Chronotropic response, safety, and accuracy of dobutamine stress echocardiography in patients with atrial fibrillation and known or suspected coronary artery disease

Ninety-two consecutive patients with atrial fibrillation (AF) who underwent dobutamine stress echocardiography were compared with a control group of patients in sinus rhythm matched for age, sex, and resting heart rate. Patients with AF had an increased chronotropic response to dobutamine, but there were no adverse effects and no evidence that the lower doses of dobutamine typically given to patients with AF were insufficient to induce ischemia.     

Long-term prognostic value of dobutamine-atropine stress echocardiography in 1737 patients with known or suspected coronary artery disease: A single-center experience

BACKGROUND: The purpose of this study was to assess the long-term value of dobutamine-atropine stress echocardiography (DSE) for prediction of late cardiac events in patients with proven or suspected coronary artery disease. METHODS AND RESULTS: Clinical data and DSE results were analyzed in 1734 consecutive patients undergoing DSE between 1989 and 1997. Seventy-four patients who underwent revascularization within 3 months of DSE and 1 patient lost to follow-up were excluded; the remaining 1659 (median age, 62 years; range, 14 to 99 years) were followed up for 36 months (range, 6 to 96 months). Wall motion abnormalities at rest and the presence and extent of stress-induced wall motion abnormalities (ischemia) were scored for each patient. Cardiac events were related to clinical and ECG data and DSE results. Four hundred twenty-eight cardiac events occurred in 366, documented cardiac death in 108 (total death, 247), nonfatal infarction in 128, and late revascularization in 192 patients. In a multivariable Cox proportional-hazards model, the ratio of documented cardiac death or (re)infarction was increased in the presence of stress-induced ischemia (hazard ratio, 3.3; 95% CI, 2.4 to 4.4) and extensive rest wall motion abnormalities (hazard ratio, 1.9; 95% CI, 1.3 to 2.6). The number of ischemic segments was predictive for late cardiac events. A normal DSE carried a relatively good prognosis, with an annual event rate of cardiac death or infarction of 1.3% over a 5-year period. CONCLUSIONS: In a large group of patients, DSE has an added value for predicting late cardiac events during long-term follow-up, improving the separation between high- risk and very-low-risk patients.     

Evaluation of patients with diabetes mellitus for coronary artery disease using dobutamine stress echocardiography

BACKGROUND: There is a high prevalence of coronary artery disease (CAD) in patients with diabetes mellitus. Detection of inducible ischaemia using treadmill exercise testing may be limited by the relatively poor inherent predictive accuracy of the test. The purpose of this study was to determine the value of dobutamine stress echocardiography (DSE) for the detection of CAD in patients with diabetes mellitus. METHODS: Patients with diabetes mellitus referred for cardiac assessment were considered eligible for study. DSE was performed in a standard fashion. Significant CAD was defined as a > 50% luminal diameter stenosis on coronary angiography. RESULTS: A total of 52 patients (mean age 59 years) with diabetes mellitus were studied prospectively using DSE. Risk factors for CAD included hypertension in 19, family history in 21, hypercholesterolaemia in 14, history of smoking in 38. The sensitivity, specificity, positive and negative predictive values of DSE for detection of CAD were 82, 54, 84 and 50% respectively. CONCLUSION: The specificity of DSE for CAD in patients with diabetes mellitus is low. Whether this reflects an underdetection of small vessel disease by contrast coronary angiography or whether it relates to test performance is unclear.     

Prognostic value of myocardial hypoperfusion indexes in patients with suspected or known coronary artery disease

BACKGROUND: We evaluated the prognostic value of exercise 201Tl indexes of myocardial hypoperfusion in patients with suspected or known coronary artery disease. METHODS AND RESULTS: Patients were divided into two groups: group I consisted of 332 patients with diagnostic electrocardiographic stress test results and group II consisted of 144 patients with nondiagnostic (inadequate or uninterpretable) stress electrocardiograms. At the 2-year follow-up, 20 hard events (16 cardiac deaths and 4 nonfatal myocardial infarctions) and 80 soft events (coronary revascularization procedures) occurred in group I. Considering total events, thallium imaging provided significant prognostic information in addition to clinical and exercise stress test data in the total study population (p < 0.001) and in patients with previous myocardial infarction (p < 0.001); in patients without previous infarction, thallium imaging added incremental prognostic value only in those with positive electrocardiographic stress test results (p < 0.01). When only hard events were considered, thallium variables added further information only in patients with previous myocardial infarction (p < 0.05). In group II at the end of follow-up, 15 hard and 39 soft events had occurred. In these patients occurrence of total (p < 0.001), hard (p < 0.05), and soft (p < 0.001) events was higher in those with abnormal thallium scintigraphic results than in those without. Moreover, no clinical and exercise variable, except history of myocardial infarction, was significantly related to outcome, whereas both indexes of extent and severity of hypoperfusion were significant. CONCLUSIONS: The results of this study demonstrate that scintigraphic indexes of myocardial hypoperfusion obtained by qualitative planar thallium imaging give unique prognostic information in patients with nondiagnostic electrocardiographic stress test results. Thallium imaging provides incremental prognostic information even in patients with diagnostic electrocardiographic stress test results but not in the low-risk subset of patients without previous infarction who have negative electrocardiographic stress test results.     

Optimal criteria for the diagnosis of coronary artery disease by dobutamine stress echocardiography

Left ventricular remodeling occurs spontaneously among patients with hypertrophic cardiomyopathy in several ways: (1) wall thickening in children; (2) wall thinning associated with cavity enlargement in midlife; and possibly (3) a very gradual wall thinning process occurring over long periods of time in adulthood.     

Assessment of patients after coronary artery bypass grafting by dobutamine stress echocardiography

Dobutamine stress echocardiography is an accurate method for the diagnosis and localization of vascular compromise in patients evaluated after coronary artery bypass graft surgery. The test provides useful data for selection of patients for whom coronary angiography may be indicated.     

Cardiac outcomes in coronary patients with submaximum dobutamine stress echocardiography

This study evaluated the prediction of cardiac events (cardiac death, myocardial infarction, unstable angina, or late myocardial revascularization) in patients with submaximum responses to dobutamine stress, defined by attainment of <85% age-predicted heart rate. Of 1,772 patients undergoing dobutamine echocardiography over a 2-year period, 425 had a submaximum heart rate response. After exclusion of patients treated with beta-adrenoceptor blocking agents, 255 patients formed the study group. In these patients, the test was terminated after administration of the maximum dose of 40 microg/kg/min of dobutamine with atropine (end of protocol, n = 186), severe angina, ischemic ST-segment changes, or intolerable side effects (n = 69). Dobutamine-induced changes (ischemia, viability, or both) were detected in 46 patients, involving ischemia in 133 segments, viability in 23, and ischemia and viability in 16 segments. Patients were followed for an interval of 28 +/- 17 months; 5 (1.2%) were lost to follow-up. Of the medically treated patients, cardiac events occurred in 73 of 228 (31%), including cardiac death in 25 (11%), nonfatal myocardial infarction in 11 (4.8%), severe unstable angina in 35 (15%), and late revascularization in 2 (0.9%). Cardiac events occurred in 11 of 30 (36%) with inducible abnormalities, and 62 of 198 without inducible abnormalities (31%, p = NS). Thus, cardiac event rates are high in patients with inadequate chronotropic responses to dobutamine stress, irrespective of whether stress-induced changes are detected. A negative dobutamine echocardiogram at submaximum heart rate should be considered nondiagnostic.     

Long-term prognostic significance of dobutamine echocardiography in patients with suspected coronary artery disease: results of a 5-year follow-up study

OBJECTIVES:This study sought to assess the long-term prognostic utility of dobutamine stress echocardiography in predicting fatal and nonfatal cardiac events. BACKGROUND: Although dobutamine stress echocardiography has improved sensitivity and specificity for detection of coronary artery disease, little is known of its predictive value for long-term cardiac events. Therefore, we followed up 120 consecutive patients who underwent dobutamine echocardiography for suspected coronary disease from March 1989 to August 1991. METHODS: All patients presenting for coronary angiography for chest pain were eligible for recruitment. Follow-up was 100% complete at 5 years (range 3.0 to 6.1). Cardiac events were defined as cardiac death or nonfatal myocardial infarction or the need for coronary revascularization (coronary angioplasty or bypass surgery). RESULTS: Positive (n = 78) and negative (n = 42) dobutamine test groups differed in their rates of coronary artery bypass graft surgery (37.2% vs. 9.5%, p < 0.001, respectively) and mortality. Of 26 total deaths, 22 occurred in the group with positive dobutamine test results (28% vs. 9.5%, p < 0.018); all 7 cardiac deaths occurred in this group as well (9% vs. 0%, p < 0.045). By multivariate regression analysis, positive results on dobutamine echocardiography remained independently predictive of future cardiac death after left ventricular ejection fraction and other clinical variables were accounted for. CONCLUSIONS: A positive finding on dobutamine echocardiography is an independent predictor of long-term cardiac mortality, whereas a negative finding confers a significantly reduced likelihood of cardiac death as much as 5 years from initial testing. We conclude that dobutamine stress echocardiography can be used to predict which patients with suspected coronary artery disease are at low risk for cardiac death and do not require concurrent nuclear or invasive testing.     

Comparison of dobutamine stress echocardiography and treadmill exercise electrocardiography for detection of coronary artery disease

BACKGROUND: Critical analysis of treadmill exercise testing (TMET) for the detection of coronary artery disease has revealed many shortcomings. Excellent diagnostic accuracy has been reported for dobutamine stress echocardiography (DSE). METHODS: A prospective comparison of DSE and TMET for the detection of coronary artery disease in routine clinical practice was performed using contrast cineangiography (significant stenosis > or = 50%) as a gold standard. RESULTS: A total of 116 patients (82 men, 34 women) were studied. Significant stenosis was detected by coronary angiography in 92 patients (79%). Single vessel disease occurred in 28, double-vessel disease in 32, and multivessel disease in 32 patients. Although sensitivity of DSE was better than that of TMET (82 versus 40%), specificity was worse (63 versus 79%). Positive predictive values for both DSE and TMET were good at 89 and 87%, respectively, whereas negative predictive values were poor for both (47% for DSE, 26% for TMET). CONCLUSIONS: Overall, DSE performs better than TMET in terms of sensitivity and positive and negative predictive value. Its lower specificity than that of TMET may lead to more patients being referred for diagnostic coronary angiography. The poor negative predictive value of DSE and TMET means that one should not be falsely reassured by normal results.     

Haemodynamic effects of dobutamine in patients with coronary artery disease

The Femininity Study was administered tl 31 alcoholic females, 146 college females, and 152 female schizophrenic patients. The data were factor analyzed: five major factors were identified: (1) heterosexual social role inadaptability; (2) parental role inadaptability; (3) homemaker role inadaptability; (4) general affective (neurotic) instability; and (5) maternal role inadaptability. The institutionalized women showed much greater incidence of all types of inadaptability.     

Usefulness of isometric hand grip exercise in detecting coronary artery disease during dobutamine atropine stress echocardiography in patients with either stable angina pectoris or another type of positive stress test

Dobutamine atropine stress echocardiography (DASE) detects coronary artery disease (CAD) by increasing myocardial oxygen demand causing ischemia. The sensitivity of the test for detection of CAD is reduced in patients with submaximal stress. We hypothesized that increasing cardiac work load by adding isometric exercise would improve the detection of ischemia during DASE. We studied 31 patients, mean age 57+/-11 years, with angiographically documented CAD. Patients underwent DASE using incremental dobutamine doses from 5 to 40 microg/kg/min, followed by atropine if peak heart rate was <85% of predicted maximal. Hand grip was then performed for 2 minutes at 33% of maximal voluntary contraction, while dobutamine infusion was maintained at the peak dose. The addition of hand grip during dobutamine stress was associated with a significant increase in systolic blood pressure (143+/-21 vs 164+/-24 mm Hg, p = 0.001) and left ventricular end-systolic circumferential wall stress (72+/-30 x 10(3) dynes/cm2 vs 132+/-34 x 10(3) dynes/cm2, p = 0.004). Wall motion score index increased from 1.0 at rest to 1.15+/-0.18 with dobutamine (p = 0.0004 vs rest), and increased further to 1.29+/-0.22 with the addition of hand grip (p = 0.004 vs dobutamine). Ischemia was detected in 19 patients (62%) with dobutamine-atropine stress alone and in 25 (83%) after the addition of hand grip (p <0.05). The addition of hand grip during DASE is feasible, and improves the detection of myocardial ischemia.     

Complications of pharmacologic stress echocardiography in coronary artery disease

In the last few years, pharmacologic stress echocardiography is emerging as a promising diagnostic tool with a favorable cost/benefit ratio. Its main clinical applications include the assessment of coronary artery disease, the identification of viable myocardium, and risk stratification before major vascular surgery. However, cardiac (arrhythmic, ischemic, or hemodynamic) as well as noncardiac complications have been reported, so that a risk/benefit analysis is advisable in view of the extensive introduction of this technique in the clinical arena. The most popular pharmacologic agents employed for stress echocardiography are dipyridamole, dobutamine, and adenosine. A comparative analysis with exercise stress testing, the classical standard a reference of all ischemia-provoking tests, confirms that in terms of safety and tolerability pharmacologic stress echocardiography may be considered a good alternative in patients unable to exercise maximally. No appreciable difference among the safety profiles of the most common pharmacologic agents has been found, but a careful evaluation of the risk/benefit ratio is advisable for any stressor in the individual patient by considering the relative importance of the expected diagnostic contribution and the pharmacodynamic impact of the test. Finally, adequate training of the operator and monitoring of the patient during stress and recovery are essential for getting optimal safety conditions.     

Improved identification of coronary artery disease in patients with left bundle branch block by use of dobutamine stress echocardiography and comparison with myocardial perfusion tomography

The purpose of this report is to compare a computed tomography (CT) injury severity scale for hepatic and splenic injury with the following outcome measures: requirement for surgical hemostasis, requirement for blood transfusion and late complications. Sixty-nine children with isolated hepatic injury and 53 with isolated splenic injury were prospectively classified at CT according to extent of parenchymal involvement. Clinical records were reviewed to determine clinical outcome. Ninety-seven children (80%) were managed non-operatively without transfusion. One child with hepatic injury required surgical hemostasis, and 17 (25%) required transfusion of blood. Increasing severity of hepatic injury at CT was associated with progressively greater frequency of transfusion (P = 0.002 by chi 2-test). One child with splenic injury underwent surgery and eight (15%) required transfusion of blood. Splenic injury grade at CT did not correlate with frequency (P = 0.41 by chi 2-test) or amount (P = 0.35 by factorial analysis of variance) of transfusion. There was one late complication in the nonsurgical group. A majority of children with hepatic and splenic injury were managed non-operatively without requiring blood transfusion. The severity of injury by CT scan did not correlate with need for surgery. Increasing grade of hepatic injury at CT was associated with increasing frequency of blood transfusion. CT staging was not discriminatory in predicting transfusion requirement in splenic injury.     

Prognostic significance of systolic blood pressure changes during dobutamine-atropine stress technetium-99m sestamibi perfusion scintigraphy in patients with chest pain and known or suspected coronary artery disease

To investigate the prognostic value of dobutamine stress-induced changes in systolic blood pressure (BP) 418 patients (mean age 60 years, 238 men) with chest pain and known or suspected coronary artery disease, who underwent a dobutamine-atropine stress technetium-99m sestamibi myocardial perfusion scintigraphic study, were followed up for 25 +/- 15 months. Blood pressure was measured by automatic sphygmomanometry every 3 minutes. A marked decrease and increase in systolic BP from rest to peak were defined as changes of > or = 20 mm Hg, and > or = 30 mm Hg, respectively. Worst outcome events were cardiac death (n = 30), nonfatal myocardial infarction (n = 17), and hospitalization for congestive heart failure (n = 8). A decrease in systolic BP (prevalence 16%) was associated with older age and higher baseline systolic BP. Fixed and reversible sestamibi perfusion defects and follow-up results were similar to patients without a systolic BP decrease. In contrast, an increase in systolic BP (prevalence 24%) was associated with younger age, lower baseline systolic BP, and with absence of a history of prior congestive heart failure or treatment with angiotensin-converting enzyme inhibitors. Furthermore, these patients had fewer fixed perfusion defects and tended to have fewer annual event rates (3.5% vs 7.5%, p < 0.10). In a multivariate model, an increase in systolic BP was not an independent predictor for subsequent events. In conclusion, a dobutamine-induced decrease in systolic BP is not associated with fixed or reversible sestamibi defects or adverse prognosis. An increase in systolic BP, however, is associated with less fixed sestamibi defects and a tendency toward less annual event rates.     

Results of dobutamine stress echocardiography in patients with syndrome X

This study describes the results of Dobutamine stress echocardiography in 10 patients with Syndrome X. The diagnosis of Syndrome X was made on the basis of the presence of exertional angina, positive exercise stress test, negative ergonovine stress test and normal coronary arteries at angiography. All patients underwent Dobutamine stress echocardiography after interruption of any antianginal therapy. Dobutamine was infused starting with a dose of 5 mcg/kg/min over 3 minutes with incremental steps of 5 mcg/kg/min every 3 minutes up to a maximal dose of 40 mcg/kg/min. Two-dimensional echocardiography and 12-lead electrocardiography was monitored during the infusion of the drug. Nine patients received the maximal dose while one patient prematurely stopped the test for the occurrence of side effects. None of the ten patients developed segmental left ventricular wall motion abnormalities indicative of myocardial ischemia; ST-segment depression diagnostic for ischemia developed in 30% of patients; angina was elicited in one of these patients and in two additional patients. A hyperkinetic response to Dobutamine infusion involving all the segments of the left ventricle was observed both in patients with and without chest pain or electrocardiographic changes. In patients with Syndrome X Dobutamine induces a hyperkinetic left ventricular response indicative of normal contractile reserve despite the presence in some cases of angina and electrocardiographic signs of ischemia.     

Stress echocardiography with dobutamine in the identification of coronary disease in patients with left bundle branch block

Spectral analysis of heart rate variability is studied in 10 healthy growing premature infants to investigate the changes in autonomic balance achieved as a function of changes in skin temperature. Heart rate is obtained from ECG recordings and the power spectrum of beat-to-beat heart rate fluctuations is computed. The infants maintain mean rectal temperature within 36.3-37.2 degrees C, while skin temperature changes. The respiratory rate does not change at the different servocontrol set points. Heart rate is found to increase slightly, but consistently. The low-frequency band (0.02-0.2 Hz), reflecting the interplay of the sympathetic and parasympathetic tone and known to be maximum at the thermoneutral zone, is maximum at 35.5 and 36 degrees C and decreases gradually to a lower level at a servocontrol temperature of 36.5-37 degrees C. The high-frequency band (0.2-2.0 Hz), coinciding with the respiratory peak and reflecting parasympathetic activity, is significantly elevated at 36 degrees C (p < 0.01). The minimum low: high ratio, indicating the minimum sympathetic-parasympathetic balance and possibly reflecting the most comfortable conditions, occurs at 36 degrees C, although the differences are not statistically significant. Servocontrol skin temperature may thus be adapted, and possibly selected at 36 degrees C for growing premature infants in an attempt to achieve thermal comfort and more balanced autonomic activity.     

Incremental value of rubidium-82 positron emission tomography for prognostic assessment of known or suspected coronary artery disease

Myocardial perfusion imaging using positron emission tomography (PET) may be more accurate for the diagnosis of coronary artery disease (CAD) than conventional imaging. The purpose of this study was to evaluate the prognostic implications of perfusion abnormalities in 685 patients (age 62 +/- 11 years, 199 women) studied by PET, and to assess the incremental value of these data in relation to prognostic implications of clinical and angiographic findings. Rubidium (Rb)-82 PET was performed before and after dipyridamole stress. Transient defects were detected in 227 patients (33%), and were moderate or greater in severity (> 15% of the left ventricle) in 84 (12%). Resting defects were present in 435 (64%) and were moderate or greater in severity in 216 (32%). The total extent of abnormally perfused myocardium was small (< 15% of the left ventricle) in 198 (29%), moderate in 216 (32%), and extensive in 105 (15%). Clinic review or standardized phone interview in 657 patients (96%) identified 151 cardiac events, including 81 cardiac deaths, 16 patients with myocardial infarction, 7 with unstable angina, and 47 with late revascularization (> 3 months after PET). Normal scans had a 90% event-free survival, compared with 87% in patients with small, 75% with moderate, and 76% with extensive defects (log rank chi-square 30, p <0.0001). Functional class, extent of CAD, and the presence and extent of perfusion defects (both at rest and during stress) were independent predictors of cardiac death and total cardiac events. In sequential Cox proportional-hazards models, the results of PET were incremental to those of clinical and angiographic evaluation. Thus, the presence and extent of damaged and jeopardized myocardium are independent and incremental predictors of outcome in patients undergoing Rb-82 PET.     

Improved specificity of transesophageal dobutamine stress echocardiography compared to standard tests for evaluation of coronary artery disease in women presenting with chest pain

The detection of coronary artery disease (CAD) by noninvasive methods has been hindered in women by the high rate of false-positive results. To determine the feasibility and accuracy of transesophageal dobutamine stress echocardiography for identification of CAD in women, we studied 84 patients (age 51 +/- 11 years) who underwent symptom-limited exercise treadmill testing, exercise thallium-201 scintigraphy, and coronary angiography for evaluation of anginal chest pain. Of the 84 patients, 62 had normal coronary arteries or nonsignificant coronary lesions, and 22 had significant stenosis of > or = 1 major coronary artery. During treadmill exercise, repolarization changes were observed in 16 of 21 patients with CAD and in 19 of 60 patients with normal coronary arteries. With thallium scintigraphy, a reversible defect was observed in 19 of 22 patients with CAD and in 12 of 60 patients with normal coronary arteries. Regional wall motion abnormalities during dobutamine infusion developed in 18 of 22 patients with CAD and in none of the 62 patients with normal coronary arteries. All 3 tests had similar sensitivity for detection of CAD (76% for exercise treadmill test, 86% for thallium scintigraphy, and 82% for transesophageal dobutamine stress echocardiography). However, transesophageal dobutamine stress echocardiography had significantly higher specificity than the other 2 tests (100% vs 68% for exercise treadmill test and 80% for thallium scintigraphy; p = 0.0001). Thus, transesophageal dobutamine stress echocardiography is accurate for evaluation of CAD among women presenting with chest pain; its use should be considered when more conventional tests are equivocal or technically suboptimal.