Dipyridamole Thallium Scintigraphy Research Articles

Applying preoperative dipyridamole thallium-201 scintigraphy for preventing cardiac mortality and complications for patients with secondary hyperparathyroidism undergoing parathyroidectomy

To evaluate the value of preoperative dipyridamole thallium-201 scintigraphy for reducing cardiovascular complication in secondary hyperparathyroidism (SHPTH) patients. Thallium scintigraphy was arranged for all dialysis patients who underwent parathyroidectomy from Jan 2011 to July 2015. Management of defects on thallium scintigraphy included cardiac catheterization and ultrasonography. Analysis includes 30-day mortality, morbidity and the predicting factors for thallium scintigraphy defect. Of 249 patients with SHPTH, 19 (7.6%) had defects on thallium scintigraphy, 15 (88%) of whom had coronary artery disease on angiography. History of acute coronary syndrome (ACS, p<0.001), diabetes mellitus (DM, p=0.03), male sex (p=0.03), and higher body mass index (BMI, p=0.001) were significant predictors of positive thallium scintigraphy results. History of ACS was the most significant predictor after adjustment in the multivariate logistic analysis (odds ratio, 22.56; 95% confidence interval, 7.02-72.53). All the patients survived the 30-day postoperative period, with minimal cardiovascular morbidity. Preoperative dipyridamole thallium-201 scintigraphy is useful for SHPTH patients to minimized surgical mortality and morbidity.

Asymptomatic papillary fibroelastoma of the aortic valve

A previously healthy 63-year-old woman with multiple risk factors for coronary artery disease was referred to the outpatient clinic with a three-month history of atypical chest pain. At physical examination no abnormalities could be detected and the ECG was completely normal. At transthoracic echocardiography and transoesophageal echocardiography a mass, 1 cm in diameter and attached to the right coronary cusp of the aortic valve, was detected. The mass had the echocardiographic appearance of a nonhomogeneous, round, dense, mobile structure, typical features of a fibroelastoma (figure 1). On dipyridamole-thallium scintigraphy, no coronary insufficiency could be demonstrated. Since cardiac papillary fibroelastomas are associated with a risk of thromboembolic events, the patient underwent complete tumour excision by a simple shave excision (figure 2).

Long-term results of elective open repair for abdominal aortic aneurysm

腹的大动脉的动脉瘤(AAA ) 有高倾向破裂。自从他们，由有接枝的常规外科的代替的修理 ofAAA 是治疗的标准标志 1960 年代。因为进展在外科，麻木并且特别护理技术，选任的开的 AAA 修理的结果常常改善了。与 endovasculartechniques 的改进，然而，开的修理的角色正在被质问。越来越多的 stents 正在被部署住院病人因为他们的不太侵略的特征。我们我们经验的十年关于 endoluminal 和开的修理与选任的开的 AAA 修理和最近的报纸考察了让 AAA 在中国为 AAA 讨论开的修理的地位和未来。

The role of myocardial perfusion scanning, heart rate variability and D-dimers in predicting the risk of perioperative cardiac complications after peripheral vascular surgery.

To study the value of a number of proposed prognostic factors in prediction of the risk of perioperative cardiac events after vascular surgery. Two hundred and ninety-seven patients undergoing peripheral vascular surgery were prospectively studied. Patients underwent preoperative 24 h ambulatory electrocardiography, measurement of haemostatic variables, myocardial assessment of perfusion by dipyridamole-thallium scintigraphy and radionuclide ventriculography. The primary endpoint was cardiac death or nonfatal myocardial infarction within 30 days of surgery. A combined endpoint included the primary endpoint plus occurrence of cardiac failure, unstable angina or serious arrhythmias. The primary endpoint occurred in 21 (7%), and the combined endpoint in 41 (14%) of patients. On multivariate analysis, increased age, previous myocardial infarction, aortic surgery, impaired heart rate variability and a positive thallium scan were independent predictors of primary end-points. Preoperative atrial fibrillation and increased fibrin D-dimer were additional predictors of the combined endpoint. Construction of receiver-operator characteristic curves to examine the incremental value of predictive models showed that sensitivity and specificity of clinical data alone for primary endpoints was 71% and 72% respectively, while for the full model (incorporating heart rate variability and thallium data) this rose to 84% and 80% (p=0.0001). Preliminary screening using clinical data has limited value in risk assessment prior to vascular surgery but preoperative heart rate variability, D-dimers and thallium scanning provide modest incremental predictive value.

High incidence of silent myocardial ischemia in elderly patients with non insulin-dependent diabetes mellitus

The present study was designed to reveal the incidence of silent myocardial ischemia in asymptomatic elderly non-insulin-dependent diabetic (NIDDM) patients (aged over 60 years). As a first step screening, maximal treadmill exercise test was performed. Of 140 patients studied, 54 (38.6%) were unable or not expected to achieve diagnostic levels of exercise during treadmill testing. A positive exercise test was noted in 39 of 86 (45.3%) subjects. As a second step examination, dipyridamole thallium scintigraphy was performed for 93 subjects who exhibited a positive exercise test and could not perform a maximal exercise test. Abnormal perfusion pattern was found in 39 of 93 (41.9%), who were finally considered to have a silent myocardial ischemia. Coronary angiography was performed in 18 subjects with diagnosis of silent myocardial ischemia, who gave their consent. Significant coronary artery stenosis was in fact found in 17 of 18 (94.4%) subjects studied, confirming a very high positive predictive value of this diagnostic procedure. In conclusion, elderly NIDDM patients (aged over 60 years) had an extremely high prevalence (estimated 26.3%) of silent myocardial ischemia. This evidence suggests that early and intensive detection may be needed as a part of routine care for this group.

Long-term prognostic value of preoperative dipyridamole thallium imaging and clinical indexes in patients with diabetes mellitus undergoing peripheral vascular surgery

The objective of this study is to assess the prognostic impact of preoperative dipyridamole thallium imaging and clinical variables on the long-term outcome of diabetic patients undergoing peripheral vascular surgery. Complete follow-up was obtained in 101 consecutive patients with diabetes mellitus undergoing routine dipyridamole thallium scintigraphy before vascular surgery (mean 4.2 ± 3.2 years, range 1 month to 11 years). Low risk was defined by diabetes alone with a normal resting electrocardiogram. High risk was defined as a history of angina, myocardial infarction, congestive heart failure, or resting electrocardiogram abnormalities. There were 71 deaths in 98 patients discharged alive from the hospital (median survival 4.4 years). Age, the presence of resting electrocardiogram abnormalities, and an abnormal thallium scan were independent predictors of late death. After adjusting for age >70 years and thallium abnormalities, high-risk patients had a death rate 4.8 times (95% confidence interval 1.7 to 13.4, p <0.002) greater than low-risk patients. The presence of >2 reversible thallium defects was useful in further risk stratification of both low- and high-risk patients. Low-risk patients with >2 reversible defects had a median survival of 4.0 years compared with 9.4 years in those with ≤2 reversible defects (p <0.001). Similarly, high-risk patients with ≤2 reversible defects had an intermediate median survival rate of 4.7 years compared with 1.8 years in the group with >2 reversible defects (p <0.001). Therefore, advanced age and the presence of resting electrocardiographic or thallium abnormalities identifies a subset of diabetic patients with a poor long-term outcome after vascular surgery. Combined clinical and thallium variables may identify a population in whom intensive medical or surgical interventions may be warranted to reduce both perioperative and late cardiac events.

Preoperative assessment of cardiac risk in noncardiac major vascular surgery

We evaluated whether a preoperative clinical algorithm allows an adequate stratification in cardiac risk and the predictive value of dipyridamole thallium-201 scintigraphy and rest echocardiography for postoperative adverse cardiac outcomes. Three hundred twenty patients undergoing 338 vascular surgery procedures were prospectively stratified into low, intermediate, and high risk. The low- and intermediate-risk patients underwent surgery without further diagnostic evaluation. In 7 high-risk patients the vascular procedure was canceled (1 died of myocardial infarction at 6-month follow-up), 9 underwent presurgical myocardial revascularization (1 died of myocardial infarction), and 49 underwent vascular surgery with perioperative intensive care treatment. Hospital mortality was 3.8%. Cardiac mortality and morbidity were 1.5% and 10.4%, respectively. We observed a significant difference in “hard” (death, myocardial infarction, pulmonary edema, major arrhythmias) and “soft” (myocardial ischemia, minor arrhythmias) events between groups, p <0.001. Previous pulmonary edema was a predictive variable of cardiac outcomes (multiple logistic regression analysis). Ninety-nine of 220 intermediate-risk patients randomly underwent dipyridamole thallium-201 scintigraphy: 37 had redistribution, 10 persistent, and 52 no defects; 7 of 13 soft and hard cardiac events occurred in patients without redistribution defects. Sensitivity, specificity, and positive and negative predictive values of redistribution defects for postoperative adverse outcomes were 38%, 63%, 14%, 87%, respectively. This algorithm may provide a safe and cost-effective approach (average cost saving per patient $1,500) to cardiac risk stratification. These results suggest that routine use of dipyridamole thallium-201 scintigraphy for screening of intermediate-risk patients may not be warranted.

Preoperative cardiac evaluation is unnecessary in most patients undergoing vascular operations

Background: This study evaluated the impact of Goldman’s index (GI), radionuclide ventriculography (RVG), and dipyridamole-thallium scintigraphy (DTS) on predicting cardiac outcome after vascular operations. Methods: A total of 463 consecutive patients undergoing vascular operations were divided into those who had no DTS, those who had reversible ischemia by DTS, and those who had no reversible ischemia by DTS. GI, ejection fraction, wall motion abnormalities, rate of coronary angiography, and revascularization were determined for each group. Results: Coronary revascularization was ultimately performed in 8% of patients with no DTS, 7% of patients with no ischemia by DTS, and 9% of patients with ischemia by DTS. The GI of 6.1 in patients who died postoperatively was significantly higher than the GI of 3.6 in patients who survived ( P = 0.02). RVG did not predict mortality, morbidity, or need for coronary revascularization. Conclusion: Clinical assessment remains a good predictor for cardiac outcome in patients undergoing vascular operations. More extensive cardiac testing should be reserved for patients with higher GI and active cardiac problems.

Prognosis in patients with left bundle branch block and normal dipyridamole thallium-201 scintigraphy

Background. The presence of complete left bundle branch block (LBBB) is commonly associated with a poorer prognosis, especially in patients with coronary artery disease (CAD). In the general population with suspected CAD and normal intraventricular conduction, a normal dipyridamole-thallium scintigraphy is a strong marker of a favorable outcome. Objective. Our objective was to assess the prognosis in patients with LBBB and a normal dipyridamole thallium-201 scintigram. Population and methods. Patients with complete LBBB and normal myocardial perfusion on dipyridamole SPECT thallium-201 scintigraphy performed in our center for suspected CAD between 1988 and 1995 were monitored for clinical events. Results. Sixty-nine patients (36 women and 33 men) with a mean age of 59 years (range 56 to 61) were monitored for a mean period of 33 months (range 25 to 35). During this period, 4 patients had unstable angina, 2 of whom underwent myocardial revascularization. There were no deaths or myoardial infarction. All events occurred at least 2 years after the thallium-201 scintigraphy. Conclusion. The presence of a normal myocardial perfusion with dipyridamole thallium-201 scintigraphy in this group of patients with suspected CAD and LBBB was associated with a very good prognosis, a low rate of clinical events occurring only 2 years after the myocardial scintigraphy, and no hard events.

Assessment of cardiovascular perioperative risk in non-cardiac surgery

Patients with cardiovascular disease undergoing non cardiac surgery are exposed to three cardiac risks: myocardial infarction, heart failure and death. To estimate cardiac risk, clinical predictors of perioperative cardiovascular risk are classified as major, intermediate and minor and non cardiac surgery is stratified in high risk (greater than 5%), intermediate (from 1 to 5%), minor (lower than 1%) procedures. Efficient perioperative assessment of cardiac patients is obtained by teamwork and usually, indications for further cardiac investigations are the same as those in the nonoperative setting. An simplified algorithm, easier to use than original algorithm given in the guidelines of the American college of cardiology and the American heart association, may be helpful for the indication of further investigations. Five questions must be answered before using algorithm: is it an emergency surgical procedure?, was a coronary revascularization required in the past five years? has the patient had a coronary evaluation in the past two years?, are there identified clinical predictors of cardiac risk?, is it major or minor surgery? Three tests evaluate the preoperative cardiac risk: exercise testing, dipyridamole thallium scintigraphy, dobutamine stress echocardiography. Their accuracy is similar, their negative predictive value is high, their positive predictive value is low. These guidelines may be helpful to indicate further cardiac investigations which will have an impact on patient's treatment, monitoring during or after surgery and outcome.

Dipyridamole thallium-201 scintigraphy for early risk stratification of patients after uncomplicated myocardial infarction

ObjectiveTo determine the safety and prognostic value of dipyridamole thallium-201 scintigraphy performed in patients within three to five days of acute myocardial infarction, including those receiving thrombolytic treatment.DesignA prospective study...

57. Quantitative dipyridamole-thallium scintigraphy and blood pool ventriculography in the prediction of perioperative infarction following peripheral vascular surgery

57. Quantitative dipyridamole-thallium scintigraphy and blood pool ventriculography in the prediction of perioperative infarction following peripheral vascular surgery

Reduced Morbidity and Mortality Following Carotid Endarterectomy: The Value of Preoperative Cardiac Screening

Carotid endarterectomy can be recommended for stroke prophylaxis when performed with low perioperative cardiac morbidity and mortality. In this study the authors evaluate the effectiveness of a cardiac screening protocol using dipyridamole-thallium scintig raphy to identify and treat coexistent coronary artery disease (CAD). The authors reviewed the medical records of 164 patients undergoing carotid endarterectomy between 1988 and 1993 at the John L. Doyne Hospital and at the Zablocki Veterans Administration Hospital in Milwaukee, Wisconsin. Results of the preop erative cardiac evaluations and the incidence of perioperative cardiac events were recorded. Forty patients without any evidence of cardiac disease by history or electrocardio gram went on to surgery without further screening. Eight patients underwent coronary catheterization without dipyridamole-thallium scan, owing to the severity of their cardiac symptoms. A cardiology consultation and dipyridamole-thallium scan were obtained preoperatively in the remaining 116 patients with a history of CAD. Of these 116 patients, 62 (53.4%) were diagnosed as normal. Thirty-five (30%) scans demonstrated reversible reperfusion defects, leading to preoperative coronary angiography in 17 patients and to cardiac revascularizations in 8. Nineteen (16.4%) scans demonstrated a fixed perfusion defect; 3 of these patients underwent coronary catheterization, leading to cardiac revas- cularization in 1 patient. Of 2 patients (1.7%) who suffered a postoperative myocardial infarction, 1 patient had a fixed perfusion defect and 1 was found to have a two-vessel disease on coronary catheterization. There were no perioperative deaths. In the follow- up period (15.9 months; range one to sixty), no cardiac deaths occurred. With this treatment algorithm using selective dipyridamole-thallium scan evaluation, perioperative and long-term cardiac morbidity and mortality can be minimized.

Mechanism of silent myocardial ischemia in elderly patients with coronary artery disease--assessment by dipyridamole thallium scintigraphy

To evaluate the clinical significance of silent myocardial ischemia in elderly patients with coronary artery disease, 147 patients (aged 65 years and older) underwent coronary angiography and dipyridamole thallium scintigraphy. Seventy-four patients (44 men, 30 women) who showed reversible defects (RD) and ischemic ST depression during scintigraphy were divided into two groups: 13 with silent RD (18%, 12 men, 1 woman), and 61 with painful RD (82%, 32 men, 29 women). Most patients with silent RD were men. The prevalence of myocardial infarction was similar in patients with silent RD (62%) and in patients with painful RD (49%). The prevalence of multivessel disease was also similar in the two groups: 85% in patients with silent RD and 82% in patients with painful RD. Among 38 patients with infarction, 8 had silent RD and 30 had painful RD. The prevalence of RD in the area of infarction was greater in patients with silent RD (63%) than in patients with painful RD (47%), but the difference was not statistically significant. The prevalence of extensive infarction (fixed defects) was greater in patients with silent RD (75%) than in patients with painful RD (30%, p < 0.05). Among 36 patients without infarction, there was no scintigraphic parameter which showed significant difference. Bypass grafting and angioplasty were initially performed in 23% of the patients with silent RD and in 36% of the patients with painful RD (ns). When the two groups were treated medically during the follow-up period of 29 +/- 22 months, the incidences of cardiac events were similar: 10% in patients with silent RD and 13% in patients with painful RD. The prevalence of silent RD is not high in elderly patients with significant coronary artery disease. Compared with the patients with painful RD, those with silent RD were more likely to have an old and extensive myocardial infarction, and they tended to have RD in the area of the infarct.

Macrovascular Disease Is Associated With Increased Plasma Apolipoprotein A-IV Levels in NIDDM

Apolipoprotein A-IV (apoA-IV) might play an important role in lipoprotein metabolism, including modulation of triglyceride-rich lipoprotein catabolism, reverse cholesterol transport and cholesteryl ester transfer protein (CETP) activity. Increased apoA-IV levels have been reported in plasma from NIDDM patients. The aim of the present study was to look for a possible association between plasma apoA-IV level and prevalence of macrovascular disease in NIDDM. One hundred and thirty-six NIDDM patients were studied (71 men, 65 women). Macrovascular disease was assessed in each patient by a standardized questionnaire, physical examination, resting electrocardiogram (ECG), and laboratory evaluation (ankle/arm blood pressure ratio, continuous wave Doppler velocimetry). Moreover, patients without any history of coronary heart disease and showing a normal resting ECG underwent a bicycle exercise test or a dipyridamole thallium scintigraphy to detect possible silent myocardial ischemia. Among the 136 NIDDM patients, 56 had macrovascular disease. ApoA-IV levels were significantly higher in NIDDM patients with macrovascular disease than in NIDDM patients without macrovascular disease (20.9 +/- 8.6 vs. 13.3 +/- 5.3 mg/dl; P < 0.001). The influence of different factors, such as age, BMI, cigarette smoking, hypertension, total cholesterol, triglycerides, HDL cholesterol, apoA-IV level, apoA-IV phenotype, fasting glycemia, fasting C-peptide, and microalbuminuria, on the prevalence of macrovascular disease was analyzed using a logistic regression model. In the univariate analysis, apoA-IV level (P < 0.00001), age (P = 0.0087), hypertension (P = 0.012), microalbuminuria (P = 0.018), triglycerides (P = 0.02), and fasting C-peptide (P = 0.03) were positively associated with macrovascular disease. In the multivariate analysis, macrovascular disease was positively associated only with apoA-IV (P < 0.0001) and age (P = 0.003) and negatively associated with HDL cholesterol (P = 0.013). These results indicate that increased plasma apoA-IV level is associated with an increased prevalence of macrovascular disease in NIDDM. Moreover, apoA-IV, in NIDDM patients, appears to be a better marker for macrovascular disease than triglycerides.

Prognosis in patients with left bundle branch block and normal dipyridamole thallium-201 scintigraphy

Prognosis in patients with left bundle branch block and normal dipyridamole thallium-201 scintigraphy

Prediction of late cardiac events by dipyridamole thallium scintigraphy in patients with intermittent claudication and occult coronary artery disease

Concomitant coronary artery disease often occurs in patients with peripheral vascular disease, but it may be asymptomatic. Despite being asymptomatic, cardiovascular events are the main source of morbidity and mortality in this group of patients. Dipyridamole thallium scintigraphy has been shown to be of prognostic value in patients with peripheral vascular disease and symptomatic coronary artery disease, but its effect on the long-term outcome in the asymptomatic group of patients is less defined. Eighty-four consecutive patients with peripheral vascular disease and no symptoms of coronary artery disease were therefore evaluated by clinical assessment, dipyridamole thallium imaging, radionuclide ventriculography, and cardiac catheterization and followed for a mean of 66 months. Abnormal perfusion patterns were found on thallium scintigraphy in 48 patients (57%); fixed, mixed, and reversible defects were present in 14 (17%), 11 (13%), and 23 (27%) patients, respectively. Significant coronary artery disease was present in 52 patients (69%) and mean left ventricular ejection fraction was 44%. During the followup period, 23 patients had a cardiac event (nonfatal myocardial infarction or cardiac death). Univariate analysis of 15 clinical, scintigraphic, radionuclide, and angiographic variables revealed that age, angiographic extent of coronary artery disease, and an abnormal thallium scan were significant predictors of subsequent cardiac events. Multivariate stepwise logistic regression analyses selected fixed and mixed thallium defects and diffuse coronary artery disease as the only significant independent predictors of outcome. Thus, the present study shows the value of dipyridamole thallium scintigraphy as a valuable prognostic indicator for long-term event-free survival in a cohort of patients with peripheral vascular disease and no history or symptoms of coronary artery disease.

Cardiac complications in noncardiac surgery: Relative value of resting two-dimensional echocardiography and dipyridamole thallium imaging

Although perfusion imaging studies are extensively used as a preoperative screening test for risk stratification of patients undergoing noncardiac surgery, no single cardiac noninvasive test has been shown to be ideal for risk stratification. We investigated the relative impact of transthoracic two-dimensional echocardiography (ECHO) compared with dipyridamole thallium scintigraphy (DT) in predicting major cardiac complications in patients undergoing noncardiac surgery. Eighty-seven consecutive patients undergoing 96 procedures (56 vascular, 40 general) underwent preoperative evaluation first with DT and then with ECHO before surgery. Complications were prospectively defined as myocardial infarction (MI), cardiac death (of MI, heart failure, or arrhythmia), or need of revascularization before surgery. DT showed one or more reversible defects in 44 (51%) patients, whereas ECHO demonstrated a reduced left ventricular ejection fraction (LVEF) in 25 (29%) patients. Major postoperative cardiac complications occurred in 10 patients: 5 deaths (2 ventricular fibrillation, 3 fatal MIs) and 5 nonfatal MIs. Four additional patients required urgent revascularization (coronary bypass graft surgery in 3 and percutaneous transluminal coronary angioplasty in 1). Of the 20 patients with both abnormal DT and ECHO, 11 (55%) had major complications, compared with none of the 26 (0%; p < 0.01) with an abnormal DT but normal LVEF. The sensitivity of DT and ECHO were not significantly different (79% [95% CI, 52% to 93%] vs 86% [60% to 96%], respectively), although the specificity of DT was lower (51% [40% to 62%] vs 81% [70% to 88%]; p < 0.05). The positive predictive value of DT was significantly improved from 22% (12% to 35%) to 52% (32% to 72%) when both DT and ECHO were abnormal. The results were not significantly different when the 4 patients who underwent revascularization were excluded. In conclusion, (1) in spite of similar sensitivity of ECHO and DT, ECHO appears to be relatively more specific in predicting major CC, and (2) when ECHO and DT are both abnormal, the risk of CC related to noncardiac surgery is significantly increased. Use of the combination of DT and ECHO before major noncardiac surgery can improve the identification of patients at risk for complications.

Selection of patients for cardiac evaluation before peripheral vascular operations

This study evaluated the value of preoperative cardiac screening with dipyridamole thallium scintigraphy and radionuclide ventriculography in vascular surgery patients. From July 1, 1989, to Dec. 31, 1991, we routinely (irrespective of the patient's cardiac history or symptomatology) performed dipyridamole thallium scintigraphy (DTS) and radionuclide ventriculography (RVG) in 394 patients being considered for an elective vascular operation. Patients with reversible defects on DTS underwent coronary arteriography. DTS results were normal in 146 patients (37%), showed a fixed defect in 75 (19%), and showed a reversible defect in 173 (44%). Patients with and without a history of angina or myocardial infarction had identical rates of reversible defects. Normal left ventricular function (> 50%) was noted in 76% of the patients; 17% had moderate dysfunction (35% to 50%) and 7% had a low ejection fraction (< 35%). The finding of severe coronary artery disease led to cardiac revascularization in 17 patients who had no prior history of cardiac disease and in 13 patients with a history of angina or myocardial infarction. Two deaths and nine major complications were associated with coronary arteriography and cardiac revascularization. Vascular procedures (144 aortic, 53 carotid, 146 infrainguinal) were ultimately performed in 343 patients, with a mortality rate of 1.7% (3.5% aortic, 0% carotid, and 0.7% infrainguinal bypass). The nonfatal perioperative myocardial infarction rate was 2.0%. We monitored all 394 patients for cardiovascular events, with a mean follow-up of 40 months. Patients who underwent cardiac revascularization had a 4-year survival rate of 75%, which was similar to those with a normal DTS. Late cardiac events were significantly more frequent in patients who had either a reversible DTS or RVG < 35%. Routine cardiac screening of vascular surgery patients had similar impact on patients irrespective of their prior history or current symptoms suggesting coronary artery disease. Routine screening did not result in substantial benefit. Screening studies such as DTS or RVG may be most useful as part of an overall risk versus benefit assessment in patients without active symptoms of coronary artery disease who have less compelling indications for vascular intervention (claudication, moderate-sized aortic aneurysms, or asymptomatic carotid disease).

Cost-effectiveness comparison of dobutamine stress echocardiography and dipyridamole thallium scintigraphy in >4,000 vascular surgery candidates: D. Douglas Miller, M.D., Leslee J. Shaw, Ph.D. for the Economics of Noninvasive Diagnosis (END) Study Group, St. Louis, MO, Durham, NC

Cost-effectiveness comparison of dobutamine stress echocardiography and dipyridamole thallium scintigraphy in >4,000 vascular surgery candidates: D. Douglas Miller, M.D., Leslee J. Shaw, Ph.D. for the Economics of Noninvasive Diagnosis (END) Study Group, St. Louis, MO, Durham, NC