Long-term outcome after primary stenting versus balloon angioplasty for acute myocardial infarction

The objective of the present prospective multicenter case-control study was to investigate the long-term clinical outcome (5 years) of primary stenting compared to primary percutaneous transluminal coronary angioplasty (PTCA) without stenting (POBA) in patients with acute myocardial infarction at 7 cardiovascular centers in Hokkaido, Japan. Forty-one patients with acute myocardial infarction treated with successful primary stenting (stent group: case) and paired with 41 matched control subjects with acute myocardial infarction treated by successful primary PTCA without stenting (POBA group: control) were analyzed. After 1 year, the stent group had a lower incidence of the combined clinical endpoint (death, rehospitalization due to congestive heart failure, nonfatal myocardial infarction, repeat angioplasty, CABG, or cerebrovascular events) compared to the POBA group (17.1% versus 39.0%, P = 0.049). After 5 years, the incidences of congestive heart failure and cardiac death were the same in both groups. However, compared to the POBA group, the stent group had a lower combined clinical endpoint (34.1% versus 61.0%, P = 0.027). The Kaplan-Meier event-free survival curves of the stent group showed a significantly lower occurrence of clinical events compared to the POBA group (P = 0.0116). Multiple logistic regression analysis of clinical events identified age > or = 69 years (P = 0.0092, odds ratio = 4.179) and stenting (P = 0.0158, odds ratio = 0.279) as explanatory factors. Compared with POBA, primary stenting for acute myocardial infarction results in a better long-term clinical outcome.     

Predictors of left ventricular thrombus formation in acute myocardial infarction treated with successful primary angioplasty with stenting

BACKGROUND: There are limited data referring to the incidence of left ventricle (LV) thrombus formation after successful primary percutaneous coronary intervention (PCI) with stenting, which is now the treatment of choice in patients with acute myocardial infarction (AMI). Previously reported results were often based on low or heterogeneous patient populations. METHODS: To evaluate the prevalence of LV thrombus in the early period of AMI, 2,911 patients who had undergone successful primary stenting were retrospectively studied. Baseline demographic characteristics, angiographic findings, and antiplatelet treatment were analyzed to find predictors of thrombus formation. LV thrombus was diagnosed by 2-dimensional echocardiography within 3 to 5 days after PCI. RESULTS: This complication was detected in 73 patients (2.5%). Patients with thrombus and patients without it were at the same age and had diabetes mellitus, prior myocardial infarction, and lipid disorders at the same frequency. The extent of coronary artery disease was similar in both groups. The incidence of LV thrombi was similar in patients treated with and without glycoprotein IIb/IIIa inhibitors (2.02% vs 2.9%, NS). According to results of multiple log-regression analysis, the presence of LV thrombus was strongly associated with anterior AMI, ejection fraction <40%, and previous hypertension. CONCLUSIONS: The incidence of left ventricular thrombus early after AMI is very low if primary PCI with stenting is successful, probably due to the salvage of myocardium at risk. Localization of AMI and the size of myocardium damage remain the most important independent predictors of LV thrombus formation irrespective of various treatments.     

Coronary artery stenting for acute closure complicating primary angioplasty for acute myocardial infarction

We report a case of progressive right coronary artery dissection complicating direct angioplasty for an acute inferior myocardial infarct, with successful bail-out stenting of the affected vessel.     

Sex-based differences in clinical and angiographic outcomes after primary angioplasty or stenting for acute myocardial infarction

A paucity of data exists on the importance of gender in contributing to the mortality rate after primary angioplasty, although it is has been shown that women with acute myocardial infarction (AMI) are less likely than men to undergo reperfusion treatments. This study analyzes gender-related differences in 6-month clinical and angiographic outcomes in nonselected patients with AMI who underwent primary angioplasty or stenting. We compared clinical and angiographic outcomes of 230 women and 789 men who underwent primary angioplasty or stenting from January 1995 to August 1999. The women were older than the men, and had a greater incidence of diabetes and cardiogenic shock. The 6-month mortality rate was 12% in women and 7% in men (p = 0.028). Nonfatal reinfarction occurred in 3% of the women and in 1% of the men (p = 0.010). There were no differences in repeat target vessel revascularization rates. After multivariate analysis, gender did not emerge as a significant variable in relation to 6-month mortality or to the combined end point of death, reinfarction, and repeat target vessel revascularization. Both women and men with stented infarct arteries had lower restenosis rates (29% and 26%, respectively) than patients without stents (52% and 39%, repectively). The results of outcome analysis in nonselected patients suggest that sex is not an independent predictor of mortality after primary angioplasty for AMI, and that the benefit of primary stenting is similar in men and women.     

Coronary stenting for failed angioplasty in acute myocardial infarction

Intracoronary stents were implanted in 15 patients after unsuccessful PTCA in the setting of acute myocardial infarction (AMI). The stented vessel was the left anterior descending (LAD) in 11 patients, the right coronary artery (RCA) in 3 patients, and a venous bypass graft to the LAD in a single patient. A total of 16 stents were implanted (15 Palmaz-Schatz, Johnson and Johnson; and 1 Wiktor, Medtronic). Follow-up: 1 patient died 10 days after stent implantation as a result of renal failure and cardiogenic shock. Subacute thrombosis occurred in 2 patients, 5 and 15 days after stent implantation; both underwent successful emergency coronary artery bypass grafting (CABG). The remaining 12 patients were free from major ischemic events (death, AMI, and further revascularization) after a mean follow-up of 18.7 ± 4.1 months. We conclude that the long-term results of intracoronary stenting in AMI after failed PTCA are favourable. © 1996 Wiley-Liss, Inc.     

Subacute development of a coronary artery pseudoaneurysm after primary angioplasty and stenting for acute myocardial infarction

Three months after successful primary angioplasty with stent implantation for an acute myocardial infarction, we were confronted with an intra-stent pseudoaneurysm. It was located at the proximal part of the left anterior descending coronary artery and associated with an early severe restenosis on a marginal branch; the choice was made for surgical treatment. Despite a review of the literature and an examination of the procedural data, we were not able to explain the pseudoaneurysm. We assume that either the guidewire perforated the arterial wall when it cleared the occlusion or a non-angiographically visible dissection provoked this phenomenon.     

Benefit of coronary reperfusion before intervention on outcomes after primary angioplasty for acute myocardial infarction

Primary percutaneous transluminal coronary angioplasty has become the preferred reperfusion strategy for acute myocardial infarction in most institutions with interventional facilities and experienced operators. The benefit of establishing coronary reperfusion, with or without pharmacologic therapy, before primary angioplasty has not been established. Consecutive patients (n = 1,490) with acute myocardial infarction treated with aspirin and heparin followed by primary percutaneous transluminal coronary angioplasty were followed for 13 years. Follow-up angiography was obtained in 737 patients at 7.7 months. Thrombolysis In Myocardial Infarction (TIMI) 2 to 3 flow in the infarct artery at initial angiography was present in 18.3% of patients, and TIMI 0 to 1 flow in 81.7% of patients. Baseline variables were similar between the 2 groups, except patients with initial TIMI 2 to 3 flow had significantly less cardiogenic shock (1.7% vs 9.4%, p <0.0001) and a lower incidence of depressed ejection fraction <40% (12.6% vs 19.9%, p = 0.007). Procedural success was better in patients with initial TIMI 2 to 3 flow (97.4% vs 93.8%, p = 0.02), and catheterization laboratory events were less frequent. Patients with initial TIMI 2 to 3 flow had lower peak creatine kinase values (1,328 vs 2,790 IU/L, p <0.0001), higher acute ejection fraction (54.3% vs 51.6%, p = 0.05), higher late ejection fraction (59.2% vs 54.9%, p = 0.004), and lower 30-day mortality (4.8% vs 8.9%, p = 0.02). These data indicate that when reperfusion occurs before primary angioplasty, outcomes are strikingly better with less cardiogenic shock, improved procedural outcomes, smaller infarct size, better preservation of left ventricular function, and reduced mortality. This should encourage new strategies to establish reperfusion before "primary" angioplasty with "catheterization laboratory friendly" platelet inhibitors and/or low-dose thrombolytic drugs.     

直接冠状动脉内支架置入术治疗急性心肌梗死

目的观察急性心肌梗死(AMI)时行无球囊预扩张直接置入冠状动脉内支架治疗的临床效果.方法对22例AMI患者在发病12小时内,未经球囊预扩张而直接置入冠状动脉内支架.梗死相关血管(IRA)(共22支血管),左前降支12例(54.5%),左回旋支5例(22.7%),右冠状动脉5例(22.7%).心肌梗死溶栓试验(TIMI)血流1级5例(22.7%),2级13例(59.1%),3级4例(18.2%).结果 22例患者共置入22个支架,支架置入后 TIMI血流3级21例(95.5%),2级1例(4.5%),残余狭窄为3.2±2.9%,支架置入成功率100%.住院期间无一例死亡、再次心肌梗死及再次靶病变需重复再通治疗.结论急性心血肌梗死(AMI)时行无球囊预扩张直接置入冠状动脉内支架治疗,成功率高、并发症少,TIMI血流3级达到率高.     

Retrospective comparative study of primary intracoronary stenting versus balloon angioplasty for acute myocardial infarction

Balloon angioplasty has been shown to be an effective therapy for the treatment of acute myocardial infarction but is associated with a high restenosis rate, substantial early recoil, persistent thrombus and need for intracoronary thrombolysis, and a high rate of reclosure. Because many of the limitations of balloon angioplasty in the noninfarction setting are addressed by intracoronary stenting, we examined the results of primary stenting of 18 consecutive patients treated for acute myocardial infarction, and compared the results to those achieved with primary balloon angioplasty in 18 prior cases. Despite the presence of thrombus prior to angioplasty in 13 of the stented patients, no intracoronary thrombolytic therapy was required. Mean percent stenosis using quantitative coronary angiography was 17.7 ± 10.2% after primary stenting compared with 43.7 ± 20.3% after primary balloon angioplasty (P < .001). One stent patient who had all anticoagulant and antiplatelet therapy withdrawn early suffered subacute thrombosis. Patients were followed up to 3 yr. Complications were similar in the two groups. We conclude that primary stenting for acute myocardial infarction results in superior angiographic appearance as well as resolution of thrombus without the need for routine thrombolysis, and is associated with a low complication rate and excellent short-term clinical patency. Cathet. Cardiovasc. Diagn. 40:235–239, 1997. © 1997 Wiley-Liss, Inc.     

Long-term follow-up of a randomized study of primary stenting versus angioplasty in acute myocardial infarction

PURPOSE: Primary stenting leads to better short-term outcomes than does balloon angioplasty among patients with acute myocardial infarction, but there are no data available on long-term follow-up. SUBJECTS AND METHODS: We designed a randomized study with long-term follow-up to compare primary angioplasty with angioplasty accompanied by implantation of a silicon carbide-coated stent in patients within 24 hours after the onset of acute myocardial infarction. All 88 patients had lesions that were suitable for coronary stenting. RESULTS: There were 44 patients in each of the randomization groups. During long-term follow-up (mean +/- SD: 710+/-282 days), primary stenting was associated with a reduction in the combined endpoint of death, reinfarction, or target vessel revascularization (10 [23%] versus 19 [43%], P = 0.03); death (4 [9%] versus 8 [18%], P = 0.18); reinfarction (1 [2%] versus 4 [9%], P = 0.18); and target lesion revascularization (7 [16%] versus 15 [34%], P = 0.04). Rehospitalization due to ischemic events (unstable angina or reinfarction) was also less frequent in the stent group (6 [14%] versus 10 [23%], P = 0.20). CONCLUSION: Primary stenting in acute myocardial infarction is significantly superior to angioplasty alone in both short-term and long-term follow-up.     

Right bundle branch block in acute myocardial infarction treated by primary coronary angioplasty and stenting

Patients with right bundle branch block (RBBB) in acute myocardial infarction (AMI) have a significantly higher mortality rate even with the advent of thrombolytic therapy. This study was undertaken to assess the impact of primary percutaneous transluminal coronary angioplasty (PTCA) and stenting on the outcome of patients with RBBB in AMI. A total of 600 patients with AMI who underwent primary PTCA and stenting (rate: 61%) < 12 hours of onset were studied. A 12-lead ECG was obtained at least every 6 hours. Serial creatine kinase was measured, and left ventricular ejection fraction was obtained during the hospital stay. Among 600 patients with AMI, 94 patients (15.7%) had RBBB; it was persistent in 31 (33%) and transient in 63 (67%). In-hospital mortality rate was 7.3% in patients without RBBB, 7.9% in transient RBBB, and 25.8% in persistent RBBB (p < 0.02). The incidence of heart failure was 26.5% in those without RBBB, 34.9% in transient RBBB, and 58.1% in persistent RBBB (p < 0.001). There was no significant difference among these 3 groups in ventricular arrhythmias and complete atrioventricular block. Peak creatine kinase was 3,214+/-2,293 U/L in those without RBBB, 4,558+/-3,316 U/L in transient RBBB (p < 0.001), and 5,635+/-3,920 U/L in persistent RBBB (p < 0.001). Left ventricular ejection fraction was 50+/-11% in those without RBBB, 47+/-11% in transient RBBB (p < 0.05), and 42+/-13% in persistent RBBB (p < 0.001). Patients with AMI treated by primary PTCA and stenting had an increased incidence of transient RBBB, especially following reperfusion therapy, although the clinical outcome was similar to that of those without RBBB. In contrast, there was no satisfactory improvement in clinical outcomes in those with persistent RBBB.     

Effect of audit on door-to-inflation times in primary angioplasty/stenting for acute myocardial infarction

We found that after audit and physician-guided changes in our protocol, the door-to-inflation times for primary angioplasty/stenting were markedly reduced. Because our preaudit mean time was similar to the national average, this may have wide applicability.     

Predictors of stent thrombosis after primary stenting for acute myocardial infarction

The aim of the study was to determine if a hypercoagulable state that may persist for several months after an acute myocardial infarction may contribute to an increased incidence of stent thrombosis. Primary stenting was performed in 104 consecutive patients with acute myocardial infarction using 147 coronary stents. Twenty-eight patients (27%) were diabetic and 55 patients (53%) were smokers. A single stent was placed in 63%, two stents in 33%, and more than two stents in 4% of the patients. Procedural success was obtained in 97% of the patients. All stents were deployed using high-pressure balloon inflation. The reference vessel diameter and minimal lumen diameter after stent deployment were 3.30 ± 0.42 and 3.23 ± 0.42 mm, respectively. Six patients (5.7%) developed stent thrombosis within 1 month after the procedure complicated by reinfarction in five of the six patients. At 1-month follow-up, all patients remained alive. On multivariate analysis, independent predictors of stent thrombosis were diabetes mellitus (relative risk [RR] 5.2; 95% confidence interval [CI] 1.8, 25.1), tobacco use (RR 4.5; 95% CI 1.3, 24.5), number of stents: 1 vs. > 1 (RR 3.7; 95% CI 1.1, 15.9), minimal lumen diameter poststent placement (RR 0.03; 95% CI 0.0002, 0.74), and duration of chest pain before intervention (RR 1.1; 95% CI 1.01, 1.25). Stent thrombosis had not been associated with diabetes mellitus and tobacco use previously but is in agreement with the enhanced platelet aggregability, coagulation factor abnormalities, and impaired fibrinolysis characteristic of these patients. Cathet. Cardiovasc. Intervent. 47:415–422, 1999. © 1999 Wiley-Liss, Inc.     

Prehospital administration of enoxaparin before primary angioplasty for ST-elevation acute myocardial infarction.

We hypothesized that primary percutaneous coronary intervention (PCI) could be performed with prehospital injections of enoxaparin for ST segment elevation myocardial infarction (STEMI). Enoxaparin has been studied in combination with fibrinolysis in STEMI, but has not been evaluated as anticoagulant regimen for primary PCI. In a prospective registry, 143 consecutive patients with STEMI received prehospital 0.5 mg/kg intravenous (i.v.) bolus followed by 1 mg/kg subcutaneous enoxaparin before immediate transport for PCI. We focused on anti-Xa activities before and after PCI, bleedings, infarct-related artery patency, and major adverse cardiac events at day 30. Anti-Xa activity was at the target level (>0.5 IU/ml) in 99% of patients during PCI, and in 100% 4 hr after injections; over-anticoagulation (>1.5 IU/ml) was noted in 9 and 2%, respectively at start and 4 hr after injections. Bleeding complications with enoxaparin were rare: major in 1.4% (no intracranial hemorrhages), minor in 2.1%. A patent infarct-related artery (TIMI 2 + 3) was observed in 40.6% of the patients before PCI. TIMI 3 flow was obtained in 88.1% of the cases after PCI. Major adverse cardiac events at 30 days occurred in 5.6% of cases: death 2.8%, reinfarction 3.5%, and target lesion revascularisation 3.5%. Prehospital i.v. and subcutaneous enoxaparin provides simple and rapid anticoagulation for PCI in STEMI patients. Enoxaparin dose needs to be reduced regarding the 9% of over-anticoagulation. This study suggests the potential of enoxaparin as an alternative anticoagulant regimen for primary PCI.     

Relation between coronary thrombus and angiographic no-flow during primary angioplasty in patients with acute myocardial infarction

No flow is an unsolved issue in primary percutaneous transluminal coronary angioplasty (PTCA) for patients with acute myocardial infarction (AMI), and the pathophysiology of no-flow is undetermined. To evaluate the potential participation of coronary thromboembolism in no-flow during primary PTCA, the present study reviewed cinefilms of 256 consecutive patients who underwent primary PTCA for AMI within 24h after the onset of chest pain between January 1992 and June 1998, focusing on the thrombus size. Angiographic no-flow was defined as the cessation of flow into the distal coronary circulation of the treated vessel with a to-and-fro contrast movement, not attributable to high-grade stenosis or spasm of the original target lesion. The coronary thrombus size was determined by using the 2-cm balloon catheter as a reference after crossing the infarct-related occluded artery with a guide wire. Angiographic no-flow was observed in 37 patients (37/256, 14%): 14 of 29 cases (48%) with a large thrombus (> or =2cm) versus 23 of 227 cases (9%) with a small thrombus (<2cm, 14/29 vs 23/227, p<0.01). Among 37 patients who experienced angiographic no-flow, overt distal emboli were observed in 14 patients. A thrombolytic agent was used through a guiding catheter in 102 cases prior to or after balloon dilatation to prevent or attenuate distal embolism, particularly in all those cases with a large thrombus (29/29 100%), and angiographic no-flow was seen in 27 cases of this subgroup (27/102, 26%). It is suggested that distal thromboembolism plays an important role in the mechanism of angiographic no-flow during primary PTCA performed for AMI.