Intravenous and intracoronary fibrinolytic therapy in acute myocardial infarction: overview of results on mortality, reinfarction and side-effects from 33 randomized controlled trials

Defining the exit meta-analysis

INTRODUCTION

In recent decades, clinical research has seen significant advancements, both in the generation and synthesis of evidence through meta-analyses. Despite these methodological advancements, there is a growing concern about the accumulation of repetitive and redundant literature, potentially contributing to research waste. This highlights the necessity for a mechanism to determine when a meta-analysis has conclusively addressed a research question, signaling no further need for additional studies-a concept we term an "exit" meta-analysis.

METHODS

We introduced a convergence index, the Doi-Abdulmajeed Trial Stability (DAts) index, and a convergence plot to determine the exit status of a meta-analysis. The performance of DAts was examined through simulation and applied to two real-world meta-analyses.

RESULTS

The DAts index and convergence plot demonstrate highly effective discriminative ability across varying study scenarios. This represents the first attempt to define an exit meta-analysis using a quantitative measurement of stability (as opposed to sufficiency) and its corresponding plot. The application to real-world scenarios further validated the utility of DAts and the convergence plot in identifying a conclusive (exit) meta-analysis.

CONCLUSION

The new development of DAts and the convergence plot provide a promising tool for investigating the conclusiveness of meta-analyses. By identifying an exit status for meta-analysis, the scientific community may be equipped to make better-informed decisions on the continuation of research on a specific topic, thereby preventing research waste and focusing efforts on areas with unresolved questions.

A Critical Analysis of the FDA's Omics-Driven Pharmacodynamic Biomarkers to Establish Biosimilarity

Demonstrating biosimilarity entails comprehensive analytical assessment, clinical pharmacology profiling, and efficacy testing in patients for at least one medical indication, as required by the U.S. Biologics Price Competition and Innovation Act (BPCIA). The efficacy testing can be waived if the drug has known pharmacodynamic (PD) markers, leaving most therapeutic proteins out of this concession. To overcome this, the FDA suggests that biosimilar developers discover PD biomarkers using omics technologies such as proteomics, glycomics, transcriptomics, genomics, epigenomics, and metabolomics. This approach is redundant since the mode-action-action biomarkers of approved therapeutic proteins are already available, as compiled in this paper for the first time. Other potential biomarkers are receptor binding and pharmacokinetic profiling, which can be made more relevant to ensure biosimilarity without requiring biosimilar developers to conduct extensive research, for which they are rarely qualified.

Don't go breakin' my heart: cardioprotective alterations to the mechanical and structural properties of reperfused myocardium during post-infarction inflammation

Myocardial infarctions (MIs) kickstart an intense inflammatory response resulting in extracellular matrix (ECM) degradation, wall thinning, and chamber dilation that leaves the heart susceptible to rupture. Reperfusion therapy is one of the most effective strategies for limiting adverse effects of MIs, but is a challenge to administer in a timely manner. Late reperfusion therapy (LRT; 3 + hours post-MI) does not limit infarct size, but does reduce incidences of post-MI rupture and improves long-term patient outcomes. Foundational studies employing LRT in the mid-twentieth century revealed beneficial reductions in infarct expansion, aneurysm formation, and left ventricle dysfunction. The mechanism by which LRT acts, however, is undefined. Structural analyses, relying largely on one-dimensional estimates of ECM composition, have found few differences in collagen content between LRT and permanently occluded animal models when using homogeneous samples from infarct cores. Uniaxial testing, on the other hand, revealed slight reductions in stiffness early in inflammation, followed soon after by an enhanced resistance to failure for cases of LRT. The use of one-dimensional estimates of ECM organization and gross mechanical function have resulted in a poor understanding of the infarct's spatially variable mechanical and structural anisotropy. To resolve these gaps in literature, future work employing full-field mechanical, structural, and cellular analyses is needed to better define the spatiotemporal post-MI alterations occurring during the inflammatory phase of healing and how they are impacted following reperfusion therapy. In turn, these studies may reveal how LRT affects the likelihood of rupture and inspire novel approaches to guide scar formation.

Fibrinolytic Therapy in Patients with Acute ST-elevation Myocardial Infarction

Fibrinolytic agents provide an important alternative therapeutic strategy in individuals presenting with ST-elevation myocardial infarction (STEMI). Ultimately, primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy for most patients with STEMI, including elderly patients and patients with coronavirus disease 2019 (COVID-19) infection. Fibrinolytic therapy should always be considered when timely primary PCI cannot be delivered appropriately. Clinicians should promptly recognize the signs of fibrinolytic therapy failure and consider rescue PCI. When fibrinolytics are used, coronary angiography and revascularization should not be conducted within the initial 3 hours after fibrinolytic administration.

Adjuvant or early salvage radiotherapy for the treatment of localised and locally advanced prostate cancer: a prospectively planned systematic review and meta-analysis of aggregate data

BACKGROUND

It is unclear whether adjuvant or early salvage radiotherapy following radical prostatectomy is more appropriate for men who present with localised or locally advanced prostate cancer. We aimed to prospectively plan a systematic review of randomised controlled trials (RCTs) comparing these radiotherapy approaches.

METHODS

We used a prospective framework for adaptive meta-analysis (FAME), starting the review process while eligible trials were ongoing. RCTs were eligible if they aimed to compare immediate adjuvant radiotherapy versus early salvage radiotherapy, following radical prostatectomy in men (age ≥18 years) with intermediate-risk or high-risk, localised or locally advanced prostate cancer. We searched trial registers and conference proceedings until July 8, 2020, to identify eligible RCTs. By establishing the ARTISTIC collaboration with relevant trialists, we were able to anticipate when eligible trial results would emerge, and we developed and registered a protocol with PROSPERO before knowledge of the trial results (CRD42019132669). We used a harmonised definition of event-free survival, as the time from randomisation until the first evidence of either biochemical progression (prostate-specific antigen [PSA] ≥0·4 ng/mL and rising after completion of any postoperative radiotherapy), clinical or radiological progression, initiation of a non-trial treatment, death from prostate cancer, or a PSA level of at least 2·0 ng/mL at any time after randomisation. We predicted when we would have sufficient power to assess whether adjuvant radiotherapy was superior to early salvage radiotherapy. Investigators supplied results for event-free survival, both overall and within predefined patient subgroups. Hazard ratios (HRs) for the effects of radiotherapy timing on event-free survival and subgroup interactions were combined using fixed-effect meta-analysis.

FINDINGS

We identified three eligible trials and were able to obtain updated results for event-free survival for 2153 patients recruited between November, 2007, and December, 2016. Median follow-up ranged from 60 months to 78 months, with a maximum follow-up of 132 months. 1075 patients were randomly assigned to receive adjuvant radiotherapy and 1078 to a policy of early salvage radiotherapy, of whom 421 (39·1%) had commenced treatment at the time of analysis. Patient characteristics were balanced within trials and overall. Median age was similar between trials at 64 or 65 years (with IQRs ranging from 59 to 68 years) across the three trials and most patients (1671 [77·6%]) had a Gleason score of 7. All trials were assessed as having low risk of bias. Based on 270 events, the meta-analysis showed no evidence that event-free survival was improved with adjuvant radiotherapy compared with early salvage radiotherapy (HR 0·95, 95% CI 0·75-1·21; p=0·70), with only a 1 percentage point (95% CI -2 to 3) change in 5-year event-free survival (89% vs 88%). Results were consistent across trials (heterogeneity p=0·18; I²=42%).

INTERPRETATION

This collaborative and prospectively designed systematic review and meta-analysis suggests that adjuvant radiotherapy does not improve event-free survival in men with localised or locally advanced prostate cancer. Until data on long-term outcomes are available, early salvage treatment would seem the preferable treatment policy as it offers the opportunity to spare many men radiotherapy and its associated side-effects.

FUNDING

UK Medical Research Council.

The median and the mode as robust meta-analysis estimators in the presence of small-study effects and outliers

Meta‐analyses based on systematic literature reviews are commonly used to obtain a quantitative summary of the available evidence on a given topic. However, the reliability of any meta‐analysis is constrained by that of its constituent studies. One major limitation is the possibility of small‐study effects, when estimates from smaller and larger studies differ systematically. Small‐study effects may result from reporting biases (ie, publication bias), from inadequacies of the included studies that are related to study size, or from reasons unrelated to bias. We propose two estimators based on the median and mode to increase the reliability of findings in a meta‐analysis by mitigating the influence of small‐study effects. By re‐examining data from published meta‐analyses and by conducting a simulation study, we show that these estimators offer robustness to a range of plausible bias mechanisms, without making explicit modelling assumptions. They are also robust to outlying studies without explicitly removing such studies from the analysis. When meta‐analyses are suspected to be at risk of bias because of small‐study effects, we recommend reporting the mean, median and modal pooled estimates.

Feasibility and Safety of Low-Dose Intra-Coronary Tenecteplase During Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction (ICE T-TIMI 49)

Following primary percutaneous coronary intervention (PPCI) for ST segment elevation myocardial infarction, microvascular perfusion is often impaired secondary to thrombotic embolization. Intracoronary (IC) fibrinolytic administration may reduce thrombotic burden and distal embolization. The ICE-T-TIMI-49 study evaluated the feasibility and safety of low-dose IC tenecteplase (TNK) during PPCI. The study randomized 40 PPCI patients to a volume matched bolus of IC TNK (4 mg) (n = 20) or IC saline placebo (n = 20) before and following PPCI. The primary end point was percent diameter stenosis of the culprit lesion following first bolus. The primary end point did not differ between IC placebo (median 100%, interquartile range [IQR] 83.0,100.0) and IC TNK (median 100% stenosis, IQR 91.0,100.0; p = 0.522). However, the proportion of patients with reduction in thrombus following first bolus tended to be greater with IC TNK (placebo: 12.5% vs IC TNK: 40.0%, p = 0.133). Following PPCI, the corrected Thrombolysis In Myocardial Infarction (TIMI) frame count (cTFC) was lower (faster) with placebo (16.0 frames [IQR 12.0,24.0] vs 24.0 frames [22.0,32.0], p = 0.045) due to a trend towards greater frequency of hyperemia (cTFC <14), a marker of distal embolization (50.0% vs 8.3%, p = 0.056). There was no difference in TIMI major bleeds and no intracranial hemorrhage. In conclusion, treatment with low-dose IC TNK appears safe and well tolerated during PPCI. Although IC TNK administration did not improve percent stenosis, a trend towards reduced thrombus burden was demonstrated with less hyperemia (a marker of distal embolization). Our findings provide support for a large randomized study.

The evolution of myocardial infarction treatment over the past decades. The significance of E.I. Chazov works

The review is a brief historical insight into the study of myocardial infarction, in which the main discoveries are analyzed that have played an important role in improving the diagnosis and treatment of the disease. A special place in the review is occupied by the work of the outstanding cardiologist and health care organizer E.I. Chazov. More than the half - age, E.I. Chazov investigated various aspects of myocardial infarction, organized a system of medical care for heart attack at all stages. Many studies E.I. Chazov are recognized worldwide.

A new improved graphical and quantitative method for detecting bias in meta-analysis

Detection of publication and related biases remains suboptimal and threatens the validity and interpretation of meta-analytical findings. When bias is present, it usually differentially affects small and large studies manifesting as an association between precision and effect size and therefore visual asymmetry of conventional funnel plots. This asymmetry can be quantified and Egger's regression is, by far, the most widely used statistical measure for quantifying funnel plot asymmetry. However, concerns have been raised about both the visual appearance of funnel plots and the sensitivity of Egger's regression to detect such asymmetry, particularly when the number of studies is small. In this article, we propose a new graphical method, the Doi plot, to visualize asymmetry and also a new measure, the LFK index, to detect and quantify asymmetry of study effects in Doi plots. We demonstrate that the visual representation of asymmetry was better for the Doi plot when compared with the funnel plot. We also show that the diagnostic accuracy of the LFK index in discriminating between asymmetry due to simulated publication bias versus chance or no asymmetry was also better with the LFK index which had areas under the receiver operating characteristic curve of 0.74-0.88 with simulations of meta-analyses with five, 10, 15, and 20 studies. The Egger's regression result had lower areas under the receiver operating characteristic curve values of 0.58-0.75 across the same simulations. The LFK index also had a higher sensitivity (71.3-72.1%) than the Egger's regression result (18.5-43.0%). We conclude that the methods proposed in this article can markedly improve the ability of researchers to detect bias in meta-analysis.

Changing patterns of medical treatment in acute myocardial infarction

TYPE OF STUDY

Descriptive study of trends in the drug therapy for acute myocardial infarction.

SETTING

Population-based register of acute coronary events compiled for the years 1984 to 1990 in the course of the Perth MONICA project.

CASES

5294 cases meeting clinical criteria for acute myocardial infarction.

RESULTS

Striking changes were seen in the use of aspirin before admission to hospital (from 4% to 18%). During the stay in hospital the use of beta-blockers increased steadily from 52% to 76%, while the use of aspirin increased 3.5-fold from 25% to 88% and the use of streptokinase increased 13.5-fold from 2.4% to 32.4%. The proportion of patients prescribed beta-blockers on discharge from hospital increased from 46% to 65% and that for aspirin rose from 16% to 83%. There were also major relative increases in the use of lipid-lowering agents and declines in the use of antiarrhythmic drugs.

CONCLUSION

These trends in the pharmacological management of myocardial infarction mirror the emerging evidence from clinical trials, although the increases in the use of certain types of drugs antedated publication of the results of major randomised studies. The changes in therapy would partly explain observed improvements in case fatality and may have contributed to the decline in coronary mortality observed in the Perth community.

Contemporary Management of Cardiogenic Shock: A Scientific Statement From the American Heart Association

Cardiogenic shock is a high-acuity, potentially complex, and hemodynamically diverse state of end-organ hypoperfusion that is frequently associated with multisystem organ failure. Despite improving survival in recent years, patient morbidity and mortality remain high, and there are few evidence-based therapeutic interventions known to clearly improve patient outcomes. This scientific statement on cardiogenic shock summarizes the epidemiology, pathophysiology, causes, and outcomes of cardiogenic shock; reviews contemporary best medical, surgical, mechanical circulatory support, and palliative care practices; advocates for the development of regionalized systems of care; and outlines future research priorities.

Cardiac Auscultation for Noncardiologists: Application in Cardiac Rehabilitation Programs: PART I: PATIENTS AFTER ACUTE CORONARY SYNDROMES AND HEART FAILURE

During outpatient cardiac rehabilitation after an acute coronary syndrome or after an episode of congestive heart failure, a careful, periodic evaluation of patients' clinical and hemodynamic status is essential. Simple and traditional cardiac auscultation could play a role in providing useful prognostic information.Reduced intensity of the first heart sound (S1), especially when associated with prolonged apical impulse and the appearance of added sounds, may help identify left ventricular (LV) dysfunction or conduction disturbances, sometimes associated with transient myocardial ischemia. If both S1 and second heart sound (S2) are reduced in intensity, a pericardial effusion may be suspected, whereas an increased intensity of S2 may indicate increased pulmonary artery pressure. The persistence of a protodiastolic sound (S3) after an acute coronary syndrome is an indicator of severe LV dysfunction and a poor prognosis. In patients with congestive heart failure, the association of an S3 and elevated heart rate may indicate impending decompensation. A presystolic sound (S4) is often associated with S3 in patients with LV failure, although it could also be present in hypertensive patients and in patients with an LV aneurysm. Careful evaluation of apical systolic murmurs could help identifying possible LV dysfunction or mitral valve pathology, and differentiate them from a ruptured papillary muscle or ventricular septal rupture. Friction rubs after an acute myocardial infarction, due to reactive pericarditis or Dressler syndrome, are often associated with a complicated clinical course.During cardiac rehabilitation, periodic cardiac auscultation may provide useful information about the clinical-hemodynamic status of patients and allow timely detection of signs, heralding possible complications in an efficient and low-cost manner.

The need for outcome studies in type 2 diabetes

Outcome studies use primary end points such as overall mortality or major morbidity to demonstrate that treatments deliver meaningful clinical benefits. Historically it was thought that most of the cardiovascular morbidity due to diabetes was related to microvascular disease, providing a marker for macrovascular disease. In diabetes an outcome study would measure all-cause death, cardiac death and cardiovascular morbidity (end points related to macrovascular disease), whereas conventional trials in diabetes have used surrogate end points, such as blood pressure, microvascular disease (retinopathy, nephropathy) or glycaemic control, which may not predict clinical benefits in the prevention of macrovascular end points. Although outcome trials are increasingly required by regulatory or funding agencies, few have been performed in diabetes; most data have come from trials with surrogate end points or subgroup analyses of cardiovascular outcome trials. Methodological constraints, particularly the large patient populations and long follow-up required, partly explain the lack of outcome studies in diabetes.

The PROspective pioglitAzone Clinical Trial In macroVascular Events (PROactive) is a macrovascular outcome study in patients with type 2 diabetes. It will involve approximately 4,000 patients who will receive pioglitazone or placebo in addition to their existing therapy. Principal end points will be all-cause mortality and severe disability due to macrovascular complications. PROactive should provide important data on the impact of therapy on the incidence of cardiovascular complications in type 2 diabetes.

Meta-Analyses of Human Cell-Based Cardiac Regeneration Therapies: What Can Systematic Reviews Tell Us About Cell Therapies for Ischemic Heart Disease?

Controversies from basic science, discrepancies from clinical trials, and divergent results from meta-analyses have recently arisen in the field of cell therapies for cardiovascular repair and regeneration. Noticeably, there are almost as many systematic reviews and meta-analyses published as there are well-conducted clinical studies. But how do we disentangle the confusion they have raised? This article addresses why results obtained from systematic reviews and meta-analyses of human cell-based cardiac regeneration therapies are still valid to inform the design of future clinical trials. It also addresses how meta-analyses are not free from limitations and how important it is to assess the quality of the evidence and the quality of the systematic reviews and finally how stronger conclusions can be drawn when several pieces of evidence converge.

Reduced In-Hospital Mortality Following Intracoronary Streptokinase Treatment of Acute Myocardial Infarction

Reduced short-term mortality following thrombolytic treatment of acute myocardial infarction has been reported by earlier studies. This study was per formed to compare data from our institution with such results.

From January, 1984, through January, 1986, a total of 628 consecutive pa tients were admitted with acute myocardial infarction. Ninety-one patients (Group A) underwent intracoronary streptokinase (IC-SK) infusion to the in farct-related vessel with a total dose of 440,000 units. The average timing for this intervention from the onset of chest pain was 4.1 ±2.7 hours. Successful recanalization was achieved in 71 of 91 patients (78%). Patients seventy-five years of age or older were not offered IC-SK infusion. In this group, most candidates suitable for coronary angioplasty or bypass surgery had the proce dure within the same hospital admission. The remaining 537 patients (Group B) underwent conventional medical therapy during their hospitalization.

In-hospital mortality for Group A was reported in 4 of 91 patients (4.4%) versus 100 of 537 patients (18.6%) from Group B. These results seem to con form with earlier data that indicate a reduced short-term in-hospital mortality from acute myocardial infarction following IC-SK treatment. Besides recanali zation, this beneficial effect in Group A could also be attributed to earlier inter ventions by revascularization procedures in the majority of patients after recognition of the extent of their coronary artery disease.

Analytic Review: Thrombolytic Therapy in Acute Myocardial Infarction

The salvage of myocardium in the setting of acute myocardial infarction has long been a goal of physicians involved in the care of patients with coronary artery disease. Understanding the role of thrombosis in the pathogenesis of acute myocardial infarction has led the way to an entirely new approach to the treatment of this entity. Thrombolytic therapy has now become a widely used form of treatment with encouraging results. Both intravenous and intracoronary administration of thrombolytic agents have been shown to promote recanalization of acutely occluded coronary arteries. Results of studies using the clot-specific agent, tissue plasminogen activator, intravenously have been most encouraging; successful reperfusion has been obtained in approximately 70% of patients treated. In addition, a recent large-scale trial has shown a reduction in morbidity and mortality with the early use of thrombolytic agents.

Ongoing trials should help delineate the precise role and timing of these agents as the initial form of therapy for acute myocardial infarction. Other issues that remain unresolved are the frequency of restenosis and the role of percutaneous transluminal coronary angioplasty in addition to thrombolytic therapy in the treatment of acute myocardial infarction.

International Comparison of Factors Associated with Delay in Presentation for AMI Treatment

BACKGROUND

Prehospital delay in response to acute myocardial infarction (AMI) symptoms is well documented in the US and Europe, but little is known about it in Asian countries where cardiovascular disease is increasing.

AIMS

We conducted an observational study of delay times and factors associated with hospital presentation times in 595 patients with AMI from the US, England, Japan and South Korea.

METHODS

Patients were interviewed about responses to symptoms within 72 h of hospital admission and the medical records were reviewed.

RESULTS

The proportions of patients with delay times of 1 h or less were: US--23%, Korea--18%, England--15% and Japan--8%. In the US and England when others present at symptom onset called an ambulance patients presented two to three times sooner. Independent predictors of presentation within an hour of symptom onset were attribution of symptoms to the heart and not waiting for symptoms to go away.

CONCLUSION

Similar education about the need to seek treatment early in response to AMI symptoms may be applicable in Western and Eastern industrialised populations.

Evaluation of a Public Education Program Delivered by Firefighters on Early Recognition of a Heart Attack

The Heart Attack Survival Kit (HASK) project is a prospective, randomized trial, testing the effectiveness of an intervention delivered door-to-door by firefighters to increase use of 911 and ingestion of aspirin for symptoms of acute myocardial infarction (AMI) among seniors in King County, Washington. Firefighters visited 24,582seniors in King County, Washington and delivered a Heart Attack Survival Kit. Another 24,191 senior households served as the control group. Outcomes of the program were measured by tracking 911 calls as well as survey data. This study reports on the results of the telephone survey with a random sample of seniors (N = 323) to assess their knowledge of and intentions to act during a heart emergency. Results of a logistic regression analysis showed that being female, be ing younger, and remembering the kit was significantly related to intentions to act appropriately to AMI symptoms. The results are discussed in terms of public education around AMI.

Characterisation of trials where marketing purposes have been influential in study design: a descriptive study

Background

Analysis of trial documentation has revealed that some industry-funded trials may be done more for marketing purposes than scientific endeavour. We aimed to define characteristics of drug trials that appear to be influenced by marketing considerations and estimate their prevalence.

Methods

We examined reports of randomised controlled trials of drugs published in six general medical journals in 2011. Six investigators independently reviewed all publications, characterising them as YES/MAYBE/NO suspected marketing trials, and then met to reach consensus. Blinded researchers then extracted key trial characteristics. We used blinded cluster analysis to determine if key variables could characterise the categories of trials (YES/MAYBE/NO).

Results

41/194 (21 %) trials were categorised as YES, 14 (7 %) as MAYBE, 139 (72 %) as NO. All YES and MAYBE trials were funded by the manufacturer, compared with 37 % of NO trials (p < 0.001). A higher proportion of YES trials had authors or contributors from the manufacturer involved in study design (83 % vs. 19 %), data analysis (85 % vs.15 %) and reporting (81 % vs. 15 %) than NO trials (p < 0.001). There was no significant difference between groups in the median number of participants screened (p = 0.49), but the median number of centres recruiting participants was higher for YES compared with NO trials (171 vs. 13, p < 0.001). YES trials were not more likely to use a surrogate (42 % vs. 30 %; p = 0.38) or composite primary outcome measure (34 % vs. 19 %; p = 0.14) than NO trials. YES trials were often better reported in terms of blinding, safety outcomes and adverse events than NO trials. YES trials more frequently included speculation that might encourage clinicians to use the intervention outside of the study population compared to NO trials (59 % vs.37 %, p = 0.03). Cluster analysis based on study characteristics did not identify a clear variable structure that accurately characterised YES/MAYBE/NO trials.

Conclusions

We reached consensus that a fifth of drug trials published in the highest impact general medical journals in 2011 had features that were suggestive of being designed for marketing purposes. Each of the marketing trials appeared to have a unique combination of features reported in the journal publications.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-1107-1) contains supplementary material, which is available to authorized users.

Fibrinolytic therapy in hospitals without percutaneous coronary intervention capabilities in China from 2001 to 2011: China PEACE-retrospective AMI study

BACKGROUND

Fibrinolytic therapy is the primary reperfusion strategy for ST-segment elevation myocardial infarction in China, and yet little is known about the quality of care regarding its use and whether it has changed over time. This issue is particularly important in hospitals without the capacity for cardiovascular intervention.

METHODS

Using a sequential cross-sectional study with two-stage random sampling in 2001, 2006, and 2011, we characterised the use, timing, type and dose of fibrinolytic therapy in a nationally representative sample of patients with ST-segment elevation myocardial infarction admitted to hospitals without the ability to perform percutaneous coronary intervention.

RESULTS

We identified 5306 patients; 2812 (53.0%) were admitted within 12 hours of symptom onset, of whom 2463 (87.6%) were ideal candidates for fibrinolytic therapy. The weighted proportion of ideal candidates receiving fibrinolytic therapy was 45.8% in 2001, 50.0% in 2006, and 53.0% in 2011 ( P_trend=0.0042). There were no regional differences in fibrinolytic therapy use. Almost all ideal patients (95.1%) were treated after admission to the hospital rather than in the emergency department. Median admission to needle time was 35 minutes (interquartile range 10-82) in 2011, which did not improve from 2006. Underdosing was common. Urokinase, with little evidence of efficacy, was used in 90.2% of patients.

CONCLUSIONS

Over the past decade in China, the potential benefits of fibrinolytic therapy were compromised by underuse, patient and hospital delays, underdosing and the predominant use of urokinase, an agent for which there is little clinical evidence. There are ample opportunities for improvement.

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.

Commonalities of cardiac rupture (left ventricular free wall or ventricular septum or papillary muscle) during acute myocardial infarction secondary to atherosclerotic coronary artery disease

Although mortality rates during acute myocardial infarction (AMI) continue to drop, cardiac rupture (left ventricular free wall [LVFW] or ventricular septum [VS] or papillary muscle [PM] or combination) remains relatively common. The aim was to identify commonalities among patients with AMI complicated by cardiac rupture. During a 22-year period (1993-2014) 64 patients hospitalized for AMI were studied and clinical and morphologic variables in those with (25 patients) - vs - those without (39 patients) cardiac rupture were compared, and previous reports on this topic were reviewed. Compared to the non-rupture cases, the rupture group was significantly older (71 years - vs - 60 years); had a much higher frequency of huge deposits of adipose tissue in the heart (floated in formaldehyde) (88% - vs - 20%) but a lower mean body mass index (28.2 Kg/m(2) - vs - 33.2 Kg/m(2)); a much lower frequency of healed myocardial infarct (scar) (4% - vs - 28%); a lower frequency of diabetes mellitus (24% - vs - 47%), and a higher frequency of thrombolytic therapy during the fatal AMI (32% - vs - 10%). None of the rupture cases had evidence of dilated left ventricular cavities or evidence of heart failure before the AMI complicated by rupture. In conclusion, cardiac rupture appears to account for a high percent of deaths during a first AMI. It most commonly occurs in patients with extremely fatty hearts and in those without evidence of prior heart failure.

Bioethics: why philosophy is essential for progress

It is the JME's 40th anniversary and my 20th anniversary working in the field. I reflect on the nature of bioethics and medical ethics. I argue that both bioethics and medical ethics together have, in many ways, failed as fields. My diagnosis is that better philosophy is needed. I give some examples of the importance of philosophy to bioethics. I focus mostly on the failure of ethics in research and organ transplantation, although I also consider genetic selection, enhancement, cloning, futility, disability and other topics. I do not consider any topic comprehensively or systematically or address the many reasonable objections to my arguments. Rather, I seek to illustrate why philosophical analysis and argument remain as important as ever to progress in bioethics and medical ethics.

Paramedics beliefs and attitudes towards pre-hospital thrombolysis

Background:

Myocardial infarction is the third leading cause of death in the developing countries. Thrombolysis as a reperfusion therapy is shown to have a great role in decreasing mortality. The efficacy of thrombolytic therapy lies in its ability to reduce the duration of occlusion by early administration. Many of the studies have supported pre-hospital thrombolysis (PHT) therapy and proven that it is beneficial in acute myocardial infarction (AMI) patients.

Methodology:

Questionnaires adopted from studies of Humphrey et al., were distributed to paramedics in Saudi Red Crescent Authority and Emergency Medical Services Departments at King Abdulaziz Medical City, King Fahad Medical City, Prince Sultan Medical Military City and Security Forces Hospital in Riyadh. A total of 7 questions were about the knowledge of risk and benefit of PHT and 12 questions were about the beliefs and attitudes of paramedics toward PHT in AMI patients.

Results:

The response rate was 87%. Nearly 72% were believed to be capable of performing PHT, 87% are confident about recording 12-lead electrocardiogram in pre-hospital settings and 77% are confident in the interpretation. 94% believe that PHT will have a significant impact on pain to needle time. 77% consider PHT to be safe for use by paramedics. 66% preferred on-line medical direction or telemedicine linked with the supervision of a physician. Regarding the knowledge part, majority gave a correct answer, but the major concern was that 43% of the paramedics overestimated direct relation of bleeding to thrombolysis therapy.

Conclusion:

Majority of paramedics in Riyadh support the principle of PHT in patients with AMI via online medical direction. They believe that they are confident in their ability to administer PHT despite the concern of authorities on their level of training, the related risks and medico-legal issues. Nevertheless, since the total duration of PHT course for paramedics is just 2 days, we consider that the procedure should be performed under expert supervision until they achieve expertise.

Dissecting intramural hematoma of esophagus after thrombolytic therapy: a case report

Esophageal hematoma is a relatively rare event. We report a case of severe chest pain associated with myocardial infarction and recurrent chest pain after administration of a thrombolytic agent. The chest pain was different from the presenting symptom and accompanied by 2 episodes of hematemesis. Esophageal hematoma was confirmed after endoscopy and computed tomography. Esophageal hematoma is a relatively rare event after thrombolytic therapy.

A study of coronary artery patency in relation to the index event in patients with myocardial infarction thrombolysed with streptokinase

BACKGROUND

Restoration of infarct vessel patency is the key treatment for acute ST-elevation myocardial infarction.

OBJECTIVE

The purpose of the study was to confirm the effectiveness of streptokinase (STK) for successful thrombolysis of the infarct-related artery (IRA) in patients with acute myocardial infarction (AMI), in relation to the time of the index event and age compared with newer thrombolytic agents, in a tertiary care centre.

METHODS

100 patients (77% male) thrombolysed with STK underwent coronary angiography within 48 h of presentation. Patency of the IRA was used to assess successful thrombolysis.

RESULTS

The mean pain-to-needle time was 3.24 h. 76 patients (76%) treated with thrombolysis had patent arteries with thrombolysis in myocardial infarction (TIMI) 2 or 3 flow. In subgroup analysis of time from the index event, patency rates were 83.3%, 77.5%, 68.7% and 40% in patients presenting within 0-2, 2-4, 4-6 and 6-12 h, respectively. In subgroup analysis, all patients less than 30 years of age had patent arteries with TIMI 2 or 3 flow. Coronary angiography showed the IRA was the left anterior descending artery (LAD) in 55%, the right coronary artery (RCA) in 33% and the left circumflex artery (LCX) in 12%. The patency rates of the LAD, RCA and LCX were 74.5%, 69.6% and 100%, respectively.

CONCLUSIONS

We found STK to be as effective as newer thrombolytic agents reported in other studies. In patients with AMI thrombolysed within 4 h, STK results in higher patency in young compared to older patients.

Advances in catheter ablation: atrial fibrillation ablation in patients with mitral mechanical prosthetic valve

Atrial fibrillation (AF) is common in patients with mitral valve replacement (MVR). Treatment of AF in these subjects is challenging, as the arrhythmia is often refractory to antiarrhythmic drug therapy. Radiofrequency catheter ablation (RFCA) is usually avoided or delayed in patients with MVR due to the higher perceived risks and difficulty of left atrial catheter manipulation in the presence of a mechanical valve. Over the last few years, several investigators have reported the feasibility and safety of RFCA of AF in patients with MVR. Five case-control studies have evaluated the feasibility and safety of RFCA of AF or perimitral flutter (PMFL) in patients with MVR. Overall, a total of 178 patients with MVR have been included (21 undergoing ablation of only PMFL), and have been compared with a matched control group of 285 patients. Total procedural duration (weigthed mean difference [WMD] = +24.5 min, 95% confidence interval [CI] +10.2 min to +38.8 min, P = 0.001), and fluoroscopy time (WMD = +13.5 min, 95% CI +3.7 min to +23.4 min, P = 0.007) were longer in the MVR group. After a mean follow-up of 11.5 ± 8.6 months, 64 (36%) patients in the MVR group experienced recurrence of AF/PMFL, as compared to 73 (26%) patients in the control group, accounting for a trend toward an increased rate of recurrences in patients with MVR (odds ratio [OR] = 1.66, 95% CI 0.99 to 2.78, P = 0.053). Periprocedural complications occurred in 10 (5.6%) patients in the MVR group, and in 8 (2.8%) patients in the control group (OR = 2.01, 95% CI 0.56 to 7.15, P = 0.28). In conclusion, a quantitative analysis of the available evidence supports a trend toward a worse arrhythmia-free survival and a higher absolute rate of periprocedural complications in patients with MVR undergoing RFCA of AF or PMFL, as compared to a matched control group without mitral valve disease. These data would encourage the adoption of RFCA of AF in MVR patients mostly by more experienced Institutions.

Current development in clinical trials: issues old and new

Clinical trials, especially the randomized clinical trial, have been and will remain the gold standard for the evaluation of new interventions, including pharmaceuticals, biologics, medical devices, procedures, or behavioral modifications. Despite more than five decades of experience, there are still challenges in their design, conduct, monitoring, and analyses. Some of these challenges remain and some are emerging, in part due to the progress in genomics and proteomics. These issues may be statistical, logistical, or a combination. Included are follow-up of subjects who withdraw from intervention, the proposed use of recent adaptive designs, implementing noninferiority designs, reliance on surrogate markers, and gene transfer studies. Comparative effectiveness studies are of increasing interest but present major design and analysis issues. Forces external to the trial are also becoming more common.

Streptokinase antibodies in patients presenting with acute coronary syndrome in three rural New Zealand populations

BACKGROUND

New Zealand Māori have some of the highest rates of Group A streptococcal infection (GAS) in the world. GAS elevates titres of antistreptokinase (SK) neutralising antibodies and may induce resistance to SK.

METHODS

Anti-SK titres were measured in 180 patients presenting with symptoms consistent with an acute coronary syndrome to three New Zealand rural hospitals, selected because they provide care for patients from communities with different socio-economic and ethnic mixes (Māori proportions varying between 6% and 67%).

FINDINGS

Compared with the community with the lowest proportion of Māori, patients in the community with the highest proportion of Māori had mean anti-SK titres that were 2.8 times higher (p=0.05). They were 2.5 times more likely to have a high anti-SK titre (33% vs 13% p=0.035).

INTERPRETATION

Alternatives to reperfusion with SK should be the first-choice therapy in hospitals serving communities with high rates of GAS such as some predominantly Māori and Pacific Island communities.

Homocysteine and vascular disease: review of published results of the homocysteine-lowering trials

Moderately elevated homocysteine levels have been associated with a higher risk of cardiovascular disease in observational studies, but whether these associations are causal is uncertain. Randomized trials of dietary supplementation with B vitamins were set up to assess whether lowering homocysteine levels could reduce the risk of vascular disease. This review is based on a meta-analysis of published results of eight homocysteine-lowering trials for preventing vascular disease. The eight trials comprised a total of 37,485 individuals and provided comparisons of the effects of B vitamins on 5,074 coronary heart disease (CHD) events, 1,483 stroke events, 2,692 incident cancer events, and 5,128 deaths. Our meta-analysis assessed the effects of lowering homocysteine levels by about 25% for about 5 years. Allocation to B vitamins had no beneficial effects on any cardiovascular events, with hazard ratios (95% confidence intervals) of 1.01 (0.96-1.07) for CHD and 0.96 (0.87-1.07) for stroke. Moreover, allocation to B vitamins had no significant adverse effects on cancer [1.08 (0.99-1.17)], or for death from any cause [1.02 (0.97-1.07)]. Thus, supplementation with B vitamins had no statistically significant effects on the risks of cardiovascular events, total mortality rates, or cancer. A meta-analysis based on individual participant data from all available trials will assess the effects of lowering homocysteine levels on a broader range of outcomes, overall and in all relevant subgroups. However, available evidence does not support the routine use of B vitamins to prevent cardiovascular disease.

Thrombolytics and myocardial infarction

Coronary artery disease is the single leading cause of death in the United States. Occlusion of the coronary artery was identified to be the cause of myocardial infarction almost a century ago. Following a series of investigations, streptokinase was discovered and demonstrated to be beneficial for the treatment of patients with acute myocardial infarction in terms of reducing short- and long-term mortality. Newer agents including tissue plasminogen activators such as alteplase, reteplase, tenecteplase were developed subsequently. In the present era, thrombolytic therapy and primary percutaneous coronary intervention has revolutionized the way patients with acute myocardial infarction are managed resulting in significant reduction in cardiovascular death. This article provides an overview of the various thrombolytic agents utilized in the management of patients with acute myocardial infarction.

Chemotherapy and supportive care versus supportive care alone for advanced non-small cell lung cancer

BACKGROUND

Since our individual patient data (IPD) meta-analysis of supportive care and chemotherapy for non-small cell lung cancer (NSCLC), published in 1995, many trials have been completed. We have carried out an updated IPD meta-analysis to assess newer regimens and determine conclusively the effect of chemotherapy.

OBJECTIVES

To assess the effect on survival of supportive care and chemotherapy versus supportive care alone in advanced NSCLC.

SEARCH STRATEGY

All randomised controlled trials (RCTs), published or unpublished. We searched bibliographic databases, trials registers, conference proceedings and reference lists of relevant trials. Searches were completed to November 2009.

SELECTION CRITERIA

Trials had to have commenced accrual on or after 1 January 1965 and should have included patients with NSCLC who had received either chemotherapy and supportive care or supportive care alone. Patients should have not received any previous chemotherapy or had any prior malignancy.

DATA COLLECTION AND ANALYSIS

For trials included in 1995 we sought updated follow up. For new trials we sought survival and baseline characteristics for all patients. We combined results from RCTs to calculate individual and pooled hazard ratios (HRs).

MAIN RESULTS

We obtained data on 2714 patients from 16 RCTs. There were 1293 deaths among 1399 patients assigned supportive care and chemotherapy and 1240 among 1315 assigned supportive care alone. Results showed a significant benefit of chemotherapy (HR = 0.77; 95% CI 0.71 to 0.83, P < 0.0001), equivalent to a relative increase in survival of 23%, an absolute improvement in survival of 9% at 12 months, increasing survival from 20% to 29% or an absolute increase in median survival of 1.5 months (from 4.5 months to six months). There was no clear evidence that this effect was influenced by the drugs used (P = 0.63) or whether they were used as single agents or in combination (P = 0.40). Despite changes in patient demographics, the effect of chemotherapy in recent trials did not differ from those included previously (P = 0.77). There was no clear evidence of a difference in the relative effect of chemotherapy across patient subgroups. Quality of life could not be formally assessed.

AUTHORS' CONCLUSIONS

All trials were of good methodological quality with no risk of bias. This meta-analysis of chemotherapy in the supportive care setting demonstrates that chemotherapy improves overall survival in all patients with advanced NSCLC. Patients who are fit enough and wish to receive it should be offered chemotherapy.

No evidence for switching the antidepressant: systematic review and meta-analysis of RCTs of a common therapeutic strategy

OBJECTIVE

Switching antidepressants is a common strategy for managing treatment-resistant depressed patients. However, no systematic reviews have been conducted to date.

METHOD

We systematically searched MEDLINE/EMBASE/Cochrane Central Register of Controlled Trials and additional sources. We included double-blind studies of patients with depressive symptomatology who were not responding to initial antidepressant monotherapy and were subsequently randomized to another antidepressant or to continue the same antidepressant. Results were pooled for meta-analysis of response + remission rates using a fixed-effects model.

RESULTS

A total of three studies were included. Switching to another antidepressant was not superior to continuing the initial antidepressant in any of these studies. Our meta-analysis showed no significant advantages to either strategy and no significant heterogeneity of results [OR for response rates: 0.85 (95% CI: 0.55-1.30) favoring continuing].

CONCLUSION

There is a discrepancy between the published evidence and the frequent decision to switch antidepressants, indicating an urgent need for more controlled studies. Pending such studies we recommend that physicians rely on more thoroughly evaluated strategies.

Homocysteine lowering interventions for preventing cardiovascular events

BACKGROUND

Cardiovascular disease such as coronary artery disease, stroke and congestive heart failure, is a leading cause of death worldwide. A postulated risk factor is elevated circulating total homocysteine (tHcy) levels which is influenced mainly by blood levels of cyanocobalamin (vitamin B12), folic acid (vitamin B9) and pyridoxine (vitamin B6). There is uncertainty regarding the strength of association between tHcy and the risk of cardiovascular disease.

OBJECTIVES

To assess the clinical effectiveness of homocysteine-lowering interventions (HLI) in people with or without pre-existing cardiovascular disease.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (issue 3 2008), MEDLINE (1950 to August 2008), EMBASE (1988 to August 2008), and LILACS (1982 to September 2, 2008). We also searched in Allied and Complementary Medicine (AMED; 1985 to August 2008), ISI Web of Science (1993 to August 2008), and the Cochrane Stroke Group Specialised Register (April 2007). We hand searched pertinent journals and the reference lists of included papers. We also contacted researchers in the field. There was no language restriction in the search.

SELECTION CRITERIA

We included randomised clinical trials (RCTs) assessing the effects of HLI for preventing cardiovascular events with a follow-up period of 1 year or longer. We considered myocardial infarction and stroke as the primary outcomes. We excluded studies in patients with end-stage renal disease.

DATA COLLECTION AND ANALYSIS

We independently performed study selection, risk of bias assessment and data extraction. We estimated relative risks (RR) for dichotomous outcomes. We measured statistical heterogeneity using I(2). We used a random-effects model to synthesise the findings.

MAIN RESULTS

We included eight RCTs involving 24,210 participants with a low risk of bias in general terms. HLI did not reduce the risk of non-fatal or fatal myocardial infarction, stroke, or death by any cause (pooled RR 1.03, 95% CI 0.94 to 1.13, I(2) = 0%; pooled RR 0.89, 95% CI 0.73 to 1.08, I(2) = 15%); and pooled RR 1.00 (95% CI 0.92 to 1.09, I(2): 0%), respectively.

AUTHORS' CONCLUSIONS

Results from available published trials suggest that there is no evidence to support the use of HLI to prevent cardiovascular events.

Pharmacogenetics in cardiovascular antithrombotic therapy

Thrombosis is the most important underlying mechanism of coronary artery disease and embolic stroke. Hence, antithrombotic therapy is widely used in these scenarios. However, not all patients achieve the same degree of benefit from antithrombotic agents, and a considerable number of treated patients will continue to experience a new thrombotic event. Such lack of clinical benefit may be related to a wide variability of responses to antithrombotic treatment among individuals (i.e., interindividual heterogeneity). Several factors have been identified in this interindividual heterogeneity in response to antithrombotic treatment. Pharmacogenetics has emerged as a field that identifies specific gene variants able to explain the variability in patient response to a given drug. Polymorphisms affecting the disposition, metabolism, transporters, or targets of a drug all can be implicated in the modification of an individual's antithrombotic drug response and therefore the safety and efficacy of the aforementioned drug. The present paper reviews the modulating role of different polymorphisms on individuals' responses to antithrombotic drugs commonly used in clinical practice.

Intravenous thrombolytic treatment for acute myocardial infarction. Effects of early intervention and early examination

Intravenous thrombolytic treatment (streptokinase or anisoylated plasminogen streptokinase activator complex (APSAC) was given to 50 consecutive patients within 3 hours after onset of symptoms of acute myocardial infarction. Left heart catheterisation with coronary angiography and simultaneous double view left ventriculography were performed approximately 4 hours after start of thrombolytic treatment. This examination showed that the acute infarct-related coronary artery was open in 36 patients (72%) and closed in 14 patients (28%). A higher left ventricular ejection fraction was found among patients with open, than among patients with closed infarct-related artery (58.8% vs. 48.4%, p = 0.05). The group with open artery also had a lower score of regional left ventricular dysfunction (1.7 vs. 2.4, p less than 0.05, on a scale from 0-3). Single, double and triple vessel coronary heart disease was found in 22, 14 and 13 patients respectively. Mean age was lower in the group with single vessel disease as compared to double and triple vessel disease (48.4 years vs. 53.4 and 55.4 years, p less than 0.05 and p less than 0.005). Independently of whether the infarct-related artery was open or closed, there tended to be an inverse correlation between number of diseased vessels and preservation of left ventricular function (statistical significance only for single vessel versus triple vessel disease with respect to score of regional left ventricular dysfunction, 1.8 vs. 2.4, p less than 0.05). These findings suggest that early thrombolytic treatment within 3 hours of onset of symptoms may preserve myocardial tissue during the evolution of acute infarction. Furthermore, a presumably better collateralisation from adjacent coronary arteries without stenoses may be important for myocardial preservation. Finally, early angiographic examination can be performed safely and is a good support for determination of further treatment, which in the actual patients was coronary bypass surgery in 8 cases, transluminal angioplasty, PTCA, in 20 cases, and medical treatment alone in 22 cases.

Shifting Our Thinking About Uncommon Disease Trials: The Case of Methotrexate in Scleroderma

Objective.

Randomized trials for uncommon diseases suffer from methodological challenges: difficulty in recruiting sufficient numbers of patients and low power to detect important treatment effects. Using traditional (frequentist) analysis, p values > 0.05 mean investigators are unable to reject the null hypothesis (of no treatment effect). The medical community often labels trials with p values > 0.05 as “negative.” Our study demonstrates how Bayesian analysis conveys more relevant information to clinicians — using the example of methotrexate (MTX) in systemic sclerosis (SSc).

Methods.

Data from 71 patients with diffuse SSc (n = 35 MTX, n = 36 placebo) in the trial were reanalyzed using Bayesian models. We examined 3 primary outcomes: modified Rodnan skin score (MRSS), University of California Los Angeles (UCLA) skin score, and physician global assessment of overall disease activity. Using noninformative prior probability distributions, the probability of beneficial treatment effects for each outcome and the probability of simultaneous benefit in outcomes were computed.

Results.

The probability that treatment with MTX results in better mean outcomes than placebo was 94% for MRSS, 96% for UCLA skin score, and 88% for physician global assessment. There was 96% probability that at least 2 of 3 primary outcomes were better on treatment.

Conclusion.

Bayesian analysis of uncommon disease trials allows for more flexible and clinically relevant interpretations of the data. From the trial data, clinicians can infer that MTX has a high probability of beneficial effects on skin score and global assessment.

Benefits of reperfusion beyond infarct size limitation

The most critical determinant of prognosis in patients with acute myocardial infarction (MI) is infarct magnitude, which can be established within several hours of an attack. The importance of the subsequent healing process is not negligible, however. In fact, much experimental and clinical evidence suggests that late reperfusion of the infarct-related coronary artery--i.e. at times too late to salvage the myocardium within the area at risk-is beneficial for reducing left ventricular remodelling and decreasing mortality ('open artery hypothesis'). For instance, one recent study highlighted the beneficial effects of late reperfusion therapy on the infarct tissue cell dynamics following acute MI. Nonetheless, several recent large, randomized clinical trials have failed to provide evidence of such benefits, refuting the clinical efficacy of late reperfusion. In addition, they also underscore the need for revised clinical studies in which there is less heterogeneity in the timing of reperfusion and in the initial infarct size, as well as the need for sustained patency of the recanalized artery. This review focuses on the effects of late reperfusion on the pathophysiology of MI in the context of the infarct tissue dynamics and clinical outcomes. We also discuss the issues that need to be resolved to improve clinical application.