Immediate angioplasty after thrombolysis: a systematic review

Efficacy and safety of a routine early invasive strategy in relation to time from symptom onset to fibrinolysis (a subgroup analysis of TRANSFER-AMI)

The aim of this study was to assess the efficacy and safety of an early invasive strategy post-fibrinolysis in relation to time from symptom onset to fibrinolysis in patients with ST-elevation myocardial infarction (STEMI). The Trial of Routine Angioplasty and Stenting after Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI) randomized 1,059 patients receiving fibrinolysis for STEMI to an early invasive strategy versus standard therapy. The primary end point was the composite of death, reinfarction, recurrent ischemia, new or worsening heart failure, or cardiogenic shock at 30 days. In this post hoc subgroup analysis, we examined the effect of an early invasive strategy on efficacy and safety outcomes after stratification by time from symptom onset to fibrinolysis (<2 or ≥2 hours). Of 1,059 patients in TRANSFER-AMI, 557 (53%) received fibrinolysis <2 hours and 502 (47%) ≥2 hours after symptom onset. Compared to patients who received fibrinolysis within 2 hours of symptoms, patients who received fibrinolysis ≥2 hours after symptom onset had higher Global Registry of Acute Coronary Events risk scores (median 127 vs 122, p = 0.004). The effect of an early invasive strategy did not differ between symptom-to-fibrinolysis time strata for the primary efficacy end point (p-heterogeneity = 0.67), 30-day mortality, the composite of death or reinfarction at 30 days, 6 months, or 1 year, or bleeding (all p-heterogeneity >0.40). In conclusion, the efficacy and safety of an early invasive strategy in patients undergoing fibrinolysis for STEMI do not vary in relation to time (<2 or ≥2 hours) from symptom onset to fibrinolysis.

Are cardiovascular trial results systematically different between North America and Europe? A study based on intra-meta-analysis comparisons

BACKGROUND

It is often assumed that differences in the efficacy of treatments between countries (or regions) will be neither negligible nor minor and therefore cannot be overlooked when assessing the potential benefit of treatments in one country (or region) on the basis of trials conducted in another country (or region).

AIM

To assess differences in the results of cardiovascular trials between Europe and North America on the basis of data from an extensive collection of trials.

METHODS

A systematic search was conducted of Medline (from the year 2005 to 2008) and the Cochrane Library (from 2000 to 2008) for all meta-analyses of randomized controlled trials aimed at treating and preventing cardiovascular disease. Within each meta-analysis that satisfied given criteria, trial results were compared between Europe and North America with respect to a fatal and/or non-fatal endpoint by forming separate estimates of treatment efficacy for each of these continents.

RESULTS

The literature search found 59 meta-analyses that satisfied all the inclusion criteria. For most meta-analyses, it was the case that relative to the control, the intervention was more favoured in trials conducted in Europe than in North America with regard to both fatal endpoints (28 out of 43 meta-analyses) and non-fatal endpoints (28 out of 40 meta-analyses). However, it was only with regard to non-fatal endpoints that this imbalance turned out to be statistically significant at the 5% level (P=0.017). Also, the lack of statistically significant differences in trial results between Europe and North America within individual meta-analyses meant that it was not possible to determine for which types of intervention these intercontinental differences are likely to be more pronounced than others.

CONCLUSION

There is some evidence to support the theory that, relative to controls, interventions are more favoured in cardiovascular trials conducted in Europe than in North America, when treatment efficacy is measured in terms of a non-fatal endpoint. However, the overall support for systematic differences in cardiovascular trial results between Europe and North America is weak, which may be surprising given the amount of data collected.

Efficacy and safety of a routine early invasive strategy after fibrinolysis stratified by glycoprotein IIb/IIIa inhibitor use during percutaneous coronary intervention: a pre-specified subgroup analysis of the TRANSFER-AMI randomised controlled trial

OBJECTIVE

We evaluated the efficacy and safety of an early invasive strategy post-fibrinolysis in relation to glycoprotein (GP) IIb/IIIa inhibitor use.

METHODS

The Trial of Routine Angioplasty and Stenting after Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI) randomised 1059 ST elevation myocardial infarction patients to an early invasive strategy or standard therapy post-fibrinolysis. The primary end point was the composite of death, reinfarction, recurrent ischaemia, new or worsening heart failure, or cardiogenic shock at 30 days. In this pre-specified analysis, we examined efficacy and safety outcomes of an early invasive strategy after stratification by GPIIb/IIIa inhibitor use, which was permitted during percutaneous coronary intervention (PCI) at the discretion of the treating physician.

RESULTS

A total of 695 patients (65.6%) received GPIIb/IIIa inhibitors. There was significant heterogeneity (p<0.001) in the efficacy of an early invasive strategy compared to standard therapy, between the strata with GPIIb/IIIa inhibitor use (primary end point 9.6% vs 22.3% respectively, p<0.001) and without GPIIb/IIIa inhibitor use (primary end point 14.8% vs 10.4% respectively, p=0.21). Patients who received GPIIb/IIIa inhibitors had lower Global Registry of Acute Coronary Events (GRACE) risk scores compared to those without GPIIb/IIIa inhibitor use (median 121 vs 130, p<0.001). After adjusting for the interaction between GRACE risk score and treatment assignment, the heterogeneity in the efficacy of an early invasive strategy with respect to GPIIb/IIIa inhibitor use was no longer significant (p interaction=0.08).

CONCLUSIONS

The apparent difference in the efficacy of an early invasive strategy between GPIIb/IIIa inhibitor strata likely reflects an association between GPIIb/IIIa inhibitor use and baseline risk. GPIIb/IIIa inhibitor use during PCI at the discretion of the treating physician does not appear to modulate the efficacy of an early invasive strategy post-fibrinolysis.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov/ct2/show/NCT00164190, NCT00164190.

Routine early angioplasty after fibrinolysis for acute myocardial infarction

BACKGROUND

Patients with a myocardial infarction with ST-segment elevation who present to hospitals that do not have the capability of performing percutaneous coronary intervention (PCI) often cannot undergo timely primary PCI and therefore receive fibrinolysis. The role and optimal timing of routine PCI after fibrinolysis have not been established.

METHODS

We randomly assigned 1059 high-risk patients who had a myocardial infarction with ST-segment elevation and who were receiving fibrinolytic therapy at centers that did not have the capability of performing PCI to either standard treatment (including rescue PCI, if required, or delayed angiography) or a strategy of immediate transfer to another hospital and PCI within 6 hours after fibrinolysis. All patients received aspirin, tenecteplase, and heparin or enoxaparin; concomitant clopidogrel was recommended. The primary end point was the composite of death, reinfarction, recurrent ischemia, new or worsening congestive heart failure, or cardiogenic shock within 30 days.

RESULTS

Cardiac catheterization was performed in 88.7% of the patients assigned to standard treatment a median of 32.5 hours after randomization and in 98.5% of the patients assigned to routine early PCI a median of 2.8 hours after randomization. At 30 days, the primary end point occurred in 11.0% of the patients who were assigned to routine early PCI and in 17.2% of the patients assigned to standard treatment (relative risk with early PCI, 0.64; 95% confidence interval, 0.47 to 0.87; P=0.004). There were no significant differences between the groups in the incidence of major bleeding.

CONCLUSIONS

Among high-risk patients who had a myocardial infarction with ST-segment elevation and who were treated with fibrinolysis, transfer for PCI within 6 hours after fibrinolysis was associated with significantly fewer ischemic complications than was standard treatment. (ClinicalTrials.gov number, NCT00164190.)

Systematic review of fibrinolytic-facilitated percutaneous coronary intervention: potential benefits and future challenges

BACKGROUND

Facilitated percutaneous coronary intervention (PCI) is defined as the administration of fibrinolytic therapy and/or glycoprotein (GP) IIb/IIIa inhibitors to minimize myocardial ischemia time while waiting for PCI. A pooled meta-analysis suggested that facilitated PCI was associated with higher rates of mortality and morbidity compared with nonfacilitated PCI.

OBJECTIVE

The heterogeneous and complex trials of facilitated PCI were systematically reviewed to identify where this strategy may be beneficial and deserving of further research.

METHODS

MEDLINE, EMBASE, the Cochrane database, the Internet and conference proceedings were searched to obtain relevant trials. Human studies that randomly assigned patients to fibrinolytic-facilitated PCI (administration of fibrinolytic therapy alone or in combination with GP IIb/IIIa inhibitors before angiography) versus nonfacilitated PCI were included.

RESULTS

Nine trials encompassing 3836 patients were reviewed. The facilitated PCI strategy was fibrinolytic therapy alone in seven trials and half-dose fibrinolytic therapy plus GP IIb/IIIa inhibitors in two trials. In patients who had fibrinolysis less than 2 h after symptom onset (mainly in the prehospital setting) and/or slightly delayed PCI 3 h to 24 h after fibrinolysis, facilitated PCI was associated with the greatest Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow and a trend toward reduced mortality. Overall, facilitated PCI was associated with increased intracranial hemorrhage and reinfarction. Combining half-dose fibrinolytic therapy and GP IIb/IIIa inhibitors reduced reinfarction but increased major bleeding.

CONCLUSIONS

Facilitated PCI cannot be recommended outside of experimental protocols at this time. Further research should focus on selecting patients with higher benefit-to-risk ratios and performing prehospital fibrinolysis with optimal antiplatelet or antithrombin therapy, as well as slightly delayed PCI in patients who are stable or geographically removed from PCI facilities.

Rationale and design of the Trial of Routine ANgioplasty and Stenting After Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI)

BACKGROUND

Most patients with ST-elevation myocardial infarction present to hospitals without percutaneous coronary intervention (PCI) facilities and receive fibrinolysis. The role of routine early PCI after fibrinolysis, using stents and contemporary pharmacotherapy, has not been studied in a large adequately powered randomized trial.

OBJECTIVE

To compare a pharmacoinvasive strategy of transfer for routine PCI within 6 hours after fibrinolysis with standard treatment after fibrinolysis (including predefined criteria for rescue PCI and delayed cardiac catheterization for patients who do not require rescue PCI).

METHODS

A total of 1200 patients with high-risk ST-elevation myocardial infarction presenting to non-PCI centers will be randomized to a pharmacoinvasive strategy (transfer for routine PCI within 6 hours of fibrinolysis) or to standard treatment after fibrinolysis. The primary end point is the 30-day composite of death, reinfarction, recurrent ischemia, heart failure, or shock.

RESULTS

More than 900 patients have been enrolled as of April 2007. An interim safety analysis of the first 536 patients demonstrated no safety concerns. Enrolment is expected to be completed in late 2007.

CONCLUSIONS

This study will provide important data on whether routine early PCI within 6 hours after fibrinolysis is safe and superior to the standard treatment of fibrinolysis with rescue PCI or delayed cardiac catheterization.

Transfer for urgent percutaneous coronary intervention early after thrombolysis for ST-elevation myocardial infarction: the TRANSFER-AMI pilot feasibility study

BACKGROUND

Most hospitals in Canada do not have percutaneous coronary intervention (PCI) facilities and use thrombolysis as reperfusion therapy for ST-elevation myocardial infarction (STEMI). Urgent PCI after thrombolysis may optimize reperfusion and prevent reinfarction and recurrent ischemia.

OBJECTIVE

To determine the feasibility of transferring high-risk STEMI patients from community hospitals in Ontario to PCI centres for urgent PCI within 6 h of thrombolysis.

METHODS

Patients with anterior or high-risk inferior STEMI received tenecteplase and were urgently transferred to PCI centres. PCI was performed if at least 70% stenosis was present in the infarct-related artery, regardless of flow, using coronary stents. Transfer of stable patients back to community hospitals was encouraged 24 h to 48 h after PCI.

RESULTS

Eighteen patients were transferred and underwent PCI a median of 3.9 h (range 2.7 h to 6.4 h) after thrombolysis. No complications occurred during transfer. One death occurred that was related to failed reperfusion and cardiogenic shock. Minor access-site bleeding occurred in five patients. Fifteen patients were transferred back to their community hospitals within 24 h of PCI. There were no further deaths or reinfarctions at one-year follow-up.

CONCLUSIONS

Transfer of high-risk STEMI patients for urgent PCI within 6 h after thrombolysis appears feasible. The randomized trial phase of the Trial of Routine ANgioplasty and Stenting after Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI) will compare this strategy with standard treatment after thrombolysis.

Facilitated Percutaneous Coronary Intervention

The goal of the initial treatment for ST-segment elevation myocardial infarction is rapid and effective reperfusion. Randomized trials have demonstrated that primary angioplasty is preferred over thrombolysis if done in a timely manner and by an experienced team. However, due to many factors, performance of primary angioplasty within the goal of 90 min is often not possible. A combined strategy of immediate thrombolysis in the emergency room or in the ambulance followed by angioplasty theoretically could provide early reperfusion with subsequent angioplasty to insure complete reperfusion. Over 17 clinical trials have been reported. Compared with thrombolysis, facilitated angioplasty in the most recent trials has been shown to have a more favorable long-term outcome. Trials comparing facilitated angioplasty with full- or half-dose thrombolysis versus primary angioplasty have been far less favorable with the largest trial to date, the ASSENT (Assessment of the Safety and Efficacy of a New Treatment Strategy with Percutaneous Coronary Intervention)-4 trial, demonstrating a worse outcome in the primary end point of death, congestive heart failure, or shock at 90 days. Pending the results of the FINESSE (Facilitated Intervention with Enhanced Reperfusion Speed to Stop Events) trial, current data suggest that facilitated angioplasty does not offer any advantage over primary angioplasty and may be harmful.

Optimizing use of revascularization and clinical outcomes in ST-elevation myocardial infarction: insights from the GUSTO-V trial

AIMS

To examine the relationship between revascularization within 7 days and 1-year mortality among ST-elevation myocardial infarction patients enrolled in GUSTO-V trial (n=13 451). To examine the relative contribution of system and patient level factors to the variation in international revascularization rates, and their impact on mortality outcomes.

METHODS AND RESULTS

Patients from North America (USA, Canada), Australia, and Europe (UK, France, Germany, Italy, Spain, Poland, Norway, The Netherlands, Belgium, Finland) were included in the study. Revascularization was associated with lower 1-year mortality. Norway, Belgium, Spain, Poland, and Italy also had lower than expected revascularization rates but higher than expected mortality rates. France and USA had almost two times the expected rate of 7-day revascularization, which was associated with modest mortality benefits. Patients' propensity for revascularization based on clinical factors alone was associated with lower 1-year mortality (OR 0.97, 95% CI: 0.96-0.99). Country-level factors had an impact on propensity for revascularization but no impact on 1-year mortality.

CONCLUSION

Our study reveals the potential for some countries with lower than expected 7-day revascularization rates to improve their clinical outcomes. Also highlighted is the possibility for more economically efficient delivery of care in USA and France.