A comparison of systematic stenting and conventional balloon angioplasty during primary percutaneous transluminal coronary angioplasty for acute myocardial infarction. STENTIM-2 Investigators

Primary stenting versus primary balloon angioplasty for treating acute myocardial infarction

BACKGROUND

Balloon angioplasty following myocardial infarction (MI) reduces death, non-fatal MI and stroke compared to thrombolytic reperfusion. However up to 50% of patients experience restenosis and 3% to 5% recurrent myocardial infarction. Therefore, primary stenting may offer additional benefits compared to balloon angioplasty in patients with acute myocardial infarction.

OBJECTIVES

To examine whether primary stenting compared to primary balloon angioplasty reduces clinical outcomes in patients with acute myocardial infarction.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, Pascal, Index medicus and The Cochrane Controlled Trials Register (The Cochrane Library) from 1979 to March 2002.

SELECTION CRITERIA

Randomised controlled trials of primary stenting or balloon angioplasty prior to the invasive procedure; intervention in native coronary arteries within 24 hours after onset of symptoms of myocardial infarction; report of death or reinfarction; and follow-up of at least 1 month. Trials were excluded when randomisation occurred after an invasive procedure and if they exclusively included patients with cardiogenic shock.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected and extracted data from identified trials. Outcomes included mortality, reinfarction, coronary artery bypass grafting, target vessel revascularization, need for vascular repair or blood transfusion. Peto odds ratios were calculated. To explore the stability of the overall treatment effect various sensitivity analyses were performed.

MAIN RESULTS

We included nine trials of 4433 participants. Odds ratios for mortality after stenting compared to balloon angioplasty at 30 days, 6 and 12 months were 1.16 (95% CI 0.78 to 1.73), 1.27 (95% CI 0.89 to 1.83), and 1.06 (95% CI 0.77 to 1.45). At 30 days, 6 and 12 months odds ratios for reinfarction after stenting compared to balloon angioplasty were 0.52 (95% CI 0.31 to 0.87), 0.67 (95% CI 0.45 to 1.00), and 0.67 (95% CI 0.45-0.98) and odds ratio for target vessel revascularization after stenting compared to balloon angioplasty were 0.45 (95%CI 0.34 to 0.60), 0.42 (95% CI 0.35 to 0.51), and 0.47 (95% CI 0.38 to 0.57). The odds ratio for post-interventional bleeding complications after stenting compared to balloon angioplasty was 1.34 (95% CI 0.95 to 1.88; test of heterogeneity p > 0.1).

AUTHORS' CONCLUSIONS

There is no evidence to suggest that primary stenting reduces mortality when compared to balloon angioplasty. Stenting seems to be associated with a reduced risk of reinfarction and target vessel revascularization, but potential confounding due to unbalanced post-interventional antithrombotic/anticoagulant therapies can not be ruled out on basis of this review.

[Long-term follow-up after primary angioplasty: is stenting beneficial?]

BACKGROUND

Primary stenting leads to a better short-term outcome than balloon angioplasty for acute myocardial infarction in randomised trials. However few data are available about the long-term outcome of primary stenting in acute myocardial infarction (AMI).

OBJECTIVES

The aim of this study was to compare the three-year outcome after primary stenting versus balloon angioplasty in patients with acute myocardial infarction.

METHODS

We conducted a retrospective study including 157 patients with AMI in a single center. Patients underwent balloon angioplasty (N = 48) or primary stenting (N = 109) within six hours after the onset of chest pain. We looked at the outcome during three years focusing on global mortality, major adverse cardiac events (MACE), reinterventions and target vessel revascularization (TVR).

RESULTS

The two groups are similar for their baseline characteristics. No difference was noted for in-patient mortality in the balloon angioplasty group and the primary stenting group (2.1 vs 2.8%; P = ns). The three-year mortality was not significantly different in the two groups. Regarding MACE (27.8 vs 31.7; P = 0.95), reinterventions (20.4 vs 24.7%; P = 0.98) and TVR (18.6 vs 17.8%; P = 0.69), both groups were statistically not different.

CONCLUSION

In the long-term patients treated with stent placement have similar rates of MACE, reinterventions or TVR than patients undergoing balloon angioplasty. If few studies noted a benefit in short-term outcomes, primary stenting doesn't improve the prognosis of acute myocardial infarction on long-term follow-up, which is dependent on atherosclerosis.

Angioplasty and stents in coronary artery disease: a systematic review and meta-analysis

OBJECTIVES

To undertake a systematic review of the clinical effectiveness of routine percutaneous transluminal coronary angioplasty (PTCA) plus stenting vs PTCA alone.

DATA SOURCES

MEDLINE; EMBASE; Science Citation Index; The Cochrane Library; cardiovascular journals and conference proceedings; Internet resources (including industry supported web pages); and reference lists of included studies and relevant reviews.

REVIEW METHODS

Study selection included published and unpublished randomized controlled trials (RCTs) comparing the use of coronary stents to PTCA. Outcome measures assessed included death, acute myocardial infarction (AMI), event rate (such as major cardiac adverse events (MACE) or other composite measures), and binary restenosis (BR). Data extraction and quality assessment were conducted according to internationally recognized methods. Data synthesis included meta-analysis of assessed outcomes, reported as odds ratios (ORs).

RESULTS

Fifty RCTs involving 16,500 patients met the inclusion criteria (39 full articles, 11 abstracts). Of these, 23 studies compared stenting with PTCA in patients with non-specific coronary artery disease (CAD), 11 compared stents with PTCA following AMI, 8 included patients with small coronary arteries and 8 included patients whose vessels had chronic total occlusion. There were no differences in rates of death or AMI. There were reductions in the rates of MACE (death, AMI or revascularization) with stents compared to PTCA (at 6 months, for non-specific group OR: 1.64, 95% CI 1.44-1.87; for AMI group OR: 2.36, 95% CI 1.92-2.89; for small vessel group OR: 1.38, 95% CI 1.10-1.74; at 12 months, for non-specific group OR: 1.31, 95% CI 1.11-1.55; for AMI OR: 2.26, 95% CI 1.47-3.46). Reporting of combined major adverse cardiac events was inconsistent across studies. Most events were revascularizations that may have been partly driven by protocol-required angiograms. Stents reduced BR rates at angiogram at 6 months compared to PTCA in all groups.

CONCLUSION

We found no differences in mortality or AMI, but the studies were not powered to identify changes in these endpoints. Coronary stenting is associated with reduced restenosis and combined adverse cardiac events, primarily revascularizations. However, the frequency of revascularization may have been distorted by protocol-dictated angiography.

Sex-related differences in outcome after ST-segment elevation myocardial infarction treated by primary angioplasty: data from the Zwolle Myocardial Infarction study

BACKGROUND

Several studies have found that among patients with ST-elevation myocardial infarction (STEMI) treated by thrombolysis, female sex is associated with a worse outcome. The aim of this study was to investigate sex-related differences in clinical and angiographic findings and in long-term outcome in patients with STEMI treated with primary angioplasty.

METHODS

Our population is represented by 1548 consecutive patients with STEMI treated by primary angioplasty from April 1997 to October 2001. All clinical, angiographic, and follow-up data were prospectively collected.

RESULTS

Among 1548 patients, 353 were women (22.8%). Female sex was associated with more advanced age, higher prevalence of diabetes, hypertension, more advanced Killip class, longer ischemia time, and smaller vessel caliber. No difference was observed in terms of procedural success, postprocedural epicardial flow, myocardial perfusion, ST-segment resolution, and enzymatic infarct size. At 1-year follow-up, female sex was associated with a significantly higher 1-year mortality rate at univariate (9.3% vs 4.9 %, RR [95% CI] = 1.79 [1.14 to 2.8], P = .002) but not at multivariate analysis (RR [95% CI] = 1.41 [0.86 to 2.32], P = NS).

CONCLUSIONS

This study shows that in patients with STEMI treated by primary angioplasty, women are associated with higher mortality rate in comparison with men, mainly because of their high-risk profile and angiographic features. Female sex did not emerge as an independent predictor of death.

Color of culprit lesion at 6 months after plain old balloon angioplasty versus stenting in patients with acute myocardial infarction

BACKGROUND

Although the healing process of disrupted yellow plaques at myocardial infarction (MI) culprit lesions has been reported, the effect of stenting on this process has not been clarified. Stenting has been reported to deteriorate the endothelial function after percutaneous coronary intervention (PCI). Therefore, we compared the angioscopic morphology of culprit lesions at 6 months after plain old balloon angioplasty (POBA) and stenting to clarify the effect of stenting on the healing of disrupted culprit plaques of acute MI.

METHODS

Patients with acute MI who had yellow culprit plaque, successful reperfusion therapy with POBA (n = 21) or stenting (n = 22), and a successful 6-month follow-up angioscopic examination were included in this study. Oral ticlopidine (200 mg/day) was administered for 3 to 6 months after stenting.

RESULTS

At 6 months after reperfusion therapy, the color of the culprit lesion became white in significantly more patients treated with stenting than treated with POBA (50% vs 14%; P = .01). However, the prevalence of thrombus appeared to be higher in patients treated with stenting than in patients treated with POBA (27% vs 5%; P = .04). Although there was some difference in the patients' characteristics in the groups, logistic regression analysis revealed no significant influence of those factors on the color of or on the prevalence of thrombus at the culprit lesion.

CONCLUSIONS

Coronary stenting in patients with acute MI leads to the disappearance of yellow color at a significantly higher rate than POBA; however, whether it stabilizes the plaque requires further investigation.

Combined Abciximab REteplase Stent Study in acute myocardial infarction (CARESS in AMI)

BACKGROUND

Most patients with acute myocardial infarction (AMI) are admitted to hospitals without percutaneous transluminal coronary angioplasty (PTCA) facilities or are initially managed in a prehospital mobile unit. Thrombolysis remains the most readily available reperfusion treatment in those settings, but the optimal subsequent strategy in those patients is unclear. If a mechanical recanalization is likely to be performed in an emergency, it is probably desirable that the patient receives abciximab, the glycoprotein IIb/IIIa antagonist with the strongest evidence of benefit for angioplasty in AMI.

OBJECTIVE

The aim of this trial is to compare the effects on clinical outcome and cost-effectiveness of 2 strategies after immediate treatment with abciximab and half-dose reteplase for ST-elevation AMI: to manage the patients conservatively (referring them for rescue PTCA only if needed) or to immediately send all patients for emergency coronary angioplasty.

METHODS

The Combined Abciximab RE-teplase Stent Study in Acute Myocardial Infarction (CARESS in AMI) is an open, prospective, randomized, multicenter clinical trial conducted in patients with high-risk ST-segment elevation AMI treated within 12 hours from symptom onset in hospitals without PTCA facilities or in a prehospital mobile intensive care unit. Apart from contraindications to thrombolysis, the main exclusion criteria are age > or =75 years and a past history of CABG surgery or a percutaneous coronary intervention procedure involving the infarct-related artery. Enrollment will be performed in hospitals without PTCA facilities or directly in the ambulance if a dedicated system is in place for prehospital diagnosis and treatment of AMI. Patients will receive half-dose reteplase and full-dose abciximab and will subsequently be randomized to conventional medical therapy (with referral for emergency rescue PTCA allowed in selected cases) or emergency angioplasty. The primary end point is the 30-day combined incidence of mortality, reinfarction, and refractory ischemia. In order to obtain a 95% power (2-sided) to detect a 42% reduction in the primary end point, 900 patients are required in each arm of the study. Secondary end points include the 1-year composite end point of mortality, reinfarction, refractory ischemia, and hospital readmission because of heart failure; resource use at 30 days and 1 year; and the incidence of inhospital stroke and bleeding complications in the 2 groups.

RESULTS

Seventy-four patients have been randomized (as of March 10, 2004); results are expected in June 2005.

CONCLUSION

This study will establish whether angioplasty must be started as soon as possible in all patients who receive combined pharmacologic reperfusion with the glycoprotein IIb/IIIa inhibitor abciximab and half-dose thrombolysis or whether it can be postponed or skipped in patients with signs of successful reperfusion, with obvious organizational advantages.

Impact of coronary artery stents on mortality and nonfatal myocardial infarction: meta-analysis of randomized trials comparing a strategy of routine stenting with that of balloon angioplasty

BACKGROUND

A strategy of routine stenting has been shown to reduce the need for target-vessel revascularization compared with a strategy of balloon angioplasty alone; however, the impact on mortality and frequency of nonfatal myocardial infarction is unclear. The aim of this study was to provide a quantitative comparison of the impact of coronary stenting on the rates of mortality and myocardial infarction with that of balloon angioplasty with provisional stenting.

METHODS

We performed a meta-analysis of randomized trials comparing routine coronary stenting to percutaneous transluminal coronary angioplasty (PTCA), including only those trials that used combination antiplatelet therapy (aspirin and a thienopyridine) as an adjuvant to stenting. Such trials included: the Belegian Netherlands Stent Study (BENESTENT) II, Optimal Coronary Balloon Angioplasty With Provisional Stenting Versus Primary Stent (OCBAS), Balloon Optimization vs Stent Study (BOSS), Evaluation of Platelet IIb/IIIa Inhibitor for Stenting (EPISTENT), Optimum Percutaneous Transluminal Coronary Angioplasty Compared With Routine Stent Strategy (OPUS-1), French Optimal Stenting Trial (FROST), Angioplasty or Stent (AS), and Doppler Endpoint Stenting International Investigation (DESTINI) trials for de novo coronary artery lesions; the Stent vs Percutaneous Angioplasty in Chronic Total Occlusion (SPACTO), Total Occlusion Study of Canada (TOSCA), Stent or Angioplasty after Recanalization of Chronic Coronary Occlusions (SARECCO), and Mayo-Japan Investigation for Chronic Total Occlusion (MAJIC) trials for coronary occlusions; the Primary Angioplasty Versus Stent Implantation in Acute Myocardial Infarction (PASTA), Gianturco-Roubin in Acute Myocardial Infarction (GRAMI), Florence Randomized Elective Stenting in Acute Coronary Occlusions (FRESCO), Immediate Coronary Angioplasty with Elective Wiktor Stent Implantation Compared with Conventional Balloon Angioplasty in Acute Myocardial Infarction (STENTUIM-2), Stent Primary Angioplasty in MI (Stent-PAMI), Zwolle, and Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trials for acute ST-segment elevation myocardial infarction; and the Intracoronary Stenting or Angioplasty for Restenosis Reduction in Small Arteries (ISAR-SMART), Park, Stenting in Small Arteries (SISA), and Bestent in Small Arteries (BESMART) trials for small vessels.

RESULTS

The 23 trials enrolled 10,347 patients, with 5130 patients randomized to receive stent and 5217 patients randomized to receive balloon angioplasty. A total of 902 (17 %) of patients crossed over from a strategy of balloon angioplasty to stent placement because of the inability to achieve a satisfactory result with a balloon. No significant difference was observed between the stent group and PTCA group in the rates of death or myocardial infarction, despite a significant reduction in the frequency of major adverse cardiac events (odds ratio, 0.59; 95% CI, 0.50-0.70; P <.001), which was driven entirely by a reduction in target vessel revascularization.

CONCLUSIONS

An initial strategy of stent placement versus balloon angioplasty with provisional stenting is associated with a similar mortality rate and frequency of nonfatal myocardial infarction after a mean follow-up period of 12.8 months. Patients who underwent stent placement had a significantly lower risk of major adverse cardiac events only when target revascularization is included as an end point.

Effects of percutaneous coronary arterial thrombectomy during acute myocardial infarction on left ventricular remodeling

The benefit of primary angioplasty for acute myocardial infarction (AMI) is limited by the no-reflow phenomenon, resulting in chronic left ventricular (LV) remodeling. The aim of this study was to evaluate the impact of thrombectomy with the Rescue percutaneous thrombectomy catheter on LV function after AMI. We performed a retrospective study comparing conventional angioplasty with the combination of angioplasty and thrombectomy using the Rescue catheter. The study population was comprised of 109 consecutive patients with AMI who underwent angioplasty and thrombectomy and 86 controls treated with conventional angioplasty. Baseline clinical and lesion characteristics were similar in the 2 groups. Postprocedural restoration of normal flow (Thrombolysis In Myocardial Infarction grade 3) was more frequent in the thrombectomy group (82% vs 69%, p = 0.03). No differences were observed in cardiac events, including death, reinfarction, and target vessel revascularization (thrombectomy vs controls, 27% vs 33%; p = 0.44) or changes in ejection fraction (p = 0.22) during 6-month follow-up. The incidence of LV remodeling, defined as an increase in LV end-diastolic volume index of >20%, was significantly lower in the thrombectomy group (22% vs 44%; p = 0.01). Multiple logistic regression analysis revealed that thrombectomy with the Rescue catheter contributed significantly to reduction of both no-reflow and LV remodeling. In the setting of primary angioplasty, adjunctive pretreatment with a rescue catheter reduces the no-reflow phenomenon and protects against LV remodeling.

Clinical outcomes of primary stenting versus balloon angioplasty in patients with myocardial infarction: a meta-analysis of randomized controlled trials

PURPOSE

To examine whether primary stenting as compared with primary balloon angioplasty reduces clinical outcomes in patients with myocardial infarction.

METHODS

Major medical databases from 1979 to March 2002 were searched for randomized controlled trials that compared primary stenting with balloon angioplasty in patients with myocardial infarction. Two independent reviewers selected and extracted data from identified trials. The outcomes were mortality at 30 days, 6 months, and 12 months; recurrent events; and bleeding.

RESULTS

Nine trials with a total of 4433 patients fulfilled the inclusion criteria. The odds ratios for mortality after stenting as compared with balloon angioplasty were 1.17 (95% confidence interval [CI]: 0.78 to 1.74) at 30 days, 1.07 (95% CI: 0.76 to 1.52) at 6 months, and 1.09 (95% CI: 0.80 to 1.50) at 12 months (P for heterogeneity >0.1 for each comparison). The odds ratios for reinfarction after stenting as compared with balloon angioplasty were 0.52 (95% CI: 0.31 to 0.87) at 30 days, 0.67 (95% CI: 0.45 to 1.00) at 6 months, and 0.67 (95% CI: 0.45 to 0.99) at 12 months; for target vessel revascularization, they were 0.46 (95% CI: 0.34 to 0.61) at 30 days, 0.42 (95% CI: 0.35 to 0.51) at 6 months, and 0.48 (95% CI: 0.39 to 0.59) at 12 months (P for heterogeneity >0.1 for all estimates with the exception of reinfarction at 12 months where P=0.08). The odds ratio for postinterventional bleeding complications after stenting as compared with balloon angioplasty was 1.34 (95% CI: 0.95 to 1.88; P for heterogeneity >0.1).

CONCLUSION

Compared with balloon angioplasty, primary stenting is not associated with lower mortality, but is associated with a lower risk of reinfarction and target vessel revascularization.

Effectiveness of primary percutaneous coronary intervention compared with that of thrombolytic therapy in elderly patients with acute myocardial infarction

BACKGROUND

Few data exist from a community-based perspective on the relative effectiveness of primary percutaneous coronary intervention (PCI) as compared with thrombolytic therapy (TT) in elderly patients with ST-elevation myocardial infarction (STEMI), particularly in the current era of coronary stents and newer antithrombotic agents.

METHODS

We evaluated data from patients, aged > or =70 years, with STEMI who were enrolled in the Global Registry of Acute Coronary Events study between April 1999, and September 2002.

RESULTS

Of the 2975 elderly patients eligible for reperfusion therapy, 365 (12.7%) underwent primary PCI and 769 (26.7%) received TT. The median delay from hospital arrival to therapy was 105 minutes for primary PCI and 40 minutes for TT. Inhospital complications for primary PCI versus TT included mortality (13.5% vs 14.8%), reinfarction (1.1% vs 5.7%), composite of death or reinfarction (14.3% vs 18.7%), cardiogenic shock (11.3% vs 11.6%), major bleeding (8.6% vs 5.9%), and stroke (1.1% vs 2.8%). After adjustment for baseline differences and propensity score, patients receiving primary PCI showed a lower rate of reinfarction (odds ratio [OR], 0.15; 95% CI, 0.05-0.44) and mortality (OR, 0.62; 95% CI, 0.39-0.96) and the composite of reinfarction or death (OR, 0.53; 95% CI, 0.35-0.79), with no difference in other outcome measures.

CONCLUSION

Our data suggest that, compared with TT, primary PCI is associated with a decrease in reinfarction and mortality, with no change in other outcome measures, in elderly patients with STEMI. These findings from an observational registry require further confirmation in future randomized clinical trial assessing the optimal reperfusion strategy in the elderly cohort with STEMI.

Clinical and angiographic correlates and outcomes of suboptimal coronary flow inpatients with acute myocardial infarction undergoing primary percutaneous coronary intervention

OBJECTIVES

The purpose of this study was to determine the clinical and angiographic correlates and outcomes of patients with suboptimal coronary flow after primary percutaneous coronary interventions (PCI).

BACKGROUND

The clinical and angiographic correlates and outcomes of Thrombolysis in Myocardial Infarction (TIMI) < or =2 flow in patients treated with primary PCI are not known.

METHODS

We evaluated 3,362 patients with ST elevation myocardial infarction enrolled in various Primary Angioplasty in Myocardial Infarction trials, who underwent primary PCI.

RESULTS

Post-procedural final TIMI < or =2 flow occurred in 232 (6.9%) patients. Multivariate analysis identified age > or =70 years (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.1 to 2.2), diabetes (OR 1.9; 95% CI, 1.3 to 2.7), symptom onset to emergency room presentation (OR 1.1; 95% CI, 1.1 to 1.2); initial TIMI < or =1 flow (OR 3.2; 95% CI, 1.9 to 5.5), and left ventricular ejection fraction <50% (OR 1.7; 95% CI, 1.2 to 2.4) as independent correlates of final TIMI < or =2 flow. In-hospital (composite of reinfarction, ischemic target vessel revascularization, or death, as well as these events individually) and one-year (reinfarction and/or death) events occurred more frequently in patients with TIMI < or =2 flow. The Cox proportional hazards model identified TIMI < or =2 flow to be independently associated with one-year mortality (hazard ratio 3.8, 95% CI, 2.5 to 5.7).

CONCLUSIONS

Final TIMI < or =2 flow, although uncommon after primary PCI, was strongly associated with hospital and one-year adverse events. The clustering of final TIMI < or =2 flow in high-risk groups may partially explain the poor prognosis of these patients. Awareness of these risk factors may be useful to clinicians to triage and treat patients undergoing primary PCI.

Effects of a Distal Protection Device During Primary Stenting in Patients With Acute Anterior Myocardial Infarction

BACKGROUND

The angiographic no-reflow phenomenon is an adverse prognostic factor in patients with acute myocardial infarction (AMI). The aim of the present study was to evaluate the effects of an occlusive balloon type distal protection device (PercuSurge GuardWire: GW) during primary stenting in patients with anterior AMI.

METHODS AND RESULTS

The GW group included 42 patients treated by primary stenting with GW protection and the control group included 30 patients treated by primary stenting after thrombectomy without distal protection. Left ventricular (LV) function was measured and compared by left ventriculography obtained soon after percutaneous coronary intervention (PCI) and 3 weeks after onset. The corrected TIMI frame count values were lower in the GW group than in the control group (27.5+/-2.3 vs 35.1 +/-2.5, p=0.030). The number of patients with myocardial blush grade 3 after PCI was higher in the GW group than in the control group (45.7 vs 20.0%, p=0.029). Peak concentration of creatine kinase myocardial fraction was lower in the GW group than in the control group (326.6+/-41.5 vs 454.9+/-46.2 mg/dl, p=0.043). GW patients showed greater improvement at 3 weeks after PCI in terms of LV ejection fraction (+4.6+/-1.2 vs -1.1+/-1.5, p=0.004), LV end-systolic volume index (+0.5+/-2.4 vs +9.0+/-2.7, p=0.023), and regional wall motion abnormalities (-2.03+/-0.14 vs -2.51+/-0.14, p=0.018).

CONCLUSION

Primary stenting with GW protection can restore epicardial coronary flow and myocardial perfusion, and also preserve LV function in anterior AMI.

Morphologic changes in infarct-related plaque after coronary stent placement: a serial angioscopy study

OBJECTIVES

The aim of this study was to investigate the morphologic changes in infarct-related lesions after stenting in acute or recent myocardial infarction (MI) with coronary angioscopy.

BACKGROUND

There is no information on the serial morphologic changes, which occur after stenting, and the time course of neointimal coverage of stents for disrupted unstable plaques.

METHODS

Forty-three patients with MI within seven days of onset were examined. Angioscopy was serially performed for the infarct-related lesions at baseline (n = 43), after balloon angioplasty (n = 35), and after stenting following balloon angioplasty (n = 39) and at one (n = 36) and six months (n = 30) after stenting.

RESULTS

At baseline, most of the lesions had complex morphology, yellow plaque color, and protruding thrombus (96%, 96%, and 74%, respectively). Although balloon angioplasty reduced the protruding thrombus, it remained in 37%, and an intimal flap was observed in 89% of the lesions. After stenting, the protruding thrombus and intimal flap disappeared, with an increased luminal size obtained in all lesions. At one-month follow-up, an irregular and yellow surface, along with a lining thrombus, was still observed, with partial neointimal stent coverage in most of the lesions. At six-month follow-up, the neointima was found to have sufficiently formed over the stent. The plaque shape and color were almost all classified as smooth (97%) and white (93%).

CONCLUSIONS

These results suggest that a stent not only compressed and covered a disrupted plaque with a protruding thrombus and intimal flap, leading to a wide vessel lumen, but also helped to seal the unstable plaque through neointimal proliferation.

In-stent restenosis and lesion morphology in patients with acute myocardial infarction

We investigated the correlation between lesion morphology with preintervention intravascular ultrasound and in-stent restenosis in 72 patients with acute myocardial infarction (AMI). Multivariate logistic regression analysis showed that the presence of ruptured plaque was the only predictive factor of in-stent restenosis after primary stenting for AMI.

12-lead ECG interpretation and chest pain management: 1

The National Service Framework for Coronary Heart Disease provides guidance on important aspects of therapy that may make a substantial difference to patient care (Department of Health (DoH), 2001). It highlights the need to identify and fast-track patients with an acute coronary syndrome so that thrombolysis or appropriate interventional care can take place as soon as possible, to optimize myocardial salvage and reduce door-to-needle time (DoH, 2001; Castle, 2002). It is therefore extremely important that nurses in acute clinical areas are able to record and interpret 12-lead electrocardiograms so that the treatment modality can be initiated as soon as possible, leading to better clinical outcomes for this patient group. Although nurses work within a healthcare team, it is often the nurse who initially assesses, implements and coordinates care for patients with chest pain, be it in the emergency department, cardiac unit, general ward setting or general practice.

Outcomes of optimal or “stent-like”balloon angioplasty in acutemyocardial infarction: the CADILLAC trial

OBJECTIVES

We sought to compare outcomes between patients with acute myocardial infarction (AMI) undergoing percutaneous transluminal coronary angioplasty (PTCA) with an optimal or "stent-like" result versus patients who underwent routine stent placement.

BACKGROUND

Recent studies in patients with AMI undergoing stent implantation have suggested that PTCA may no longer be a relevant treatment modality for stent eligible lesions. However, whether routine stent placement is superior or necessary when an optimal PTCA or "stent-like" result is achieved is unknown.

METHODS

In the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial, 2,082 patients with AMI were randomly assigned to undergo PTCA alone, PTCA + abciximab, stenting alone, or stenting + abciximab. Outcomes were compared in patients achieving an optimal acute PTCA result (residual core laboratory diameter stenosis <30% without significant dissection) versus those assigned to routine stenting.

RESULTS

Optimal PTCA was achieved in 40.7% of patients randomized to balloon angioplasty, including 38.5% and 42.7% assigned to PTCA alone and PTCA + abciximab, respectively. Ischemic target vessel revascularization (TVR) at 30 days occurred more frequently after optimal PTCA than routine stenting (5.1% vs. 2.3%, p = 0.007). The one-year composite adverse event rate (death, reinfarction, disabling stroke, or TVR) was greater after optimal PTCA than routine stenting (21.9% vs. 13.8%, p < 0.001), driven largely by increased rates of ischemic TVR (19.1% vs. 9.1%, p < 0.001); no significant differences were present in the rates of death, reinfarction, or disabling stroke between the two groups. Angiographic restenosis also was more common with optimal PTCA than routine stenting (36.2% vs. 22.2%, p = 0.003). Even a post-PTCA diameter stenosis of <20% (realized in 12% of patients) did not result in outcomes equivalent to stenting.

CONCLUSIONS

Even if an optimal result is achieved after primary PTCA in AMI, early and late outcomes can be further improved with routine stent implantation.

Reperfusion in acute myocardial infarction: current concepts

Myocardial reperfusion is the treatment of choice in acute myocardial infarction. Pharmacological thrombolysis restores coronary artery patency in about two thirds of patients with acute myocardial infarction. However, mechanical reperfusion with primary angioplasty and stenting achieves higher patency rates with less complications, especially in high-risk patients. Adjunctive pharmacotherapy and new device technology may improve the outcome of primary angioplasty. Facilitated angioplasty using a combination of half-dose thrombolysis, platelet glycoprotein IIb/IIIa antagonists, and early intervention, appears to be a promising strategy for the treatment of acute myocardial infarction in the modern era. The efficacy and safety of this approach are currently evaluated in several ongoing trials.

Glycoprotein IIb/IIIa inhibition in early intent-to-stent treatment of acute coronary syndromes: EPISTENT, ADMIRAL, CADILLAC, and TARGET

The acute coronary syndromes (ACS), with or without ST-segment elevation, share a common pathophysiology of activated platelets and thrombin generation stimulated by plaque erosion and rupture. Both mechanical and pharmacologic treatment strategies have evolved in an attempt to improve reperfusion at the myocardial tissue level. Intracoronary stents have lowered the incidence of abrupt vessel closure and restenosis, while potent platelet inhibition from intravenous glycoprotein IIb/IIIa antagonists has reduced the rate of periprocedural myocardial infarction and late mortality. Abciximab has well-established clinical benefits in percutaneous revascularization trials, and several recent landmark studies have evaluated the efficacy of concomitant abciximab during mechanical reperfusion therapy in the setting of ACS. These trials are reviewed, and an overall perspective is provided.

Acute Myocardial Infarction: Antithrombotic Therapy

The treatment of acute myocardial infarction is centered on pharmacology-based strategies designed to prevent or attenuate thrombotic processes occurring within the coronary arterial system. Antithrombotic therapies used currently in clinical practice represent the "fruits of labor" derived from randomized trials and carefully constructed patient management guidelines.

Myocardial viability, coronary flow reserve, and in-hospital predictors of late recovery of contractility following successful primary stenting for acute myocardial infarction

OBJECTIVE

To assess the relation between myocardial viability, coronary flow reserve, and recovery of myocardial contractility after stenting for acute myocardial infarction.

DESIGN

Consecutive sample prospective study.

SETTING

University hospital.

PATIENTS

41 patients with single vessel disease and successful primary stenting for a first acute myocardial infarction.

INTERVENTIONS

(201)Tl single photon emission computed tomography, contrast ventriculography, and intracoronary Doppler performed 7 (1) days after primary stenting.

MAIN OUTCOME MEASURES

Regional contractility recovery assessed by contrast ventriculography at 6 (1) months' follow up.

RESULTS

On univariate analysis, contractility recovery was correlated to prereperfusion anterograde and collateral flow grades (r = 0.41, p = 0.03 and r = 0.55, p = 0.0004), viability index (r = 0.55, p = 0.04), peak creatine kinase concentrations (r = -0.55, p = 0.0005), left ventricular ejection fraction (r = 0.45, p = 0.005), end diastolic pressure (r = -0.62, p < 0.0001), end systolic volume index (r = -0.47, p = 0.01), and the extent of hypokinetic area (r = -0.48, p = 0.003), but not the coronary flow reserve. On multivariate analysis, independent predictors of late contractility recovery were prereperfusion anterograde and collateral flow grades and viability index. Relative coronary flow reserve, reflecting the culprit vessel's microvascular function, was correlated only to the extent of the infarct risk area (r = -0.45, p = 0.003).

CONCLUSIONS

Independent predictors of contractility recovery between the seventh day and the sixth month after successful stenting for acute myocardial infarction are prereperfusion anterograde and collateral flows and myocardial viability. The culprit vessel's microvascular dysfunction is independent of myocardial viability and contractility and correlated to the extent of "jeopardised microvasculature".

Hyperoxemic perfusion for treatment of reperfusion microvascular ischemia in patients with myocardial infarction

In patients with acute myocardial infarction (AMI) primary angioplasty and stent placement is a more effective and better tolerated treatment than thrombolysis, and therefore, when logistics allow, this treatment is preferred and routinely used. However, successful reopening of an occluded coronary artery does not necessarily lead to recovery of left ventricular (LV) function. Post-AMI reduction in contractile function and ventricular remodeling may result in heart failure. There is evidence that reduced contractile function in the infarct zone is related to poor microvascular perfusion even after normalization of large-vessel flow by angiographic criteria following coronary recanalization. Failure to re-establish adequate tissue perfusion may be because of reperfusion injury, ischemia-induced microvascular damage, and plugging of the microcirculation by thrombus and plaque during mechanical recanalization. Experimental data support the hypothesis that reperfusion microvascular ischemia contributes to myocardial tissue injury over a prolonged time period. Hyperbaric oxygen therapy (HBO) attenuates microvascular dysfunction and reperfusion microvascular ischemia, as demonstrated in both experimental models and patients with AMI. However, treating patients in an HBO chamber or with a conventional oxygenator is impractical and difficult. Aqueous oxygen (AO) is a newly developed solution containing extremely high oxygen concentrations (1-3 ml O(2)/mL saline). The AO system mixes AO solution with a patient's blood from an arterial puncture and delivers the hyperoxemic blood to targeted ischemic myocardium via an infusion catheter for regional correction of hypoxemia and production of hyperoxemia. The system precisely controls the level of pO(2) without clinically significant microbubble formation. Hyperoxemic coronary infusion of AO in experimental models of AMI improved LV function and reduced infarct size compared with normoxemic controls,very likely as a result of microvascular blood flow improvement. The first clinical experiences with intracoronary infusion of AO solution demonstrated the therapy to be a safe and well tolerated in the setting of AMI after successful primary percutaneous transluminal coronary angioplasty. Its use was associated with significant progressive improvement in LV function as measured by ejection fraction and wall motion score index. Interestingly, such improvement was primarily due to functional recovery of infarct zone contractility. A larger randomized trial is currently underway to define the role of hyperoxemic coronary infusion in patients with AMI.

Safety and implementation of exercise testing and training after coronary stenting in patients with acute myocardial infarction

The purpose of this study was to determine the incidence of subacute stent thrombosis related to exercise testing (ETT) or exercise training in cardiac rehabilitation (exercise cardiac rehabilitation (ECR)) and to clarify the appropriate timing of ETT and ECR in patients with acute myocardial infarction (AMI) treated with coronary stenting, because the safety and appropriate timing of ETT and ECR after coronary stenting for AMI have not been established. Forty-six institutes performing emergency percutaneous coronary intervention (PCI) for AMI were surveyed for the incidence of exercise-related subacute stent thrombosis and the timing of the start of ETT and ECR in patients with AMI in 1996-1998. Among the total 13,685 patients with AMI, 4,360 (31.9%) underwent coronary stenting. Of the 132 (3.0%) subacute stent thromboses that developed within 1 month after stenting, only one event was related to maximal ETT and occurred in a patient not receiving ticlopidine. No stent thrombosis occurred in association with submaximal ETT or ECR. In 7 institutes, maximal ETT was routinely performed at 14 days after stenting for AMI without any adverse events, and in 6 institutes, ECR was routinely started within 7 days without any adverse events. This survey found that only 21.0% of all AMI patients participated in ECR. In conclusion, subacute stent thrombosis related to ETT or ECR is extremely rare (0-0.02%) in patients with AMI, especially when they are receiving ticlopidine, and therefore ETT and ECR for stented patients with AMI need not be delayed (ie, approximately 7 days after stenting for submaximal ETT and ECR, and 14 days after stenting for maximal ETT). The rate of participation of post-AMI patients in ECR is low in Japan, even in major hospitals that are actively working in the field.

Coronary vasodilator reserve: a clue to the explanation of (201)Tl redistribution patterns early after successful primary stenting for acute myocardial infarction

OBJECTIVES

We sought to assess the mechanism and significance of different (201)Tl redistribution patterns after successful primary stenting following acute myocardial infarction (AMI).

BACKGROUND

The mechanism of (201)Tl reverse redistribution and the impact of different redistribution patterns on the recovery of contractility after successful reperfusion therapy for AMI remain unclear.

METHODS

We studied 41 consecutive patients with successful primary stenting for a first AMI. Patients underwent predischarge and six-month follow-up dipyridamole stress-reinjection single photon emission tomography (SPECT), coronary and left ventricular angiography. Intracoronary Doppler assessment of coronary flow reserve (CFR) was performed before discharge.

RESULTS

Four patient groups were identified according to predischarge SPECT: patients with I: nonreversible defects (n = 8), II: redistribution (n = 7), III: reverse redistribution (n = 21), IV: no defect (n = 5). At follow-up contractility recovery increased in a stepwise fashion from groups I to IV (19 +/- 41%, 40 +/- 53%, 70 +/- 28%, 78 +/- 33%, p = 0.01). Compared with patients with redistribution, those with reverse redistribution had lower infarct-related artery (IRA) CFR (2.2 +/- 0.5 vs. 2.8 +/- 0.9, p = 0.03) but higher contractility recovery.

CONCLUSIONS

Variable (201)Tl redistribution patterns, early after successful stenting for AMI, may predict different degrees of late contractility recovery. The lower IRA CFR and the higher contractility recovery in areas with reverse redistribution suggest more severe microvascular dysfunction and less severe myocardial injury in such areas compared with those with redistribution.

Rationale for on-site cardiac surgery for primary angioplasty: a time for reappraisal

Since the early 1990s, with significant improvement in the procedural success of percutaneous coronary interventions (PCIs), there has been a concomitant reduction in the need for emergency coronary artery bypass graft surgery. This review article focuses on the need for on-site cardiac surgery in patients with acute myocardial infarction undergoing primary angioplasty at centers without on-site cardiac surgical backup. It gives an overview of the need for emergency bypass surgery in both the large trial setting and the community hospital setting. Special consideration is also given to the risks and benefits of primary angioplasty compared with thrombolytic therapy, transfer to an institution with an on-site cardiac surgical facility compared with primary PCI, the frequency and indications for emergency cardiac surgery related and unrelated to primary angioplasty and the requirements for primary angioplasty that must be met in hospitals without the capability of on-site cardiac surgery.

Comparison of angioplasty with stenting, with or without abciximab, in acute myocardial infarction

BACKGROUND

As compared with thrombolytic therapy, primary percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction reduces the rates of death, reinfarction, and stroke, but recurrent ischemia, restenosis, and reocclusion of the infarct-related artery remain problematic. When used in combination with PTCA, coronary stenting and platelet glycoprotein IIb/IIIa inhibitors may further improve outcomes.

METHODS

Using a 2-by-2 factorial design, we randomly assigned 2082 patients with acute myocardial infarction to undergo PTCA alone (518 patients), PTCA plus abciximab therapy (528), stenting alone with the MultiLink stent (512), or stenting plus abciximab therapy (524).

RESULTS

Normal flow was restored in the target vessel in 94.5 to 96.9 percent of patients and did not vary according to the reperfusion strategy. At six months, the primary end point - a composite of death, reinfarction, disabling stroke, and ischemia-driven revascularization of the target vessel - had occurred in 20.0 percent of patients after PTCA, 16.5 percent after PTCA plus abciximab, 11.5 percent after stenting, and 10.2 percent after stenting plus abciximab (P<0.001). There were no significant differences among the groups in the rates of death, stroke, or reinfarction; the difference in the incidence of the primary end point was due entirely to differences in the rates of target-vessel revascularization (ranging from 15.7 percent after PTCA to 5.2 percent after stenting plus abciximab, P<0.001). The rate of angiographically established restenosis was 40.8 percent after PTCA and 22.2 percent after stenting (P<0.001), and the respective rates of reocclusion of the infarcted-related artery were 11.3 percent and 5.7 percent (P=0.01), both independent of abciximab use.

CONCLUSIONS

At experienced centers, stent implantation (with or without abciximab therapy) should be considered the routine reperfusion strategy.

Mini-invasive strategy in acute coronary syndromes: direct coronary stenting using 5 Fr guiding catheters and transradial approach

The purpose of this study was to assess the feasibility and safety of direct coronary stenting in acute coronary syndromes using 5 Fr guiding catheters by transradial approach. A series of 119 patients with an acute coronary syndrome (unstable angina, n = 55; acute myocardial infarction, n = 45; recent acute myocardial infarction, n = 19) explored by transradial approach and eligible for direct stenting were included. A large proportion of patients (52%) was treated during the procedure by platelet IIb/IIIa receptor blockade. Only Medtronic 5 Fr guiding catheters were used in this study. Direct coronary stenting was attempted in all 119 highly selected patients. Failure of direct stenting was observed in only five cases (3.9%) and the stent successfully retrieved in each case in the 5 Fr guiding catheter. In these five cases, balloon predilation was performed and then the stent implanted successfully. Different stents were used: ACS stent (54%), AVE stent (33%), Velocity stent (10%), Nir stent (3%), with diameter ranging from 2.5 to 4 mm. In four cases, the dilation was finally performed using 6 Fr guiding catheters because the backup of the 5 Fr catheter was considered to be too low (3%). No vascular access site complications occurred in this series of patients. We conclude that direct coronary stenting using transradial approach and 5 Fr guiding catheters yields excellent procedural success rate. In the setting of acute coronary syndromes requiring platelet IIb/IIIa receptor blockade or after failure of thrombolysis, this mini-invasive strategy is very attractive because of the low risk of access site complications.

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.

Cost-effectiveness of coronary stenting in acute myocardial infarction: results from the stent primary angioplasty in myocardial infarction (stent-PAMI) trial

BACKGROUND

Although several randomized trials have demonstrated that coronary stenting improves angiographic and clinical outcomes for patients with acute myocardial infarction (AMI), the cost-effectiveness of this practice is unknown. The objective of the present study was to evaluate the long-term costs and cost-effectiveness (C/E) of coronary stenting compared with primary balloon angioplasty as treatment for AMI. Methods and Results- Between December 1996 and November 1997, 900 patients with AMI were randomized to undergo balloon angioplasty (PTCA, n=448) or coronary stenting (n=452). Detailed resource utilization and cost data were collected for each patient's initial hospitalization and for 1 year after randomization. Compared with conventional PTCA, stenting increased procedural costs by approximately $2000 per patient ($6538+/-1778 versus $4561+/-1598, P<0.001). During the 1-year follow-up period, stenting was associated with significant reductions in the need for repeat revascularization and rehospitalization. Although follow-up costs were significantly lower with stenting ($3613+/-7743 versus $4592+/-8198, P=0.03), overall 1-year costs remained approximately $1000/patient higher with stenting than with PTCA ($20 571+/-10 693 versus 19 595+/-10 990, P=0.02). The C/E ratio for stenting compared with PTCA was $10 550 per repeat revascularization avoided. In analyses that incorporated recent changes in stent technology and pricing, the 1-year cost differential fell to <$350/patient, and the C/E ratio improved to $3753 per repeat revascularization avoided. The cost-utility ratio for primary stenting was <$50 000 per quality-adjusted life year gained only if stenting did not increase 1-year mortality by >0.2% compared with PTCA.

CONCLUSIONS

As performed in Stent-PAMI, primary stenting for AMI increased 1-year medical care costs compared with primary PTCA. The overall cost-effectiveness of primary stenting depends on the societal value attributed to avoidance of symptomatic restenosis, as well as on the relative mortality rates of primary PTCA and stenting.

Development of high-performance stent: gelatinous photogel-coated stent that permits drug delivery and gene transfer

Hydrogel-coated metallic stents may provide supplementary functions such as local drug delivery and gene transfer in addition to mechanical dilation function. To this end, we used a photoreactive material consisting of gelatin macromer (multiple styrene-derivatized gelatin) and carboxylated camphorquinone (photo-initiator). A few minutes of visible light irradiation of a stent after dip-coating of an aqueous solution of the photoreactive material resulted in the formation of a homogeneously crosslinked gelatinous layer on the entire exterior surface of the stent. As the metal stent, gold stents under development were used. Rhodamine-conjugated albumin as a model drug or adenoviral vector expressing bacterial beta-galactosidase (AdLacZ) as a model gene were photo-immobilized in the gelatinous gel layer. In vitro experiments using hybrid tubular tissue, which is a self-shrinkaged, vascular smooth muscle cell-incorporated type-I collagen gel, as a vascular model, showed that the immobilized dye-derivatized albumin was released on and permeated into tissues, as observed by confocal laser microscopy, and that the cells transfected with immobilized AdLacZ produced beta-galactosidase up to almost 3 weeks, as observed by x-gal staining. In preliminary in vivo experiments these drug- or adenovirus-immobilized stents were implanted in rabbit common carotid arteries. Within 3 weeks of implantation, drug permeation and gene expression in the vascular tissues were observed, indicating that the gelatinous photogel effectively serves as a matrix or coating for a bioactive stent,which permits drug release as well as gene transfer. This intraluminal approach has the potential to realize drug and gene therapy in atherosclerotic plaque.

Quality of life after balloon angioplasty or stenting for acute myocardial infarction. One-year results from the Stent-PAMI trial

OBJECTIVES

The goal of this study was to compare the impact of primary stenting or percutaneous transluminal coronary angioplasty (PTCA) on health-related quality of life (HRQOL) in patients undergoing direct angioplasty for acute myocardial infarction (AMI).

BACKGROUND

Previous studies have demonstrated that coronary stenting reduces clinical and angiographic restenosis compared with PTCA. However, the impact of stenting on HRQOL from the patient's perspective remains unknown.

METHODS

We administered the Seattle Angina Questionnaire and the Medical Outcomes Study Short-form Survey at 1, 6 and 12 months after initial treatment to all North American patients in the Stent-Primary Angioplasty for Myocardial Infarction trial (Stent-PAMI) (n = 509)-a randomized trial comparing primary stenting to conventional PTCA for patients with AMI.

RESULTS

At one month, most HRQOL measures were similar for the two groups, but stent patients reported less bodily pain than PTCA patients (p = 0.03). At six-month follow-up, stenting resulted in significant improvements in several dimensions of HRQOL including reduced anginal frequency and bodily pain as well as improved disease perception (all p < or = 0.03) and a trend towards better anginal stability (p = 0.056). By 12-month follow-up, however, none of these differences remained statistically significant. These differences in HRQOL were largely explained by the greater need for ischemia-driven target-vessel repeat revascularization procedures in PTCA patients during the first six months (16.0% vs. 6.2%, p < 0.001).

CONCLUSIONS

In patients undergoing revascularization for AMI, initial stent placement is associated with improvements in several dimensions of health status during the first six months of follow-up. In the absence of differences in mortality, these findings add to the overall argument in favor of initial stenting in patients treated with mechanical reperfusion for myocardial infarction.

Defining the role of abciximab for acute coronary syndromes: lessons from CADILLAC, ADMIRAL, GUSTO IV, GUSTO V, and TARGET

Acute coronary syndromes (ACS), including those associated with or without ST-segment elevation, share a common pathophysiology mediated by activated platelets and thrombin. It is becoming increasingly appreciated that reperfusion therapies using primary mechanical or pharmacologic strategies result in suboptimal reperfusion at the myocardial tissue level. Complete reperfusion of the coronary microvasculature has recently been shown to be an important predictor for survival following myocardial infarction. Abciximab has well-established clinical benefits in numerous interventional trials. Through its anti-platelet and anti-thrombotic activities, abciximab reduces thrombus formation and hence minimizes risk of thrombotic microvascular embolization and improves tissue-level reperfusion. Several recent landmark trials have evaluated the clinical efficacy of adjunctive abciximab during mechanical or pharmacologic reperfusion therapy in the setting of ACS. This article provides an update of the role of abciximab in the treatment for ACS based on the results of these clinical trials.

Evolution in the practice of primary angioplasty: effect of adjunctive coronary stenting and glycoprotein IIb/IIIa inhibitors on long-term outcomes

Primary angioplasty strategies have evolved dramatically, including increasing adjunctive use of stents and glycoprotein (GP) IIb/IIIa inhibitors. The purpose of this study was to examine the specific effects of these adjunctive therapies on long-term outcomes after primary angioplasty. From 1996 to 1998, 257 unselected, consecutive patients underwent primary PTCI at our institution. In-hospital mortality was 5.4% (2.9% for patients without cardiogenic shock). The remaining 243 patients were followed for 2.0 +/- 0.7 years. Adjunctive stenting was associated with increased late mortality (8.7% vs. 2.3%, P = 0.02). GP IIb/IIIa inhibitors were associated with reduced late mortality among patients receiving stents (6.9% vs. 21.4%, P = 0.07), but not in those patients treated with balloon angioplasty alone (2.9% vs. 0%, P > 0.20). Coronary stenting remained a significant predictor of late mortality (hazard ratio 5.6, 95% CI 1.5-21.2) after adjustment for other established risk factors. In this unselected series, adjunctive coronary stenting was associated with higher late mortality among hospital discharge survivors. Concomitant GP IIb/IIIa inhibitors partially corrected for this increase. These results are limited by the small sample size and retrospective design of this study. Additional long-term studies are required to test these findings and evaluate for possible mechanisms.

Keeping the coronary arteries open: current opportunities

Thrombolysis has reduced mortality from myocardial infarction, but effective opening of the artery with normal flow continues to be an important goal. Thrombolysis is not always as successful as it should be; alternatives include adjunctive therapy and mechanical opening of the arteries. In patients with acute coronary occlusion opening the artery should continue to be the primary aim.

Percutaneous coronary intervention in st-elevation myocardial infarction

This review traces the development of coronary angioplasty as a direct, primary means of establishing reperfusion in an acutely occluded infarct-related artery. As a therapeutic strategy for the early management of patients with ST-elevated acute myocardial infarction, this mechanical-invasive procedure arose virtually simultaneously with the demonstration that intravenous administration of fibrinolytic agents to such patients results in a relative reduction in early mortality by as much as 25% to 30%. Over the past 15 years, more than a dozen randomized, controlled trials have investigated the question, "Which is the better means of administrating reperfusion therapy?" The recent demonstration that the combination of coronary stenting plus glycoprotein IIb/IIIa inhibitors used in the early stages of ST-elevation acute myocardial infarction salvages more myocardium than the administration of front-loaded tissue plasminogen activator offers a convincing answer. This is further supported by the evidence that clinical outcomes also improved in these patients, with the greater improvement in ventricular function. It is likely, however, that the development of newer pharmacologic agents plus the combination of both strategies will keep this a hotly debated issue for some time to come.

Long term outcome and cost-effectiveness of stenting versus balloon angioplasty for acute myocardial infarction

OBJECTIVE

To investigate the long term clinical outcome and cost-effectiveness of stenting compared with balloon angioplasty in patients with acute myocardial infarction.

METHODS

Patients with acute myocardial infarction were randomly allocated to primary stenting (112) or balloon angioplasty (115). The primary end point was the cumulative first event rate of death, non-fatal reinfarction, or target vessel revascularisation. Secondary end points were restenosis at six months and the cost-effectiveness at follow up.

RESULTS

After 24 months, the combined clinical end point of death/reinfarction was 4% after stenting and 11% after balloon angioplasty (p = 0.04). Subsequent target vessel revascularisation was necessary in 15 patients (13%) after stenting and in 39 (34%) after balloon angioplasty (p < 0.001). The cumulative cardiac event-free survival rate was also higher after stenting (84% v 62%, p < 0.001). The angiographic restenosis rate after stenting was less than after balloon angioplasty (12% v 34%, p < 0.001). Despite the higher initial costs of stenting (Dfl 21 484 v Dfl 18 625, p < 0.001), the cumulative costs at 24 months were comparable with those of balloon angioplasty (Dfl 31 423 v Dfl 32 933, p = 0.83).

CONCLUSIONS

Compared with balloon angioplasty, primary stenting for acute myocardial infarction results in a better long term clinical outcome without increased cost.

Stenting versus thrombolysis in acute myocardial infarction trial (STAT)

OBJECTIVES

We sought to directly compare primary stenting with accelerated tissue plasminogen activator (t-PA) in patients presenting with acute ST-elevation myocardial infarction (AMI).

BACKGROUND

Thrombolysis remains the standard therapy for AMI. However, at some institutions primary angioplasty is favored. Randomized trials have shown that primary angioplasty is equal or superior to thrombolysis, while recent studies demonstrate that stent implantation improves the results of primary angioplasty.

METHODS

Patients presenting with AMI were randomly assigned to primary stenting (n = 62) or accelerated t-PA (n = 61). The primary end point was the composite of death, reinfarction, stroke or repeat target vessel revascularization (TVR) for ischemia at six months.

RESULTS

The primary end point was significantly reduced in the stent group compared with the accelerated t-PA group, 24.2% versus 55.7% (p < 0.001). The event rates for other outcomes in the stent group versus the t-PA group were as follows: mortality: 4.8% versus 3.3% (p = 1.00); reinfarction: 6.5% versus 16.4% (p = 0.096); stroke: 1.6% versus 4.9% (p = 0.36); recurrent unstable ischemia: 9.7% versus 26.2% (p = 0.03) and repeat TVR for ischemia: 14.5% versus 49.2% (p < 0.001). The median length of the initial hospitalization was four days in the stent group and seven days in the t-PA group (p < 0.001).

CONCLUSIONS

Compared with accelerated t-PA, primary stenting reduces death, reinfarction, stroke or repeat TVR for ischemia. In centers where facilities and experienced interventionists are available, primary stenting offers an attractive alternative to thrombolysis.

The acute management of myocardial infarction

Acute myocardial infarction (AMI) is a common and potentially fatal condition. Primary prevention by reducing the risk of developing coronary atheroma disease has had an important effect on the incidence of the disease. However, for many, the first clinical presentation of their coronary atheroma is the development of acute coronary occlusion. The acute nature of such presentation is the result of the dynamic nature of the plaque event. Thus while measures such as increasing public education in areas of primary prevention are always important it needs to be recognised that real differences in outcome need to and can be made even once the event has occurred. Individuals developing chest pain need to be encouraged to present early, especially if they have a history of ischaemic heart disease. Once they have arrived at point of medical contact, rapid triage, early diagnosis and the institution of therapies designed to reduce the extent of myocardial damage are paramount.