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.

Sealing of coronary artery aneurysm by using a new stent graft.

Coronary stenting has begun to play an increasingly important role in the management of coronary artery aneurysms. A case of successful and complete sealing of a coronary aneurysm by using a new stent graft is described. Further studies in a large patient population are required to confirm the safety and efficacy of this method. Cathet. Cardiovasc. Intervent. 48:96-99, 1999.

Intracoronary stent placement proximal to a myocardial bridge: immediate and long-term results.

The intracoronary stent placement in a lesion proximal to a myocardial bridge is of special importance and is considered to be a challenge for the interventional cardiologist. In this study 4 cases of stent implantation proximal to a coronary bridged segment are described. In all cases complications were observed after the procedure. The patients remained free of symptoms and the exercise TI201 test was negative for ischemia 8.5+/-2.6 months later. Although there is skepticism because of the abnormal coronary flow pattern, the endothelial dysfunction and the subsequent thrombogenicity, the stent placement proximal to a myocardial bridge was safe and with favorable long term results in all 4 cases. However, further studies in large populations are necessary.

Elective intracoronary Micro-Stent II implantation without quantitative coronary angiography or intravascular ultrasound guidance and without subsequent anticoagulation: short- and long-term results.

Intracoronary stenting has been shown to reduce acute closure and restenosis rate in patients treated with coronary angioplasty. The use of high inflation pressures and intravascular ultrasound guidance allowed the substitution of anticoagulants with antiplatelet agents but increased the cost. The aim of this study was to investigate the effectiveness, safety, and long-term outcome of the elective implantation of a relatively new type of stent (Micro-Stent II), without the use of quantitative coronary angiography or intravascular ultrasound guidance and without subsequent anticoagulation. The study included 361 patients who underwent elective microstent implantation. Stent expansion was performed at 8 atm followed by higher inflation pressure at 14-20 atm. Heparin was given intraarterially only once immediately after the arterial sheath insertion. Ticlopidine was started at least 48 hours before the procedure and continued for 1 month while aspirin was continued indefinitely. All patients were followed up for 12.9 +/- 3.6 months. Short term outcome (first month): Stent implantation was successfully achieved in 361 of 366 patients (98.6%). Seven patients (1.9%) were excluded from the study and received anticoagulants because of a suboptimal result. In total, 423 stents were implanted. There was no subacute thrombosis, but acute vessel closure occurred in one patient (0.3%). Non-Q wave myocardial infarction occurred in six patients (1.7%), Q wave myocardial infarction occurred in one patient (0.3%), and only one death (0.3%) of nonischemic origin was reported. No major peripheral vascular complications were observed. Late results: Q or non-Q wave infarction occurred in 13 patients (3.6%), 26 patients (7.2%) underwent a repeat angioplasty, eight patients (2.2%) underwent coronary artery bypass grafting, and four patients (1.1%) died. Overall, 284 patients (78.7%) were free of symptoms, while 77 (21.3%) had recurrent coronary ischemia. In conclusion, Micro-Stent II implantation without quantitative coronary angiography or intravascular ultrasound guidance and without anticoagulation was found to be effective, safe, and with good long-term outcome.

Non-invasive evaluation of coronary reserve. Assessment of coronary reserve in patients with coronary artery disease by transesophageal-Doppler echocardiography.

We assessed coronary flow reserve using transesophageal Doppler echocardiography in patients with coronary artery disease. The study included 33 coronary artery disease patients who were undergoing coronary arteriography. The blood flow velocities of the left anterior descending artery before and after intravenous infusion (0.56 mg/min for 4 min) of dipyridamole were recorded using transesophageal Doppler echocardiography. Fourteen normal healthy individuals, matched for age, served as a control group. The index of coronary flow reserve, i.e. the ratio of dipyridamole to baseline maximum diastolic velocity, was calculated. Maximal coronary flow reserve in coronary artery disease patients was significantly lower than in the control group (1.4+/-0.2 vs. 2.8+/-0.3, P<0.001). The coronary artery disease patients were classified into three groups: Group A included 10 patients with <50% left anterior descending artery stenosis; Group B included seven patients with 50-69% left anterior descending artery stenosis; 16 patients with >70% left anterior descending artery stenosis constituted Group C. The maximum coronary flow reserve was significantly different for A vs. B and A vs. C. (A, 1.77+/-0.18; B, 1.51+/-0.1; C, 1.28+/-0.24). A strong and significant correlation was found between the maximum coronary flow reserve and the degree of proximal left anterior descending artery stenosis (r=0.78, P<0.001). Coronary artery disease patients without left anterior descending artery stenosis on the arteriogram exhibited lower maximum coronary flow reserve compared to the control subjects (1.78+/-0.19 vs. 2.8+/-0.3, P=0.000).

New method for placement of intracoronary stents in order to avoid their embolization in the intravascular space.

Stent dislodgment from the delivery catheter is a well-known complication of angioplasty with stent implantation. The aim of our study was to investigate the feasibility, effectiveness, and safety of a new technique of intracoronary stent implantation in order to avoid stent loss in the intravascular space. Fifty consecutive patients were candidates for angioplasty and stent placement. During angioplasty, a technique was followed according to which the guide wire "hindered" the dislodgment of the stent from the balloon catheter. Successful angioplasty and stent placement were performed in 46 out of 50 patients (92% success rate). In three cases of failure of stent implantation, the stent moved onto the balloon catheter; however, this was impeded by the guide wire. One non-Q-wave myocardial infarction occurred. No major complications (Q-wave myocardial infarction, CABG, or death) were observed. In conclusion, the technique applied was feasible enough, safe, and effective. However, the appropriate modification of its "hardware" will render it even more feasible and user-friendly.

Entrapment of angiographic catheter in the right coronary artery: a trap for the nonexperienced operator.

A case of angiographic catheter entrapment in the right coronary artery during coronary angiography in a patient with excessive tortuosity of the right iliac artery is described. Alternative manipulations in order to avoid this problem are presented.

Stent implantation in patient with visible intracoronary thrombus and compromised left ventricular function, after local thrombolysis using the Dispatch catheter.

The case of a patient with unstable angina and angiographic findings of significant (approximately 90%) right coronary artery stenosis with an intracoronary thrombus next to the lesion, total left anterior descending and circumflex occlusion and an ejection fraction of approximately 22% is described. The case was treated with stent implantation after local thrombolysis with the use of the Dispatch infusion catheter.

Successful management of right coronary air embolus after intracoronary administration of verapamil.

A case of a 50 year-old male with a coronary air embolism is described. The case was successfully treated with intracoronary administration of verapamil.

Transesophageal echocardiographic Doppler study of coronary flow in a patient with myocardial bridging--a case report.

A case report of myocardial bridging of the left anterior descending artery is described. Coronary flow proximal to the myocardial bridge was studied with transesophageal echo Doppler. The patient, a 62-year-old farmer who sustained an anterior myocardial infarction, underwent thrombolysis and was admitted. He subsequently underwent coronary angiography and left ventriculography, which showed a severe myocardial bridge of the midshaft of the left anterior descending artery. The ejection fraction improved from 25 to 48% after thrombolysis, as measured by using echocardiography. Transesophageal Doppler study proximal to the myocardial bridge revealed a relative increase of the diastolic coronary flow velocity (increased acceleration), which reached its peak value in early diastole. Despite the presence of severe myocardial bridging, coronary flow reserve increased substantially two minutes after the infusion of dipyridamole (0.56 mg/kg iv for 4 minutes). Transesophageal Doppler study of coronary blood flow proximal to the myocardial bridge in the left anterior descending artery showed a characteristic waveform that may prove to be indicative of this condition.

Angioplasty followed by coronary stenting at the anastomotic site of saphenous vein bypass graft with the native vessel: a case that needs special procedural strategy.

In this report we describe a case in which a saphenous vein graft stenosis at the site of anastomosis with the left anterior descending artery (LAD) was dilated with a special Controlled Angioplasty Technology (CAT) balloon, and then stented. Balloon angioplasty and stenting at the site of anastomosis represents a technical problem because of diameter discrepancy and needs special attention in order to avoid minor or major complications.

Angioplasty without the use of "Y connector": a new, easier, bloodless method.

The "Y connector" that is used in angioplasty has the following disadvantages: 1) it is not blood-tight; 2) we need to "screw and unscrew" every time we want to inject contrast material or measure the pressure; and 3) it does not allow the advancement of the guidewire or the balloon catheter during the injection of contrast material. We created a new type of connection composed of a cut sheath for the femoral artery, connected with a cut (at the "hub") guiding catheter. The aim of this study was to examine the feasibility, efficacy, and safety of the new method. Using the new technique we performed plain-balloon angioplasty, implantation of stent, and atherectomy in 350 patients. The technical success of the method was 100%, and no complications related to the method were seen. In conclusion, the novel connection that we created eliminated all the disadvantages of the "Y connector" and was found to have 100% technical success and safety.

Communication between a nongrafted left internal mammary artery and left anterior descending coronary artery following saphenous vein bypass grafting.

A case is described in which a pericardial branch of a nongrafted left internal mammary artery communicated directly with the distal left anterior descending artery, following saphenous vein bypass grafting. This type of collateralization following coronary artery bypass surgery seems to be very rare, and perhaps could protect the myocardium from severe ischemia.

Echocardiographic detection of the extent of coronary artery disease in the elderly using dobutamine and adenosine infusion.

BACKGROUND: The high prevalence of asymptomatic multivessel disease in the elderly and the fact that most of them can not carry out an exercise stress testing renders the application of other stress modalities necessary. The aim of this study is to compare the diagnostic value of dobutamine and adenosine stress echocardiography and their accuracy in determining the extent of coronary artery disease in elderly people. METHODS: Dobutamine and adenosine stress echocardiography were performed in 128 consecutive patients > or = 70 years-of-age with known or suspected coronary artery disease. All patients underwent coronary angiography within 2 weeks of the stress tests. RESULTS: The presence of any echocardiographic abnormality on dobutamine (odds ratio 30.8) and adenosine (odds ratio 18.1) test, the need for cessation of dobutamine test and the ST depression during dobutamine infusion, were independent predictors of significant coronary artery disease. Both tests proved more sensitive for detecting multivessel disease (89% for dobutamine, 74% for adenosine test), than one-vessel disease (74 and 39%, respectively). This difference was statistically significant only for the adenosine echocardiography test (P = 0.008). In patients with localized resting wall motion abnormalities, the accuracy of dobutamine test to predict a remotely diseased vessel (70%), was statistically superior to the accuracy of adenosine test (57%, P = 0.008). Patients with multivessel disease showed delayed resolution of test-induced wall motion abnormalities, during the recovery period after both tests, compared with those who suffered from one-vessel disease. CONCLUSIONS: Dobutamine echocardiography was more sensitive and accurate than adenosine echocardiography in detecting and determining the extent and the severity of coronary artery disease in the elderly. A positive adenosine echocardiography result reflected the presence of advanced coronary artery disease. The two tests, combined with clinical data, could classify the elderly into low- and high-risk subgroups for ischemic heart disease.