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Stress testing remains the cornerstone for noninvasive assessment of patients with possible or known coronary artery disease (CAD). The most important application of stress testing is risk stratification. Most patients who present for evaluation of stable CAD are categorized as low risk by stress testing. These low-risk patients have favorable clinical outcomes and generally do not require coronary angiography. Standard exercise treadmill testing is the initial procedure of choice in patients with a normal or near-normal resting electrocardiogram who are capable of adequate exercise. Stress imaging is recommended for patients with prior revascularization, uninterpretable electrocardiograms, or inability to adequately exercise., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: The incremental prognostic value of thallium 201 imaging in patients with nonspecific ST-T abnormalities on the resting electrocardiogram (ECG) may be different from those with a normal resting ECG., Methods: Nine hundred thirty-nine consecutive patients with nonspecific ST-T abnormalities on their resting ECG who had undergone exercise 201 Tl imaging were followed for a median duration of 7.0 y (94% complete). The Cox proportional hazards regression model was used in a stepwise fashion to generate (1) a clinical (Cl) model, (2) a clinical and exercise (Cl + Ex) model, (3) and a clinical, exercise, and thallium (Cl + Ex + Tl) model, for the prediction of cardiac death., Results: Age, sex, and diabetes composed the Cl model (chi2 = 63, P < .0001). The Duke treadmill score added to the Cl + Ex model (chi2 = 71, P < .0001). Increased lung uptake (P < .0001) added significantly and summed reversibility score ( P = .03) added modestly to the Cl + Ex + Tl model (chi2 = 96, P < .0001). On the basis of the Cl + Ex + Tl model, the low-, intermediate-, and high-risk groups had a 7-y survival free of cardiac death of 99%, 88%, and 58%, respectively (P < .0001). Using the Cl + Ex + Tl model, only a small number of low-risk and high-risk patients by the Cl + Ex model were reclassified. However, 48% of the 230 patients in the intermediate-risk group by the Cl + Ex model were reclassified as low risk or high risk., Conclusions: 201 Tl imaging has incremental prognostic value in patients with nonspecific abnormalities on their resting ECG. However, patients classified as low risk or high risk by exercise testing using the Cl + Ex model do not require 201 Tl imaging. Intermediate-risk patients should be further risk-stratified by 201 Tl imaging.

Background: Patients with ischemic electrocardiographic (ECG) findings during exercise stress testing but normal perfusion images generally have a low risk of cardiac death or myocardial infarction (<1% per year). During vasodilator stress testing, however, the prognostic significance of the combination of normal perfusion images and ischemic ECG changes is unknown., Methods and Results: Among 5526 patients who underwent vasodilator stress single photon emission computed tomography (SPECT), 49 (0.9%) had normal images but ischemic ECG changes. A unique feature of this population was that 43 (88%) were women with a mean age of 67 +/- 10 years. Ischemic ECG changes occurred at a mean heart rate of 101 +/- 15 beats per minute and persisted for 6.8 +/- 4.7 minutes after termination of drug infusion. During follow-up of 28 +/- 20 months, cardiac death occurred in 2 patients and nonfatal myocardial infarction in 4 patients. The rate of cardiac death or nonfatal myocardial infarction was 4% at 1 year, 10% at 2 years, and 14% at 3 years. Of the 12 patients who underwent coronary angiography or autopsy during follow-up, 11 had multivessel coronary artery disease, indicating that these patients likely had false-negative SPECT image results. Eight patients required coronary revascularization., Conclusions: The finding of ischemic ECG changes with normal SPECT images during vasodilator infusion is uncommon, occurs primarily in older women, and is associated with a higher subsequent cardiac event rate than is customarily associated with normal images.

Objective: To determine whether a simple clinical score, which was shown previously to predict the likelihood of severe coronary artery disease (CAD) in patients referred for coronary angiography, could predict prognosis in a separate cohort of patients with normal or mildly abnormal findings on their resting electrocardiogram (ECG) who were undergoing noninvasive evaluation for possible CAD., Patients and Methods: The study group included 2255 symptomatic patients with normal (n=1466) or mildly abnormal (nonspecific ST-T-wave abnormalities; n=789) findings on their resting ECG who were referred for exercise thallium testing between 1989 and 1991. Follow-up was 94% complete at a mean +/- SD duration of 6.9+/-1.5 years. The clinical score, which ranged from 0 (lowest risk) to 10 (highest risk), was calculated by awarding 1 point each for male sex, history of myocardial infarction, typical angina, diabetes mellitus, insulin use, and each decade of age older than 40 years., Results: In each ECG group, the clinical score was a significant predictor of cardiac death, nonfatal myocardial infarction, or late revascularization, considered individually or combined, unadjusted or with adjustment for age. Most patients had a score lower than 5; these patients had an excellent 5-year cardiac survival rate (99.7% for the normal ECG findings group and 98.8% for the ST-T-wave abnormalities group). The small subset of patients with a score higher than 5 had a much lower 5-year survival rate (923% for the 8% of patients with normal ECG findings and 86.6% for the 14% of patients with ST-T-wave abnormalities). For patients with a score of 5, the 5-year survival rate was 97.7% for the normal ECG findings group and 95.9% for the ST-T-wave abnormalities group., Conclusion: In symptomatic patients with known or suspected CAD and normal or mildly abnormal resting ECG findings, this simple, easily computed clinical score is a useful and valid tool to help determine prognosis.

Background: Systemic hypertension and an exaggerated blood pressure (BP) response with exercise have been associated with ‘false-positive’ findings on stress electrocardiography and echocardiography; however, limited data is available for stress myocardial perfusion imaging (MPI). The purpose of this study was to investigate whether an exaggerated elevation in BP with exercise is associated with an increased prevalence of abnormal MPI. Methods: BP responses to exercise were assessed in a cohort of 7,205 patients who underwent stress testing with technetium 99m-SPECT MPI (7/1999-6/2005) for the evaluation of chest pain or dyspnea. Results: A hypertensive response, defined as a peak systolic BP≥220 mmHg, occurred in 355 (4.9%) and was not associated with higher rates of ischemic ECG changes (16.1 versus 16.6%; P = .7), differences in Duke treadmill scores (4.7 ± 4 versus 5.1 ± 5; P = .3) or an increased prevalence of abnormal perfusion images (30.1% versus 32.9%; P = .3) to those without a hypertensive exercise response. Patients with a hypertensive response and either intermediate or high-risk MPI (on the basis of summed-difference-scores) referred for coronary angiography, had a high prevalence of coronary artery disease which was similar to those without a hypertensive response (88% versus 83%; P = .5). In an analysis of a community-based patient subset, a hypertensive response was not associated with a difference in either all-cause mortality or subsequent myocardial infarction, coronary revascularization or cardiac death (8% versus 9%; P = .7). Conclusion: A hypertensive BP response to exercise is not associated with increased rates of ischemic ECG changes, higher-risk Duke treadmill scores, greater degrees of abnormal MPI or worse clinical outcome. [Copyright &y& Elsevier]

: ObjectivesThe purpose of this study was to determine whether a previously validated clinical score (CS) could identify patients with a low-risk Duke treadmill score who had a higher risk of adverse events and, therefore, in whom myocardial perfusion imaging would be valuable for risk stratification.: BackgroundCurrent American College of Cardiology/American Heart Association guidelines recommend using a standard exercise test without imaging as the initial test in patients who have an interpretable electrocardiogram and are able to exercise.: MethodsWe studied 1,461 symptomatic patients with low-risk Duke treadmill scores (≥5) who underwent myocardial perfusion imaging. The CS was derived by assigning one point to each of the following variables: typical angina, history of myocardial infarction, diabetes, insulin use, male gender, and each decade of age over 40 years. A CS cutoff ≥5 or <5 was used to categorize patients as high risk (n = 303 [21%]) or low risk (n = 1,158 [79%]). Perfusion scans were categorized as low, intermediate, or high risk on the basis of the global stress score (GSS).: ResultsHigh-risk scans were more common in patients with a high-risk CS (26.4% vs. 9.5%, p < 0.0001). The CS and GSS were significant independent predictors of cardiac death. However, in patients with a low CS, seven-year cardiac survival was excellent, regardless of the GSS (99% for normal scans, 99% for mildly abnormal scans, and 99% for severely abnormal scans). In contrast, patients with a high CS had a lower seven-year survival rate (92%), which varied with GSS (94% for normal scans, 94% for mildly abnormal scans, and 84% for severely abnormal scans; p < 0.001).: ConclusionsIn symptomatic patients with low-risk Duke treadmill scores and low clinical risk, myocardial perfusion imaging is of limited prognostic value. In patients with low-risk Duke treadmill scores and high clinical risk, annual cardiac mortality (>1%) is not low, and myocardial perfusion imaging has independent prognostic value. [Copyright &y& Elsevier]

Assesses the exercise electrocardiogram (ECG) in women versus men using tomographic myocardial perfusion imaging as the reference standard. Clinical characteristics of patients; Exercise sestamibi results; Analysis of the exercise ECG in the coronary angiographic subset.

Studies the prognostic accuracy of the Duke treadmill score in patients with symptoms of chest pain or dyspnea who had nonspecific ST-T abnormalities on resting electrocardiogram (ECG). Symptomatic patients who underwent exercise thallium testing; Rates of overall mortality and cardiac death for subjects classified by Duke treadmill score group.

Objective: To assess the incremental value and cost-effectiveness of exercise tomographic thallium-201 imaging compared with clinical and exercise electrocardiographic variables for detecting three-vessel or left main coronary artery disease in patients with normal at-rest electrocardiograms.Design: Prospective cohort study.Participants: 411 patients (77 [19%] had three-vessel or left main disease) with normal at-rest electrocardiograms who underwent exercise tomographic thallium-201 studies and subsequently had coronary angiography.Measurements: Clinical, exercise, and thallium-201 variables; univariate followed by multivariate logistic regression analysis to determine predictors of three-vessel or left main disease (clinical variables; clinical and exercise electrocardiographic variables; and clinical, exercise, and thallium-201 variables). Patients were classified by each of these models into low-, intermediate-, and high-risk groups.Setting: A tertiary referral center.Results: Among the clinical variables, diabetes mellitus, sex, age, and typical angina were independently associated with severe coronary disease (46% of patients were correctly classified into low- or high-risk groups). The peak exercise heart rate-blood pressure product and the magnitude of the exercise-induced ST depression added independent information to clinical variables. Among the thallium variables, the change in the global thallium-201 score (a measure of redistribution) added independent information to clinical and exercise variables, resulting in only 3% of the patients being reclassified regarding their predicted risk for severe coronary disease. The cost per additional reclassification was estimated to be $20,550. Twenty-one cardiac events occurred (7 cardiac deaths and 14 myocardial infarctions) after thallium study (follow-up, 2.8 +/- 1.0 years). Event-free survival was 94% to 97% regardless of the predicted probability of developing three-vessel or left main coronary artery disease by any model.Conclusions: When the at-rest electrocardiogram is normal, thallium-201 scintigraphy adds little information to clinical and exercise variables in identifying patients with severe coronary artery disease. The high cost of this information may not justify the routine use of sophisticated imaging for this purpose. [ABSTRACT FROM AUTHOR]