A prospective randomized clinical trial of intracoronary streptokinase versus coronary angioplasty for acute myocardial infarction

Epicardial placement of human placental membrane protects from heart injury in a swine model of myocardial infarction

Cardiac ischemic reperfusion injury (IRI) is paradoxically instigated by reestablishing blood-flow to ischemic myocardium typically from a myocardial infarction (MI). Although revascularization following MI remains the standard of care, effective strategies remain limited to prevent or attenuate IRI. We hypothesized that epicardial placement of human placental amnion/chorion (HPAC) grafts will protect against IRI. Using a clinically relevant model of IRI, swine were subjected to 45 min percutaneous ischemia followed with (MI + HPAC, n = 3) or without (MI only, n = 3) HPAC. Cardiac function was assessed by echocardiography, and regional punch biopsies were collected 14 days post-operatively. A deep phenotyping approach was implemented by using histological interrogation and incorporating global proteomics and transcriptomics in nonischemic, ischemic, and border zone biopsies. Our results established HPAC limited the extent of cardiac injury by 50% (11.0 ± 2.0% vs. 22.0 ± 3.0%, p = 0.039) and preserved ejection fraction in HPAC-treated swine (46.8 ± 2.7% vs. 35.8 ± 4.5%, p = 0.014). We present comprehensive transcriptome and proteome profiles of infarct (IZ), border (BZ), and remote (RZ) zone punch biopsies from swine myocardium during the proliferative cardiac repair phase 14 days post-MI. Both HPAC-treated and untreated tissues showed regional dynamic responses, whereas only HPAC-treated IZ revealed active immune and extracellular matrix remodeling. Decreased endoplasmic reticulum (ER)-dependent protein secretion and increased antiapoptotic and anti-inflammatory responses were measured in HPAC-treated biopsies. We provide quantitative evidence HPAC reduced cardiac injury from MI in a preclinical swine model, establishing a potential new therapeutic strategy for IRI. Minimizing the impact of MI remains a central clinical challenge. We present a new strategy to attenuate post-MI cardiac injury using HPAC in a swine model of IRI. Placement of HPAC membrane on the heart following MI minimizes ischemic damage, preserves cardiac function, and promotes anti-inflammatory signaling pathways.

Interobserver Variability Among Experienced Electrocardiogram Readers To Diagnose Acute Thrombotic Coronary Occlusion In Patients with Out of Hospital Cardiac Arrest: Impact of Metabolic Milieu and Angiographic Culprit

OBJECTIVES

We sought to evaluate interobserver concordance among experienced electrocardiogram (ECG) readers in predicting acute thrombotic coronary occlusion (ATCO) in the context of abnormal metabolic milieu (AMM) following resuscitated out of hospital cardiac arrest (OHCA).

METHODS

OHCA patients with initial shockable rhythm who underwent invasive coronary angiography (ICA) were included. AMM was defined as one of: pH < 7.1, lactate > 2 mmol/L, serum potassium < 2.8 or > 6.0 mEq/L. The initial ECG following ROSC but prior to ICA was adjudicated by 2 experienced readers using classic ST elevation myocardial infarction [STEMI] and expanded criteria and their combination to predict ATCO on ICA.

RESULTS

152 consecutive patients (mean age 58 years, 76% male) met inclusion criteria. AMM was present in 77%; and 42% had ATCO on ICA. Sensitivity, specificity, PPV, NPV using classic STEMI criteria were 50%, 98%, 94%, 72% (c-statistic 0.74); whereas for combined (STEMI + expanded) criteria they were 69%, 88%, 81%, 79% respectively (c-statistic 0.79). Inter-observer agreement (kappa) was 0.7 for classic STEMI criteria, and 0.66 for combined criteria. Agreement between readers was consistently higher when ATCO was absent and with NMM (kappa 0.78), but lower in AMM (kappa 0.6).

CONCLUSIONS

Despite experienced ECG readers, there was only modest overall concordance in predicting ATCO in the context of resuscitated OHCA. Significant interobserver variations were noted dependent on metabolic milieu and angiographic ATCO. These observations fundamentally question the role of the 12-lead ECG as primary triaging tool for early angiography among patients with OHCA.

Primary percutaneous coronary intervention is appropriate in transient ST-elevation myocardial infarction

INTRODUCTION

Reperfusion therapy by primary percutaneous coronary intervention (PPCI) is generally indicated in patients suffering from acute myocardial infarction (MI) with ST-segment elevation (STEMI). Prior to hospital admission, full ST-segment resolution (fSTR) may occur. Optimal management of such patients with transient STEMI (TSTEMI) is potentially challenging. Our aim was to evaluate the hypothesis that in TSTEMI patients, patency of infarct related artery (IRA) is achieved before PPCI, and to compare the outcome of TSTEMI and STEMI patients during a prolonged follow-up.

MATERIAL AND METHODS

Three hundred consecutive adult STEMI patients were referred to catheterization laboratory. In all patients, standard 12 lead ECGs were obtained both at the time of the first medical contact, and on catheterization laboratory admission.

RESULTS

TSTEMI occurred in 20 patients (6.7%). Despite fSTR (isoelectric ST segment), occluded IRA was found in 5 of these patients (25%). Pre-PPCI TIMI flow grade 2 was found in 6 TSTEMI patients (30%). Troponin T value at 24 h after symptom onset was lower in the TSTEMI group (1.8±2.5 mg/L vs. 3.6±3.5 mg/L, P=0.008). These patients also had a lower value of brain natriuretic peptide (156.3±119.5 ng/L vs. 438.5±429.0 ng/L, P<0.001) and higher left ventricular ejection fraction (59.9±6.3% vs. 51.6±10.2%, P<0.001). All patients were followed for a median of 5.6 years during which the overall survival did not differ between the TSTEMI and STEMI groups.

CONCLUSION

Primary PCI is strongly recommended in TSTEMI patients because of a relatively high incidence of occluded infarct related arteries. The rate of patients with TSTEMI is relatively low.

Left ventricular apical thrombi: Silent but terrifying

We present a case with a large left ventricular (LV) thrombus that presented to the emergency department with dyspnea. Bedside transthoracic echocardiography demonstrated a huge hypermobile thrombus with a maximum of 8.6 × 2 cm in size extending to the aortic valve originating from the aneurysmatic apical wall of the LV. Treatment of the patient included complete thrombus resection with aneurysmectomy.

COURAGE, ORBITA, and ISCHEMIA: Percutaneous Coronary Intervention for Stable Coronary Artery Disease

This review article summarizes key landmark trials that have shaped understanding of the role of percutaneous coronary intervention (PCI) in stable coronary artery disease (CAD). The relationship between stenosis, ischemia, and angina is more complex than first imagined. Anginal relief remains the primary indication for PCI in stable CAD. The first placebo-controlled PCI trial showed a surprisingly small effect size, suggesting a significant placebo effect. PCI in stable CAD has not been shown to improve mortality or overall myocardial infarction rates, even in the presence of significant ischemia. Rather, risk reduction medical therapy remains the main intervention for improving outcomes.

Downstream Influence of Coronary Stenoses on Microcirculatory Remodeling: A Histopathology Study

OBJECTIVE

Inducible myocardial ischemia is influenced by contributions of both the epicardial artery and the coronary microcirculation. Experimental studies have found adverse microcirculatory remodeling to occur downstream of severe coronary stenoses. Coronary physiology studies in patients contradict the experimental findings, as the minimal microvascular resistance is not modified by stenoses. The objective was to determine whether microcirculatory remodeling occurs downstream of coronary stenoses in the human coronary circulation. Approach and Results: Myocardium corresponding to 115 coronary arteries of 55 deceased patients was investigated. Histopathologic staining of the microcirculation was performed using antibodies against SMA-α (smooth muscle actin-α) and CD31, to stain arterioles and capillaries, respectively. The following parameters were analyzed: ratio between lumen and vesel area, ratio between lumen and vessel diameter (both ratios for arterioles of <40, 40-100, and 100-200 µm diameter), arteriolar density, and capillary density. From the 55 patients, 32 pairs of an unobstructed coronary artery and a coronary artery with a stenosis were formed. No statistically significant differences between any of the microcirculatory parameters were found. A confirmatory unpaired analysis compared 3 groups: (1) coronary arteries in patients without coronary artery disease (n=53), (2) unobstructed coronary arteries in patients with a stenosis in one of the other coronary arteries (n=23), and (3) coronary stenoses (n=39). No statistically significant differences were observed between the groups.

CONCLUSIONS

The microcirculation distal to noncritical stenoses does not undergo structural remodeling in the human coronary circulation.

Pentraxin Level is the Key to Determine Primary Percutaneous Coronary Intervention (PCI) or Fibrinolysis

AIMS

To examine if pentraxin can help identify patients benefitting most from primary Percutaneous Coronary Intervention (PCI) vs. fibrinolysis.

METHODS

Patients with acute ST-Elevation Myocardial Infarction (STEMI) were consecutively recruited from a community center without PCI and a tertiary center with PCI facilities. Left ventricular ejection fraction (LVEF) was determined echocardiographically at baseline and 5 days after the index admission; the difference between two measurements was considered as the magnitude of improvement. We used regression models to test the hypothesis that the magnitude of the advantage of PCI over fibrinolysis in preserving LVEF 5 days after STEMI is modified by pentraxin 3 (PTX3).

RESULTS

The functional advantage (LVEF) of the PCI over fibrinolysis has been determined by PTX3. LVEF was attenuated and even reversed as PTX3 level increased. The primary PCI of the participants with less than 7 ng.ml-1 PTX3 level, achieved a clinically significant increase in the LVEF as compared to fibrinolysis. At lower levels of PTX3, PCI shows a conspicuous advantage over fibrinolysis in terms of the probability of developing an LVEF <40%.

CONCLUSION

We demonstrated not only the functional advantage of PCI over fibrinolysis performed within the recommended time frames but also the relative advantage of its relevance to the baseline PTX3 levels. PTX3 can play a role in determining the choice of best therapy. More than 75% of patients with STEMI who have PTX3 levels ≤7 ng.ml-1 imply the need of PCI.

Stenting in Primary Percutaneous Coronary Intervention for Acute ST-Segment Elevation Myocardial Infarction

The treatment of ST-segment elevation myocardial infarction (STEMI) has advanced dramatically over the past 30 years since the introduction of reperfusion therapies, such that mechanical reperfusion with primary percutaneous coronary intervention is now the standard of care. With STEMI, as with other forms of acute coronary syndrome, stent deployment in culprit lesions is the dominant form of reperfusion in the developed world and is supported by contemporary guidelines. However, the precise timing of stenting and the extent to which both culprit and non-culprit lesions should be treated continue to be active areas of study. In this review, we revisit key data that support the use of mechanical reperfusion therapy in STEMI patients and explore the optimal timing for and extent of stent implantation in this complex patient group. We also review data surrounding the deleterious effects of untreated residual myocardial ischemia, the importance of complete revascularization, and the recent data exploring culprit-only versus multivessel stenting in the STEMI setting.

Comparing mortality between fibrinolysis and primary percutaneous coronary intervention in patients with acute myocardial infarction: a systematic review and meta-analysis of 27 randomized-controlled trials including 11 429 patients

OBJECTIVES

We aimed to improve the limitations encountered in previously published studies and then compare mortality in patients with acute myocardial infarction (AMI) who were treated with either fibrinolysis or a primary percutaneous coronary intervention (PPCI).

METHODS

EMBASE, MEDLINE, and the Cochrane databases were searched for trials comparing fibrinolysis with PPCI in patients with AMI. The only endpoint that was assessed in this analysis was all-cause mortality. Therefore, in-hospital, short-term, mid-term, and long-term mortality were analyzed, whereby odds ratios (OR) with 95% confidence intervals (CIs) were calculated using the RevMan 5.3.

RESULTS

A total of 11 429 patients obtained from 37 studies (involving 27 trials) were included. The results of this analysis showed that fibrinolytic therapy was associated with significantly higher in-hospital and mid-term mortality (OR: 0.61; 95% CI: 0.46-0.82, P=0.001 and OR: 0.73; 95% CI: 0.54-0.99, P=0.04, respectively). Short-term and long-term mortality were also significantly higher in the fibrinolytic group (OR: 0.76; 95% CI: 0.65-0.90, P=0.001, and OR: 0.82; 95% CI: 0.71-0.96, P=0.01, respectively) compared with PPCI.

CONCLUSION

This analysis of 11 429 patients showed a significantly higher mortality rate to be associated with fibrinolysis compared with PPCI in these patients with AMI. Hence, compared with fibrinolysis, PPCI is expected to be the preferred method of revascularization in patients with AMI, especially in PCI-capable centers.

Controversies in the Treatment of Women with ST-Segment Elevation Myocardial Infarction

Coronary artery disease is the leading cause of death in women. Women with ST-segment elevation myocardial infarctions continue to have worse outcomes compared with men despite advancements in therapies. Furthermore, these differences are particularly pronounced among young men and women with myocardial infarctions. Differences in the pathophysiology of coronary artery plaque development, disease presentation, and recognition likely contribute to these outcome disparities. Despite having worse outcomes compared with men, women clearly benefit from aggressive treatment and the latest therapies. This article reviews the treatment options for ST-segment elevation myocardial infarctions and the outcomes of women after treatment with reperfusion therapies.

Bleeding events associated with fibrinolytic therapy and primary percutaneous coronary intervention in patients with STEMI: A systematic review and meta-analysis of randomized controlled trials

From the year 1986 onwards, several studies have been published focusing on the comparison between fibrinolysis and primary percutaneous coronary intervention (PPCI) in patients with ST segment elevated myocardial infarction (STEMI). However, because antiplatelet and anticoagulating medications are used in approximation, before and during these procedures, bleeding events have been reported to be associated with both reperfusion therapies. This study aimed to compare the bleeding events associated with fibrinolytic therapy and primary angioplasty in patients with STEMI. Randomized controlled trials (RCTs) comparing fibrinolysis and primary angioplasty in patients with STEMI were searched from Medline, PubMed, EMBASE, and the Cochrane databases. Bleeding complications following 30 days from hospitalization were considered as the primary clinical endpoints in this study. Secondary endpoints included all-cause mortality, re-infarction, stroke, and shock. Antiplatelet and anticoagulating drugs used during these 2 different procedures were compared. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated and the pooled analyses were performed with RevMan 5.3 software. Twelve studies involving 10 RCTs consisting of a total number of 5561 patients (2784 patients from the fibrinolysis group and 2777 patients from the PPCI group) were included in this meta-analysis. Our results showed no significant difference in the overall bleeding complications during a 30-day period between these 2 reperfusion therapies with OR 1.02; 95% CI 0.89 to 1.17, P = 0.78. Nonintracranial bleeding was also not statistically significant with OR 0.85; 95% CI 0.70 to 1.04, P = 0.12. However, fibrinolytic therapy was associated with a significantly higher rate of intracranial bleeding with OR 0.17; 95% CI 0.06 to 0.50, P = 0.001 than PPCI. In addition, death, re-infarction, and stroke significantly favored primary angioplasty. According to the results of this study, even if the rate of nonintracranial bleeding was not statistically significant between these 2 reperfusion therapies, fibrinolytic therapy was associated with a significantly higher rate of intracranial bleeding than PPCI. In addition, PPCI was associated with a significantly lower rate of death, reinfarction, and stroke. Therefore, PPCI should be recommended in patients with STEMI, especially in PCI-capable hospitals.

Reperfusion therapy for acute myocardial infarction: Concepts and controversies from inception to acceptance

More than 20 years of misconceptions derailed acceptance of reperfusion therapy for acute myocardial infarction (AMI). Cardiologists abandoned reperfusion for AMI using fibrinolytic therapy, explored in 1958, because they no longer attributed myocardial infarction to coronary thrombosis. Emergent aortocoronary bypass surgery, pioneered in 1968, remained controversial because of the misconception that hemorrhage into reperfused myocardium would result in infarct extension. Attempts to limit infarct size by pharmacotherapy without reperfusion dominated research in the 1970s. Myocardial necrosis was assumed to progress slowly, in a lateral direction. At least 18 hours was believed to be available for myocardial salvage. Afterload reduction and improvement of the microcirculation, but not reperfusion, were thought to provide the benefit of streptokinase therapy. Finally, coronary vasospasm was hypothesized to be the central mechanism in the pathogenesis of AMI. These misconceptions unraveled in the late 1970s. Myocardial necrosis was shown to progress in a transmural direction, as a "wave front," beginning with the subendocardium. Reperfusion within 6 hours salvaged a subepicardial ischemic zone in experimental animals. Acute angiography provided in vivo evidence of the high incidence of total coronary occlusion in the first hours of AMI. In 1978, early reperfusion by transluminal recanalization was shown to be feasible. The pathogenetic role of coronary thrombosis was definitively established in 1979 by demonstrating that intracoronary streptokinase rapidly restored flow in occluded infarct-related arteries, in contrast to intracoronary nitroglycerine which rarely did. The modern reperfusion era had dawned.

Therapy in ST-elevation myocardial infarction: reperfusion strategies, pharmacology and stent selection

OPINION STATEMENT

The estimated annual incidence of new and recurrent myocardial infarction (MI) in the U.S. is 715,000 events. Primary percutaneous coronary intervention (PCI) is the reperfusion strategy of choice in most patients with acute ST-elevation myocardial infarction (STEMI). Recent advances in percutaneous techniques and devices, including manual aspiration catheters and newer generation drug eluting stents and pharmacologic therapies, such as novel antiplatelets and anticoagulants have led to significant improvements in the acute and long-term outcomes for these patients. Implementation of community-wide systems directed to shorten treatment times tied to closely monitored quality improvement processes have led to further advances in STEMI care. Recent data suggests that transradial access for primary PCI is associated with improved outcomes. This contemporary review discusses the strategies for reperfusion, pharmacological therapy and stent selection process involved in STEMI.

Acute right ventricular infarction: insights for the interventional era

Acute right ventricular infarction is associated with higher in-hospital morbidity and mortality related to life-threatening hemodynamic compromise and arrhythmias during acute occlusion and abruptly with reperfusion, complications which have implications for interventional management. Acute right coronary artery occlusion proximal to the right ventricular (RV) branches results in depressed RV systolic function, leading to diminished transpulmonary delivery of left ventricular preload and resulting in low-output hypotension. Under these conditions, RV pressure generation and output are dependent on left ventricular-septal contraction via paradoxical septal motion. With culprit lesions distal to the right atrial (RA) branches, augmented RA contractility enhances RV performance and cardiac output, whereas proximal occlusions induce RA ischemia, which exacerbates hemodynamic compromise. Hypotension may respond to volume resuscitation and restoration of a physiologic rhythm. Refractory cases usually respond to parenteral inotropes, though in some cases mechanical support is required. The right ventricle is relatively resistant to infarction and usually recovers even after prolonged occlusion. Acute percutaneous mechanical reperfusion enhances recovery of RV performance and improves the clinical course and survival of patients with right ventricular infarction.

Setting Up a Population-Based Program to Optimize ST-Segment Elevation Myocardial Infarction Care

The development of ST-segment elevation myocardial infarction (STEMI) systems of care at the city, region, or nation levels has not only improved the speed of reperfusion but also enhanced the reach of primary angioplasty to areas far from percutaneous coronary intervention (PCI) centers. Setting up a STEMI system of care is a sophisticated process that requires a solid PCI hospital and emergency medical services infrastructure, disciplined collaboration, and a focus on outcomes measurement and continuous quality improvement. This article reviews the accumulated evidence supporting the development of STEMI systems of care and offers practical insights into this process.

Interventions for ST Elevation Myocardial Infarction in Women

The management of ST-segment elevation myocardial infarction (STEMI) has significantly advanced from supportive care to reperfusion therapies with thrombolytics and percutaneous coronary revascularization techniques. These advances have improved the outcomes of patients with STEMI. Although cardiovascular disease is the leading cause of death in both men and women, the minority of patients in trials studying the impact of these therapies on outcomes are women. Multiple studies have shown that men and women do not have equivalent outcomes after STEMI. This article reviews the treatment options for STEMI and the outcomes of women after treatment with reperfusion therapies.

Effect of additional treatment with EXenatide in patients with an Acute Myocardial Infarction (EXAMI): study protocol for a randomized controlled trial

Background

Myocardial infarction causes irreversible loss of cardiomyocytes and may lead to loss of ventricular function, morbidity and mortality. Infarct size is a major prognostic factor and reduction of infarct size has therefore been an important objective of strategies to improve outcomes. In experimental studies, glucagon-like peptide 1 and exenatide, a long acting glucagon-like peptide 1 receptor agonist, a novel drug introduced for the treatment of type 2 diabetes, reduced infarct size after myocardial infarction by activating pro-survival pathways and by increasing metabolic efficiency.

Methods

The EXAMI trial is a multi-center, prospective, randomized, placebo controlled trial, designed to evaluate clinical outcome of exenatide infusion on top of standard treatment, in patients with an acute myocardial infarction, successfully treated with primary percutaneous coronary intervention. A total of 108 patients will be randomized to exenatide (5 μg bolus in 30 minutes followed by continuous infusion of 20 μg/24 h for 72 h) or placebo treatment. The primary end point of the study is myocardial infarct size (measured using magnetic resonance imaging with delayed enhancement at 4 months) as a percentage of the area at risk (measured using T2 weighted images at 3-7 days).

Discussion

If the current study demonstrates cardioprotective effects, exenatide may constitute a novel therapeutic option to reduce infarct size and preserve cardiac function in adjunction to reperfusion therapy in patients with acute myocardial infarction.

Trial registration

ClinicalTrials.gov: NCT01254123

Differences in patients with acute myocardial infarction treated with primary angioplasty or thrombolytic therapy. Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) Study Group

BACKGROUND

Little is known about the differences in patients with acute myocardial infarction (AMI) treated with primary angioplasty or intravenous thrombolysis in clinical practice.

METHODS

In all, 5,906 patients with AMI were registered by the Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) study. Of these, 491 (8.3%) patients were treated with primary angioplasty and 2,817 (47.7%) with intravenous thrombolysis.

RESULTS

There were only minor differences in baseline characteristics between the two groups. Prehospital delay time (median) was longer in the angioplasty group than in the thrombolysis group (161 vs. 120, p = 0.001), as was door-to-treatment time (88 vs. 30 min; p = 0.001). Patients treated with primary angioplasty more often had contraindications for thrombolytic therapy (12.9 vs. 6%, p = 0.001) and received beta blockers (65 vs. 58.1%, p = 0.004), heparin (98.2 vs. 91.6%, p = 0.001), angiotensin-converting enzyme (ACE) inhibitors (64.8 vs. 50%, p = 0.001) and "optimal" concomitant medication (56.4 vs. 42.9%, p = 0.001) more often. Univariate analysis showed a significant lower incidence of heart failure (5.3 vs. 16.5%, p = 0.001), postinfarct angina (7.3 vs. 16.4%, p = 0.001), in-hospital death (7.9 vs. 11.7%, p = 0.015) and the combined end point (21.6 vs. 40.3%, p = 0.001) in these patients. Stepwise logistic regression analysis revealed optimal concomitant medication [odds ratio (OR) = 0.94, 95% confidence interval (CI): 0.89-0.98) and the type of revascularization (OR = 0.65, 95% CI: 0.58-0.73) to be associated with a significant reduction in the incidence of the combined end point. Similar results were obtained in all predefined subgroups.

CONCLUSIONS

In clinical practice, patients treated with primary angioplasty are more often treated with beta blockers and ACE inhibitors than patients treated with intravenous thrombolysis. Thus, the selection of patients and the type of revascularization contributes to the reduction in mortality, overt heart failure, and postinfarct angina in these patients.

Correlates of bundle-branch block in patients undergoing primary angioplasty for acute myocardial infarction

BACKGROUND

Early reperfusion therapy has reduced the infarct size and mortality rate in patients with acute myocardial infarction (AMI). The occurrence of bundle-branch block in AMI is related to the amount of myocardial damage and the insult to the conduction system.

HYPOTHESIS

To evaluate the clinical and angiographic factors related to the occurrence of bundle-branch block (BBB) in patients with primary percutaneous transluminal coronary angioplasty (PTCA), we investigated consecutive series of patients with their first Q-wave AMI and successful PTCA.

METHODS

Coronary angiogram at the time of admission, electrocardiogram, and echocardiogram were evaluated in 279 patients with their first Q-wave AMI and successful PTCA.

RESULTS

Bundle-branch block was detected in 26 patients (9%); 16 patients had transient and 10 patients had persistent block, while 16 patients had bifascicular block and 10 patients had right BBB. The patients with BBB had a significantly larger number of left ventricular asynergic segments, higher incidence of total occlusion of infarct-related artery, angiographic no reflow, and pericardial rub than those without BBB. When the multivariate analysis was performed using five clinical markers of infarct severity, angiographic no reflow (F = 20.2, p < 0.001) and total occlusion of infarct-re-lated artery (F = 4.2, p = 0.04) were found to be the significant variables related to BBB.

CONCLUSIONS

Despite successful primary PTCA, absence of antegrade flow in the infarct-related artery at the onset of AMI and/or angiographic no reflow resulted in more severe transmural myocardial damage and, hence, the occurrence of BBB.

Trends in reperfusion strategies, door-to-needle and door-to-balloon times, and in-hospital mortality among patients with ST-segment elevation myocardial infarction enrolled in the National Registry of Myocardial Infarction from 1990 to 2006

BACKGROUND

Among patients with ST-segment elevation myocardial infarction (STEMI), rapid reperfusion is associated with improved mortality. As such, door-to-needle (D2N) and door-to-balloon (D2B) times have become metrics of quality of care and targets for intense quality improvement.

METHODS

The National Registry of Myocardial Infarction (NRMI) collected data regarding reperfusion therapy, its timing and in-hospital mortality among STEMI patients from 1990 through 2006.

RESULTS

Since 1990, NRMI has enrolled 1,374,232 STEMI patients at 2,157 hospitals. Among those, 774,279 (56.3%) were eligible for reperfusion upon arrival. The proportion receiving fibrinolytic therapy fell from 52.5% in 1990 to 27.6% in 2006 (P < .001), while the proportion undergoing primary percutaneous coronary intervention (pPCI) increased from 2.6% to 43.2%. Among reperfusion-eligible patients who received fibrinolytic therapy, there was a nearly linear decline in median D2N time from 59 minutes in 1990 to 29 minutes in 2006 (P < .001 for trend) as well as a decrease in mortality from 7.0% in 1994 to 6.0% in 2006 (P < .001). Among those undergoing pPCI, D2B time among nontransfer patients declined linearly from 111 minutes in 1994 to 79 minutes in 2006 (P < .001) with a decline in mortality from 8.6% to 3.1% (P < .001). The relative improvement in mortality attributable to improvements in D2N time was 16.3% and to D2B time was 7.5%.

CONCLUSIONS

Since 1990, there has been a progressive decline in D2N and D2B time among reperfusion-eligible STEMI patients. These improvements have contributed, at least in part, to a progressive decline in mortality.

Comparison of left ventricular ejection fraction and inducible ventricular tachycardia in ST-elevation myocardial infarction treated by primary angioplasty versus thrombolysis

Electrophysiologic studies predict the risk for sudden death after myocardial infarction (MI). Although primary angioplasty has become the preferred method of treatment for ST-elevation MI, intravenous thrombolysis remains the first-line treatment in 30% to 70% of cases worldwide. Rates of ventricular tachyarrhythmias may vary according to type of reperfusion treatment. This study was undertaken to examine the hypothesis that the left ventricular ejection fraction (LVEF) and rates of inducible ventricular tachycardia may be more favorable in treatment with primary angioplasty rather than thrombolysis. Consecutive patients receiving primary angioplasty (n = 225) or thrombolysis (n = 195) for ST-elevation MI were included. The mean LVEF was 48 +/- 12% for the primary angioplasty group and 46 +/- 13% for the thrombolysis group (p = 0.30). The proportion of patients with LVEFs <40% was 30% in the primary angioplasty group and 30% in the thrombolysis group (p = 0.98). Patients with LVEFs <40% underwent electrophysiologic studies. Ventricular tachycardia was inducible in 23 of 66 primary angioplasty patients (34.8%) compared with 21 of 55 (38.1%) thrombolysis patients (p = 0.69). Implantable cardiac defibrillators were inserted in 30 patients, of whom 8 (27%) had appropriate device activations. The mean time from MI to first spontaneous activation was 387 +/- 458 days. In conclusion, patients treated with thrombolysis or primary angioplasty for ST-elevation MIs had similar resultant LVEFs and rates of inducible ventricular tachycardia. There was a surprisingly high rate of spontaneous defibrillator activations, often occurring late after MI.

WITHDRAWN: Primary angioplasty versus intravenous thrombolysis for acute myocardial infarction

BACKGROUND

Intravenous thrombolytic therapy is the standard care for patients with acute myocardial infarction, based upon its widespread availability and ability to reduce patient mortality well demonstrated in randomised trials. Despite its proven efficacy, thrombolytic therapy has limitations. Many patients are ineligible for treatment with thrombolytics. Of those given thrombolytic therapy, 10 to 15 percent have persistent occlusion or reocclusion of the infarct-related artery. Consequently, primary angioplasty (primary PTCA) has been advocated as a better treatment of myocardial infarction.

OBJECTIVES

To determine whether primary coronary angioplasty is superior to thrombolytic therapy for the treatment of patients with acute myocardial infarction.

SEARCH STRATEGY

Electronic search of The Cochrane Library (1998; Issue 2). MEDLINE (to January 1998); references from reviews, trials and previously published meta-analyses; and experts. Date of most recent searches January 1998.

SELECTION CRITERIA

All unconfounded, randomised controlled trials comparing primary angioplasty against intravenous thrombolysis in patients with acute myocardial infarction

DATA COLLECTION AND ANALYSIS

At least two independent reviewers abstracted data on morbidity and mortality and trial characteristics. The following outcomes were assessed: total mortality at the end of the study, reinfarction, stroke of any type, composite endpoint of death and reinfarction, recurrent ischemia, severe bleeding and coronary artery bypass grafting.

MAIN RESULTS

Ten trials including 2573 subjects were identified. Compared to thrombolytic therapy, primary angioplasty was associated with a significant reduction in short-term mortality at the end of the studies (relative reduction in risk RRR = 32% 95%CI = 5%;50%). Similar reductions were observed for the rate of reinfarction (RRR = 52%, 95%CI = 30%;67%), recurrent ischemia (RRR = 54%; 95%CI = 39%,66%) and for the combined criteria death or reinfarction (RRR = 46%; 95%CI=30%;58%). The frequency of strokes of any cause was significantly decreased by 66% (95%CI=28%;84%). No significant difference was observed for the incidence of major bleeding (relative risk RR =1.18, 95%CI = 0.73;1.90) but the confidence interval was large. The superiority of the primary angioplasty over thrombolysis in terms of the composite endpoint (mortality and reinfarction) was less with accelerated t-PA (RR=0.70, 95%CI=0.51;0.97) than with streptokinase (RR=0.30, 95%CI=0.17;0.53). The biggest and most recent trial, Gusto 2B (GUSTO-2B 97), which involved general as well as highly specialised centres, obtained less favorable results.

AUTHORS' CONCLUSIONS

This meta-analysis suggests that angioplasty provides a short-term clinical advantage over thrombolysis which may not be sustained. Primary angioplasty when available promptly at experienced centres, may be considered the preferred strategy for myocardial reperfusion. In most situations, however, optimal thrombolytic therapy should still be regarded as an excellent reperfusion strategy.

The impact of percutaneous coronary interventions on outcomes for acute myocardial infarction in Pennsylvania

This research estimates the benefits associated with percutaneous coronary interventions (PCIs) for patients with acute myocardial infarction (AMI) treated at hospitals in Pennsylvania. We studied 31 351 patients with AMI in Pennsylvania during the year 2000, including 10 170 who received PCI. Univariate comparisons between groups were made using chi2 tests for categorical outcomes and Student's t tests for continuous outcomes. A logit model for proportions was used to model the relationship between mortality and the proportion of AMI patients who received PCI. The mortality rate for patients undergoing PCI was significantly lower than for those being treated medically (1.4% vs 15.8%, P<.0001). Furthermore, significant survival benefits associated with PCI persisted when patients were stratified by age, sex, type of infarction, and severity at admission. At the hospital level, higher rates of PCI were associated with a significantly lower overall mortality rate among patients with AMI (P<.0001).

The no-reflow phenomenon: A basic mechanism of myocardial ischemia and reperfusion

Both animal models of experimental myocardial infarction and clinical studies on reperfusion therapy for acute myocardial infarction have provided evidence of impaired tissue perfusion at the microvascular level after initiation of reperfusion despite adequate restoration of epicardial vessel patency. Characteristics of this "no-reflow" phenomenon found in basic science investigations, such as distinct perfusion defects, progressive decrease of resting myocardial flow with ongoing reperfusion and functional vascular alterations are paralleled by clinical observations demonstrating similar features during the course of reperfusion. In experimental animal investigations of coronary occlusion and reperfusion, this no-reflow phenomenon could be characterized as a fundamental mechanism of myocardial ischemia and reperfusion. Major determinants of the amount of no-reflow are the duration of occlusion, infarct size, but also the length of reperfusion, as rapid expansion of perfusion defects occurs during reperfusion. Moreover, no-reflow appears to persist over a period of at least four weeks, a period when major steps of infarct healing take place. The significant association of the degree of compromised tissue perfusion at four weeks and indices of infarct expansion, found in chronic animal models of reperfused myocardial infarction, might be the pathoanatomic correlate for the prognostic significance observed in the clinical setting.

Overview of contemporary reperfusion strategies in acute ST-elevation myocardial infarction

The rupture of an atherosclerotic plaque in an epicardial coronary artery with subsequent occlusive coronary thrombosis has been established as the decisive event in the pathogenesis of an acute coronary syndrome, which encompasses the clinical entities of unstable angina, non-ST- and ST-elevation myocardial infarction. This article focuses on contemporary treatment strategies for patients with acute ST-elevation myocardial infarction and reviews the role of pharmacologic thrombolysis and mechanical reperfusion by percutaneous transluminal approaches. Statements of the latest guidelines for the treatment of ST-elevation myocardial infarction are included, as well as some recently distributed information not covered by the guideline publications. Finally, some future perspectives for the treatment of acute ST-elevation myocardial infarction are outlined.

The revised role of ACE-inhibition after myocardial infarction in the thrombolytic/primary PCI era

Many studies have investigated the process of left ventricular (LV) dilatation and the effects of angiotensin-converting enzyme (ACE) inhibitors after myocardial infarction (MI). It has been generally accepted that progression of LV dilatation is a major predictor of heart failure and death after MI. Also, attenuation of LV dilatation is thought to be one of the main mechanisms by which ACE inhibitors (ACE-Is) produce their beneficial effects. However, evidence for this hypothesis came from studies that were performed before thrombolytic therapy and primary percutaneous coronary intervention (PCI) were routinely used after acute MI. Nowadays, reperfusion is obtained much more frequently and LV dilatation after MI has become less prevalent. Nevertheless, ACE-Is proved effective in reducing cardiac morbidity and mortality. Therefore, mechanisms other than attenuation of LV dilatation, such as anti-atherosclerotic effects or plaque stabilisation, may explain the long-term beneficial effects of ACE-Is after MI. In the present overview, we evaluate the role of LV dilatation and the effects of ACE-Is after MI in the thrombolytic/primary PCI era and provide recommendations on ACE-I use in clinical practice.

Estimation with Tc-99m tetrofosmin SPECT of salvaged myocardial mass after emergent reperfusion therapy in acute myocardial infarction

OBJECTIVES

The purpose of this study was to validate a new quantitative index of salvaged myocardial mass calculated from Tc-99m tetrofosmin SPECT for evaluating the therapeutic effect of emergent reperfusion therapy in acute myocardial infarction (AMI).

METHODS

Tc-99m tetrofosmin SPECT was performed before and after emergent percutaneous transluminal coronary angioplasty (PTCA) in eight patients with AMI. In the pre-PTCA study, Tc-99m tetrofosmin was injected before emergent PTCA. Two weeks after the PTCA, post-PTCA study was performed. As a quantitative index of salvaged myocardial mass, salvaged myocardial volume (SMV) was defined as the difference of myocardial functional volume between the SPECT studies before and after the PTCA. To investigate the clinical significance of SMV, SMV was compared with the grade of therapeutic efficacy determined visually from pre- and post-PTCA SPECT images and clinical parameters, namely peak creatine phosphokinase level (pCK) and the time from the onset of the AMI to reperfusion (RPT).

RESULTS

SMV showed a significant correlation with the visual grade of therapeutic efficacy (r = 0.737, p < 0.037) and a trend toward significant correlation with pCK (r = -0.622, p < 0.1). SMVs in early- and late-reperfusion groups (RPT < or = 6 hr and RPT > 6 hr) were 30.0 +/- 14.0 and -6.2 +/- 25.5 ml, showing a greater mean SMV value in the early-reperfusion group (p < 0.07).

CONCLUSION

SMV could be used as a quantitative index of salvaged myocardial mass for evaluating the therapeutic effect of emergent reperfusion therapy.

Evaluation of Salvaged Myocardium After Acute Myocardial Infarction Using Single Photon Emission Computed Tomography After 201Tl-Glucose-Insulin Infusion

BACKGROUND

GIK-201Tl imaging reportedly improves the detection of viable myocardium, so the present study evaluated whether it can detect myocardial viability after acute myocardial infarction (AMI).

METHODS AND RESULTS

Resting 201Tl and 99mTc-pyrophosphate (PYP) dual single photon emission computed tomography (SPECT) and 201Tl SPECT after 201Tl with GIK (10% glucose, insulin 5 U, and KCl 10 mmol) infusion (GIK-201Tl) were performed in 25 AMI patients within 10 days of admission. GIK-201Tl SPECT images were obtained immediately and 4 h after infusion. Left ventriculography (LVG) was performed within 3 weeks and at 6 months when follow-up 201Tl SPECT was also performed. From 20 SPECT segments, both the summed defect score (RDS) and the number of defect segments (ES) were calculated. The infarcted area was defined as 99mTc-PYP uptake segments. Wall motion was estimated in 7 LVG segments. The ES of R-201Tl (5.5 +/- 2.8), immediate GIK-201Tl (4.0 +/- 2.3), and 4-h GIK-201Tl (5.6 +/- 2.7) were lower than that of 99mTc-PYP (7.5 +/- 4.1) (p<0.05), and the ES had significantly declined 6 months later on 201Tl (3.5 +/- 2.8) (p<0.05). Although the RDS of R-201Tl (11.3 +/- 7.9) and 4-h GIK-201Tl (11.2 +/- 6.3) were greater than at the 6-month 201Tl (7.1 +/- 6.5), immediate GIK-201Tl (7.4 +/- 6.5) was equivalent to follow-up 201Tl. The sensitivity of immediate GIK-201Tl was highest among the imaging methods.

CONCLUSION

To detect myocardial viability after AMI, early imaging with GIK-201Tl is more useful than resting 201Tl imaging.

Synergistic treatment of ST-segment elevation myocardial infarction with pharmacoinvasive recanalization

Both pharmacologic and mechanical approaches designed to limit infarct size by recanalization of infarct-related arteries have reduced mortality associated with ST-segment elevation myocardial infarction (STEMI). Early efforts to combine the two were attenuated because of complications encountered. Primary percutaneous coronary intervention (PCI) and thrombolysis became viewed as alternative rather than complementary modalities. Time to recanalization and adequacy of restoration of perfusion were found to be pivotal determinants of a favorable outcome with either approach. Because pharmacologic intervention can be initiated immediately in virtually any hospital, it is a promising initial step. Because PCI proffers more complete recanalization, it may be a particularly salutary initial or subsequent step. Because of unavoidable delay often confronting implementation of PCI, optimal advantage may accrue from the use of both approaches in combination. We seek to emphasize the potential synergy by referring to the combined approach as "pharmacoinvasive recanalization" rather than by the conventional term "facilitated PCI." Virtually all patients with STEMI can benefit from prompt, sustained, and complete coronary recanalization. Thus, investigations focusing on identification of pharmacologic regimens that can safely initiate recanalization as early as possible, minimize bleeding, and broaden the temporal window available for efficacy of subsequent, optimally timed PCI should provide particularly valuable information.

Effects of prior beta-blocker therapy on clinical outcomes after primary coronary angioplasty for acute myocardial infarction

We hypothesized that pretreatment with beta blockers may improve clinical outcomes after primary angioplasty for acute myocardial infarction. We pooled clinical, angiographic, and outcomes data on 2,537 patients enrolled in the Primary Angioplasty in Myocardial Infarction (PAMI), PAMI-2, and Stent PAMI trials. We classified patients into a beta group (n = 1,132) if they received beta-blocker therapy before primary angioplasty or a no-beta group (n = 1,405) if they did not. We evaluated procedural complications and in-hospital and 1-year outcomes (death and major adverse cardiac events [death, reinfarction, target vessel revascularization, or stroke]) between groups. Beta patients were younger, had higher systolic blood pressure and heart rate, and were more likely to be in Killip class I at admission. They had lower left ventricular ejection fraction, greater door-to-balloon time, greater likelihood of having a left anterior descending artery culprit lesion, but a similar incidence of Thrombolysis In Myocardial Infarction 3 flow after angioplasty (92.6% vs 92.7%, p = 0.91). The beta group had less procedural complications (23% vs 34%, p <0.0001) and a lower incidence of death (1.8% vs 3.7%, p = 0.0035) and major adverse cardiac events (5.5% vs 7.8%, p = 0.027) during hospitalization. At 1 year, mortality remained lower in beta patients (4.9% vs 6.7%, log-rank p = 0.055). After adjustment for baseline differences, beta patients had significantly lower in-hospital mortality (odds ratio 0.41; 95% confidence interval 0.20 to 0.84; p <0.0148) and nonsignificantly lower 1-year mortality (odds ratio 0.72; 95% confidence interval 0.47 to 1.08; p = 0.11). Thus, pretreatment with beta blockers has an independent beneficial effect on short-term clinical outcomes in patients undergoing primary angioplasty for acute myocardial infarction.

Predicting angiographic distal embolization following percutaneous coronary intervention in patients with acute myocardial infarction

The aim of this study was to investigate the relation between lesion morphology identified by intravascular ultrasound (IVUS) before intervention and angiographic distal embolization after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). PCI for AMI has already been established as beneficial therapy, although some complications remain unresolved. Distal embolization is 1 of the important complications of PCI. Recently, some new devices have been developed for the prevention of distal embolization. However, few studies exist that look into the relation between lesion morphology and distal embolization. IVUS was performed safely in 140 consecutive patients with AMI before coronary intervention. No patient received thrombolytic therapy. From the incidence of angiographic distal embolization, patients were divided into 2 groups--an embolization group and a nonembolization group--and clinical background, IVUS, and angiographic information were evaluated. Distal embolization was observed in 12 patients (9%). Peak creatine kinase levels (3,877 +/- 2,285 vs 2,293 +/- 1,792 IU/L, p <0.05) and the incidence of angiographic thrombus (25% vs 5%, p <0.05) and intracoronary mobile mass detected by IVUS (75% vs 16%, p <0.001) were higher for patients in the embolization group. From the multivariate logistic regression analysis, only an intracoronary mobile mass detected by IVUS emerged as a predictor of distal embolization (odds ratio 53, 95% confidence interval 2.7 to 1,040, p <0.01). Patients with an intracoronary mobile mass detected by IVUS are prone to distal embolization after PCI and larger infarction. IVUS imaging before PCI may be useful for determining which patients need a distal protection device.

Primary angioplasty versus intravenous thrombolytic therapy for acute myocardial infarction: a quantitative review of 23 randomised trials

BACKGROUND

Many trials have been done to compare primary percutaneous transluminal coronary angioplasty (PTCA) with thrombolytic therapy for acute ST-segment elevation myocardial infarction (AMI). Our aim was to look at the combined results of these trials and to ascertain which reperfusion therapy is most effective.

METHODS

We did a search of published work and identified 23 trials, which together randomly assigned 7739 thrombolytic-eligible patients with ST-segment elevation AMI to primary PTCA (n=3872) or thrombolytic therapy (n=3867). Streptokinase was used in eight trials (n=1837), and fibrin-specific agents in 15 (n=5902). Most patients who received thrombolytic therapy (76%, n=2939) received a fibrin-specific agent. Stents were used in 12 trials, and platelet glycoprotein IIb/IIIa inhibitors were used in eight. We identified short-term and long-term clinical outcomes of death, non-fatal reinfarction, and stroke, and did subgroup analyses to assess the effect of type of thrombolytic agent used and the strategy of emergent hospital transfer for primary PTCA. All analyses were done with and without inclusion of the SHOCK trial data.

FINDINGS

Primary PTCA was better than thrombolytic therapy at reducing overall short-term death (7% [n=270] vs 9% [360]; p=0.0002), death excluding the SHOCK trial data (5% [199] vs 7% [276]; p=0.0003), non-fatal reinfarction (3% [80] vs 7% [222]; p<0.0001), stroke (1% [30] vs 2% [64]; p=0.0004), and the combined endpoint of death, non-fatal reinfarction, and stroke (8% [253] vs 14% [442]; p<0.0001). The results seen with primary PTCA remained better than those seen with thrombolytic therapy during long-term follow-up, and were independent of both the type of thrombolytic agent used, and whether or not the patient was transferred for primary PTCA.

INTERPRETATION

Primary PTCA is more effective than thrombolytic therapy for the treatment of ST-segment elevation AMI.

Facilitated primary percutaneous transluminal coronary angioplasty for acute ST segment elevation myocardial infarction: rationale for reuniting pharmacologic and mechanical revascularization strategies

The primary goal of therapy for acute ST segment elevation myocardial infarction is to preserve left ventricular systolic function and to decrease mortality by achieving rapid, complete, and sustained restoration of blood flow in the infarct-related artery. Early studies assessing the safety and efficacy of combining full-dose thrombolytic therapy with primary percutaneous transluminal coronary angioplasty (PTCA) were disappointing due to an increased incidence of abrupt closure, reinfarction, emergent coronary bypass surgery, and mortality. The observation that the presence of normal coronary blood flow at the time of primary PTCA is an independent predictor of survival coupled with interest in the patency of the downstream microvasculature has prompted investigators to revisit the concept of combining pharmacologic and mechanical strategies. The adjunctive use of pharmacologic therapy with mechanical reperfusion has been coined facilitated primary PTCA and involves the use of reduced-dose thrombolytics, platelet glycoprotein IIb/IIIa inhibitors, or both. The primary goal is to achieve pharmacologic reperfusion before performing definitive mechanical reperfusion. While the preliminary data presented is promising, we must await the results of ongoing large, randomized trials that have been specifically designed to address this question.

Early prediction of improvement in ejection fraction after acute myocardial infarction using low dose dobutamine echocardiography

OBJECTIVE

To evaluate the relation between changes in ejection fraction during the first three months after acute myocardial infarction and myocardial viability.

PATIENTS

Myocardial viability was assessed using low dose dobutamine echocardiography in 107 patients at mean (SD) 3 (1) days after acute myocardial infarction. Cross sectional echocardiography was repeated three months later. Left ventricular volumes and ejection fraction were determined from apical views using the Simpson biplane formula.

RESULTS

In patients with viability, ejection fraction increased by 4.4 (4.3)%; in patients without viability it remained unchanged (0.04 (3.6)%; p < 0.001). A > or = 5% increase in ejection fraction was present in 21 of 107 patients (20%). Receiver operating characteristic analysis showed that myocardial viability in > or = 2 segments predicted this increase in ejection fraction with a sensitivity of 81% and a specificity of 65%. Multivariate logistic regression analysis was used to define which clinical and echocardiographic variables were related to > or = 5% improvement in ejection fraction. Myocardial viability, non-Q wave infarction, and anterior infarction all emerged as independent predictors, myocardial viability being the best (chi(2) = 14.5; p = 0.0001). Using the regression equation, the probability of > or = 5% improvement in ejection fraction for patients with a non-Q wave anterior infarct with viability was 73%, and for patients with a Q wave inferior infarct without viability, only 2%.

CONCLUSIONS

Myocardial viability after acute myocardial infarction is the single best predictor of improvement in ejection fraction. In combination with infarct location and Q wave presence, the probability of > or = 5% improvement can be estimated in individual patients at the bedside.