Long-term prognostic value of ejection fraction changes during dobutamine-atropine stress echocardiography

OBJECTIVE: Dobutamine stress echocardiography (DSE), using subjective wall motion scoring, provides incremental prognostic information over clinical data. The aim of the study was to test the additional prognostic value of left ventricular ejection fraction (LVEF) changes during DSE at different stages. METHODS: The study population comprised 106 consecutive patients (mean age 60+/-11 years, 73% men) with suspected or known coronary artery disease referred for DSE. Stress-induced ischemia was defined as new or worsening wall motion abnormalities. LVEF was measured at rest, peak stress and recovery. Follow-up was successful in 104 (98%) patients. Four patients who underwent revascularization within 60 days were excluded from the analysis. End-points during follow-up were cardiac death, non-fatal myocardial infarction and late revascularization. RESULTS: During a mean follow-up of 5.3+/-2.1 years, 26% of patients died: 13% due to cardiac death, 6% patients experienced non-fatal myocardial infarction and 38% underwent late revascularization. Rest-to-peak LVEF increase was lower in patients who experienced cardiac death or non-fatal myocardial infarction (4.9+/-8.6 compared with 9.2+/-7.5, P=0.04) and any cardiac events (6.0+/-8.5 compared with 10.5+/-6.7, P=0.004). An inverse correlation was found between left ventricular ejection increase and the number of ischemic segments (P<0.0001). A multivariable Cox proportional hazard model demonstrated that, in addition to clinical data and new wall motion abnormalities, lower LVEF increase had an incremental prognostic value in predicting hard cardiac events (hazard ratio 1.1, 95% confidence interval 1.0-1.2). CONCLUSION: Failure of LVEF to significantly increase during DSE, denoting more extensive ischemia, identifies a higher-risk subgroup for late cardiac events.     

The prevalence and prognosis of unrecognized myocardial infarction and silent myocardial ischemia in patients undergoing major vascular surgery

OBJECTIVE: The aim of this study is to determine the prevalence and prognosis of unrecognized myocardial infarction (MI) and silent myocardial ischemia in vascular surgery patients. METHODS: In a cohort of 1092 patients undergoing preoperative dobutamine stress echocardiography and noncardiac vascular surgery, unrecognized MI was determined by rest wall motion abnormalities in the absence of a history of MI. Silent myocardial ischemia was determined by stress-induced wall motion abnormalities in the absence of angina pectoris. Beta blockers and statins were noted at baseline. During follow-up (mean: 6+/-4 years), all-cause mortality and major cardiac events (cardiac death or nonfatal MI) were noted. RESULTS: The prevalence of unrecognized MI and silent myocardial ischemia was 23 and 28%, respectively. Both diabetes and heart failure were important predictors of unrecognized MI and silent myocardial ischemia. During follow-up, all-cause mortality occurred in 45% and major cardiac events in 23% of patients. In multivariate analysis, unrecognized MI and silent myocardial ischemia were significantly associated with increased risk of mortality [hazard ratio (HR), 1.86; 95% confidence interval (CI), 1.53-2.25 and HR, 1.74; 95% CI, 1.46-2.06, respectively] and major cardiac events (HR, 2.15; 95% CI, 1.59-2.92 and HR, 1.86; 95% CI, 1.43-2.41, respectively). In patients with unrecognized MI, beta-blockers and statins were significantly associated with improved survival. Statins improved survival in patients with silent myocardial ischemia. CONCLUSIONS: In patients undergoing major vascular surgery, unrecognized MI and silent myocardial ischemia are highly prevalent (23 and 28%) and associated with increased long-term mortality and major cardiac events.     

Prolongation of the QT-corrected interval during dobutamine stress echocardiography: a marker for ischemia

BACKGROUND: Dobutamine stress echocardiography (DSE) has become a very reliable non-invasive tool in the diagnosis of ischemic heart disease based on the determination of new wall motion abnormalities rather than electrocardiographic changes. METHODS: In this study, we assessed the usefulness of the corrected QT (QTc) interval and delayed heart rate recovery in predicting ischemia during the infusion of dobutamine. In this retrospective analysis, we analyzed the electrocardiograms of 100 patients who underwent DSE for the diagnosis of coronary artery disease. The QTc interval obtained at peak heart rate during the infusion of dobutamine was compared with the QTc interval at rest. RESULTS: A total of 32 patients had new wall motion abnormalities during DSE, suggestive of ischemia. In these patients, the mean QTc interval at rest was 442.6 ms as compared to 461.0 ms during the peak infusion of dobutamine (P<0.05). In contrast, there was no statistical difference between the mean QTc interval at rest and that noted during DSE in patients without ischemia (439.8 ms and 440.1 ms respectively, P =ls; NS). The QTc interval increased in 40% of patients with ischemia on DSE despite the absence of any accompanying ST-segment depressions. In addition, there was a statistically slower heart rate recovery. Changes in heart rate 2 min into recovery from peak heart rate were 7.3+/-9.5 beats/min in patients with ischemia compared to 12.5+/-11.9 beats/min in those without ischemia (P<0.027). A more significant change was noted 4 min into recovery when compared with the peak heart rate, 14.8+/-10 beats/min in patients with ischemia, compared with 22.2+/-15.7 beats/min in those without ischemia, (P<0.007). CONCLUSIONS: These results suggest that the development of new wall motion abnormalities suggestive of ischemia during DSE is associated with prolongation of the QTc interval and delayed heart rate early in the recovery period. These two parameters should be further studied not only as additional markers in the identification of ischemia in patients referred for DSE but also to assess their potential significance during short- and long-term follow-up.     

Prognostic value of stress echocardiogram in patients with angiographically significant coronary artery disease

The purpose of this study was to evaluate the prognostic value of stress echocardiography in patients with angiographically significant coronary artery disease (CAD). Two hundred sixty patients (mean age 63 ± 10 years, 58% men) who underwent stress echocardiography (41% treadmill, 59% dobutamine) and coronary angiography within 3 months and without intervening coronary revascularization were evaluated. All patients had significant CAD as defined by coronary stenosis ≥70% in major epicardial vessels or branches (45% had single-vessel disease, and 55% had multivessel disease). The left ventricle was divided into 16 segments and scored on a 5-point scale of wall motion. Patients with abnormal results on stress echocardiography were defined as those with stress-induced ischemia (increase in wall motion score of ≥1 grade). Follow-up (3.1 ± 1.2 years) for nonfatal myocardial infarction (n = 23) and cardiac death (n = 6) was obtained. In patients with angiographically significant CAD, stress echocardiography effectively risk stratified normal (no ischemia, n = 91) in contrast to abnormal (ischemia, n = 169) groups for cardiac events (event rate 1.0%/year vs 4.9%/year, p = 0.01). Multivariate logistic regression analysis identified multivessel CAD (hazard ratio 2.53, 95% confidence interval 1.16 to 5.51, p = 0.02) and number of segments in which ischemia was present (hazard ratio 4.31, 95% confidence interval 1.29 to 14.38, p = 0.01) as predictors of cardiac events. A Cox proportional-hazards model for cardiac events showed small, significant incremental value of stress echocardiography over coronary angiography (p = 0.02) and the highest global chi-square value for both (p = 0.004). In conclusion, in patients with angiographically significant CAD, (1) normal results on stress echocardiography conferred a benign prognosis (event rate 1.0%/year), and (2) stress echocardiographic results (no ischemia vs ischemia) added incremental prognostic value to coronary angiographic results, and (3) stress echocardiography and coronary angiography together provided additive prognostic value, with the highest global chi-square value.     

Functional and prognostic significance of silent ischemia during dobutamine stress echocardiography in the elderly.

BACKGROUND: The functional and prognostic significance of silent ischemia relative to symptomatic ischemia during non-invasive testing remains controversial. DESIGN: The aim of this prospective study was to assess whether the presence of dobutamine-induced silent ischemia was associated with the amount of myocardial ischemic burden and to determine the prognostic significance of painless ischemia in elderly people with stable coronary artery disease. METHODS: A cohort of 289 patients > or =70 years of age with positive dobutamine stress echocardiography result and significant coronary artery disease proven by coronary arteriography, were followed up during a 35 +/- 13 month period for the development of cardiac events. RESULTS: The prevalence of silent ischemia during dobutamine infusion was 63%. Patients with painful ischemia were more likely to have lower peak heart rate (P < 0.01) and showed ST segment depression more frequently during the dobutamine stress test than did patients with painless ischemia (52 versus 31%, P < 0.05). There was no significant difference between the patients with and without angina according to wall motion score index at rest (1.35 +/- 0.29 versus 1.32 +/- 0.37) and at peak stress (1.61 +/- 0.35 versus 1.58 +/- 0.44), stress-rest wall motion index difference (0.27 +/- 0.09 versus 0.25 +/- 0.08), the presence of dyskinesia at peak stress (36 versus 31%), the number of segments with regional > or =2 point change from rest to peak stress (38 versus 29%) and the decrease of left ventricular end systolic volume at peak stress (89 versus 86%). During the follow-up period a total of 269 patients developed 153 (57%) cardiac events: 15 cardiac deaths, 19 non-fatal myocardial infarctions, 119 episodes of unstable angina. No significant difference in cardiac mortality and in total cardiac event rate was observed between patients with or without angina (6 versus 5% and 60 versus 55%, respectively). CONCLUSIONS: Our data demonstrate that the magnitude of myocardial dysfunction assessed by dobutamine stress echocardiography is comparable in elderly patients with or without anginal chest pain. The presence of painful ischemia is not accompanied by an increased risk for subsequent cardiac events in this cohort of patients.     

Association of myocardial ischemia with mortality and implantable cardioverter-defibrillator therapy in patients with coronary artery disease at risk of arrhythmic death.

OBJECTIVES: We sought to assess the relation between myocardial ischemia during stress echocardiography and major events in patients with implantable cardioverter-defibrillator (ICD). BACKGROUND: The association of myocardial ischemia with subsequent ICD therapy and mortality is unknown. METHODS: We studied 90 patients (age 65 +/- 13 years, 27 women) with history of coronary heart disease who received ICD for primary (53 patients) or secondary (37 patients) prevention of sudden cardiac death. Sixty-five (72%) patients had a previous coronary artery bypass surgery. Patients underwent exercise treadmill or dobutamine stress echocardiography. Ischemia was defined as new or worsening wall motion abnormalities. End points were death and appropriate ICD therapy. RESULTS: Mean ejection fraction was 34 +/- 12%. During a mean follow-up of 2.8 +/- 1.5 years, 5 patients died and 19 patients had ICD therapy. Ischemia was detected in 20 of 24 patients with subsequent events and in 24 of 66 patients without (83% vs. 36%, p < 0.001). Events occurred in 17 of the 32 patients (53%) with both ischemia and inducible ventricular tachycardia (VT) on electrophysiologic (EP) studies. None of the 16 patients without ischemia or inducible VT on EP studies had events. In a Cox multivariate analysis model, independent predictors of events were a history of spontaneous sustained VT (hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.3 to 3.8), inducible VT on EP studies (HR 1.7, 95% CI 1.2 to 4.5), and ischemia (HR 2.1, 95% CI 1.2 to 3.5). CONCLUSIONS: Ischemia during stress echocardiography is an independent predictor of death and ICD therapy in patients with coronary heart disease at high risk of arrhythmic death. Patients without inducible ischemia or VT on a previous EP study have a very low risk of events. A combination of ischemia and a positive EP study is associated with a very high risk of events.     

Prognostic Value of Dobutamine Stress Echocardiography in Patients Undergoing Diagnostic Coronary Arteriography

There are only a few studies addressing the prognostic value of dobutamine stress echocardiography in patients with suspected coronary artery disease and none have assessed its value compared with coronary arteriography. Accordingly, graded dobutamine stress echocardiography was performed in 121 patients who underwent coronary arteriography based on symptoms and the findings of treadmill exercise electrocardiography. During the follow-up period of mean (SD) months (15 ± 9) there were 41 cardiac events (death [n = 5], acute myocardial infarction [n = 2], unstable angina [n = 29], and congestive heart failure [n = 5]). There were a greater number of patients with inducible wall motion abnormality (88%) on dobutamine stress with cardiac events compared with those without (55%, p <0.001). The wall motion score indexes at rest (1.6 ± 0.6) and at peak stress (2.1 ± 0.8) were worse in patients with cardiac events compared with those without (1.2 ± 0.3, p <0.001 and 1.5 ± 0.6, p <0.001, respectively). When multivariate analysis was performed using clinical, exercise, echocardiographic, and coronary arteriographic data the independent predictors of cardiac events were exercise duration (p = 0.01), presence of inducible wall motion abnormality (p = 0.03), and wall motion score index at peak stress (p <0.001). Thus, dobutamine stress echocardiography is a powerful predictor of future cardiac events in patients undergoing exercise testing and coronary arteriography for evaluation of chest pain and is superior to both exercise electrocardiography and coronary arteriography for the prediction of subsequent cardiac events.

Graded dobutamine stress echocardiography was performed in 121 patients undergoing diagnostic coronary arteriography for suspected coronary artery disease based on symptoms and findings of exercise electrocardiography. Stepwise Cox regression analysis using clinical, exercise electrocardiographic, echocardiographic, and coronary arteriography variables revealed that wall motion score index at peak stress (p <0.001), inducible ischemia (p = 0.03), and exercise duration (p = 0.04) were the only independent predictors of cardiac events.     

Prognostic value of mental stress testing in coronary artery disease

This study assesses the prognostic value of mental stress-induced ischemic left ventricular wall motion abnormalities and hemodynamic responses in patients with stable coronary artery disease (CAD). Seventy-nine patients (76 men and 3 women) with prior positive exercise test results were exposed to mental arithmetic and a simulated public speech stress in 2 prior studies. Ischemic wall motion abnormalities were monitored using echocardiography or radionuclide ventriculography (RNV). During mental stress testing, new or worsened ischemic wall motion abnormalities to mental stress and exercise were ascertained, as were peak changes in blood pressure and heart rate to mental stress. The occurrence of subsequent cardiac events (including cardiac death, nonfatal myocardial infarction, or revascularization procedures) was ascertained. New cardiac events were observed in 28 of 79 patients (35%) after a median follow-up duration of 3.5 years (range 2.7 to 7.3). Survival analysis indicated that 20 of 45 patients with mental stress ischemia (44%) experienced new cardiac events more frequently than those without mental stress ischemia (8 of 34; 23%; p = 0.048). Type of cardiac event did not differ between mental stress-positive and stress-negative patients. After controlling for baseline blood pressure and study group status (echocardiography vs RNV), there was a significantly higher relative risk of subsequent events for patients with high versus low peak stress-induced diastolic blood pressure responses (RR = 2.4, confidence interval 1.1 to 5.2; p = 0.03). These results demonstrate that ischemic and hemodynamic measures obtained from mental stress testing may be useful in assessing prognosis in CAD patients with prior positive exercise test results.     

Long-term prediction of mortality in elderly persons by dobutamine stress echocardiography

BACKGROUND: Dobutamine stress echocardiography (DSE) was shown to provide incremental prognostic information. However, its role in the prediction of mortality in elderly persons is not well defined. We assessed the value of DSE in the prediction of mortality and hard cardiac events during long-term follow-up in patients older than 65 years. METHODS: We studied 1434 patients >65 years old (mean age 72 +/- 3 years) who underwent DSE for evaluation of coronary artery disease. Ischemia was defined as new or worsening wall motion abnormalities. Follow-up events were total mortality and hard cardiac events (cardiac mortality and nonfatal myocardial infarction). Multivariable Cox regression analysis was used to identify the independent predictors of follow-up events. RESULTS: Ischemia was detected in 675 patients (47%). Five hundred six patients (35%) had a normal study, and 253 (18%) had fixed wall motion abnormalities. During a mean follow-up of 6.5 years, 532 (37%) deaths occurred, of which 249 (17%) were due to cardiac causes. A nonfatal myocardial infarction occurred in 45 patients (3%). Independent predictors of all-cause mortality in a multivariate analysis model were age (hazard ratio [HR] 1.06; 95% confidence interval [CI], 1.05-1.08), male sex (HR 1.5; 95% CI, 1.2-1.8), hypertension (HR 1.2; 95% CI, 1.1-1.4), smoking (HR 1.3; 95% CI, 1.1-1.6), diabetes (HR 1.4; 95% CI, 1.1-1.8), rest wall motion abnormalities (HR 1.07; 95% CI, 1.06-1.09), and ischemia (HR 1.3; 95% CI, 1.1-1.6). Independent predictors of hard cardiac events were age (HR 1.07; 95% CI, 1.05-1.09), male sex (HR 1.3; 95% CI, 1.1-1.7), smoking (HR 1.3; 95% CI, 1.1-1.6), diabetes (HR 1.6; 95% CI, 1.2-2.2), rest wall motion abnormalities (HR 1.13; 95% CI, 1.12-1.16), and ischemia (HR 2.1; 95% CI, 1.5-2.8). CONCLUSION: DSE provides independent prognostic information to predict all-cause mortality and hard cardiac events in elderly patients.     

Comparison of late outcome in patients with versus without angina pectoris having reversible perfusion abnormalities during dobutamine stress technetium-99m sestamibi single-photon emission computed tomography

The aim of this study was to assess the prognostic significance of reversible perfusion abnormalities in patients without angina during dobutamine stress technetium-99m sestamibi single-photon emission computed tomography (SPECT). The study comprised 224 patients (age 60 +/- 11 years, 144 men) with completely or partially reversible perfusion abnormalities during dobutamine stress sestamibi SPECT. Follow-up end points were hard cardiac events (cardiac death and nonfatal myocardial infarction). Angina occurred in 93 patients (42%) during the dobutamine stress test (symptomatic ischemia group). The 131 patients without dobutamine-induced angina represented the silent ischemia group. There was no significant difference between patients with and without angina with regard to summed stress perfusion score (5.3 +/- 2.5 vs 5.2 +/- 2.2, p = 0.9) or summed ischemic score (3.1 +/- 1.7 vs 3.2 +/- 1.4, p = 0.7). During a median follow-up of 7.2 years, cardiac death occurred in 14 patients (15%) with and in 21 patients (16%) without angina. Nonfatal myocardial infarction occurred in 8 patients (9%) with and in 13 patients (10%) without angina. In a multivariate analysis model of clinical and perfusion data, independent predictors of cardiac events were age (hazard ratio 1.02, confidence intervals [CI] 1.01 to 1.05 per year increment), diabetes mellitus (hazard ratio 1.9, CI 1.2 to 3.4), and ischemic perfusion score (hazard ratio 2.1, CI 1.3 to 3.8). Patients with silent ischemia defined as reversible perfusion abnormalities without associated angina during dobutamine stress sestamibi SPECT imaging had similar incidences of ischemia and similar cardiac event rates compared with patients with symptomatic ischemia. Therefore, the absence of angina in association with reversible perfusion abnormalities should not be interpreted as a sign of a more benign prognosis.     

Novel stress echocardiographic model incorporating the extent and severity of wall motion abnormality for risk stratification and prognosis

The prognostic value of stress echocardiography to predict future cardiac events using the extent and severity of wall motion abnormalities is not well defined. The objective of this study was to develop and validate a prognostic model for interpretation of stress echocardiographic studies by using the extent and severity of wall motion abnormalities. We evaluated 1,500 patients (59 +/- 13 years old; 51% men) who underwent stress echocardiography (34% on the treadmill exercise and 66% on dobutamine). Left ventricular regional wall motion was assessed by consensus of 2 experienced echocardiographers. Follow-up periods (mean 2.7 +/- 1.0 years) for confirmed myocardial infarction (n = 31) and cardiac death (n = 44) were identified. Multivariate regression analysis identified 2 independent predictors of cardiac events: the number of left ventricular wall segments with new wall motion abnormalities (an index of the extent of ischemia) and the maximal magnitude of new wall motion abnormalities (an index of the severity of ischemia). The ischemic extent (chi-square 48.7, p <0.0001) and maximal severity (chi-square 52.0, p <0.0001) were exponentially correlated with an increase in event rate. On the basis of these data, a prognostic model was defined that uses ischemic extent and maximal severity as stress-dependent orthogonal variables. With this 3-dimensional model, the predicted event rate ranged over sevenfold, from a low of 0.9%/year in patients without any wall motion abnormalities to a high of 6.7%/year in patients with extensive and severe wall motion abnormalities. The extent and severity of wall motion abnormalities by stress echocardiography are independent and cumulative predictors of prognosis in patients who have suspected or known ischemic heart disease.     

Role of right ventricular wall motion abnormalities in risk stratification and prognosis of patients referred for stress echocardiography.

OBJECTIVES: The purpose of this study was to evaluate the prognostic value of assessing right ventricular (RV) wall motion abnormalities during stress echocardiography (SE). BACKGROUND: The results of SE are usually interpreted based on wall motion abnormalities of the left ventricle (LV). There is increasing recognition of the prognostic importance of RV. However, RV is still a "forgotten" chamber during routine SE. METHODS: We evaluated 2,703 patients referred for SE. The LV was evaluated on a 16-segment model 5-point scale and the RV was evaluated on a 3-segment model 5-point scale for wall motion abnormalities. An abnormal RV or LV was defined as one with new (ischemic) or fixed (infarction) wall motion abnormalities. Follow-up (2.7 +/- 1.0 years) for confirmed myocardial infarction and cardiac death (n = 122) were obtained. RESULTS: An abnormal RV was seen in 112 patients (4%). In the presence of an abnormal LV, patients with abnormal RV had a worse prognosis than those with normal RV. Abnormal RV was a significant predictor of events (adjusted hazard ratio 2.69, 95% confidence interval 1.22 to 5.92; p = 0.014) independent of LV ischemia and ejection fraction. A forward conditional Cox model showed that peak RV wall motion score index provided incremental prognostic value over rest and conventional SE variables (global chi-square increased from 141.4 to 161.8 to 197.0; p < 0.0001 and p = 0.006, respectively). CONCLUSIONS: In patients referred for SE, RV wall motion analysis provides prognostic value independent of LV ischemia and ejection fraction and provides incremental value over rest and conventional SE variables. Right ventricular wall motion analysis should be routinely performed in patients referred for SE for effective risk stratification.     

Clinical and prognostic implications of angina pectoris developing during dobutamine stress echocardiography in the absence of inducible wall motion abnormalities

This study assessed the incidence, clinical correlates, and prognostic significance of angina during dobutamine stress echocardiography (DSE) in patients who did not have inducible wall motion abnormalities. We studied 2,117 patients (61 +/- 13 years of age; 1,149 men) who underwent large-dose DSE and had no new or worsening wall motion abnormalities during DSE. Follow-up events were hard cardiac events (cardiac death or nonfatal myocardial infarction) and myocardial revascularization. Angina was induced in 217 patients (10%) during stress. DSE was normal in 1,198 patients (57%), whereas 919 patients (43%) had fixed wall motion abnormalities. During a mean follow-up of 5.5 +/- 3.7 years, 143 patients (7%) died of cardiac causes and 78 (4%) had nonfatal myocardial infarction. Patients who developed angina during DSE were more likely to have a history of exertional angina (64% vs 16%, p <0.001) and had a higher wall motion score index at rest (1.29 +/- 0.5 vs 1.17 +/- 0.4, p = 0.01) compared with patients who did not have angina. Annual hard cardiac event rates were 2.2% in patients who had dobutamine-induced angina (DIA) and 2.1% in patients who did not (p = NS). Myocardial revascularization was performed more frequently in patients who had DIA than in those who did not (39% vs 14%, p <0.0001). In Cox's regression model, independent predictors of hard events were age (RR 1.03, 95% confidence interval [CI] 1.02 to 1.04), male gender (RR 1.6, 95% CI 1.1 to 2.2), smoking (RR 1.5, 95% CI 1.1 to 2.9), and wall motion score index at rest (RR 2.6, 95% CI 1.8 to 3.8). In conclusion, in patients who do not have ischemia by echocardiographic criteria during DSE, inducible angina pectoris is associated with a high incidence of revascularization during follow-up. However, the hard cardiac event rate does not differ in patients who develop DIA from those who do not.     

Value of myocardial viability estimation using dobutamine stress echocardiography in assessing risk preoperatively before noncardiac vascular surgery in patients with left ventricular ejection fraction <35%

Patients with heart failure (HF) scheduled for vascular surgery have an increased risk of adverse postoperative outcome, and stratification usually depends on dichotomous risk factors. A quantitative prognostic model for patients with HF was developed using wall motion patterns during dobutamine stress echocardiography (DSE). A total of 295 consecutive patients (mean age 67 +/- 12 years) with ejection fraction < or =35% were studied. During DSE, wall motion patterns of dysfunctional segments were scored as scar, ischemia, or sustained improvement. Cardiac death and myocardial infarction were noted perioperatively and during 5 years of follow-up. Of 4,572 dysfunctional segments; 1,783 (39%) had ischemia, 1,280 (28%) had sustained improvement, and 1,509 (33%) had scar. In 212 patients, > or =1 ischemic segment was present; 83 had only sustained improvement. Perioperative and late cardiac event rates were 20% and 30%, respectively. Using multivariate analysis, number of ischemic segments was associated with perioperative cardiac events (odds ratio per segment 1.6, 95% confidence interval 1.05 to 1.8), whereas number of segments with sustained improvement was associated with improved outcome (odds ratio per segment 0.2, 95% confidence interval 0.04 to 0.7). Multivariate independent predictors of late cardiac events were age and ischemia. Sustained improvement was associated with improved survival. In conclusion, DSE provides accurate risk stratification of patients with HF undergoing vascular surgery.     

Prognostic value of pharmacologic stress echocardiography in patients with left bundle branch block

PURPOSE: Although coronary artery disease is a frequent cause of left bundle branch block, the prognostic value of myocardial ischemia in patients with this conduction abnormality has not been defined. We investigated the value of pharmacologic stress echocardiography in risk stratification of patients with left bundle branch block. PATIENTS AND METHODS: Three hundred eighty-seven patients [230 men and 157 women, mean (+/- SD) age, 64 +/- 9 years] with complete left bundle branch block on the resting electrocardiogram underwent dobutamine (n = 217) or dipyridamole (n = 170) stress echocardiography to evaluate suspected or known coronary artery disease. A summary wall motion score (on a one to four scale) was calculated. The primary end points were cardiac death and nonfatal myocardial infarction. RESULTS: A positive echocardiographic result (evidence of ischemia) was detected in 109 (28%) patients. During a mean follow-up of 29 +/- 26 months, there were 21 cardiac deaths and 20 myocardial infarctions, 63 patients underwent coronary revascularization, and 1 patient received a heart transplant. In a multivariate analysis, four clinical and echocardiographic variables were associated with increased risk of cardiac death: resting wall motion score index [hazard ratio (HR) = 7.5 per unit; 95% confidence interval (CI), 2.8 to 20; P = 0.001], previous myocardial infarction (HR = 2.9; 95% CI, 1.1 to 7.3; P = 0.02), diabetes (HR = 2.7; 95% CI, 1.1 to 6.6; P = 0.03), and the change in wall motion score index from rest to peak stress (HR = 3.0 per unit; 95% CI, 1.0 to 8.6; P = 0.04). The 5-year survival was 77% in the ischemic group and 92% in the nonischemic group (P = 0.02). Four variables were associated with increased risk of cardiac death or infarction: previous myocardial infarction (HR = 3.4; 95% CI, 1.7 to 6.8; P = 0.0005), diabetes (HR = 2.4; 95% CI, 1.2 to 4.6; P = 0.01), resting wall motion score index (HR = 2.2 per unit; 95% CI, 1.1 to 4.1; P = 0.02), and positive echocardiographic result (HR = 2.2; 95% CI, 1.1 to 4.5; P = 0.03). The 5-year infarction-free survival was 60% in the ischemic group and 87% in the nonischemic group (P < 0.0001). Stress echocardiography significantly improved risk stratification in patients without previous myocardial infarction (P = 0.0001), but not in those with previous myocardial infarction (P = 0.08). In particular, it provided additional value over clinical and resting echocardiographic findings in predicting cardiac events among patients without previous infarction. CONCLUSIONS: Myocardial ischemia during pharmacologic stress echocardiography is a strong prognostic predictor in patients with left bundle branch block, particularly in those without previous myocardial infarction.     

Practical applications in stress echocardiography: risk stratification and prognosis in patients with known or suspected ischemic heart disease

OBJECTIVES: The purpose of this study was to define appropriate parameters for risk stratification and prognosis in patients undergoing stress echocardiography. BACKGROUND: Stress echocardiography is an established technique for the diagnosis of coronary artery disease. However, current data on risk stratification of patients undergoing stress echocardiography are limited. METHODS: We evaluated 1,500 patients (59 +/- 13 years old; 51% male) undergoing stress echocardiography (34% with treadmill exercise and 66% with dobutamine). Resting left ventricular ejection fraction (EF) and regional wall motion were assessed by the consensus of two echocardiographers. Follow-up (mean 2.7 +/- 1.0 years) for confirmed non-fatal myocardial infarction (n = 31) and cardiac death (n = 44) were performed. RESULTS: By univariate analysis, both the peak wall motion score index (WMSI) (p < 0.0001) and EF (p < 0.0001) were significant predictors of cardiac events. Peak WMSI effectively risk stratified patients into low (0.9%/year), intermediate (3.1%/year), and high (5.2%/year) risk groups (p < 0.0001). A threshold of 45% EF provided further risk stratification of all WMSI groups. By multivariate logistic regression analysis, peak WMSI (relative risk [RR] 2.1, 95% confidence interval [CI] 1.0 to 4.4; p = 0.04) and EF (RR 1.0, 95% CI 0.9 to 1.0; p = 0.01) were both predictors of cardiac events. CONCLUSIONS: Stress echocardiography yields prognostic information for risk stratification of patients with known or suspected ischemic heart disease. A normal stress echocardiographic study (peak WMSI = 1.0) confers a benign prognosis (0.9%/year cardiac event rate). Peak WMSI >1.7 and EF < or =45% are independent markers of patients at high risk of an adverse clinical outcome.     

Usefulness of stress echocardiography for risk stratification of patients after percutaneous coronary intervention

The prognostic value of stress echocardiography in patients with previous percutaneous coronary intervention (PCI) remains undefined. The aim of this study was to investigate the prognostic implication of stress echocardiography after PCI. The study group comprised 1,063 patients (794 men, 65 +/- 10 years of age) who underwent stress echocardiography with exercise (n = 105), dipyridamole (n = 780), or dobutamine (n = 178) after a median of 10 months from a successful PCI. Of these patients, 616 (58%) complained of chest pain and 447 (42%) were asymptomatic. Stress echocardiogram was positive for inducible ischemia in 328 patients (31%). During a median follow-up of 20 months, there were 167 events (61 deaths, 106 infarctions). Independent predictors of mortality were age (hazard ratio [HR] 1.06, 95% confidence interval [CI] 1.03 to 1.09, p <0.0001), wall motion score index at rest (HR 3.91, 95% CI 2.19 to 6.99, p <0.0001), and ischemia at stress echocardiography (HR 1.82, 95% CI 1.05 to 3.16, p = 0.03). Five-year mortalities were 20% in patients with and 9% in those without ischemia (p = 0.006). Independent predictors of hard events were ischemia at stress echocardiography (HR 3.82, 95% CI 2.75 to 5.29, p <0.0001), age (HR 1.02, 95% CI 1.01 to 1.04, p = 0.009), wall motion score index at rest (HR 1.98, 95% CI 1.30 to 3.02, p = 0.002), multivessel disease at time of PCI (HR 1.45, 95% CI 1.05 to 2.02, p = 0.02), and female gender (HR 1.44, 95% CI 1.03 to 2.01, p = 0.03). Five-year hard event rates were 53% in patients with and 16% in those without ischemia (p <0.0001). Stress echocardiographic positivity added prognostic information to clinical and at-rest echocardiographic parameters in symptomatic and asymptomatic patients. Moreover, it identified a subset of patients at higher risk of developing hard events independent of the subtending coronary anatomy (multivessel or single vessel disease). In conclusion, stress echocardiography is effective in risk-stratifying patients with previous PCI. In particular, inducible ischemia is a strong and independent predictor of mortality and hard events.     

Quantitative analysis of myocardial response to dobutamine by measurement of left ventricular wall motion using omnidirectional M-mode echocardiography

Although dobutamine stress echocardiography is important for assessing cardiac ischemia and viability, analysis of wall motion is qualitatively performed. We quantitatively evaluated left ventricular wall motion using a newly developed omnidirectional M-mode echocardiography that can depict the M-mode at the site of region of interest on the 2-dimensional image in real time, and established its usefulness for analyzing the myocardial response to dobutamine infusion. Dobutamine stress echocardiography with omnidirectional M-mode was performed in 57 patients with coronary lesions. In 38 of these patients, exercise stress single-photon emission computed tomographic thallium scintigraphy (Tl-201 SPECT) was performed. Endocardial excursion of 103 regions was measured from omnidirectional M-mode at baseline, low-dose (6 microg/kg/min), and at peak dose (30 microg/kg/min) dobutamine. A decrease and increase in wall excursion was scored (from -3 to 3) for a changes of every 2 mm, and a quantitative wall motion score (QWMS) was calculated as a summation of the scores from baseline to low dose and from low to peak doses. Quantitative coronary stenosis score (QCSS) was calculated as a summation of stenotic and collateral scores. The stenosis scores were graded as: 1 = 0% to 50%, 2 = 50% to 75%, 3 = 75% to 90%, 4 = 90% to 95%, 5 = 95% to 100%; collateral scores were graded as: -1 = poor collateral, -2 = good collateral. Based on the QWMS at each dose of dobutamine, the serial changes in wall motion were divided into 4 groups: augmented, biphasic, no change, and worsening. The QCSS was clearly different among these groups. QWMS was significantly correlated with QCSS (r = 0.657, p <0.001). The incidence of redistribution in Tl-201 SPECT was high in the region with low score of QWMS. In conclusion, omnidirectional M-mode is useful for quantitatively determining the grade of cardiac ischemia by assessing the serial change of ventricular wall motion during dobutamine infusion.     

Dobutamine stress echocardiography: Detection of coronary artery disease in patients with dilated cardiomyopathy

Objectives. This study attempted to determine the safety and accuracy of dobutamine stress echocardiograpby for detection of coronary artery disease in patients with dilated cardiomyopathy.Background. Detection of regional wall motion abnormalities at rest does not reliably distinguish ischemic front nonischemic cardiomyopathy. Previous studies have shown that dobutamine stress echocardiography safely and accurately identifies coronary artery disease in patients without dilated cardiomyopathy.Methods. Seventy patients with dilated cardiomyopathy under-went dobutamine stress echocardiography. Echocardiograms were obtained at baseline and at low (5 to 10 μg/kg body weight per min) and peak doses of dobutamine. Rest and stress left ventricular wall motion scores were derived from analysis of regional wall motion. Fifty-four subjects underwent coronary angiography.Results. Dobutamine infusion was terminated after achievement of the target heart rate or maximal protocol dose in 49 patients (70%), ischemia in 12 (17%), arrhythmia in 4 (6%) and side efects in 5 (7%). No patient had prolonged ischemia or sustained arrhythmia. Of those with angiographic studies, 40 had significant coronary artery disease (≥50% diameter stenosis). Use of the change in global wall motion score index from low to peak dose resulted in a sensitivity of 83% for dobutamine stress echocardiography and a specificity of 71% for detection of coronary artery disease. Sensitivity for detection of triple-,double-and single-vessel disease was 100%, 83% and 69%, respectively.Conclusions. Dobutamine stress echocardiography safely provides diagnostic information in patients with dilated cardiomyopathy. This technique has high sensitivity for multivessel coronary artery disease but only moderate specificity.     

Exercise echocardiography for the prognostic stratification of patients with low pretest probability of coronary artery disease.

PURPOSE: The aim of this study was to determine whether exercise echocardiography provides incremental data for risk stratification of patients with a low pretest probability of coronary artery disease. PATIENTS AND METHODS: The study included patients referred for exercise echocardiography whose probability of coronary artery disease was 25% or less. We calculated an exercise wall motion score index (on a 1-5 scale), an indicator of the extent and severity of exercise-induced abnormalities. The primary outcomes of the study were subsequent cardiac events (cardiac death and nonfatal myocardial infarction). RESULTS: We studied 571 men and 1047 women; their mean (+/- SD) age was 55 +/- 13 years. During a median follow-up of 3 years, there were 19 cardiac events (6 cardiac deaths and 13 nonfatal myocardial infarctions); an additional 37 patients underwent coronary revascularization. In a multivariate analysis of clinical, exercise electrocardiographic, and echocardiographic parameters, exercise wall motion score index (hazard ratio [HR] = 2.1 per 0.5 units; 95% confidence interval [CI]: 1.3 to 3.4), and age (HR = 2.0 per decade; 95% CI: 1.2-2.8) were independently associated with the risk of cardiac events. Although exercise echocardiographic variables contributed significantly (P = 0.01) to a model of the risk of adverse events, only 9 (47%) of the 19 patients with cardiac events were identified by an abnormal exercise echocardiogram. CONCLUSION: Among patients with low pretest probability of coronary artery disease by clinical criteria, exercise echocardiography identifies some, but not all, patients at risk of future events. Because of the low event rate, routine application of exercise echocardiography in a patient with a low pretest probability does not appear to be cost-effective and therefore cannot be recommended.