A meta-analysis of randomized trials of rescue percutaneous coronary intervention after failed fibrinolysis

No-Reflow Phoenomenon by Intracoronary Thrombus in Acute Myocardial Infarction

Recently, percutaneous coronary intervention has been the treatment of choice in most acute myocardial infarction cases. Although the results of percutaneous coronary interventions have ben good, the no-reflow phenomenon and distal embolization of intracoronary thrombus are still major problems even after successful interventions. In this article, we will briefly review the deleterious effects of no-reflow and distal embolization of intracoronary thrombus during percutaneous coronary interventions. The current trials focused on the prevention and treatment of the no-reflow phenomenon and intracoronary thrombus.

Influence of the Timing of Percutaneous Coronary Intervention on Clinical Outcomes in Non-ST-Elevation Myocardial Infarction

Background and Objectives

We have intended to investigate the influence of the timing of invasive procedures on all-cause mortality, recurrent myocardial infarction (MI), re-hospitalization due to cardiac causes and left ventricular function over a 3-month period among patients with Non-ST-elevation myocardial infarction (NSTEMI).

Subjects and Methods

A total of 131 NSTEMI patients with moderate-high Thrombolysis in Myocardial Infarction risk scores, who had been admitted to our department between July 2011-December 2011 were included in our study. They had been randomized into 2 groups according to the timing of the percutaneous coronary intervention (PCI). Patient undergoing PCI in the first 24 hours of hospitalization were named the "Early Invasive Group" and those undergoing PCI between 24-72 hours of hospitalization were named the "Delayed Invasive Group". All patients were followed up for 3 months.

Results

Third month left ventricular ejection fraction (LVEF) values were higher in the early invasive group (59.9±6.0% vs. 54.1±8.7%; p<0.001). Recurrent MI rates were lower in the early invasive group (2.9% vs. 14.5%; p=0.016). Similarly, hospitalization rates due to cardiac events were lower in the early invasive group (8.7% vs. 30.6%; p=0.001). All cause mortality appeared to be lower in the early invasive group, although not to a statistically significant degree (0% vs. 4.8%; p=0.065).

Conclusion

The early invasive strategy appears to be more effective for the reduction of recurrent MI, re-hospitalization due to cardiac events, and the preservation of 3rd month LVEF in patients with moderate-high risk NSTEMI when compared to a delayed invasive strategy.

A strategy for addressing aspirin hypersensitivity in patients requiring urgent PCI

Aspirin is key to the treatment of acute myocardial infarction, particularly if stent implantation is considered. In patients with a history of hypersensitivity to aspirin, the optimal management of ST-segment elevation acute myocardial infarction is unclear. We suggest a strategy for addressing this problem by performing percutaneous coronary intervention with antiplatelet therapy by intravenous glycoprotein IIb/IIIa receptor blockers and performing rapid oral desensitization in the ensuing hours, once the patient has stabilized.

Acute coronary syndromes: Diagnosis and management, part II

At the most severe end of the spectrum of acute coronary syndromes is ST-segment elevation myocardial infarction (STEMI), which usually occurs when a fibrin-rich thrombus completely occludes an epicardial coronary artery. The diagnosis of STEMI is based on clinical characteristics and persistent ST-segment elevation as demonstrated by 12-lead electrocardiography. Patients with STEMI should undergo rapid assessment for reperfusion therapy, and a reperfusion strategy should be implemented promptly after the patient's contact with the health care system. Two methods are currently available for establishing timely coronary reperfusion: primary percutaneous coronary intervention and fibrinolytic therapy. Percutaneous coronary intervention is the preferred method but is not always available. Antiplatelet agents and anticoagulants are critical adjuncts to reperfusion. This article summarizes the current evidence-based guidelines for the diagnosis and management of STEMI. This summary is followed by a brief discussion of the role of noninvasive stress testing in the assessment of patients with acute coronary syndrome and their selection for coronary revascularization.

Prehospital fibrinolytic therapy followed by urgent percutaneous coronary intervention in patients with ST-elevation myocardial infarction

In patients with ST-segment elevation myocardial infarction (STEMI) the shorter the reperfusion time, the better the outcome is, regardless of the reperfusion method. Effective, early and rapid reperfusion is the most important goal in the treatment of patients with STEMI. In majority cases of STEMI, transport or transfer to a percutaneous coronary intervention (PCI)-capable center will occur, sometimes bypassing the closest hospital facilities that are not PCI centers. The timely optimal reperfusion strategy might be a prehospital initiated pharmacological reperfusion with subsequent PCI. Reduced-dose prehospital fibrinolysis allows safe transport of STEMI patients to PCI centers for urgent culprit artery PCI, and may be a superior approach compared with transporting patients to the closest non-PCI hospital for fibrinolytic therapy. In this review we will discuss the evidence regarding reperfusion strategies in STEMI patients.

Reperfusion options in ST-elevation myocardial infarction patients with expected delays

Primary percutaneous coronary intervention (PPCI) is the optimal reperfusion strategy for ST-elevation myocardial infarction (STEMI) patients when performed in a timely manner by experienced providers. Unfortunately, only 25% of US hospitals have percutaneous coronary intervention (PCI) capability. Transfer for PPCI has also been shown to improve outcomes if transfer times are short and PCI can be performed within 90 minutes. However, many STEMI patients cannot be transferred in a timely fashion because of long distances, adverse weather, or process-of-care delays. Recent data support strategies that combine fibrinolysis with transfer for PCI under these circumstances. The critical issue that is still debated is the timing of PCI (immediate vs delayed vs rescue). The significance of time to reperfusion to mortality is important but less critical for PCI than for fibrinolysis, but time still matters. To optimize time to reperfusion for STEMI patients, all hospitals need to have predetermined protocols in place based on hospital characteristics and proximity to a catheterization laboratory.

Role of adjunctive thrombectomy and embolic protection devices in acute myocardial infarction: a comprehensive meta-analysis of randomized trials

AIMS

Adjunctive thrombectomy and embolic protection devices in acute myocardial infarction have been extensively studied, although outcomes have mainly focused on surrogate markers of reperfusion. Therefore, the effect of adjunctive devices on clinical outcomes is unknown. This study sought to determine whether the use of a thrombectomy or embolic protection device during revascularization for acute myocardial infarction reduces mortality compared with percutaneous coronary intervention (PCI) alone.

METHODS AND RESULTS

The Cochrane and Medline databases were searched for clinical trials that randomized patients with ST-elevation acute myocardial infarction to an adjuvant device prior to PCI compared with PCI alone. Devices were grouped into catheter thrombus aspiration, mechanical thrombectomy, and embolic protection. There were a total of 30 studies with 6415 patients who met our selection criteria. Over a weighted mean follow-up of 5.0 months, the incidence of mortality among all studies was 3.2% for the adjunctive device group vs. 3.7% for PCI alone (relative risk, 0.87; 95% confidence interval, 0.67-1.13). Among thrombus aspiration studies, mortality was 2.7% for the adjunctive device group vs. 4.4% for PCI alone (P = 0.018), for mechanical thrombectomy, mortality was 5.3% for the adjunctive device group vs. 2.8% for PCI alone (P = 0.050), and for embolic protection, mortality was 3.1% for the adjunctive device group vs. 3.4% for PCI alone (P = 0.69).

CONCLUSION

Catheter thrombus aspiration during acute myocardial infarction is beneficial in reducing mortality compared with PCI alone. Mechanical thrombectomy appears to increase mortality, whereas embolic protection appears to have a neutral effect.

Critical care aspects in the management of patients with acute coronary syndromes

The spectrum of acute coronary syndromes (ACS) includes several clinical complexes that frequently cause critical instability in affected patients. This article focuses on several critical care aspects of these unstable ACS patients. The management of cardiogenic shock can be particularly challenging because the mechanical defects are varied in cause, severity, and specific treatment. Complications of fibrinolytic therapy are potentially deadly and arrhythmias are relatively common in the ACS patients. Discussions on the management of these problems should help the emergency physician more effectively to treat critically ill patients with ACS.

Percutaneous coronary intervention for myocardial infarction with left ventricular dysfunction

Patients who have had a myocardial infarction (MI) are at high risk for developing left ventricular dysfunction (LVD), which predisposes them to heart failure and is associated with an increased mortality risk. Early coronary revascularization, either with percutaneous coronary intervention or coronary artery bypass graft surgery, plays an important role in the preservation and restoration of left ventricular function after MI. This article discusses the effects of primary and nonemergent percutaneous coronary revascularization procedures on survival, left ventricular function, and the occurrence of complications, such as recurrent MI and stroke, compared with the effects of thrombolytic therapy. In addition, this article describes rescue revascularization procedures for patients who failed thrombolysis and those presenting relatively late or with negative electrocardiographic findings. Advanced interventional techniques, such as percutaneous ventricular assist devices and bioabsorbable stents, are very promising and may potentially help improve the outcomes of post-MI patients with LVD; however, the use of these techniques requires further validation.

Early and long term outcome of rescue percutaneous coronary intervention (R-PCI): experience from a tertiary care center in Pakistan: outcome of rescue angioplasty in Pakistan

BACKGROUND

Thrombolysis is the standard of care for STEMI in Pakistan. Failed thrombolysis has a very high morbidity and mortality. Rescue PCI then remains the only option to salvage the myocardium. We sought to analyze the angiographic, immediate and long term clinical outcome of patients undergoing Rescue PCI at our institution in Karachi, Pakistan.

METHODS

58 consecutive patients who underwent rescue PCI for failed thrombolysis between 2002 and 2005 were reviewed. Clinical characteristics, angiographic and procedural details with clinical outcomes including total mortality, recurrent angina, and repeat revascularization were studied. Sources included cardiac catheterization lab database, medical records and follow up at outpatient clinics.

RESULTS

Rescue PCI was performed in 58 patients with a mean age 55 +/- 12 years with 47 (79%) male and 11 (21%) females. CAD risk factors were hypertension (53%), dyslipidemia (48%), smoking (34%) and diabetes (34%). 53% had anterior MI, 39% inferior and 8% had a lateral wall MI. The median time frames were: onset of chest pain to ER = 99 min, door to needle time = 35 min, ER to procedure start time = 250 min. The culprit vessels were: Left Anterior Descending (LAD) (53%), Right Coronary Artery (RCA) (32%) and Circumflex (CX) (15%). TIMI flow grades pre-procedural were 0/I = 52%, II = 34%, III = 14% and post procedure 0/I = 8%, II = 6%, III = 86%. The mean follow-up duration was 16.15 months at which 50 (86%) were alive and 43 (74.13%) had event free survival.

CONCLUSION

Procedural success, event free survival and mortality in our series of Rescue PCI from Pakistan are comparable to recent international trials and registries. It should be considered as a reasonable option for patients with failed thrombolysis.

Guideline adjudicated fibrinolytic failure: incidence, findings, and management in a contemporary clinical trial

BACKGROUND

Rescue percutaneous coronary intervention (PCI) is efficacious after clinical failure of fibrinolytic therapy and is recommended for those with persistent ischemia, hemodynamic, or electrical instability. We sought to describe the frequency of fibrinolytic failure (rescue eligibility) as well as the patient characteristics associated with rescue eligibility, rescue referral, and PCI.

METHODS AND RESULTS

Eligibility, indication, and referral for guideline-based rescue PCI were adjudicated in 221 patients enrolled in the WEST trial. WEST treated patients at earliest medical contact and used a tenectaplase/enoxaparin regimen. Ninety patients (41%) were adjudicated with acute myocardial infarction as rescue eligible of whom 68 were referred for rescue PCI. Baseline characteristics did not predict rescue eligibility or referral. Emergency angiography before PCI performed a median of 82 minutes (interquartile range 50-99) after rescue referral showed TIMI flow grade 2 or 3 in 34 (50%). Percutaneous coronary intervention was adjudicated as successful in 58 of 60 attempts. Procedures began approximately 45 minutes sooner in patients initially admitted to PCI-capable hospitals. Compared to those with clinically successful fibrinolytic therapy, rescue eligible patients demonstrated higher median peak creatine phosphokinase (1889 [1243-3746] vs 999 [440-2048], P < .01) and 30-day median NT-proBNP levels (748 [391-1916] vs 431 [153-1016], P < .01).

CONCLUSIONS

Rescue eligibility determined by guideline criteria is common after contemporary fibrinolysis and is not predicted by conventional baseline characteristics. Half of rescue-referred patients are patent at angiography: although contemporary PCI success rates are high, rescue eligibility is associated with larger infarctions.

Early invasive versus conservative treatment in patients with failed fibrinolysis--no late survival benefit: the final analysis of the Middlesbrough Early Revascularisation to Limit Infarction (MERLIN) randomized trial

BACKGROUND

Early (30 days) and midterm (6 months) clinical outcomes in trials comparing rescue angioplasty (rescue percutaneous coronary intervention [rPCI]) with conservative treatment of failed fibrinolysis complicating ST-segment elevation myocardial infarction have shown variable results. Whether early rPCI confers late (up to 3 years) clinical benefits is not known.

METHODS

The MERLIN trial compared rPCI and a conservative strategy in patients with failed fibrinolysis complicating ST-segment elevation myocardial infarction. Three hundred seven patients with electrocardiographic evidence of failure to reperfuse at 60 minutes were included. Patients in cardiogenic shock were excluded. Thirty-day and 1-year results have been reported. Results of 3 years of follow-up are presented.

RESULTS

Three-year mortality in the conservative arm and rPCI, respectively, was 16.9% versus 17.6% (P = .9, relative difference [RD] -0.8, 95% CI [-9.3 to 7.8]). Death rates were similar (3.9% vs 3.2%) between 1- and 3-year follow-up, respectively. The incidence of the composite secondary end point of death, reinfarction, stroke, unplanned revascularization, or heart failure was significantly higher in the conservative arm (64.3% vs 49%, P = .01, RD 15.3, 95% CI [4.2-26]). There was no significant difference in the rate of reinfarction (0.7% vs 0.7%) or heart failure (1.3% vs 2.7%) between 1 and 3 years between the conservative and rPCI arms, respectively. The incidence of subsequent unplanned revascularization at 3 years was significantly higher in the conservative arm (33.8% vs 14.4%, P < .01, RD 19.4, 95% CI [10-28.7]), most of which occurred within 1 year; the rates between 1 and 3 years were 3.9% in the conservative arm versus 2% in the rPCI arm. There was a trend toward fewer strokes in the conservative arm at 3 years (conservative arm 2.6% vs rPCI 6.5%, P = .1, RD -3.9%, 95% CI [-9.4 to 0.8]), with similar stroke rates (1.3% vs 1.3%) between 1- and 3-year follow-up.

CONCLUSIONS

Rescue angioplasty did not confer a late survival advantage at 3 years. The composite end point occurred less often in the rPCI arm mainly because of fewer unplanned revascularization procedures in the early phase of follow-up. The highest risk of clinical events in patients with failed reperfusion is in the first year, beyond which the rate of clinical events is low.