Comparison of primary coronary stenting to primary balloon angioplasty with stent bailout for the treatment of patients with acute myocardial infarction

Impact of plaque components on no-reflow phenomenon after stent deployment in patients with acute coronary syndrome: a virtual histology-intravascular ultrasound analysis

Aims

We used virtual histology-intravascular ultrasound (VH-IVUS) to evaluate the relation between coronary plaque characteristics and no-reflow in acute coronary syndrome (ACS) patients.

Methods and results

A total of 190 consecutive ACS patients were imaged using VH-IVUS and analysed retrospectively. Angiographic no-reflow was defined as TIMI flow grade 0, 1, and 2 after stenting. Virtual histology-intravascular ultrasound classified the colour-coded tissue into four major components: fibrotic, fibro-fatty, dense calcium, and necrotic core (NC). Thin-cap fibroatheroma (TCFA) was defined as focal, NC-rich (≥10% of the cross-sectional area) plaques being in contact with the lumen in a plaque burden ≥40%. Of the 190 patients studied at pre-stenting, no-reflow was observed in 24 patients (12.6%) at post-stenting. The absolute and %NC areas at the minimum lumen sites (1.6 ± 1.2 vs. 0.9 ± 0.8 mm², P < 0.001, and 24.5 ± 14.3 vs. 16.1 ± 10.6%, P = 0.001, respectively) and the absolute and %NC volumes (30 ± 24 vs. 16 ± 17 mm³, P = 0.001, and 22 ± 11 vs. 14 ± 8%, P < 0.001, respectively) were significantly greater, and the presence of at least one TCFA and multiple TCFAs within culprit lesions (71 vs. 36%, P = 0.001, and 38 vs. 15%, P = 0.005, respectively) was significantly more common in the no-reflow group compared with the normal-reflow group. In the multivariable analysis, %NC volume was the only independent predictor of no-reflow (odds ratio = 1.126; 95% CI 1.045–1.214, P = 0.002).

Conclusion

In ACS patients, post-stenting no-reflow is associated with plaque components defined by VH-IVUS analysis with larger NC and more TCFAs.

Plaque gruel of atheromatous coronary lesion may contribute to the no-reflow phenomenon in patients with acute coronary syndrome

BACKGROUND

No-reflow associated with direct angioplasty (PCI) of patients with acute coronary syndromes (ACS) is associated with unfavorable results.

METHODS AND RESULTS

We used a new thrombectomy device to treat 51 lesions in 48 consecutive ACS patients (40 male and 8 female; mean age 63 years) and conducted a microscopic analysis of aspirates and blood samples retrieved from the culprit coronary artery. The first aspirate was collected before PCI and the second was collected separately after percutaneous transluminal coronary angioplasty or stenting, including samples from the no-reflow lumen. Light microscopy showed that the materials obtained from the pre-PCI aspiration consisted of thrombus in 37.5%, thrombus and atheroma in 35.0%, and atheromatous plaque in 27.5%. The materials collected from the post-PCI aspiration were thrombus in 8.3%, thrombus and atheroma in 41.7%, and atheromatous plaque in 50.0%. We then compared the 9 lesions (19.1%) with no-reflow to those without no-reflow. There was no difference in the pre-PCI aspirates. However, after PCI, there was more atheromatous plaque retrieved from patients with no-reflow (P<0.001) as well as significantly more platelet and fibrin complex, macrophages, and cholesterol crystals in the blood aspirated from no-reflow cases. Aspiration of these elements improved the no-reflow in 7 of 9 lesions to TIMI-3 flow.

CONCLUSIONS

No-reflow after angioplasty may be caused by gruel that formed from an atheroma attributable to mechanical plaque disruption during intervention.

Infarct artery reocclusion after primary angioplasty, stent placement, and thrombolytic therapy for acute myocardial infarction

BACKGROUND

The benefits of thrombolytic therapy for acute myocardial infarction (AMI) are limited by reocclusion of the infarct-related artery, which occurs in 25% to 30% of patients after successful reperfusion. The frequency of reocclusion after balloon angioplasty and stenting in this setting is less well documented. The aim of this study was to analyze the frequency and timing of reocclusion after percutaneous transluminal coronary angioplasty (PTCA) and stent placement during AMI from all available studies compared with previously published reocclusion rates after thrombolysis.

METHODS AND RESULTS

The previously published thrombolysis data included 4231 patients in 19 studies with > or = 75 patients. Only PTCA studies with > or = 50 patients and stent studies with > or = 30 patients, in which routine angiographic follow-up was obtained in > or = 60% of patients, were included. Ten PTCA studies with a total of 1943 patients were analyzed, with follow-up angiography in 1391 (72%). Reocclusion rates ranged from 5% to 16.7%. The stent studies included 698 patients from 7 studies, with follow-up angiography in 92%. Reocclusion rates ranged from 0% to 6%. With the use of logistic regression analysis with allowance for overdispersion, there was a significantly lower rate of reocclusion after PTCA (odds ratio, 0.38; confidence interval, 0.24 to 0.57; P <.0001) and stent placement (odds ratio, 0.11; confidence interval, 0.05 to 0.22; P <.0001) compared with thrombolysis. Reocclusion after stent placement was lower than after PTCA (odds ratio, 0.28; confidence interval, 0.13 to 0.6; P <.0001).

CONCLUSIONS

Reocclusion after PTCA and stent placement during AMI is less frequent than after thrombolysis. This may contribute to the superior outcome of patients treated with PTCA and stent placement in this setting.

Stent placement for non-STRESS/BENESTENT lesions: a critical review

Stenting lesions with favorable characteristics as required for inclusion in the STRESS/BENESTENT trials have yielded superior results to that of PTCA alone. Results for less favorable lesions such as in small vessels, diffuse disease, ostial disease, and saphenous vein grafts are less well established. This review seeks to analyze available data for stent placement in this subset of non-STRESS/BENESTENT lesions.

Absence of preinfarction angina is associated with a risk of no-reflow phenomenon after primary coronary angioplasty for a first anterior wall acute myocardial infarction

BACKGROUND

No-reflow phenomenon after primary coronary angioplasty is associated with poorer left ventricular (LV) function and prognosis after acute myocardial infarction (AMI). The purpose of this study was to determine the clinical significance of preinfarction angina in the no-reflow phenomenon.

METHODS AND RESULTS

A total of 40 patients with first anterior AMI were examined. All patients underwent primary balloon angioplasty or stenting within 12 h of the onset of AMI. No-reflow, defined as TIMI grade 2 flow or less without residual stenosis after angioplasty, was observed in 15 patients. Patients with no-reflow were older (67+/-9 vs. 58+/-10 years, P=0.006) and had a lower incidence of preinfarction angina (7% vs. 48%, P=0.01) than those without no-reflow. Patients with no-reflow had poorer LV function at predischarge and a higher incidence of pump failure, LV aneurysm, malignant ventricular arrhythmias or cardiac death during the hospital course in association with higher peak serum C-reactive protein levels (12.7+/-8.0 vs. 7.1+/-5.5 mg/dl, P=0.02). Multivariate analysis showed that the absence of preinfarction angina was a major independent determinant of no-reflow (RR=17.1, P=0.02).

CONCLUSIONS

The absence of preinfarction angina is more frequently observed in patients with no-reflow. The beneficial effect of preinfarction angina on LV function may be explained, at least in part, by prevention of no-reflow after reperfusion.

Angiographic and clinical outcomes after rescue coronary stenting

The role of coronary stenting in improving outcomes after failed thrombolysis has not been well described. This study represents a registry of rescue coronary interventions performed during a 3 year period in which interventional treatment was changing for this high risk population. We analyzed acute angiographic results and clinical outcomes in 108 consecutive patients treated for thrombolytic failure with either balloon angioplasty (n = 63) or coronary stenting (n = 45). The overall in-hospital mortality rate was 5.5%, and there was no increase in complications in the stent group. Coronary stenting was associated with improved angiographic results including lower residual stenosis in the culprit artery (15 +/- 10% vs. 31 +/- 22%, P < 0.001) without increasing bleeding complications. The rate of in-hospital and long term target vessel revascularization in the stent group was significantly lower than in the unmatched PTCA group. Rescue coronary stenting is safe, improves acute angiographic results compared to PTCA alone and leads to excellent in-hospital and long term outcomes.

Outcome of patients with acute myocardial infarction who are ineligible for primary angioplasty trials

We determined acute outcome in 148 consecutive patients with ST segment elevation myocardial infarction undergoing angioplasty including 72 patients (48.7%) considered ineligible for primary angioplasty trials. Overall, in-hospital mortality for acute infarct angioplasty was 12%, with fivefold higher mortality in the trial-ineligible group (21% vs. 4%, P = 0.003). Thus, primary angioplasty trials continue to exclude nearly 50% of acute infarction patients and reported mortality rates of primary angioplasty trials are likely to be significantly lower than the unselected in-hospital mortality rates. Cathet. Cardiovasc. Intervent. 49:237-243, 2000.

Impact of cilostazol on clinical and angiographic outcome after primary stenting for acute myocardial infarction

Cilostazol, an antiplatelet drug that also may inhibit smooth muscle proliferation, was given together with aspirin after primary stenting to treat patients with acute myocardial infarction. In a randomized controlled trials of 50 patients, clinical and angiographic outcome at 6 months was significantly improved with cilostazol, depicting a significantly smaller late loss and/or loss index.

Contribution of stenting to the results of rescue PTCA

Failed thrombolysis in acute myocardial infarction (AMI) is associated with increased mortality. Controversial benefit of rescue percutaneous transluminal coronary angioplasty (PTCA) in these setting has been published. The feasibility, safety, and contribution of stenting to the outcome of AMI patients treated with this strategy is unknown. We studied the angiographic result and clinical outcome of 33 patients with failed thrombolysis referred for rescue angioplasty. Twenty-three patients had stenting and 10 patients did not have stenting. Both groups had similar clinical and angiographic characteristics. Stent indications were nonoptimal result, 40%; bailout, 40%; elective, 20%. Angiographic success was 100% with stent vs. 91% with balloon alone (P < 0.8). Postprocedure residual stenosis was 1.5% (0%-10%) with stent vs. 18.05% (0%-30%) with balloon alone (P < 0.01). Thirty-day outcome with and without stent was mortality, 0% vs. 13% (P < 1.0); reinfarction, 10% vs. 0% (P < 0.30); target vessel revascularization, 0% vs. 21% (P < 0.21). The 6-month mortality was 0% with stent vs. 14% (P < 0.5). We conclude that stenting during rescue angioplasty is feasible, safe, and is associated with better immediate angiographic results. Although no obvious clinical benefit was found, a potential decrease in the revascularization rate was suggested.

Successful cerebral artery stent placement for total occlusion of the vertebrobasilar artery in a patient suffering from acute stroke. Case report

A 64-year-old man suffering from crescendo brainstem symptoms due to acute total occlusion of the vertebrobasilar artery was successfully treated by cerebral artery stent placement. The total occlusion of a long segment of the vertebrobasilar artery was completely recanalized by implanting two flexible, balloon-expandable coronary stents. The patient's clinical outcome 30 days later was favorable. No complications occurred during or after the procedure. This therapeutic option may prove to be a useful means to revascularize an acute total occlusion of the vertebrobasilar artery.

Efficacy of transradial primary stenting in patients with acute myocardial infarction

We conducted a prospective observational study to assess the effectiveness of "transradial primary stenting" in 33 patients with acute myocardial infarction, along with acute risk stratification and accelerated patient care. With use of adequate inclusion and exclusion criteria, the radial artery can be used as an access site for catheterization, and transradial primary stenting can be performed rapidly and successfully by trained coronary interventionalists.

Percutaneous transluminal coronary angioplasty, alone or in combination with urokinase therapy, during acute myocardial infarction

To investigate the effect of pre-treatment of a thrombus with a low dose of urokinase on establishing patency in a persistent infarct-related artery (IRA) during direct percutaneous coronary angioplasty (PTCA), the frequency of acute restenosis during direct PTCA, alone, or in combination with the intracoronary administration of urokinase, was examined in a consecutive nonrandomized series of patients with acute myocardial infarction (AMI). Two hundred and seventy-two successful PTCA patients (residual stenosis <50%) were divided into 2 groups: 88 patients received pre-treatment with intracoronary urokinase following PTCA (combination group); 184 received only direct PTCA without thrombolytic therapy (PTCA group). In the present study, after achievement of a residual stenosis of less than 50%, IRA was visualized every 15 min to assess the frequency of acute restenosis, which was defined as an acute progression of IRA with more than 75% restenosis after initially successful PTCA. In the patients with a large coronary thrombus, the frequency (times) of acute restenosis was significantly lower in the combination group than in the PTCA group (0.98+/-0.19 vs 2.92+/-0.32, p<0.0001). On the other hand, in the patients with a small coronary thrombus, the frequency of acute restenosis showed no difference in either group. The present study indicates that in patients with AMI, PTCA combined with pre-treatment of a low dose of urokinase is much more effective than PTCA alone, especially for those patients who have a large coronary thrombus.