A comparison of systematic stenting and conventional balloon angioplasty during primary percutaneous transluminal coronary angioplasty for acute myocardial infarction

OBJECTIVES

In a multicenter, randomized trial, systematic stenting using the Wiktor stent was compared to conventional balloon angioplasty with provisional stenting for the treatment of acute myocardial infarction (AMI).

BACKGROUND

Primary angioplasty in AMI is limited by in-hospital recurrent ischemia and a high restenosis rate.

METHODS

A total of 211 patients with AMI <12 h from symptom onset, with an occluded native coronary artery, were randomly assigned to systematic stenting (n = 101) or balloon angioplasty (n = 110). The primary end point was the binary six-month restenosis rate determined by core laboratory quantitative angiographic analysis.

RESULTS

Angiographic success (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3 and residual diameter stenosis <50%) was achieved in 86% of the patients in the stent group and in 82.7% of those in the balloon angioplasty group (p = 0.5). Compared with the 3% cross-over in the stent group, cross-over to stenting was required in 36.4% of patients in the balloon angioplasty group (p = 0.0001). Six-month binary restenosis (≥50% residual stenosis) rates were 25.3% in the stent group and 39.6% in the balloon angioplasty group (p = 0.04). At six months, the event-free survival rates were 81.2% in the stent group and 72.7% in the balloon angioplasty group (p = 0.14), and the repeat revascularization rates were 16.8% and 26.4%, respectively (p = 0.1). At one year, the event-free survival rates were 80.2% in the stent group and 71.8% in the balloon angioplasty group (p = 0.16), and the repeat revascularization rates were 17.8% and 28.2%, respectively (p = 0.1).

CONCLUSIONS

In the setting of primary angioplasty for AMI, as compared with a strategy of conventional balloon angioplasty, systematic stenting using the Wiktor stent results in lower rates of angiographic restenosis.     

Direct coronary stenting versus predilatation followed by stent placement

Direct stenting without antecedent dilatation may reduce procedural time, costs, and radiation exposure, and may result in less vessel injury. The purpose of this investigation was to compare immediate and long-term clinical and angiographic outcomes of direct stenting with stent placement after initial balloon dilation. Three hundred thirty-five symptomatic patients with single or multiple coronary lesions (diameter reduction 60% to 95%) of < or =30 mm length and with a vessel diameter of 2.5 to 4.0 mm were randomized either to direct stenting (group A, n = 171) or stenting after predilation (group B, n = 164). Patients with vessels with excessive calcification, severe proximal tortuosity, or occlusion were excluded. All patients were asked to return for routine repeat angiography at 6 months, irrespective of symptoms. Feasibility of direct stenting was 95% in group A, with 5% requiring crossover to predilation. Successful stent placement after predilation was performed in all 164 patients in group B. Direct stenting was associated with less procedural duration (group A 42.1 +/- 18.7 minutes vs group B 51.5 +/- 23.8 minutes, p = 0.004), radiation exposure time (group A 10.3 +/- 7.7 minutes vs group B 12.5 +/- 6.4 minutes, p = 0.002), amount of contrast dye used (group A 163 +/- 69 ml vs group B 197 +/- 84 ml, p <0.0001), and lower procedural costs (group A 845 +/- 167 vs group B 1,064 +/- 175, p <0.0001). Immediate angiographic results and in-hospital clinical outcomes (death, Q-wave myocardial infarction, repeat revascularization) were not significantly different between both strategies. However, at 6-month follow-up, direct stenting was associated with a lower angiographic restenosis (group A 20% vs group B 31%, p = 0.048) and target lesion revascularization rates (group A 18% vs group B 28%; p = 0.03). This study demonstrates the feasibility, safety, and outcomes of direct stenting in eligible coronary lesions. In appropriately selected cases, direct stenting has a lower rate of angiographic restenosis up to 6 months after the procedure, resulting in fewer coronary reinterventions compared with the conventional strategy of stenting with antecedent dilatation.     

Comparison of rheolytic thrombectomy before direct infarct artery stenting versus direct stenting alone in patients undergoing percutaneous coronary intervention for acute myocardial infarction

This randomized trial compared rheolytic thrombectomy before direct infarct artery stenting with direct infarct artery stenting alone in 100 patients with a first acute myocardial infarction (AMI). The primary end point of the study was early ST-segment elevation resolution, and the secondary end points were corrected Thrombolysis In Myocardial Infarction (TIMI) frame count, infarct size, and 1-month clinical outcome. The primary end point rates were 90% in the thrombectomy group and 72% in the placebo group (p = 0.022). Randomization to thrombectomy was independently related to the primary end point (odds ratio 3.56, p = 0.032). The corrected Thrombolysis In Myocaridal Infarctions (TIMI) frame count was lower in the thrombectomy group (18.2 +/- 7.7 vs 22.5 +/- 11.0, p = 0.032), and infarct size was smaller in the thrombectomy group (13.0 +/- 11.6% vs 21.2 +/- 18.0%, p = 0.010). At 1 month, there were no major adverse cardiac events. Rheolytic thrombectomy before routine direct infarct-related artery (IRA) stenting is highly feasible and provides more effective myocardial reperfusion in patients undergoing percutaneous coronary intervention for AMI.     

A randomized comparison of direct stenting with conventional stent implantation in selected patients with acute myocardial infarction.

OBJECTIVES: We sought to determine whether direct stenting might prevent the adverse events associated with stent implantation during primary angioplasty and to compare it with conventional stent implantation in patients with acute myocardial infarction (AMI). BACKGROUND: No trial has demonstrated that stents favorably influence mortality rate. Recent studies have even suggested a negative impact of stents on coronary blood flow and clinical outcome. METHODS: Of 409 patients treated by primary angioplasty with stent implantation in our center, 206 (50%) were enrolled in this randomized, single-center trial and allocated to direct stent implantation (n = 102) or stent implantation after balloon pre-dilation (n = 104). The study end points included angiographic results (final corrected Thrombolysis In Myocardial Infarction [TIMI] frame count and a composite end point of slow and no-reflow or distal embolization), an electrocardiogram marker of myocardial reperfusion assessment (ST-segment resolution) and in-hospital clinical outcome (death and recurrent infarction). RESULTS: Direct stent implantation failed in eight patients but succeeded after pre-dilation in all. A non-significant increase in TIMI flow grade 3 was achieved after direct stenting (95.1% vs. 93.3%, p = 0.74) without significant difference in the corrected TIMI frame count (31.5 +/- 17 and 35.2 +/- 20 frames after direct and conventional stent, respectively, p = 0.42). The composite angiographic end point was significantly reduced by direct stent implantation (11.7% vs. 26.9%, p = 0.01). ST-segment resolution was also significantly improved after direct stent (no ST-segment resolution in 20.2% vs. 38.1% after direct and conventional stent, respectively, p = 0.01). Death and/or recurrent infarction occurred in six patients after conventional stent implantation and in two patients after direct stenting (p = 0.28). CONCLUSIONS: In selected patients with AMI, direct stenting can be applied safely and effectively. This strategy may result in a significant reduction of microvascular injury, as suggested by improved ST-segment resolution after reperfusion with major potential clinical consequences.     

Frequency, correlates, and clinical implications of myocardial perfusion after primary angioplasty and stenting, with and without glycoprotein IIb/IIIa inhibition, in acute myocardial infarction

OBJECTIVES: We sought to determine the prognostic importance of myocardial reperfusion after various contemporary interventional strategies in patients with acute myocardial infarction (AMI). BACKGROUND: The frequency, correlates, and clinical implications of myocardial perfusion after primary angioplasty in AMI have not been examined in a large-scale prospective study. Similarly, whether glycoprotein (GP) IIb/IIIa inhibitors and/or stents improve myocardial perfusion beyond balloon angioplasty has not been investigated. METHODS: Tissue-level perfusion assessed by the myocardial blush grade was evaluated in 1,301 patients with AMI randomized to balloon angioplasty versus stenting, each with or without abciximab. RESULTS: Despite Thrombolysis In Myocardial Infarction flow grade 3 restoration in 96.1% of patients, myocardial perfusion was normal in only 17.4% of patients, reduced in 33.9%, and absent in 48.7%. Myocardial perfusion status post-coronary intervention stratified patients into three distinct risk categories, with 1-year mortality rates of 1.4% (normal blush), 4.1% (reduced blush), and 6.2% (absent blush) (p = 0.01). Among patients randomized to angioplasty, angioplasty + abciximab, stenting, and stenting + abciximab, normal myocardial perfusion was restored in 17.7%, 17.0%, 17.5%, and 17.6%, respectively (p = 0.95), which was associated with similar 1-year rates of mortality in patients randomized to stenting versus angioplasty (4.5% vs. 4.8%, p = 0.91) and abciximab versus no abciximab (4.3% vs. 5.0%, p = 0.63). CONCLUSIONS: Restoration of normal tissue-level perfusion is a powerful determinate of survival after primary PCI in AMI and is achieved in a minority of patients. Neither stents nor GP IIb/IIIa inhibitors significantly enhance myocardial perfusion compared to balloon angioplasty alone, underlying the similar long-term mortality with these different mechanical reperfusion strategies.     

Beneficial effects of immediate stenting after thrombolysis in acute myocardial infarction

OBJECTIVES: The Southwest German Interventional Study in Acute Myocardial Infarction (SIAM III) investigated potentially beneficial effects of immediate stenting after thrombolysis as opposed to a more conservative treatment regimen. BACKGROUND: Treatment of acute myocardial infarction (AMI) by thrombolysis is compromised by Thrombolysis In Myocardial Infarction (TIMI) 3 flow rates of only 60% and high re-occlusion rates of the infarct-related artery (IRA). Older studies showed no benefit of coronary angioplasty after thrombolysis compared with thrombolytic therapy alone. This observation has been challenged by the superiority of primary stenting over balloon angioplasty in AMI. METHODS: The SIAM III study was a multicenter, randomized, prospective, controlled trial in patients receiving thrombolysis in AMI (<12 h). Patients of group I were transferred within 6 h after thrombolysis for coronary angiography, including stenting of the IRA. Group II received elective coronary angiography two weeks after thrombolysis with stenting of the IRA. RESULTS: A total of 197 patients were randomized, 163 patients fulfilled the secondary (angiographic) inclusion criteria (82 in group I, 81 in group II). Immediate stenting was associated with a significant reduction of the combined end point after six months (ischemic events, death, reinfarction, target lesion revascularization 25.6% vs. 50.6%, p = 0.001). CONCLUSIONS: Immediate stenting after thrombolysis leads to a significant reduction of cardiac events compared with a more conservative approach including delayed stenting after two weeks.     

Conventional versus direct stenting in AMI: effect on immediate coronary blood flow

There are no data regarding the potential benefits of direct stenting in the setting of AMI. The aim of this study was to evaluate the impact of direct stenting on the angiographic results and compare it to conventional stenting performed in the setting of AMI. We reviewed our institutional interventional database and identified 44 patients who had undergone stenting in the setting of AMI (29 primary and 15 rescue angioplasty). Patients were then divided into two groups; group A consisted of patients who had undergone conventional stenting (23 patients) and group B those who had undergone direct stenting (21 patients). Angiographic success was defined as TIMI flow grade 2. The baseline TIMI 0-1 flow was higher in group A compared to group B (74% vs. 24%; p < 0.05). TIMI flow rates before stenting (after balloon predilation in group A and after guidewire crossing in group B) and angiographic success (TIMI flow 2) after stenting were similar in both groups (p > 0.05). However, the final TIMI 3 flow were significantly better in group B after stenting (65% vs. 95%; p < 0.05). Although there was no no re-flow in group B, three patients in group A had no re-flow after balloon predilatation of lesions with baseline TIMI 2 flow. There was a statistical tendency to a higher TIMI 3 flow in patients treated with direct stenting in the setting of AMI. Direct stenting strategy in thrombus containing lesions seems to be a safe and feasible approach in avoiding no re-flow.     

Comparison of direct stenting versus stenting with predilation for the treatment of selected coronary narrowings.

Direct stenting may reduce costs, procedure times, and injury to the vessel wall, positively influencing acute and late results. This study was designed to demonstrate 6-month clinical outcome equivalence between direct and standard stenting techniques. Four hundred eleven patients (425 lesions) were randomized in 7 sites to undergo direct (210 patients, 216 lesions) or conventional (201 patients, 209 lesions) stent implantation. Lesions with severe calcification were excluded. Angiographic success rate was 100% in the direct stent group (2.8% requiring balloon predilation) and 98.6% in the predilation group (p = 0.12). Direct stenting was associated with decreased use of balloons (0.15 vs 1.09 balloons/lesion treated) and with a trend toward a reduction of procedure time (22.7 +/- 15.0 vs 25.6 +/- 18.2 minutes; p = 0.073). Fluoroscopy time and contrast volume were not different between groups. At 6-month follow-up, the incidences of death (direct [1.4%] vs predilation [2.5%]), myocardial infarction (5.3% vs 5.0%), and target vessel revascularization (8.2% vs 10.5%) were similar in both groups. Major adverse cardiac event-free survival rate was 87.5% for those who underwent the direct stent technique and 85.5% for patients who underwent predilation (p = 0.0002 for equivalence). In conclusion, direct stenting is at least equivalent to the standard technique in terms of 6-month clinical outcomes when performed on selected coronary lesions without significant calcification. This strategy is associated with decreased use of balloons, but, in general, does not significantly reduce procedure times.     

Predictors of recurrent restenosis after coronary stenting: an analysis of 197 patients

One of the major limitations in coronary stenting is in-stent restenosis. This study was aimed to identify clinical, angiographic, and procedural factors that may be related to recurrent in-stent restenosis. We analyzed consecutive 197 patients who underwent coronary stenting. Follow-up angiography was available in 170 patients and repeat balloon angioplasty was performed for in-stent restenosis. These patients were subdivided into 3 groups: group A consisted of 100 patients that were never restenosed, group B had 49 patients restenosed once, and in group C were 21 patients restenosed more than twice. Group C was more often female (48%) and included diabetes mellitus patients (52%). Lesion location, reference vessel size and diameter stenosis were similar for all groups. However, the incidence of calcified lesions tended to be higher (50% vs. 29%; p = 0.07), and lesion length was longer in group C than in group A (11.9+/- 5.4 mm vs. 9.0+/- 3.9 mm; p < 0.01). Diameter stenosis after predilation as well as after stenting was significantly higher in group C than in group A (50+/- 10% vs 39+/- 10%; p < 0.01, 32+/- 8% vs. 19+/- 10%; p < 0.01). The incidence of diffuse type of in-stent restenosis was significantly higher in group C than in group B (62% vs. 14%; p < 0.01). Multivariate logistic regression analysis identified diameter stenosis after stenting (p = 0.0022), female (p = 0.0135), and diameter stenosis after predilatation (p = 0.0233) as the significant correlate of recurrent in-stent restenosis. In conclusion, the major recurrent in-stent restenosis predictors identified included female gender, final diameter stenosis, and diameter stenosis after predilatation.     

A randomized trial of coronary stenting versus balloon angioplasty as a rescue intervention after failed thrombolysis in patients with acute myocardial infarction

OBJECTIVES: This study was conducted to assess whether coronary stenting produces better results compared with balloon angioplasty in patients with acute myocardial infarction (AMI) after failed thrombolysis. BACKGROUND: Little evidence exists on the value of rescue mechanical reperfusion after failed thrombolysis. METHODS: This open-label, randomized study enrolled 181 patients with AMI referred for failed thrombolysis performed within the previous 24 h. The patients had to have a Thrombolysis In Myocardial Infarction (TIMI) flow grade of 相似文献   

Percutaneous transluminal coronary angioplasty for restenosis following Palmaz-Schatz stenting: larger size balloons are more effective?]

Intracoronary stenting reduces the restenosis rate after percutaneous transluminal coronary angioplasty (PTCA). However, restenosis still occurs in 20% to 30% of patients after stenting. Management of in-stent restenosis has become a significant challenge in interventional cardiology. The efficacy of re-PTCA with a larger balloon was investigated for restenosis following Palmaz-Schatz stenting. Clinical and angiographic results were compared in 46 consecutive patients with in-stent restenosis after one Palmaz-Schatz stenting. Twenty patients underwent redilation with a slightly larger balloon than used at the stenting (Large group) and 26 underwent redilation with the same size balloon as at the stenting (Control group). The clinical factors, lesion characteristics, lesion length, reference diameter and minimal luminal diameter at re-PTCA for the in-stent restenosis did not differ significantly between the 2 groups. Minimal luminal diameter of the Large group after re-PTCA was significantly larger than that of the Control group (3.1 +/- 0.2 vs 2.9 +/- 1.2 mm, p < 0.05). Follow-up angiography showed that the minimal luminal diameter of the Large group was significantly larger (2.1 +/- 0.6 vs 1.7 +/- 0.6 mm, p < 0.05) and the re-restenosis rate of Large group tended to be lower than that of the Control group (15% vs 38%, p = 0.07). Re-PTCA for in-stent restenosis with a slightly larger balloon than used at the stenting reduces the re-restenosis rate.     

A randomized trial comparing myocardial salvage achieved by coronary stenting versus balloon angioplasty in patients with acute myocardial infarction considered ineligible for reperfusion therapy

OBJECTIVES: We assessed myocardial salvage achieved by reperfusion with percutaneous coronary interventions (PCI) and compared stenting with balloon angioplasty (PTCA) in patients with acute myocardial infarction (AMI) ineligible for thrombolysis. BACKGROUND: A substantial proportion of patients with AMI are currently considered ineligible for thrombolysis, and reperfusion treatment is frequently not recommended for them. It is not known whether these patients benefit from PCI. METHODS: The Stent or PTCA for Occluded Coronary Arteries in Patients with Acute Myocardial Infarction Ineligible for Thrombolysis (STOPAMI-3) trial, a randomized, open-label study, included 611 patients with AMI who were ineligible for thrombolysis (lack of ST-segment elevation on the electrocardiogram, late presentation >12 h after symptom onset, and contraindications to thrombolysis). Patients were randomly assigned to receive either coronary artery stenting (n = 305) or PTCA (n = 306). Scintigraphic myocardial salvage index (proportion of the initial myocardial perfusion defect that was salvaged by reperfusion) was the primary end point of the study. RESULTS: A considerable myocardial salvage was achieved with both stenting and PTCA. In patients assigned to receive stenting, the median size of the salvage index was 0.54 (25th and 75th percentiles, 0.29 and 0.87), as compared with a median of 0.50 (25th and 75th percentiles, 0.26 and 0.82) in the group assigned to receive PTCA (p = 0.20). Mortality at six months was 8.2% in the group of patients assigned to receive stenting and 9.2% in the group of patients assigned to receive PTCA (p = 0.69). CONCLUSIONS: Patients with AMI who are currently considered ineligible for thrombolysis by conventional guidelines may greatly benefit from primary PCI. The benefit seems to be comparable when a strategy of stenting is compared with a strategy of PTCA in these patients.     

Does coronary stenting affect microvascular circulation in patients with anterior acute myocardial infarction? Comparison with balloon angioplasty.

The impact of coronary stenting on microvascular circulation in the infarct area was compared with that of balloon angioplasty in 94 patients with acute myocardial infarction (AMI) who underwent coronary revascularization within 6h of onset: 49 patients were treated with balloon angioplasty alone, and 45 were treated with coronary stenting. Microvascular circulation after revascularization was assessed by Thrombolysis in Myocardial Infarction (TIMI) flow grade analysis and ST segment analysis. TIMI flow grade was assessed on the final angiographic image after coronary intervention, and the ST segment was assessed on the 12-lead electrocardiogram recordings just before revascularization and on return to the coronary care unit. The distributions of TIMI flow grade and change in sigmaST (5.1 +/- 10.8 vs 5.1 +/- 9.9mm) were similar between the 2 groups. Predischarge left ventricular ejection fraction (54 +/- 14 vs 54 +/- 15%) and in-hospital outcome were also similar between the 2 groups. The data suggest that coronary stenting did not influence microvascular circulation (improvement or detriment) in patients with reperfused AMI.     

直接冠状动脉内支架对急性心肌梗死“心肌无复流”的影响

目的评价直接置入冠脉内支架对急性心肌梗死（AMI）血管再通后“心肌无复流”现象的影响。方法将100例ST段抬高型AMI随机分为直接置入冠脉内支架组（直接支架组）和球囊预扩张置入冠脉内支架组（预扩张支架组）,应用单光子发射型计算机断层心肌灌注显像（SPECT）、心肌梗死溶栓治疗试验（TIMI）血流分级、心肌呈色分级（MBG）、肌酸激酶同工酶（CKMB）峰值和峰值时间及6个月临床随访来评价两种方法对AMI患者的心肌灌注情况及临床疗效。结果两组虽然术后即刻TIMI血流分级、术后24h内左室射血分数（LVEF）、左室舒张末期容积（LVEDV）及左室收缩末期容积（LVESV）差异无统计学意义[分别为96％、（48．14±4．43）％、（96．38土10．31）ml、（49．52±4．91）ml出境 vs 92％、（47．94±4．47）％、（99．66±13．26）ml、（48．18±5．32）ml,P〉0．05];但直接支架组与预扩张组比较,术后即刻MBG分级2～3级明显增高（90％VS74％,P〈0．05）、无复流发生率达10％ vs 26％（P〈0．05）,术后24h内SPECT心肌灌注积分（MPDS）明显降低（3．68±1．52 vs 4．93±1．84;P〈0．05）、CK-MB峰值明显减少[（217．2±96．86）U／L vs （260．22±97．78）U／L;P〈0．05）、CK-MB峰值时间明显提前[（11．72±2．67）hVS（13．7±2．06）h;P〈0．05）,而手术时间、X线曝光时间、造影剂用量显著减少[分别为（40．48土7．18）min、（12．84±3．77）min、（134．82±55．05）ml vs （44．54±6．2）min、（15．82±5．08）min、（158．12±53．9）ml;P〈0．05];随访6个月后,与预扩张组比较,直接支架组LVEF明显增高[（52．19±3．36）％ vs （50．2±5．32）％;P〈0．05],MPDS、LVEDV、LVESV显著减低[分别为2．39士1．50、（92．2±5．8）ml、（44．76±3．28）ml vs 3．11±1．74、（95．41±7．79）ml、（47．05±5．54）ml;P〈0．05]、纽约心脏病学会（NYHA）心功能分级≥2级明显减少（8％ vs 24％,P〈0．05）。结论直接置入冠脉内支架可降低AMI血管再通后心肌无复流的发生、缩小梗死面积、减轻左室重构,并可改善远期心功能。     

Differences in TIMI frame count following successful reperfusion with stenting or percutaneous transluminal coronary angioplasty for acute myocardial infarction

The Thrombolysis In Myocardial Infarction (TIMI) flow grade achieved in the infarct-related artery (IRA) during reperfusion therapy for acute myocardial infarction (AMI) is directly related to myocardial salvage. Recently, several series have demonstrated the safety of stenting in AMI and documented a larger postprocedure luminal diameter than that found at angioplasty, although no study has compared the effect of PTCA and stenting in AMI on flow characteristics of the IRA. The residual stenosis and the number of frames required to opacify standardized angiographic landmarks normalized for vessel length (corrected TIMI frame count) or compared with flow in a corresponding normal coronary artery (TIMI frame count index) were determined for the IRA of 39 patients who underwent angioplasty or stenting for AMI. Baseline characteristics were similar for the 20 patients who underwent stenting and the 19 patients who underwent percutaneous transluminal coronary angioplasty. After intervention, the luminal diameter was greater (3.24 vs 2.09 mm, p <0.0001) and the residual stenosis was less (-9.4% vs. 26.7%, p <0.0001) after stenting than after percutaneous transluminal coronary angioplasty. These changes in vessel geometry were associated with a lower corrected TIMI frame count (16.1 vs 30.7, p <0.002) and a lower TIMI frame count index (0.68 vs 1.3, p <0.002). Thus, stenting in AMI is associated with a greater postprocedure luminal diameter and improvement in coronary blood flow as measured by the TIMI frame count method.     

Coronary stenting or balloon angioplasty for chronic total coronary occlusions: the Taiwan experience (a single-center report)

The authors conducted this study to compare the restenosis and reocclusion rates of primary balloon angioplasty alone versus angioplasty followed by stenting in Taiwanese patients with chronic total occlusions. They also evaluated whether stenting reduced the incidence of restenosis and improved left ventricular function in these patients. From October 1998 to April 2000, a total of 294 patients with chronic total occlusion (Thrombolysis in Myocardial Infarction grade 0 flow) underwent recanalization using balloon angioplasty alone or followed by stent implantation. Of these, only 129 patients were included after procedural failure and patients lost to follow-up; 62 patients were placed in the stent group, while 67 patients were assigned to the percutaneous transluminal coronary angioplasty (PTCA) group. Coronary angiography was performed at baseline and at 6 months follow-up or earlier if angina or objective evidence of ischemia involving the target vessel or other vessels was present. Procedural success was 60%. Minimal lumen diameter increased significantly after stenting: 2.97 +/-0.41 vs 2.24 +/-0.41 (p < 0.001); 60% of patients in the stent group were free of restenosis, whereas only 33% in the PTCA group were free of restenosis at follow-up. Only 1 patient in the stent group had reocclusion, as opposed to 17 (25%) patients in the PTCA group (p < 0.001). The follow-up minimal lumen diameter (MLD) at 6 months was significantly larger in the stent group: 1.80 +/-0.85 mm vs 1.08 +/-0.82 mm (p < 0.001). Left ventricular function improved in the stent group, but not in the PTCA group (58.44 +/-16.58% to 63.60 +/-14.59% [p < 0.001] vs 54.13 +/-15.66% to 54.31 +/-15.60% [p = 0.885]). More patients had angina in the PTCA group than in the stented group 43 vs 29 (p = 0.053). The postprocedural MLD and reference vessel diameter (RVD) were the strong predictors of restenosis and follow-up MLD (p < 0.001). Stenting of chronically occluded arteries significantly reduced the incidence of reocclusion and restenosis, at the same time improving left ventricular function in these patients. This should be the procedure of choice after successful angioplasty of chronically occluded vessels.     

Intracoronary thrombectomy improves myocardial reperfusion in patients undergoing direct angioplasty for acute myocardial infarction

OBJECTIVES: We sought to evaluate the effects of mechanical thrombectomy on myocardial reperfusion during direct angioplasty for acute myocardial infarction (AMI). BACKGROUND: Embolization of thrombus and plaque debris may occur during direct angioplasty for AMI. This may lead to distal vessel or side branch occlusion and to obstructions in the microvascular system, resulting in impaired myocardial reperfusion. Mechanical thrombectomy is used to reduce distal embolization. METHODS: Ninety-two patients with AMI and angiographic evidence of intraluminal thrombus were randomized to either intracoronary thrombectomy followed by stenting or to a conventional strategy of stenting. Thrombectomy was performed using the X-Sizer catheter (EndiCOR Inc., San Clemente, California). Myocardial reperfusion was assessed by myocardial blush and ST resolution. RESULTS: Postprocedure Thrombolysis in Myocardial Infarction-3 flow was not different between groups (93.5% vs. 95.7%, p = 0.39). Myocardial blush-3 was observed in 71.7% of patients undergoing thrombectomy and in 36.9% of patients undergoing conventional strategy (p = 0.006). ST-segment resolution >or=50% occurred more often in patients undergoing thrombectomy (82.6% vs. 52.2%, p = 0.001). By multivariate analysis, adjunctive thrombectomy was an independent predictor of blush-3 (odds ratio, 3.27; 95% confidence interval, 1.06 to 10.05; p = 0.039). CONCLUSIONS: Intracoronary thrombectomy as adjunct to stenting during direct angioplasty for AMI improves myocardial reperfusion as assessed by myocardial blush and ST resolution.     

Comparison of direct stenting with conventional stent implantation in acute myocardial infarction

Small studies have suggested that direct stenting without balloon predilatation in ST-segment elevation myocardial infarction may reduce microcirculatory dysfunction. To examine the clinical benefits of direct stenting in a large cohort of patients who underwent primary percutaneous coronary intervention treated with contemporary pharmacotherapy, the 1-year outcomes from the multicenter, randomized Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial were analyzed. A total of 3,602 patients with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention were enrolled. The present study cohort consisted of 2,528 patients in whom single lesions (excluding bypass grafts) were treated with stent implantation. At operator discretion, direct stenting was attempted in 698 patients (27.6%), and stenting was performed after predilatation in 1,830 patients (72.4%). Propensity-score matching was performed to reduce bias. Direct stenting was successful in 677 patients (97.0%). ST-segment resolution at 60 minutes after the procedure was improved in patients who underwent direct compared to conventional stenting (median 74.8% vs 68.9%, respectively, p = 0.01). At 1-year follow-up, direct compared to conventional stenting was associated with a significantly lower rate of all-cause death (1.6% vs 3.8%, p = 0.01) and stroke (0.3% vs 1.1%, p = 0.049), with nonsignificant differences in target lesion revascularization, myocardial infarction, stent thrombosis, and major bleeding. Death at 1 year remained significantly lower in the direct stenting group after multivariate adjustment (hazard ratio 0.42, 95% confidence interval 0.21 to 0.86, p = 0.02) and in a propensity score-based analysis (hazard ratio 0.92, 95% confidence interval 0.88 to 0.95, p = 0.02). In conclusion, compared to stent implantation after predilatation, direct stenting is safe and effective in appropriately selected lesions in patients with ST-segment elevation myocardial infarction who undergo primary percutaneous coronary intervention and may result in improved survival.     

Coronary stent deployment without predilation in acute myocardial infarction: a feasible, safe, and effective technique

Direct percutaneous transcatheter revascularization (PTCR) is becoming an acceptable therapy for acute myocardial infarction (AMI). Stenting in the setting of AMI, once considered contraindicated, is emerging as a suitable option in this situation. Coronary stenting without predilation (SWOP) may potentially shorten the procedure and radiation time, reduce costs, and decrease procedural complications such as coronary dissection and distal embolization. It is expected to cause less vascular injury, with a reduction in the rate of in-stent restenosis. In this preliminary study the authors evaluated the feasibility of the SWOP procedure in 22 selected patients with AMI. Indications for catheter-based myocardial reperfusion were the following: extensive anterior wall MI (68%), inferior wall and right ventricular MI (23%), and inferior wall MI with contraindication for thrombolytic therapy (9%). Patients with cardiogenic shock or with contraindications for aspirin or ticlopidine were excluded. SWOP was successful in 21 attempts (95%), and final procedural success was achieved in all. Proximal or distal dissections were seen in three cases and were treated by additional three stents. Thrombolysis in myocardial infarction (TIMI) flow 3 was restored in all patients. There were no distal embolizations, side branch occlusions, coronary perforations, procedure-related emergency bypass operations, or deaths. It is concluded that in selected patients with AMI, coronary artery stenting without predilation is feasible and safe and does not introduce additional risk to the patients.     

Clinical and angiographic follow-up after balloon angioplasty with provisional stenting for coronary in-stent restenosis.

The objective of this study was to assess the angiographic and clinical outcome of patients with coronary in-stent restenosis treated with balloon angioplasty with provisional stenting. The study included 375 consecutive patients with in-stent restenosis managed with balloon angioplasty alone or combined with stenting. Clinical events were recorded during a 1-year follow-up period and quantitative analysis was performed on 6-month angiographic data. Of the 373 patients (451 lesions) with a successful procedure, 273 were treated with angioplasty alone and 100 with additional stenting. Target lesion revascularization was required in 23.7% of the patients: 20.7% in patients with angioplasty and 31.0% in patients with stenting. Angiographic restenosis rate was 38.9%: 35.8% in the angioplasty group and 47.7% in the stent group. Stenting in small vessels was associated with a much higher restenosis rate than in larger vessels (65.6% vs. 37.5%, respectively; P = 0.01). Thus, repeat balloon angioplasty with provisional stenting for in-stent restenosis is a safe treatment strategy associated with a relatively favorable long-term outcome. However, the long-term results might be improved if additional stenting is avoided especially in small vessels. Cathet. Cardiovasc. Intervent. 48:151-156, 1999.