Pretest Likelihood Of Coronary Artery Disease Research Articles

Risk Stratification Using Stress Echocardiography: Incremental Prognostic Value over Historic, Clinical, and Stress Electrocardiographic Variables Across a Wide Spectrum of Bayesian Pretest Probabilities for Coronary Artery Disease

We sought to evaluate the risk stratification ability and incremental prognostic value of stress echocardiography over historic, clinical, and stress electrocardiographic (ECG) variables, over a wide spectrum of bayesian pretest probabilities of coronary artery disease (CAD). Stress echocardiography is an established technique for the diagnosis of CAD. However, data on incremental prognostic value of stress echocardiography over historic, clinical, and stress ECG variables in patients with known or suggested CAD is limited. We evaluated 3259 patients (60 +/- 13 years, 48% men) undergoing stress echocardiography. Patients were grouped into low (<15%), intermediate (15-85%), and high (>85%) pretest CAD likelihood subgroups using standard software. The historical, clinical, stress ECG, and stress echocardiographic variables were recorded for the entire cohort. Follow-up (2.7 +/- 1.1 years) for confirmed myocardial infarction (n = 66) and cardiac death (n = 105) was obtained. For the entire cohort, an ischemic stress echocardiography study confers a 5.0 times higher cardiac event rate than the normal stress echocardiography group (4.0% vs 0.8%/y, P < .0001). Furthermore, Cox proportional hazard regression model showed incremental prognostic value of stress echocardiography variables over historic, clinical, and stress ECG variables across all pretest probability subgroups (global chi2 increased from 5.1 to 8.5 to 20.1 in the low pretest group, P = .44 and P = .01; from 20.9 to 28.2 to 116 in the intermediate pretest group, P = .47 and P < .0001; and from 17.5 to 36.6 to 61.4 in the high pretest group, P < .0001 for both groups). A normal stress echocardiography portends a benign prognosis (<1% event rate/y) in all pretest probability subgroups and even in patients with high pretest probability and yields incremental prognostic value over historic, clinical, and stress ECG variables across all pretest probability subgroups. The best incremental value is, however, in the intermediate pretest probability subgroup.

Diagnostic accuracy of gated Tc-99m sestamibi stress myocardial perfusion SPECT with combined supine and prone acquisitions to detect coronary artery disease in obese and nonobese patients

The diagnostic value of gated myocardial perfusion single-photon emission computed tomography (MPS) with combined supine and prone acquisitions to detect coronary artery disease (CAD) in obese and nonobese patients has not been defined. We studied 1511 patients without prior myocardial infarction or coronary revascularization who either had coronary angiography within 3 months of MPS (n = 785) or had a low pretest likelihood of CAD (n = 726). All patients underwent rest thallium 201/gated exercise or adenosine stress technetium 99m sestamibi MPS in both the supine and prone positions. According to body mass index (BMI), patients were categorized as normal weight (BMI of 18.5-24.9 kg/m2), overweight (BMI of 25.0-29.9 kg/m2), or obese (BMI > or = 30.0 kg/m2). There were no significant differences in stress, fixed, or ischemic defects among patients in different weight categories. The sensitivity of MPS was 85%, 86%, and 89% for detecting patients with 50% or greater coronary stenosis and 89%, 91%, and 92% for detecting those with 70% or greater coronary stenosis in the normal-weight, overweight, and obese groups, respectively. Normalcy rates were nearly identical among the 3 weight groups (99%, 98%, and 99%, respectively). Multivariate logistic regression analysis further confirmed that BMI was a nonsignificant predictor for the detection of CAD. In a subset of 290 patients, automated quantitative MPS analysis confirmed that combined supine and prone MPS increased specificity (86%) in identifying CAD, without a significant reduction in sensitivity (83% for > or = 50% stenosis and 88% for > or = 70% stenosis). The findings of this study suggest that MPS performed with gating and combined supine and prone acquisitions without attenuation correction had a similar diagnostic accuracy for the detection of CAD in normal-weight, overweight, and obese patients.

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 under-representation 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.

Usefulness of pharmacologic stress echocardiography for the long-term prognostic assessment of patients with typical versus atypical chest pain

T report evaluates the long-term prognostic value of pharmacologic stress echocardiography (PSE) in a large cohort of unselected patients with chest pain of unknown origin and normal left ventricular function at rest. Moreover, we sought to verify the prognostic accuracy of the test in subjects with typical or atypical chest pain. • • • All patients with chest pain of unknown origin who underwent PSE in 3 primary care cardiology centers from April 1994 to December 1999 were considered suitable for the study. Clinical characteristics and indications for testing were recorded prospectively. Inclusion criteria were: (1) history of chest pain; (2) absence of proved coronary artery disease (CAD) defined by history of myocardial infarction, previous hospital admission for unstable angina, previous coronary revascularization, or 70% diameter stenosis of 1 major coronary vessel; (3) normal wall motion at rest by 2-dimensional echocardiography; (4) sinus rhythm; and (5) availability of direct and reliable follow-up information. Exclusion criteria were: (1) significant valvular disease, (2) left bundle branch block, (3) dilated or hypertrophic cardiomyopathy, and (4) technically inadequate echocardiographic examination. Based on the previously mentioned criteria, 904 consecutive patients were enrolled in the study (mean age SD 61 10 years; 380 men and 524 women). The pretest likelihood of CAD was estimated from age, gender, and symptoms,1 and 70% probability was considered as the cut-off value between low to intermediate and high risk. Patients underwent PSE with either dipyridamole (n 594) or dobutamine (n 310). The choice of 1 test over the other was governed by several possible factors, such as clinical issue, personal experience of the operator, and known contraindications to the use of the available drug (severe obstructive pulmonary disease in the case of dipyridamole or a preexisting complex ventricular arrhythmias in the case of dobutamine). PSE was performed after washout from antianginal drugs in 703 patients (77%). The remaining patients were evaluated while receiving blockers (n 104, 11%), nitrates (n 44, 5%), calcium channel blockers (n 31, 3%), or a combined treatment of 2 of the 3 drugs (n 22, 2%). In addition, in patients evaluated by dipyridamole, the administration of any phyllinecontaining drugs or beverages was avoided during the last 12 hours before the test. Two-dimensional echocardiography and 12-lead electrocardiographic monitoring were performed during intravenous administration of either dipyridamole ( 0.84 mg over 10 minutes) or dobutamine ( 40 g/kg/min) combined with atropine ( 1 mg) in case of heart rate 85% of the maximum predicted value.2,3 Criteria for test interruption were the achievement of peak dipyridamole or dobutamine dose, achievement of 85% of the age-predicted maximum heart rate, onset of new wall motion abnormalities, severe chest pain, horizontal or downsloping ST-segment depression 0.2 mV or ST-segment elevation 0.1 mV in 2 contiguous leads, systolic blood pressure 230 mm Hg, diastolic blood pressure 120 mm Hg, decrease in systolic blood pressure 30 mm Hg, significant arrhythmias, and intolerable symptoms. Echocardiographic images were recorded on SVHS videotapes and digitally stored on magneto-optic disk for subsequent analysis. Regional wall motion was assessed with a 16-segment model of the left ventricle and semiquantitatively graded from 1 to 4 (1 normal, 2 hypokinesia, 3 akinesia, 4 dyskinesia). PSE results were considered positive for ischemia in the presence of new regional wall motion abnormalities. Any ST-segment shift 0.1 mV from baseline at 80 ms after the J point in 2 contiguous leads was also recorded for the study. Follow-up data were collected during scheduled periodic visits in our outpatient clinic by a review of the patient’s hospital records and by communication with the patient’s physician. In the absence of reliable information, a telephone interview with the patient was conducted by trained personnel. One year was the minimum accepted period of follow-up in the absence of events. Death and nonfatal myocardial infarction were the events considered for the study. Because of the difficulty of ascribing a cardiac origin to sudden death,4 overall mortality was considered. The diagnosis of acute myocardial infarction was made based on symptoms, electrocardiographic changes, and an increase in cardiac enzyme levels. Only the first event was considered for each patient. The data were anaFrom the Cardiology Division, “S. Spirito” Hospital, Rome; Cardiology Unit, “Campo di Marte” Hospital, Lucca; Cardiology Division, G.B. Grassi Hospital, Rome; and Cardiovascular Research Foundation, Castelfranco Veneto, Italy. Dr. Coletta’s address is: Via Annia 26, 00184 Rome, Italy. E-mail: cole.clau@libero.it. Manuscript received July 29, 2002; revised manuscript received and accepted October 9, 2002.

Comparison of the cost-effectiveness of stress myocardial SPECT and stress echocardiography in suspected coronary artery disease considering the prognostic value of false-negative results

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 ΔQALY 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. (J Nucl Cardiol 2002;9:515-22)

Prognostic value of stress echocardiography in women with high (⩾80%) probability of coronary artery disease

OBJECTIVETo assess the prognostic significance of stress echocardiography in women with a high probability of coronary artery disease (CAD).SETTINGSecondary and tertiary cardiology unit at a university teaching hospital.PARTICIPANTSA total of...

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

Background The outpatient prognostic assessment of coronary artery disease (CAD) by exercise electrocardiography has limitations, including the feasibility of the test and its low positive predictive value in several clinical conditions. In the current study we investigated the safety, feasibility, and prognostic value of pharmacologic stress echocardiography in a large cohort of ambulatory patients. Methods The study group was made of 1482 ambulatory patients (969 men, aged 60 ± 10 years) who underwent stress echocardiography with either dipyridamole (n = 846) or dobutamine (n = 636) for evaluation of suspected or known stable CAD.The pretest likelihood of CAD was intermediate (<70%) in 709 patients and high (≥70%) in 773 patients. Results There was no complication during the dipyridamole test, whereas 2 ischemia-dependent, sustained ventricular tachycardias occurred during the dobutamine test. Limiting side effects were observed in 2% of dipyridamole and in 3% of dobutamine stresses. The echocardiogram was positive in 459 patients. During a mean follow-up of 28 ± 24 months, 58 patients died, 33 had a nonfatal myocardial infarction, and 158 underwent early (≤3 months) and 64 late (>3 months) revascularization. Multivariate predictors of hard events (death, infarction) were positive echocardiographic results (hazard ratio [HR] 2.9) and resting wall motion score index (WMSI) (HR 2.3). In considering major events (death, infarction, late revascularization) as end points, positive echocardiographic result (HR 4.3), scar (HR 2.2), and resting WMSI (HR 1.7) were independent prognostic predictors. The 5-year survival rates for the ischemic and nonischemic groups were, respectively, 80% and 91% (HR 3.6, 95% confidence interval [CI] 3.8-8.4; P <.0001) considering hard cardiac events and 65% and 88% (HR 2.6, 95% CI 2.1-5.9; P <.0001) considering major events. Multivariate predictors of major events were positive echocardiographic results (HR 8.2) and male sex (HR 2.5) for the intermediate-risk group and positive echocardiographic results (HR 2.9), resting WMSI (HR 1.8), and prior Q-wave myocardial infarction (HR 1.8) for the high-risk group. Conclusions Pharmacologic stress echocardiography is safe, highly feasible, and effective in prognostic assessment of ambulatory patients when both a general population and groups selected on the basis of pretest likelihood of CAD are analyzed. It represents a valid complementary tool to exercise electrocardiography for prognostic purposes in outpatients. (Am Heart J 2001;141:621-9.)

Noninvasive Diagnostic Testing of Coronary Artery Disease in Women

Noninvasive diagnostic testing of coronary artery disease (CAD) is widely recognized as an area that is less studied and less accurate with regard to women than to men. Accurate and safe diagnostic testing constitutes the crucial link between early detection and optimal management of CAD. Many noninvasive diagnostic modalities are available to the clinician, including traditional electrocardiography, the relatively novel imaging of echocardiography, the emerging nuclear perfusion technology of electron beam computed tomography, exercise testing, and pharmacologic testing. The most accurate and cost-effective diagnostic method for patients depends on the patients' pretest likelihood of the disease as determined by factors such as sex, age, and cardiovascular risk factors. Noninvasive tests are most useful in the diagnosis of CAD in patients with intermediate pretest likelihood of CAD. Patients with low pretest likelihood of CAD with normal electrocardiograms may benefit from noninvasive tests or a watchful waiting strategy. Patients with a high pretest likelihood of CAD may benefit greatly from direct referral to coronary angiography. Among the noninvasive diagnostic methods, exercise electrocardiography is the most studied and least accurate with regard to women patients. Electrocardiography improves in accuracy when combined with imaging techniques such as echocardiography or nuclear single photon emission computed tomography. Combining data from all studies has shown that exercise echocardiography yields the highest diagnostic accuracy in women among all of the exercise stress tests. Patients who are unable to achieve maximal exercise capacity may undergo pharmacologic testing using dipyridamole or adenosine radionuclide perfusion or dobutamine echocardiography. Recent development of electron beam computed tomography accurately detects coronary artery calcium but has not been validated yet as a standard diagnostic test for CAD.

Contributions of nuclear cardiology to diagnosis and prognosis of patients with coronary artery disease.

In the past decade, significant advances have been made in the ability to image the heart with radionuclide tracers under stress and resting conditions in patients with suspected or known coronary artery disease (CAD) for the detection of ischemia, determination of prognosis, assessment of myocardial viability, preoperative risk assessment for patients undergoing noncardiac surgery, and evaluation of the efficacy of revascularization in patients undergoing coronary artery bypass surgery or an interventional procedure.1 For many years, planar imaging and SPECT with 201Tl constituted the only scintigraphic techniques available for detecting CAD and assessing prognosis in patients undergoing stress perfusion imaging. The major limitation of 201Tl scintigraphy is the high false-positive rate observed in many laboratories, which is attributed predominantly to image attenuation artifacts and variants of normal that are interpreted as defects consequent to a significant coronary artery stenosis. Although quantification of 201Tl images improves specificity, the false-positive rate remains problematic, particularly in women and in obese patients. Breast attenuation artifacts in women are sometimes difficult to distinguish from perfusion abnormalities secondary to inducible ischemia or myocardial scar. In recent years, new 99mTc-labeled perfusion agents have been introduced into clinical practice to enhance the specificity of SPECT and to provide additional information regarding regional and global left ventricular systolic function via ECG gating of images. It was immediately apparent that the quality of images obtained with these new 99mTc-labeled radionuclides was superior to that of images obtained with 201Tl because of the more favorable physical characteristics of 99mTc imaging with a gamma camera. With 99mTc, doses of ≈10 to 20 times higher than those that are feasible with 201Tl can be administered, yielding images with higher count density. 99mTc demonstrates less scatter and attenuation than 201Tl, which is associated …

Cost analysis of diagnostic testing for coronary artery disease in women with stable chest pain

Background. Seven clinical sites compiled data from 4638 women who were referred directly to coronary angiography (catheterization-first strategy; n = 3375) or who underwent stress myocardial perfusion imaging (MPI) first (n = 1263) followed by coronary angiography if at least one reversible myocardial perfusion abnormality was detected. The study examines the cost minimization potential of these available invasive and noninvasive diagnostic strategies in women with chest pain. Methods and Results. Women in both groups were subclassified by the core laboratory as being at low (<0.15), intermediate (0.15 to 0.60), or high (>0.60) pretest likelihood for coronary artery disease (CAD). Among the catheterization-first patients, at least one coronary stenosis >70% was present in 13% of low likelihood patients, 29% of intermediate likelihood patients, and 52% of patients with high CAD likelihood. Perfusion abnormality rates in the MPI-first group were 23% in low likelihood patients, 27% in intermediate likelihood patients, and 34% in high CAD likelihood patients. Of the MPI-first subset, 50%, 55%, and 76%, respectively, underwent catheterization in at least one coronary stenosis >70%. Cardiac death rates ranged from 0.5% to 2.2% in patients with CAD and did not differ from the 2 testing strategies ( P = not significant). The composite cost per patient of diagnostic testing plus follow-up medical care over a period of 2.5 ± 1.5 years (calculated for both strategies from inflation-corrected Medicare charges, adjusted for institutional cost-charge ratios) ranged from $2490 for patients with low likelihood to $3687 for patients with high likelihood with the catheterization-first strategy and from $1587 to S2585 for patients undergoing MPI first ( P < .01 between risk subsets and strategies). Conclusions. In women referred for diagnostic evaluation of stable chest pain, MPI followed by selective coronary angiography in patients with at least 1 perfusion abnormality minimizes the near-term composite cost per patient compared with a direct catheterization-first strategy, regardless of pretest CAD likelihood.

Pre-Test Likelihood, Experience of Operators and Additive Diagnostic Efficacy of Gated Attenuation-Corrected Myocardial SPECT in coronary Artery disease

Background and Objectives:We investigated if gated and/or attenuation-corrected SPECT improved performance of experienced or in-experienced operators in the diagnosis of coronary artery disease (CAD) or stenosed arteries in patients having intermediate or high pretest likelihood. Materials and Methods:Rest/dipyridamole stress gated attenuation-corrected SPECT was performed in 81 patients (M:F=48:33, 62±8.6 years old, of high (n=38) or intermediate (n=43) pre-test likelihood for CAD, 1 vessel;14, 2 vessel;19, 3 vessel disease; 31, normal;17). Two experienced and one novice physicians graded 1 (normal) to 5 (definitely abnormal) for each artery 1) by conventional rest Tl-201/stress Tc-99m-MIBI SPECT, 2) 1) plus viewing gated SPECT (+gated) and 3) 2) plus attenuation-corrected SPECT (+AC gated). Areas under curves (AUC) of receiver operating characteristic (ROC) curves were compared. Results:AUC was greater in patients with high likelihood than intermediate likelihood. Novice physician performed better in diagnosing RCA stenosis (AUC: 0.53 for usual, 0.58 for +gated, and 0.66 for +AC gated) in patients with intermediate likelihood. AUC was not different for the diagnosis of CAD and LAD or LCx. Performance of experienced physicians was not different regardless of pre-test likelihood. Novice operator’s specificity increased from 53% to 73% for CAD, and 62% to 89% (p<0.05) for RCA in patients with intermediate likelihood. Conclusion:We conclude that gated attenuation-corrected SPECT was helpful only for novice physician to diagnose RCA stenosis by increasing specificity in patients with intermediate likelihood. Even for inexperienced physician, these methods were not helpful in patients with high pre-test likelihood or for LAD or LCX. (Korean Circulation J 1999;29(1):36-45)

Cost-effective selection of patients for coronary angiography

In patients suspected of having coronary artery disease (CAD), noninvasive testing has been playing an increasing role in selecting patients who would require coronary angiography for either the “definitive” diagnosis of CAD or as a prelude to planning myocardial revascularization. A mathematic model is presented that defines cost-effective utility of nuclear cardiology testing for diagnosis of CAD and selection of appropriate candidates for coronary angiography, according to quantitative methods of decision analysis. Clinical utility or effectiveness was defined in terms of percent correct diagnosis of CAD. Cost was defined as dollars of medical expenditure. Six competing strategies were compared in subsets of patients with different pretest likelihoods of CAD, based on age, sex, and symptoms. Nuclear cardiology testing was the most cost-effective initial modality of choice in patients with an intermediate pretest likelihood of CAD. In patients with a low pretest likelihood of CAD, nuclear cardiology testing was cost-effective in the subgroup of patients who had abnormal exercise treadmill electrocardiograms. In patients with a high pretest likelihood of CAD, direct referral to coronary angiography was the most cost-effective strategy for diagnosis of CAD. Coronary angiography, however, is performed most often as a prelude to myocardial revascularization. Because these invasive procedures are indicated only in patients who are at high risk with medical therapy, nuclear cardiology procedures, by virtue of incremental prognostic information, identify appropriate candidates for more invasive procedures, aimed at improving survival. Strategies for cost-effective prognostication of CAD depend on not only the patient's pretest likelihood of CAD but also the status of the rest electrocardiogram. In patients with a normal rest electrocardiogram, a low pretest likelihood of CAD indicates a low risk for cardiac events with medical therapy. Therefore coronary angiography is not indicated in these patients. Patients with an intermediate likelihood of CAD should first undergo exercise electrocardiographic testing; a negative response would indicate a low risk for cardiac events and a positive response would indicate the need for nuclear cardiology testing for further cost-effective risk stratification. In patients with a high pretest likelihood of CAD, the combined exercise electrocardiographic and nuclear cardiac testing is the most cost-effective strategy; a negative or a positive nuclear test result would imply low or high risk, respectively. The latter patients would then be candidates for coronary angiography. In all patients with an abnormal rest electrocardiogram, the most cost-effective strategy is uniform referral to nuclear cardiac testing (which is performed in conjunction with exercise electrocardiography), regardless of the pretest likelihood of CAD; a negative or a positive nuclear test result would indicate low or high risk for coronary events, respectively. The latter group would be proper candidates for referral to coronary angiography.

EXERCISE TESTING IN SELECTED PATIENT GROUPS: Women, the Elderly, and the Asymptomatic

Exercise testing for coronary artery disease (CAD) has been validated primarily for middle-aged men. For women and the elderly, full assessment of individual risk and estimation of the pre-test likelihood of CAD is important before deciding to perform an exercise study. Negative electrocardiographic (ECG) findings with an exercise test in women and the elderly are predictive of good prognosis and low risk of cardiovascular events. Positive ECG findings may be falsely positive, and additional testing, nuclear or echocardiographic imaging, or coronary angiography may be indicated. Consensus guidelines are not yet available for testing in asymptomatic patients with exercise, and individual management decisions are still required.

Prognostic value of dobutamine echocardiography in patients with high pretest likelihood of coronary artery disease

To examine the value of transient regional asynergy on dobutamine stress echocardiography as a noninvasive predictor of future cardiac events, 51 symptomatic patients (aged 54 ± 9 years) with suspected coronary artery disease (CAD) were studied using an incremental regimen of 5, 10, 15 and 20 μg/kg/min. Pretest likelihood of CAD was (mean ± standard error of the percentage) 79.7 ± 5.6% before and 83.4 ± 5.2% after exercise electrocardiography using probability analysis based on age, sex and symptoms. Two-dimensional images were analyzed with reference to an 11-segment model and gave good interrater agreement. During 24 ± 4 months (range 19 to 32) of follow-up, 23 patients had events (1 myocardial infarction, 9 unstable angina, 10 coronary bypass surgery, 3 coronary angioplasty) and 28 were event free. Age, proportion with baseline asynergy and both pretest echocardiographic ejection fraction and its response to dobutamine were similar in these 2 groups (all p = not significant). Transient asynergy was seen in 17 of 23 patients (74%) with and 8 of 28 patients (29%) without events (p < 0.01); 5 of 6 patients (83%) with involvement of 3 segments had events. Myocardial infarction or unstable angina occurred in 8 of 25 (32%) with a positive and 2 of 26 (8%) with a negative stress echocardiogram (p < 0.05). Both exercise duration (389 ± 195 vs 517 ± 237 seconds, p < 0.05) and time to diagnostic ST-segment shift (291 ± 192 vs 447 ± 212 seconds, p = 0.05) were shorter in those with inducible asynergy. These data suggest that patients with probable CAD and a positive dobutamine echocardiogram are at higher risk of an adverse outcome. Dobutamine echocardiography may aid selection for coronary angiography and prognostic revascularization, particularly in patients unable to exercise.