Myocardial viability after primary coronary angioplasty: low-dose dobutamine stress echocardiography versus myocardial contrast echocardiography.

BACKGROUND: Successful reperfusion therapy in patients with acute myocardial infarction (AMI) improves survival. Indeed, after AMI myocardial dysfunction may be reversible (hibernating or stunned myocardium). Low-dose dobutamine stress echocardiography (LDDSE) provides us with the possibility of evaluating viable myocardial segments, while myocardial contrast echocardiography (MCE) allows the study of the microcirculation in the same myocardial areas. The aim of our study was to compare LDDSE and MCE, in the prediction of the recovery of segments in patients with AMI who were submitted to primary coronary angioplasty (PTCA). METHODS: We studied 14 patients with AMI. Both LDDSE and MCE with Levovist were performed after primary PTCA. The viability gold standard was a recovery of contractility detected at echocardiography 2 months later. RESULTS: For LDDSE, the sensitivity was 91%, the specificity 71% and the positive and negative predictive values were 93 and 64% respectively. For MCE, the sensitivity was 94%, the specificity 44%, the positive predictive value 89%, and the negative predictive value 59%. Two tests agreed in 81% of the cases. Stress echocardiography and contrast echocardiography agreed in 81% of cases. CONCLUSIONS: LDDSE has a very good positive accuracy, it has an acceptable negative predictive value and is relatively cheap. On the other hand, MCE has a good positive accuracy, but a low negative accuracy and carries a high cost. The integration of these two tests, which are too expensive in clinical practice, could improve our comprehension of the post-PTCA pathophysiology.     

Myocardial viability during dobutamine echocardiography predicts survival in patients with coronary artery disease and severe left ventricular systolic dysfunction

Objectives. The purpose of this study was to assess whether the presence or absence of myocardial viability during dobutamine echocardiography (DE) predicts survival in patients with coronary artery disease (CAD) and severe left ventricular (LV) dysfunction.Background. In patients with CAD, the presence of myocardial viability during DE identifies viable myocardium and predicts recovery of LV systolic function after revascularization. However, there is little data on the relation between myocardial viability and clinical outcome in patients with CAD and severe LV dysfunction.Methods. We studied 318 patients with CAD and a LV ejection fraction (EF) ≤35% who underwent DE and were followed for 18 ± 10 months. Patients were classified into four groups. Group I (n = 85) consisted of patients who had evidence of myocardial viability and subsequently underwent revascularization. Group II (n = 119) consisted of patients with myocardial viability who did not undergo revascularization. Group III (n = 30) consisted of patients who did not have myocardial viability and underwent revascularization. Finally, group IV (n = 84) patients lacked myocardial viability and did not undergo revascularization.Results. The four groups had similar baseline characteristics and rest LVEF. During follow-up there were 51 deaths (16%). The mortality rate was 6% in group I, 20% in group II, 17% in group III and 20% in group IV (p = 0.01, group I vs. other groups).Conclusions. In patients with CAD and severe LV dysfunction who demonstrated myocardial viability during DE, revascularization improved survival compared with medical therapy.     

Validation of viability assessment by electromechanical mapping by three-dimensional reconstruction with dobutamine stress echocardiography in patients with coronary artery disease

We evaluated the ability of electromechanical mapping (EMM) to discriminate between normal, viable, and nonviable (scarred) myocardium in patients with coronary artery disease versus dobutamine stress echocardiography (DSE) when the correspondence between the test and reference data sets is established via a common 3-dimensional reconstruction of the left ventricle. We studied 21 patients with coronary artery disease who underwent angiography, biplane ventriculography, and EMM within 1 month of DSE. A 3-dimensional left ventricular (LV) reconstruction was prepared from the ventriculogram and spatially aligned with EMM. EMM measurements of unipolar voltage, bipolar voltage, and local linear shortening were projected onto the three-dimensional left ventricle, averaged in each of 16 segments, and compared with DSE viability (normal, viable, scar) assessed at a core laboratory. All of the EMM measurements varied significantly (p <0.001) between the normal, viable, and scarred myocardium as assessed by DSE. Local linear shortening for normal, viable, and scarred segments was 10.4 +/- 6.5%, 7.8 +/- 5.6%, and 4.8 +/- 4.4%, respectively. In discriminating between these 3 groups, local linear shortening was more powerful than unipolar voltage or bipolar voltage (F = 20.765, F = 10.655, F = 4.795, respectively). Local linear shortening correlated best with viability, perhaps because it shares the same cognitive function as DSE. Three-dimensional analysis provides an anatomic framework that enables direct comparison of data from multiple imaging modalities rather than assuming segmental correspondence. Our results show that EMM provides significant on-line, diagnostic information on myocardial viability assessed by DSE on a segment-by-segment basis.     

老年冠心病患者冠状动脉内支架术的疗效研究

目的：探讨老年冠心病患冠状动脉内支架术的近期疗效和对远期预后的影响。方法：2000年6月-2002年6月连续240例冠心病患行选择性冠状动脉内支架术，其中86例年龄＞65岁(A组)，154例＜65岁(B组)，比较两组支架术成功率及远期随访结果。结果：A组中84例支架术成功(97．7％)，并发症率9．30％。B组中150例支架术成功(97．4％)，并发症率4．55％，两组差异均无显性(P＞0．05)。随访12．5土6．5个月，随访率95．7％。A、B两组的心功能改善(54．7％和51．9％)、心绞痛复发(30．2％和36．4％)、再入院(18．6％和20．1％)、总心脏事件发生率(18．6％和22．7％)及无心脏事件存活率(86．0％和85．1％)均无显性差异(P＞0．05)。结论：老年患冠状动脉内支架术安全、成功率高，且远期预后良好。     

Improvement of left ventricular ejection fraction, heart failure symptoms and prognosis after revascularization in patients with chronic coronary artery disease and viable myocardium detected by dobutamine stress echocardiography.

OBJECTIVES: This study was designed to address, in patients with severe ischemic left ventricular dysfunction, whether dobutamine stress echocardiography (DSE) can predict improvement of left ventricular ejection fraction (LVEF), functional status and long-term prognosis after revascularization. BACKGROUND: Dobutamine stress echocardiography can predict improvement of wall motion after revascularization. The relation between viability, improvement of function, improvement of heart failure symptoms and long-term prognosis has not been studied. METHODS: We studied 68 patients with DSE before revascularization; 62 patients underwent resting echocardiography/radionuclide ventriculography before and three months after revascularization. Long-term follow-up data (New York Heart Association [NYHA] functional class, Canadian Cardiovascular Society [CCS] classification and events) were acquired up to two years. RESULTS: Patients with > or =4 viable segments on DSE (group A, n = 22) improved in LVEF at three months (from 27+/-6% to 33+/-7%, p < 0.01), in NYHA functional class (from 3.2+/-0.7 to 1.6+/-0.5, p < 0.01) and in CCS classification (from 2.9+/-0.3 to 1.2+/-0.4, p < 0.01); in patients with <4 viable segments (group B, n = 40) LVEF and NYHA functional class did not improve, whereas CCS classification improved significantly (from 3.0+/-0.8 to 1.3+/-0.5, p < 0.01). A higher event rate was observed at long-term follow-up in group B versus group A (47% vs. 17%, p < 0.05). CONCLUSIONS: Patients with substantial viability on DSE demonstrated improvement in LVEF and NYHA functional class after revascularization; viability was also associated with a favorable prognosis after revascularization.     

Myocardial viability evaluation using magnetocardiography in patients with coronary artery disease

OBJECTIVE: Magnetocardiography (MCG) has been used to risk stratify patients in terms of sudden death or to detect ischemia. We evaluated the potential of this technique to assess myocardial viability in coronary artery disease. METHODS: Fifteen patients aged 36-75 (median, 59) years with stable single-vessel disease (> or =70% diameter stenosis) and corresponding regional wall-motion abnormality underwent (1) echocardiography to evaluate wall motion, (2) Tl dipyridamole single-photon emission computed tomography to document perfusion and (3) quantitative F-fluorodeoxyglucose positron emission tomography to assess viability in 16 left-ventricular wall segments. MCG was performed in each patient using a shielded prototype 49-channel low-temperature superconducting quantum interference device (SQUID) system. Multiple time and area parameters were extracted automatically from each baseline-corrected data set. RESULTS: Eleven patients had prior myocardial infarction. In each patient, four to 12 (median, seven) segments were lesion dependent, totalling up to 117 out of 240 segments. A total of 88 segments (75%) were viable and 29 segments (25%) represented scar. Patients were divided into three categories: (a) no scar segments (five patients), (b) scar in one to three segments (six patients) and (c) scar in > or = four segments (four patients). The three MCG parameters with the best selectivity were identified using linear discriminant analysis with forward inclusion (P<0.10). The corresponding Fisher's discriminant functions classified all patients correctly (Wilks' lambda=0.079). CONCLUSION: Selected MCG parameters yielded accurate patient classification with regard to the extension of myocardial scar within the viable tissue in retrospect. These findings indicate that MCG may contribute to the assessment of myocardial viability. Further evaluation in a comprehensive multicenter study is warranted.     

Transesophageal dobutamine stress echocardiography for evaluation of patients with coronary artery disease

Objectives. The present study was undertaken to determine the safety, feasibility and diagnostic accuracy of transesophageal dobutamine stress echocardiography for the evaluation of patients with known or suspected coronary artery disease.Background. Dobutamine stress echocardiography has proved to be a valuable method for detecting and prognosticating ischemic heart disease, In addition, it may provide accurate information about myocardial viability in patients with systolic dysfunction. However, in some patients the technique may be limited by poor myocardial imaging with the conventional transthoracic approach.Methods. Seventy-six patients (62 men, 14 women; mean age ± SD 60 ± 10 years) who underwent coronary angiography were included in the study. Transesophageal stress echocardiograms were performed after withdrawal of antianginal medications for ≥ 48 h. Dobutamine was infused at a starting dose of 2.5 μg/kg body weight per min and was increased by 5-μg/kg per min increments every 5 min to a maximum of 40 μg/kg per min. Two-dimensional views were acquired at each stage and digitized for subsequent analysis. The left ventricle was divided into 16 segments, and each segment was assigned to a major coronary artery with the use of a model of regional distribution of coronary perfusion.Results. Sixty-two of the 76 patients had angiographic evidence of coronary artery disease. New or worsening regional wall motion abnormalities developed during dobutamine infusion in 55 of these 62 patients and in none of the 14 patients with normal coronary arteries (sensitivity 89%, specificity 100%, overall accuracy 91%). Regional wall motion abnormalities in the distribution of more than one major coronary artery were seen in 3 of the 25 patients with single-vessel coronary artery disease and in 30 of the 37 patients with multivessel disease (p < 0.0001). The test was successfully completed in 73 (96%) of the 76 patients; it was discontinued in the remaining 3 patients because of intolerance to the probe. No major complications occurred in any patient. Minor complications developed in seven patients but did not affect the diagnostic accuracy of the test.Conclusions. Transesophageal dobutamine stress echocardiography is a safe, feasible and accurate method for assessing coronary artery disease. Its use should be considered in patients who have a suboptimal ultrasound window, and it provides an excellent tool for clinical investigations based on ultrasound imaging of the myocardium.     

Role of contrast-enhanced dobutamine stress echocardiography in predicting outcome in patients with known or suspected coronary artery disease

Although the application of intravenous contrast agents during stress echocardiography has been shown to improve diagnostic accuracy for detecting coronary artery disease, less information exists regarding its prognostic value. The aim of this study was to determine the role of contrast-enhanced dobutamine stress echocardiography (DSE) for predicting future cardiac events in patients with coronary artery disease (CAD). We studied 893 patients (mean age: 66, 581 men) with known or suspected CAD undergoing contrast-enhanced DSE. Positivity was defined as new/worsened wall motion abnormality or fixed abnormality during stress. All patients were followed for 15 +/- 10 months to evaluate hard cardiac events (cardiac death and nonfatal myocardial infarction) and total cardiac events (hard cardiac events, congestive heart failure, unstable angina, and late revascularization). Three patients were lost to follow-up, and 128 patients developed cardiac events, including 21 hard cardiac events. The 3-year event free survival rate was significantly lower in patients with positive DSE results than in those with negative DSE results. Stepwise Cox multivariate analysis revealed that positivity of DSE (P < 0.0001, Hazard ratio (HR): 2.48) and peak wall motion score index (WMSI) >1.5 (P < 0.0001, HR: 2.41) were independent predictors for total cardiac events. Considering hard cardiac events, the independent predictors were peak WMSI > 1.5 (P < 0.0001, HR: 6.65) and age > 70 years (P < 0.005, HR: 3.27). We conclude that contrast-enhanced DSE provides important prognostic information for future cardiac events.     

Myocardial ischemia due to coronary artery spasm during dobutamine stress echocardiography

Dobutamine stress echocardiography (DSE) is a useful and safe provocation test for myocardial ischemia. Until now, the test has been focused only on the organic lesion in the coronary artery, and positive DSE has indicated the presence of significant fixed coronary artery stenosis. The aim of the present study is to examine whether myocardial ischemia due to coronary spasm is induced by dobutamine. We performed DSE on 51 patients with coronary spastic angina but without significant fixed coronary artery stenosis. All patients had anginal attacks at rest with ST elevation on the electrocardiogram (variant angina). Coronary spasm was induced by intracoronary injection of acetylcholine, and no fixed coronary artery stenosis was documented on angiograms in all patients. DSE was performed with intravenous dobutamine infusion with an incremental doses of 5, 10, 20, 30, and 40 microg/kg/min every 5 minutes. Of the 51 patients, 7 patients showed asynergy with ST elevation. All 7 patients (13.7%) had chest pain during asynergy, and both chest pain and electrocardiographic changes were preceded by asynergy. These findings indicate that dobutamine can provoke coronary spasm in some patients with coronary spastic angina. When DSE is performed to evaluate coronary artery disease, not only fixed coronary stenosis, but also coronary spasm should be considered as a genesis of asynergy.     

Initial and long-term outcome of 354 patients after coronary balloon angioplasty of total coronary artery occlusions.

BACKGROUND. Coronary balloon angioplasty of chronic total occlusions is associated with relatively low success rates and a high incidence of restenosis. Whether there is long-term benefit in performing angioplasty of these lesions is unknown. The purpose of the present report was to analyze the long-term outcome of a large series of patients undergoing this procedure. METHODS AND RESULTS. A computerized database analysis of 354 consecutive patients (from 1979 to 1990) who underwent coronary angioplasty of a chronic total coronary occlusion was performed (mean age, 62.3 years). Initial technical success was achieved in 69%; in 66%, success was achieved without procedural death or need for coronary artery surgery. During hospitalization, six patients suffered myocardial infarction, nine required emergency bypass surgery, and nine patients died. During a mean follow-up period of 2.7 years, no difference was found in survival or freedom from myocardial infarction among 234 successfully dilated patients compared with 120 patients with a failed attempt. However, the use of coronary artery bypass surgery was significantly less after successful dilation (p less than 0.0001 versus failed attempt). No significant difference in the cumulative incidence of severe angina was observed between these two patient populations, with the majority remaining asymptomatic. Restenosis occurred in 59% of 69 patients who returned for follow-up angiography. CONCLUSIONS. Successful recanalization is achieved in the majority of patients undergoing angioplasty of chronic total occlusions and reduces the need for coronary artery bypass surgery. However, no major impact on either survival or incidence of myocardial infarction was noted after successful recanalization when patients with surgery were included.     

Coronary artery disease and coronary angioplasty in chronic hemodialysis patients

Chronic renal insufficiency leads to many cardiovascular complications and provide worst prognosis, especially when patients need hemodialysis. The atherosclerosis of chronic hemodialysis patients is qualified as "accelerated" by some authors, because of a very fast and large progression. To improve prognosis, it seems to be very important to detect and treat the frequent and serious underlying cardiovascular disease. Because of the high rate of diabetes mellitus, silent ischemia is a very frequent clinical situation. In the other hand, coronary artery disease in chronic hemodialysis patients is frequently complex, with a large coronary extension and high rate of coronary calcifications. Consequently, this disease needs a specific therapeutic approach. Even though, percutaneous coronary interventions (PCI) are more complex in this population, it provides good results, and improves patient's prognosis. However, the rate of complications of the vascular approach and the rate of restenosis is high. New devices, such as Drug Eluting Stents (DES) can critically decrease restenosis rate, and closure devices for trans-femoral approach, provides very encouraging results in this high risk population. Despite, good results of PCI with DES use, the mortality is still high in this population. To improve our efficiency, we have to progress in our therapeutic strategies and optimize medical approach to treat the important biological perturbations.     

Immediate and long-term outcome after angioplasty with stenting of the left main coronary artery

INTRODUCTION AND OBJECTIVES: Coronary artery bypass graft surgery is the treatment of choice for severe left main coronary artery stenosis. The results of a number of multicenter trials have suggested angioplasty with stenting as a possible alternative treatment. The aim of the present study was to analyze the immediate and long-term results of angioplasty with stenting of the left main coronary artery, and to identify factors predictive of death. PATIENTS AND METHOD: A total of 38 nonconsecutive patients (mean age 69 [8] years) with a severe lesion in the left main coronary artery were treated with angioplasty and stenting between November 1997 and March 2003. The procedure was elective in 27 patients and urgent in the remaining 11. In 23 patients (60.5%) the left main coronary artery was not protected by aortocoronary bypass. All patients underwent clinical follow-up examination at 25 (20) months. RESULTS: Angiographically documented success was obtained in all patients. However, one patient died from acute occlusion one hour after the operation. Four patients (10%) had a non-Q-wave myocardial infarction. In-hospital mortality was 15.8% (6/38 patients). Five of the 11 patients (45.4%) who underwent emergency angioplasty and stenting died in the hospital from acute myocardial infarction complicated by severe (Killip grade III-IV) heart failure. However, only one of 27 patients (3.7%) in the elective surgery group died (P=.007). Major clinical cardiac events during follow-up occurred in 5 patients (13%); 3 died and the other 2 had recurrent angina. All patients who died had an unprotected left main coronary artery. Cumulative survival rates for the elective group were 92 (0.5)% at 6 months, 88 (0.6)% at 1 year and 86 (0.7)% at 3 years, respectively. For the emergency surgery group cumulative survival rate was 54 (0.2)% at 6 months (P<.05). CONCLUSIONS: Elective angioplasty and stenting of the left main coronary artery in selected patients was associated with a high immediate success rate. In patients who underwent elective angioplasty and stenting, the incidence of major cardiac events during follow-up was relatively low. Emergency angioplasty and signs of left ventricular dysfunction were the main predictors of in-hospital mortality.     

Assessment of myocardial viability by dobutamine stress echocardiography in patients with ischemic heart disease

Detection of viable (hibernating) myocardium is necessary for determination of prognosis and tactics of treatment of patients with ischemic heart disease. For detection of viable myocardium and investigation of possibilities of its restoration 60 patients with ischemic heart disease (54 men, mean age 52+/-8 years) were examined before coronary artery bypass grafting or coronary angioplasty. Presence of viable myocardium was characteristic for patients with multivessel coronary artery disease (83%) with stenoses >90%, with well developed collateral circulation (81%). Sustained restoration of contractility of hibernating segments for 1 year after revascularization was noted in 70% of cases. Dobutamine stress echocardiography was found to have high diagnostic potential for detection of viable myocardium.     

Stress echocardiography in elderly patients with coronary artery disease Applicability,safety and prognostic value of dobutamine and adenosine echocardiography in elderly patients

Objectives. Our aim was to determine the applicability, safety and prognostic value of adenosine and dobutamine stress echocardiography in patients ≥70 years old.Background. These tests are sometimes mandatory because of difficulties and inaccuracies in interpreting traditional electrocardiographic stress tests. Furthermore, if these tests could be used to avoid coronary arteriography and cardiac catheterization, they would become essential in the care of the elderly, whose numbers are increasing.Methods. We performed coronary arteriography and dobutamine and adenosine stress echocardiographic tests in 120 patients (72 men) ≥70 years old who entered the hospital because of chest pain and had known or suspected coronary artery disease. The stress tests were performed on separate days, within 2 weeks of coronary arteriography. Both the arteriograms and the echocardiograms were analyzed by two experts who had no knowledge of the patients' other data or the other interpreter's report. Tests were judged to have positive or negative results, and the patients were followed up for the development of cardiac events. Univariate and multivariate analyses and other statistical modalities were applied for comparisons.Results. Documented coronary artery disease was found in 89 patients. During the 14 ± 7 months of follow-up, cardiac events developed in 50 patients, including 3 (7.9%) of 38 patients with negative dobutamine and 12 (20.7%) of 58 patients with negative adenosine test results. Demonstration of any abnormality on stress echocardiography was an independent factor for cardiac events, both for dobutamine (relative risk 7.3) and for adenosine (relative risk 3.0). Both cessation of dobutamine or adenosine tests and diagnosis of disease in two or more coronary vessels were also independent predictors. ST segment depression ≥1 mm was related to future events only with the dobutamine test.Conclusions. These echocardiographic stress tests proved safe and well tolerated. They successfully stratified this cohort of elderly patients with coronary artery disease to low or high risk subgroups for subsequent cardiac events.     

QT dispersion correlates to myocardial viability assessed by dobutamine stress echocardiography in patients with severely depressed left ventricular function due to coronary artery disease

BACKGROUND: QT dispersion is prolonged in numerous cardiac diseases, representing a general repolarization abnormality. AIM: To evaluate the influence of viable myocardium on QT dispersion in patients with severely depressed left ventricular (LV) function due to coronary artery disease. METHODS AND RESULTS: 103 patients with ischemic cardiomyopathy (LV ejection fraction [EF]: 25+/-6%) were studied. Patients underwent 12-lead electrocardiography to assess QT dispersion, and two-dimensional echocardiography to identify segmental dysfunction. Dobutamine stress echocardiography (DSE) was then performed to detect residual viability. Resting echo demonstrated 1260 dysfunctional segments; of these, 476 (38%) were viable. Substantial viability (> or =4 viable segments on DSE) was found in 62 (60%) patients. QT dispersion was lower in these patients, than in patients without viability (55+/-17 ms vs. 65+/-22 ms, P=0.012). Viable segments negatively correlated to QT dispersion (r=-0.333, P=0.001). In contrast, there was no correlation between LVEF and QT dispersion (r=-0.001, P=NS). CONCLUSIONS: There is a negative correlation between QT dispersion and the number of viable segments assessed by DSE. Patients with severely depressed LV function and a low QT dispersion probably have a substantial amount of viable tissue. Conversely, when QT dispersion is high, the likelihood of substantial viability is reduced.     

Assessment of coronary artery disease by dobutamine stress echocardiography (DSE)

Background: Dobutamine stress echocardiography (DSE) is a new non-invasive imaging modality which combines two-dimensional echocardiography with cardiovascular stress induced by dobutamine infusion. Its use in patients with suspected or documented coronary artery disease (CAD) is currently under extensive investigation. Aims: To illustrate the clinical utility, safety and diagnostic value of DSE. Methods: One hundred and thirty-seven consecutive patients referred for DSE were studied. Eighty-four patients also underwent coronary angiography. Results: Eleven patients (8%) did not undergo DSE because of poor image quality. Of the remaining 126 patients, 110 (87%) achieved their target heart rate or reached a pre-determined end point during DSE. Eight patients (6%) developed non-cardiac side effects during DSE, none of which required premature termination of the procedure. Cardiac arrhythmias were documented in 15 patients (12%) but only one required intervention. In 84 patients who underwent coronary angiography, DSE showed a sensitivity and specificity of 88% and 83%, respectively, in detecting the presence of, and 75% and 75%o, respectively, in localising significant CAD. In 35 patients who underwent DSE after uncomplicated myocardial infarction, the positive and negative predictive values for cardiac events following infarction in a six-month follow up period were 74% and 62%, respectively. Conclusions: DSE is a well tolerated, safe and useful test in detecting and localising significant CAD. It can also provide useful post-infarctional prognostic information. (Aust NZ J Med 1995; 25: 707-715.) Key words: Echocardiography, dobutamine, coronary artery disease.     

Provocation of coronary spasm by dobutamine stress echocardiography in a patient with angiographically minimal coronary artery disease

Dobutamine stress echocardiography (DSE) has been widely used for the noninvasive diagnosis of obstructive coronary artery disease. The ST-segment elevation during DSE has been reported as an infrequent event, caused by old myocardial infarction and/or critical coronary narrowings. The patient presented here was a 35-year-old man with a recent history of nonexertional chest pain. He had hyperc-holesterolemia and a history of heavy smoking as risk factors. The patient developed ST-segment elevation with chest pain during 40 mcg/min dobutamine infusion for the stress echocardiographic examination. Subsequent coronary angiograms revealed only mild coronary atherosclerosis. It is speculated that coronary spasm occurred in this patient as a paradoxical response to increased coronary blood flow with dobutamine administration.