance imaging for determining the presence and extent of inducible myocardial ischemia. Patient event-free survival, however, is largely driven by the coronary atherosclerotic disease burden, which is not directly assessed by functional testing. Direct evaluation of coronary atherosclerotic disease by coronary computed tomography angiography (coronary CTA) has emerged as the first line noninvasive imaging modality as it improves diagnostic accuracy and positively influences clinical management. Compared to functional assessment of CAD, coronary CTA-guided management results in improved patient outcomes by facilitating prevention of myocardial infarction. Other strengths of coronary CTA include detailed atherosclerotic plaque characterization and the ability to assess functional significance of specific lesions, which may further improve risk assessment and prognosis and lead to more appropriate referrals for additional testing, such as invasive coronary angiography.     

Role of multimodality cardiac imaging in preoperative cardiovascular evaluation before noncardiac surgery

The preoperative cardiac assessment of patients undergoing noncardiac surgery is common in the daily practice of medical consultants, anesthesiologists, and surgeons. The number of patients undergoing noncardiac surgery worldwide is increasing. Currently, there are several noninvasive diagnostic tests available for preoperative evaluation. Both nuclear cardiology with myocardial perfusion single photon emission computed tomography (SPECT) and stress echocardiography are well-established techniques for preoperative cardiac evaluation. Recently, some studies demonstrated that both coronary angiography by gated multidetector computed tomography and stress cardiac magnetic resonance might potentially play a role in preoperative evaluation as well, but more studies are needed to assess the role of these new modalities in preoperative risk stratification. A common question that arises in preoperative evaluation is if further preoperative testing is needed, which preoperative test should be used. The preferred stress test is the exercise electrocardiogram (ECG). Stress imaging with exercise or pharmacologic stress agents is to be considered in patients with abnormal rest ECG or patients who are unable to exercise. After reviewing this article, the reader should develop an understanding of the following: (1) the magnitude of the cardiac preoperative morbidity and mortality, (2) how to select a patient for further preoperative testing, (3) currently available noninvasive cardiac testing for the detection of coronary artery disease and assessment of left ventricular function, and (4) an approach to select the most appropriate noninvasive cardiac test, if needed.     

Clinical and economic impact of exercise electrocardiography and exercise echocardiography in clinical practice.

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.     

Non-invasive assessment of low- and intermediate-risk patients with chest pain

Coronary artery disease (CAD) remains a significant global public health burden despite advancements in prevention and therapeutic strategies. Common non-invasive imaging modalities, anatomic and functional, are available for the assessment of patients with stable chest pain. Exercise electrocardiography is a long-standing method for evaluation for CAD and remains the initial test for the majority of patients who can exercise adequately with a baseline interpretable electrocardiogram. The addition of cardiac imaging to exercise testing provides incremental benefit for accurate diagnosis for CAD and is particularly useful in patients who are unable to exercise adequately and/or have uninterpretable electrocardiograms. Radionuclide myocardial perfusion imaging and echocardiography with exercise or pharmacological stress provide high sensitivity and specificity in the detection and further risk stratification of patients with CAD. Recently, coronary computed tomography angiography has demonstrated its growing role to rule out significant CAD given its high negative predictive value. Although less available, stress cardiac magnetic resonance provides a comprehensive assessment of cardiac structure and function and provides a high diagnostic accuracy in the detection of CAD. The utilization of non-invasive testing is complex due to various advantages and limitations, particularly in the assessment of low- and intermediate-risk patients with chest pain, where no single study is suitable for all patients. This review will describe currently available non-invasive modalities, along with current evidence-based guidelines and appropriate use criteria in the assessment of low- and intermediate-risk patients with suspected, stable CAD.     

Noninvasive strategies for the estimation of cardiac risk in stable chest pain patients. The Economics of Noninvasive Diagnosis (END) Study Group

Effective allocation of medical resources in stable chest pain patients requires the accurate diagnosis of coronary artery disease and the stratification of future cardiac risk. We studied the relative predictive value for cardiac death of 3 commonly applied noninvasive strategies, clinical assessment, stress electrocardiography, and myocardial perfusion tomography, in a large, multicenter population of stable angina patients. The multicenter observational series comprised 7 community and academic medical centers and 8,411 stable chest pain patients. All patients underwent pretest clinical screening followed by stress (exercise 84% or pharmacologic 16%) electrocardiography and myocardial perfusion tomography. Risk-adjusted multivariable Cox proportional hazards models were developed to predict cardiac death. Kaplan-Meier rates of time to cardiac catheterization were also computed. Cardiac mortality was 3% during the 2.5 +/- 1.5 years of follow-up. The number of infarcted vascular territories and pretest clinical risk factors were strong predictors of cardiac mortality, whereas the number of ischemic vascular territories gained increasing importance when determining post-test resource use requirements (i.e., the decision to perform cardiac catheterization). Exertional ST-segment depression in a population with a high frequency of electrocardiographic abnormalities at rest was not a significant differentiator of cardiac death risk. Stable chest pain patients are accurately identified as being at high risk for near-term cardiac events by both physicians' screening clinical evaluation and by the results of stress myocardial perfusion imaging. Disease management strategies for stable chest pain patients aimed at risk reduction should incorporate knowledge of relevant end points in treatment and guideline development.     

Myocardial Perfusion and Viability Imaging in Coronary Artery Disease: Clinical Value in Diagnosis,Prognosis, and Therapeutic Guidance

Coronary artery disease is a leading cause of morbidity and mortality worldwide. Noninvasive imaging tests play a significant role in diagnosing coronary artery disease, as well as risk stratification and guidance for revascularization. Myocardial perfusion imaging, including single photon emission computed tomography and positron emission tomography, has been widely employed. In this review, we will review test accuracy and clinical significance of these methods for diagnosing and managing coronary artery disease. We will further discuss the comparative usefulness of other noninvasive tests—stress echocardiography, coronary computed tomography angiography, and cardiac magnetic resonance imaging—in the evaluation of ischemia and myocardial viability.     

Dipyridamole myocardial perfusion tomography in patients with severe aortic stenosis

Patients with aortic stenosis (AS) may have classic angina pectoris. The safety of exercise testing in adults with AS is controversial and, in fact, exercise testing in such patients is considered to be contraindicated especially in severe aortic stenosis (SAS). Furthermore, exercise testing has low specificity in uncovering coronary artery disease (CAD) in patients with AS, because the baseline ECG is frequently abnormal. We wished to assess the safety and diagnostic accuracy of dipyridamole stress myocardial perfusion tomography (DMPT) in the detection of CAD in patients with SAS. METHODS: The study included 30 patients with SAS (mean aortic valve area 0.57 +/- 0.09 cm(2)). All patients underwent dipyridamole myocardial perfusion scintigraphy (SPECT), coronary arteriography and catheterization, as well as Doppler echocardiography. Myocardial perfusion tomography was applied with (99m)Tc hexakis-2-methoxyisobutyl isonitrile (MIBI) by a single day rest-dipyridamole infusion protocol. Hemodynamic, electrocardiographic and clinical responses were compared with those of 50 control patients without AS. RESULTS: Hemodynamic responses during dipyridamole stress tests demonstrated no significant differences between the controls and the AS patients in the following parameters: systolic blood pressure, heart rate, rate-pressure product or incidence of headache, chest pain, dyspnea, flushing and dizziness. A reversible perfusion defect was observed in 10 patients with DMPT. The existence of coronary lesions was determined by coronary arteriography in 8 of 10 patients (sensitivity 100%, specificity 91%). CONCLUSION: The results showed that DMPT is well tolerated, even by patients with SAS and is of high diagnostic value in assessing CAD.     

Dobutamine stress echocardiography in the diagnosis of coronary artery disease in women with chest pain: comparison with different noninvasive tests

BACKGROUND: Diagnosis of coronary artery disease(CAD) in women remains elusive. The classical diagnostic armamentarium has been found to be very limited. Dobutamine stress echocardiography has emerged as a powerful test in assessing CAD in the general population, but most studies failed to include women. HYPOTHESIS: The accuracy of dobutamine stress echocardiography in the diagnosis of CAD in women with chest pain is high and superior to dipyridamole echocardiography, exercise electrocardiography, and sestamibi single-photon emission tomography (MIBI-SPECT) scintigraphy. METHODS: We studied 99 consecutive women with chest pain and no previous history of CAD who underwent dobutamine echocardiography and coronary angiography. We also compared these results with those of dipyridamole echocardiography in 63 patients. exercise stress testing in 83 (48 conclusive), and MIBI-SPECT scintigraphy during dobutamine infusion in 54. RESULTS: Significant CAD was found in 42 women. Sensitivity and specificity of dobutamine stress echocardiography were 69 and 89%, respectively. Dipyridamole echocardiography showed similar accuracy (sensitivity 72% and specificity 94%). Finally, sensitivity of exercise test and MIBI-SPECT was similar (76 and 88%, respectively) and specificity was lower (53 and 57%, respectively). After excluding patients known to have a high incidence of false positive results, MIBI-SPECT specificity rose up to 80%. CONCLUSION: Dobutamine stress echocardiography and dipyridamole echocardiography bear a high diagnostic accuracy in women with chest pain. MIBI-SPECT is also a useful tool after excluding subgroups with a high incidence of false positive results.     

Exercise echocardiography and technetium-99m MIBI single-photon emission computed tomography in the detection of coronary artery disease

To compare the relative diagnostic value of exercise echocardiography with perfusion technetium-99m metoxyisobutylisonitrile single-photon emission computed tomography (SPECT) in detecting coronary artery disease (CAD), 75 patients with suspected CAD but a normal electrocardiogram (ECG) at rest were included in a prospective correlative study. Both the exercise echocardiograms and SPECT studies were performed in conjunction with the same symptom-limited bicycle exercise test. The development of either a new wall motion abnormality or a reversible perfusion defect after exercise, or both, were regarded as a positive test for the exercise echocardiographic and SPECT studies, respectively. The results of these 2 diagnostic tests were compared with coronary arteriography. Exercise echocardiography identified 35 (71%) and SPECT 41 (84%, p = 0.13) of the 49 patients with significant CAD (defined as greater than 50% diameter stenosis). Twenty-five of the 26 patients (96%) without significant coronary stenosis had negative exercise echocardiographic results and 23 of 26 (88%) had negative SPECT results. Exercise-induced new wall motion abnormalities showed a good correlation with reversible perfusion defects, and the results of the 2 methods were concordant in 65 of 75 patients (agreement = 88%, kappa = 0.75 +/- 0.14). Both the diagnostic accuracy of exercise echocardiography and SPECT were significantly higher than the exercise ECG (81 vs 64%, p less than 0.02 and 88 vs 64%, p less than 0.005). The sensitivity and specificity for detecting individual diseased vessels were 60 and 95% for exercise echocardiography and 67 and 94% for SPECT.(ABSTRACT TRUNCATED AT 250 WORDS)     

Current evidence on diagnostic testing in women with suspected coronary artery disease: choosing the appropriate test

Marked reductions in cardiovascular mortality have been reported over the last 2 decades as a result of therapeutic advances in ischemic heart disease. Despite medical advances, case fatality rates are higher for women than men. A critical step toward improving outcomes is early diagnosis of coronary artery disease by noninvasive evaluation. The use of noninvasive testing in women has been controversial because of a perception of diminished accuracy, limited female representation, and compromise of efficacy of testing because of technical limitations (eg, thallium-201 breast artifact). Recent meta analysis and large observational series report marked improvements in the accuracy of results for women undergoing exercise treadmill, echocardiography, and nuclear testing. Exercise treadmill testing has an improved accuracy when multiple risk parameters (eg, ST deviation, chest pain, exercise time) are included in the test interpretation. For women, a low-risk Duke treadmill score is associated with a 97% 5-year survival, with 80% of these patients having no obstructive disease. Multivessel disease (70%) is common for those with a high-risk treadmill score with a 5-year survival of 90%. The diagnostic accuracy of electron beam computed tomography reveals a sensitivity and specificity of 88% and 49%. For exercise echocardiography, test diagnostic sensitivity and specificity are 86% and 79%. For nuclear imaging, 3-year cardiac survival ranged from 99% to 85% for 0 to 3 vascular territories with perfusion abnormalities. A sufficient body of evidence supports the use of noninvasive testing for intermediate-risk, symptomatic women. Diagnostic certainty may be effectively guided by the evaluation of global and regional wall motion, eg, with echocardiography. Risk assessment may be more precise with the evaluation of myocardial perfusion, eg, with stress nuclear imaging. With the use of updated evidence, informed test selection for women may result in improved diagnostic and therapeutic decision-making, with the use of available noninvasive testing modalities.     

The clinical role of stress myocardial perfusion imaging in women with suspected coronary artery disease

Cardiovascular disease remains the number one cause of mortality for women in the United States, with coronary artery disease (CAD) accounting for 54% of all cardiovascular deaths. CAD claims the lives of more than 250,000 women each year and is therefore the single largest killer of American women. For several decades, the underrepresentation of women in clinical trials led to both a lack of available sex-specific evidence and a generalized misconception that CAD was a “man's disease.” In actuality, not only are women vulnerable to CAD, they typically develop it 10 to 15 years later than men. Furthermore, sex differences exist in the mortality rates of women and men with CAD, such that once CAD is present in women, they have worse outcomes than their male counterparts. Consequently, early and accurate diagnosis of CAD is crucial for reducing mortality rates in women. Stress myocardial perfusion imaging (MPI) using contemporary techniques has been shown to have significant value in the diagnosis and prognosis of CAD in women. In the risk assessment of women with an intermediate clinical pretest likelihood of CAD, using MPI with exercise or pharmacologic stress has been shown to add incremental value to clinical variables or exercise electrocardiogram stress testing alone. This review discusses the clinical role of stress MPI in the management of women with suspected CAD.     

Comparison of stress/rest myocardial perfusion tomography, dipyridamole and dobutamine stress echocardiography for the detection of coronary disease in hypertensive patients with chest pain and positive exercise test.

OBJECTIVES: Although different noninvasive tests have been proposed for detecting coronary artery disease (CAD) in patients with hypertension and chest pain symptoms, the relative performance of the available techniques has not been systematically assessed. BACKGROUND: Patients with hypertension frequently complain of chest pain and exhibit ischemic-like ST segment changes on the exercise electrocardiogram (ECG). However, the specificity of such changes for predicting significant CAD is very low, because these patients often exhibit a normal coronary angiogram. METHODS: In 101 patients with hypertension, chest pain and positive exercise ECG, we performed stress/rest myocardial single photon emission computed tomography with 99mTc-MIBI, dipyridamole and dobutamine stress echocardiography and coronary angiography. All patients had normal global ventricular function and 57 had left ventricular hypertrophy. All were kept on ACE inhibitors during the study period. RESULTS: No patients had significant side effects during perfusion scintigraphy. Dose-limiting side effects were observed in five patients with dipyridamole and in seven patients with dobutamine. Only 56% of study patients exhibited significant CAD. Sensitivity, specificity, accuracy, positive and negative predictive values were, respectively, 98%, 36%, 71%, 67% and 94% for perfusion scintigraphy, 61%, 91%, 74%, 90% and 64% for dipyridamole and 88%, 80%, 84%, 85% and 83% for dobutamine stress echocardiography. CONCLUSIONS: This study shows that stress echo in patients with hypertension yields a satisfactory diagnostic accuracy for identifying significant epicardial CAD. Our results indicate that dobutamine might be superior to dipyridamole. The low specificity of myocardial scintigraphy probably relates to the fact that this method traces perfusion abnormalities, not necessarily caused by epicardial CAD, possibly due to microvascular disease and not causing obvious wall motion abnormalities.     

Cost-effectiveness of alternative test strategies for the diagnosis 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.