Emergent Reperfusion Research Articles

Regular dipyridamole therapy produces sustained protection against cardiac ischemia–reperfusion injury: Is it time to revisit PARIS?

BackgroundIncreased activated Akt and eNOS expression coincide with this persistent cardioprotection. Emergent coronary reperfusion therapies are rarely carried out before considerable myocardial injury has occurred. Moreover, reperfusion after prolonged ischemia produces paradoxical ischemia–reperfusion injury, attenuating the efficacy of reperfusion therapies. This has provided impetus for identifying chronic therapies to protect against ischemia–reperfusion injury in those at risk. We previously found that regular dipyridamole therapy produces a chronic preconditioning-like effect mediated through adenosine A1 receptors. MethodsTo determine how long this chronic preconditioning effect of dipyridamole remains present after discontinuing therapy, guinea pigs received 4mg/kg/day in their water for 6weeks. Ischemia–reperfusion was performed at 0, 2, 3, and 4days after dipyridamole discontinuation (0day, 2days, 3days and 4days; n=8 per group). Left ventricular developed pressure (LVDP), end-diastolic pressure (LVEDP), coronary flow (CF), infarct size, and western blot analyses for Akt and endothelial nitric oxide synthase (eNOS) were studied. ResultsAfter ischemia–reperfusion, 0day, 2days and 3days, but not 4days, had significantly higher LVDP and lower LVEDP compared to control. Myocardial infarct size was significantly reduced at 0day, 2days and 3days, but not 4days, compared to control. Western blot analyses demonstrated upregulation of phospho-Akt and phospho-eNOS expression at 0day, 2days, and 3days, but not 4days. ConclusionsA chronic preconditioning-like cardioprotection by regular dipyridamole treatment persists for 3days after discontinuing therapy. Increased activated Akt and eNOS expression may play a role in this persistent cardioprotection.

Lead aVL on electrocardiogram: emerging as important lead in early diagnosis of myocardial infarction?

Although a diagnosis of acute myocardial infarction (AMI) that mandates emergency reperfusion therapy requires ST-segment elevation greater than 1 mm in at least 2 contiguous leads, some of the early electrocardiogram (ECG) changes of AMI can be subtle. Any ST-segment depression or T-wave inversion in lead aVL may be implicated in left anterior descending artery lesion or early reciprocal changes of inferior wall myocardial infarction, particularly when the clinical context suggests ischemia. Early recognition of reciprocal changes and serial ECG help initiate early appropriate intervention. Heightened awareness of ST segment and T-wave changes in lead aVL is of paramount importance to quickly identifying life-threatening condition.

Prolonged ictal aphasia presenting as clinical-diffusion mismatch in a patient with acute ischemic stroke.

Prolonged ictal aphasia presenting as clinical-diffusion mismatch in a patient with acute ischemic stroke.

ECG Diagnosis and Classification of Acute Coronary Syndromes

In acute coronary syndromes, the electrocardiogram (ECG) provides important information about the presence, extent, and severity of myocardial ischemia. At times, the changes are typical and clear. In other instances, changes are subtle and might be recognized only when ECG recording is repeated after changes in the severity of symptoms. ECG interpretation is an essential part of the initial evaluation of patients with symptoms suspected to be related to myocardial ischemia, along with focused history and physical examination. Patients with ST-segment elevation on their electrocardiogram and symptoms compatible with acute myocardial ischemia/infarction should be referred for emergent reperfusion therapy. However, it should be emphasized that a large number of patients may have ST-elevation without having acute ST-elevation acute coronary syndrome, while acute ongoing transmural ischemia due to an abrupt occlusion of an epicardial coronary artery may occur in patients with ST-elevation less than the thresholds defined by the guidelines. Up-sloping ST-segment depression with positive T waves is increasingly recognized as a sign of regional subendocardial ischemia associated with severe obstruction of the left anterior descending coronary artery. Widespread ST-segment depression, often associated with inverted T waves and ST-segment elevation in lead aVR during episodes of chest pain, may represent diffuse subendocardial ischemia caused by severe coronary artery disease. In case of hemodynamic compromise, urgent coronary angiography has been increasingly recommended for these patients.

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Introduction: The emergent pharmacologic reperfusion of elderly patients with STEMI, although not formally contraindicated in clinical guidelines, can still be a challenge for intensive care providers. Clinical outcomes in elderly patients have not been described in comparison to younger populations. Methods: This was a retrospective study which analyzed all patients admitted with STEMI that received in-hospital fibrinolysis in a secondary care hospital between April 1999 - June 2012 (504 patients). Among them 85 cases (75 and over) and 85 controls ( <75 years old) were randomized. 9 descriptive and 17 analytic (evolution and prognosis) variables were analyzed. Statistic methods used: average ± standard deviation for the descriptive variables and t test or χ2/Fisher Test for the analytic variables. Significant results were considered with a p value <0.05. Results: Elderly patients who received fibrinolysis had higher risk of bleeding per Crusade Score (38.2 ± 13.5 vs 22.8 ± 12), higher delay until reperfusion (232 ± 153 vs 156 ± 107 minutes) and lower incidence of 2 or 3 coronary vessel disease (17.3% vs 26.6%). Concerning complications and evolution, we noted a higher incidence of acute renal injury (24% vs 2.6%), Killip III-IV class (21.3% vs 6.6%), relevant arrhythmias (45.3% vs 22.6%), heart failure (33.3% vs 6.6%), stroke (5.3% vs 0%) and cardiac tamponade (2.6% vs 0%) comparing among cases, as well as a higher mortality in the ICU, in-hospital and at 6 months postSTEMI. No significant differences were appreciated in the post-infarction ejection fraction, ICU stay, previous NYHA class or at 6 months postSTEMI. Conclusions: Elderly patients with STEMI treated with fibrinolysis have significantly greater negative outcomes when compared to younger patient populations including acute renal injury, significant arrhythmias, heart failure and higher mortality both in the ICU and at 6 months.

Postconditioning During Percutaneous Coronary Intervention in Acute Myocardial Infarction

Postconditioning During Percutaneous Coronary Intervention in Acute Myocardial Infarction

Gender disparity in early death after ST-elevation myocardial infarction.

Females with acute myocardial infarction (AMI) have a higher risk of adverse outcomes because of receiving less evidence-based medical care. Our aim was to investigate the gender disparity in early death after ST-elevation myocardial infarction (STEMI) in the current era. A total of 1429 consecutive patients with STEMI in the Liaoning district were analyzed. We compared hospital care and cardiac event data by sex for in-patients with acute STEMI within 24 hours of symptom onset. In the emergency reperfusion group (n = 754), in-hospital mortality occurred in 4.2% of the males and 11.2% of the females (P = 0.001). In the non-emergency reperfusion group (n = 675), in-hospital mortality occurred in 13.0% of the males and 22.9% of the females (P = 0.001). Multivariate Logistic regression analysis revealed female sex as an independent risk factor of death for STEMI patients during hospitalization (OR = 1.691, P = 0.007). After controlling for patients who died within 24 hr after admission, female sex was no longer an independent risk factor (OR = 1.409, P = 0.259). Female sex was an independent risk factor for in-hospital mortality of STEMI patients, which is explained by an excess of very early deaths.

026 TRENDS IN IN-HOSPITAL TREATMENTS, INCLUDING REVASCULARISATION, FOLLOWING ACUTE MYOCARDIAL INFARCTION, 2003–2010: A MULTI-LEVEL AND RELATIVE SURVIVAL ANALYSIS FOR THE NATIONAL INSTITUTE FOR CARDIOVASCULAR OUTCOMES RESEARCH (NICOR)

BackgroundIt is not known how survival has changed over time for patients who do and do not receive an early invasive strategy for the management of AMI.Table 1Patient characteristics by...

Interpretation of Serum Troponin Elevation

Interpretation of Serum Troponin Elevation

Summary of 2012 ESC Guidelines

The new guidelines deal with the management of patients with STEMI and replace the document published in 2008. It covers different aspects such as emergency care and reperfusion therapy but also special subsets such as patient population, logistics, risk assessment and long-term therapies. After the 2000 and 2007 statements the third Global MI Task Force (Joint ESC/ACCF/AHA/WHF) now recognizes in the new definition of acute myocardial infarction (MI) that very small amounts of myocardial injury or necrosis can be detected by biochemical markers and/or imaging, particularly when such necrosis occurs in the setting of the critically ill, after percutaneous coronary procedures or after cardiac surgery.

Single Centre Experience and Outcome of Primary Percutaneous Coronary Intervention for Patients with ST-Segment-Elevation Myocardial Infarction

Background: Primary percutaneous coronary intervention is an emergent coronary angiography and mechanical reperfusion of the infarct-related artery performed in patients with ST-segment elevation myocardial infarction. The present study aimed to determine the outcomes of primary percutaneous coronary intervention in a tertiary care cardiac centre. Aims: The present study carried out with the aim to determine the outcomes of primary percutaneous coronary intervention in a tertiary care cardiac centre. Methods: We evaluated 548 patients presented treated for ST-segment elevation myocardial infarction with primary percutaneous coronary intervention at Sri Venkateswara Institute of Medical Sciences, Tirupati, India from January 2011 to December 2012. Results: Total 548 patients were included in this study. Mean age of patients was 54.5 ± 11.5 years. Cardiogenic shock, complete heart block and ventricular tachycardia / ventricular fibrillation was encountered in 31 (5.7%), 40 (7.3%) and 49 (8.9%) patients respectively at hospital admission. The average door to balloon time was 62.5 ± 15.0 minutes. Thrombus aspiration was performed in 159 (29.0%) patients during the index procedure. During hospital stay, in-hospital mortality was 20 (3.6%) out of which 15 (2.7%) patients died from cardiac cause. Target vessel revascularization, major bleeding and minor bleeding observed in 5 (0.9%), 5 (0.9%) and 11 (2.0%) cases respectively. Result of this six-month outcome of the studied showed 5 (0.9%) deaths and 5 (0.9%) incidence of target vessel revascularization. Conclusions: Our data suggest that primary percutaneous coronary intervention for ST-segment elevation myocardial infarction can be safely performed in a regional institution with acceptable door to balloon time and low major adverse cardiac event rates. Keywords: Percutaneous coronary intervention, ST-segment elevation myocardial infarction, door to balloon, coronary artery disease. Read more →

Interpretation of Serum Troponin Elevation

Interpretation of Serum Troponin Elevation

Updates on the Electrocardiogram in Acute Coronary Syndromes

The electrocardiogram (ECG) is the initial test in patients with suspected ACS. The ECG is the defining element of ST-segment elevation myocardial infarction (STEMI). Its most important use is in the detection of acute coronary obstruction, and it is the most important, cost-effective, and immediately available initial test in the decision for emergency reperfusion therapy. There is a recent interest in refining the sensitivity and specificity of the ECG for coronary occlusion, and thus for identifying subtle STEMI, as well as in recognizing pseudoinfarction patterns and thus avoiding false positive cath lab activations. Studies assessing the accuracy of cath lab activation, the differentiation of precordial ST-segment elevation due to normal variant from that of anterior STEMI, the diagnosis of STEMI in the presence of left bundle branch block, the differentiation of benign inferior ST-segment elevation from that of inferior STEMI, and the importance of ST-segment elevation in lead aVR will be discussed.

Management and outcomes of patients with ST-elevation myocardial infarction in Liaoning province

Objective To analyze the management and outcomes of patients with ST-segment elevation myocardial infarction (STEMI) in Liaoning province.Methods The data were collected from a prospective and multicenter registry study including 8 tertiary hospitals and 12 secondary hospitals in Liaoning province.Total 1429 patients with acute STEMI admitted to hospitals from June 2009 to June 2010 were included in the study.A unified follow-up questionnaire was applied on patient discharged.Results The average age of patients was (63 ± 13)years.37.4％ of patients recognized the disease as heart disease and 39.7％ were transported by emergency ambulance with a median symptom-to-door time of 150 min.52.9％ patients underwent emergency reperfusion therapy,including fibrinolytic therapy (24.4％) and primary percutaneous coronary intervention (PCI,28.1％).The in-hospital treatment included aspirin (99.6％),clopidogrel (81.9％),statins (90.1％),low molecular weight heparin (89.5％),β-blocker (66.0％),angiotensin converting enzyme inhibitor (ACEI)/ angiotensin receptor blocker (ARB)(66.6％).The in-hospital mortality was 10.7％ ; the mortality in females was higher than that in males (18.3％ vs.7.9％,P ＜ 0.01) and the mortality in older patients (≥ 65 years) was higher than that in younger patients (＜65 years)(17.0％ vs.5.2％,P ＜0.01).The follow-up treatment included:aspirin (81.1％),clopidogrel (45.0％),statins (61.0％),β-blocker (48.3％),ACEI/ARB (42.4％).The follow-up mortality was 5.0％ after hospital discharge.Conclusions Longer pre-hospital delay is commonly seen in STEMI patients.There is still certain gap of emergency reperfusion therapy and the evidence-based medication with related clinical guidelines of STEMI management in Liaoning. Key words: Myocardial infarction; Myocardial reperfusion; Therapy; Cross-sectional studies

Improving Recovery After Stroke

Although stroke is a leading cause of death in the United States and around the world, many people fear this disease because of its nonfatal neurological impairments that lead to disability or dependency. Considerable research has focused on lessening the neurological effects of the acute brain injury. To date, success is limited. Despite these research efforts, only intravenous thrombolysis and endovascular interventions are accepted as effective in limiting the acute effects of ischemic stroke. Although these therapies are efficacious, only 3% to 5% of patients with stroke are receiving reperfusion-based therapies due to the very short time windows for treatment.1 No medical or surgical intervention is useful in improving outcomes after intracerebral hemorrhage. Annually, approximately 400 000 Americans need rehabilitation to help with recovery after stroke.2 Given the magnitude of the problem, effective new therapies are needed to augment the process of recovery. These therapies could be given as adjuncts to conventional rehabilitation to these patients who have potentially disabling residual neurological impairments. Because many more patients could be treated, an effective therapy that maximizes neurological recovery might have a much bigger societal impact than emergency reperfusion therapy alone.3,4 Unfortunately, relatively few clinical studies have tested interventions that might augment recovery. The basic science understandings of the process of recovery after stroke have advanced.5–10 It is now clear that the adult brain has a real capacity for physiological and anatomic modifications that lead to motor and cognitive recovery.11 This complex process is mediated by multiple mechanisms including enhanced regional metabolism and resolution of diaschisis. Cellular changes after stroke include proliferation of neural and glial cell precursors, activation of astrocytes and inflammatory cells, migration of blood vessels, increased axonal sprouting, increased branching of dendrites, and development of new synapses.12–14 …

Acute coronary syndromes: is there a place for a real pre-hospital treatment for patients “en route” to the coronary intensive care unit?

Acute initial management of patients with acute coronary syndrome (ACS) is based on a precise clinical and electrocardiographic diagnosis. Initial risk stratification in the pre-hospital phase is the key step. The last step, adequate patient routing, is decided based on emergency level and reperfusion strategies, considered right from the pre-hospital phase. The management of a patient with an ACS requires close collaboration between emergency physicians and cardiologists, according to simplified protocols for easier access to catheterisation. The next challenges for the pre-hospital management of ACS are based on: - precise knowledge of new antiplatelet and anticoagulant drugs by the emergency physicians, in order to adjust their prescriptions to the patient profile; - developing co-operation between hospitals, according to regional specificities (geographic considerations and distribution of PCI centres) in order to reduce access time to catheterisation rooms; - organising the healthcare network, where the SAMU has an essential role in coordinating the different medical actors; - regular analysis of the evolution of our professional practices, considering, e.g., the guidelines of the "HAS" (French official healthcare guidelines institute);- integrating pre-hospital medicine in health prevention programmes; - improving our understanding of the population's presentations of coronary artery disease, in order to encourage the patients and their families to call the EMS as soon as possible. The challenge of the emergency physician is to adapt the strategies to the patient's needs.

A randomized controlled trial of oxygen therapy in acute myocardial infarction Air Verses Oxygen In myocarDial infarction study (AVOID Study)

The role of routine supplemental oxygen for patients with uncomplicated acute myocardial infarction (AMI) has recently been questioned. There is conflicting data on the possible effects of hyperoxia on ischemic myocardium. The few clinical trials examining the role of oxygen in AMI were performed prior to the modern approach of emergent reperfusion and advanced medical management. Air Verses Oxygen In myocarDial infarction study (AVOID Study) is a prospective, multi-centre, randomized, controlled trial conducted by Ambulance Victoria and participating metropolitan Melbourne hospitals with primary percutaneous coronary intervention capabilities. The purpose of the study is to determine whether withholding routine supplemental oxygen therapy in patients with acute ST-elevation myocardial infarction but without hypoxia prior to reperfusion decreases myocardial infarct size. AVOID will enroll 490 patients, >18 years of age with acute ST-elevation myocardial infarction of less than 12 hours duration. There is an urgent need for clinical trials examining the role of oxygen in AMI. AVOID will seek to clarify this important issue. Results from this study may have widespread implications on the treatment of AMI and the use of oxygen in both the pre-hospital and hospital settings.

Comparison of Clinical Characteristics, Treatments and Outcomes of Patients With ST-Elevation Acute Myocardial Infarction With Versus Without New or Presumed New Left Bundle Branch Block (from NCDR®)

Guidelines recommend urgent reperfusion for patients with new left bundle branch block (LBBB), similar to patients with ST-segment elevation myocardial infarction (STEMI). However, there are limited contemporary data comparing these 2 groups of patients. Patients presenting with acute STEMI or presumed new LBBB (nLBBB) enrolled in the Acute Coronary Treatment and Intervention Outcomes Network (ACTION) Registry-Get With the Guidelines (GWTG) from January 2007 to March 2009 were evaluated for clinical characteristics, treatment patterns, and outcomes. Logistic generalized estimating equation modeling was used to examine associated risk-adjusted mortality. Of 46,006 patients with either STEMI or nLBBB, 44,405 (96.5%) had STEMI, and 1,601 (3.5%) had nLBBB. Overall, patients with nLBBB had more baseline co-morbidities compared to those with STEMI. Compared to patients with STEMI, those with nLBBB were less likely to receive acute reperfusion (93.9% vs 48.3% p <0.0001) and were less likely to have door-to-balloon times ≤90 minutes (76.8% vs 34.5%, p <0.0001). Mortality rates were higher for patients with nLBBB compared to those with STEMI (13.3% vs 5.6%, p <0.0001). After multivariate adjustment, nLBBB was not associated with an increased risk for in-hospital mortality (odds ratio 0.91, 95% confidence interval 0.75 to 1.12, p = 0.38). In conclusion, patients with nLBBB were clinically different from those with STEMI, with significantly more co-morbidities, and were less likely to receive emergent reperfusion therapy. Despite these differences, adjusted mortality rates were similar between patients with nLBBB and those with STEMI.

Abstract P202: Do Cardiac Hemodynamic Differences in Patients with Acute ST-Elevation Myocardial Infarction Contribute to Gender Differences in Outcomes?

Aim: Previous studies demonstrate higher 30-day all-cause mortality and re-infarction amongst women with ST-elevation myocardial infarction (STEMI). This study examines if gender differences exist in cardiac hemodynamic parameters assessed during an acute STEMI. Methods: The clinical, angiographic and hemodynamic features of 470 consecutive patients undergoing emergency primary percutaneous coronary intervention for an acute STEMI were evaluated with respect to gender. Patients routinely underwent right heart catheterization using a Swan-Ganz catheter, during the emergency reperfusion therapy procedure. Infarct size was estimated by evaluating the peak creatinine kinase (CK) levels. Results: The 135 STEMI female patients were significantly older than males (69±13 vs. 60±12 years, P &lt;0.001) so subsequent analyses were age-adjusted. The findings are summarized below (*p &lt; 0.05, **p&lt;0.001 compared with men). Multivariate logistic regression analysis revealed that pulmonary capillary wedge pressure (PCWP) was the strongest independent predictor of 30-day death and re-infarction (Odds Ratio for PCWP = 1.06 (95% CI = 1.01 - 1.12, p = 0.019). Conclusion: Women with an acute STEMI have a higher 30-day cardiac event rate despite similar extent of coronary artery disease, infarct size and site. However they do have higher left ventricular filling pressures, which is consistent with their poorer outcomes. The mechanism/s of this hemodynamic difference requires further investigation. Clinical and Hemodynamic Features of STEMI patients (Expressed as Mean ± SD or frequency data) Men (n = 335) Women (n =135) Acute Anterior STEMI on ECG 128 (41%) 53 (40%) Peak Creatine Kinase 2309±5894 IU 1455±1797 IU Multi-vessel disease on angiography 168 (51%) 61 (49%) Initial Heart Rate 80±22 bpm 79±25 bpm Initial systolic blood pressure 137±29 mmHg 145±99 mmHg Pulmonary capillary wedge pressure 16±7 mmHg 20±7 mmHg* Arterial oxygen saturation 97±4.5% 97±2.9% Mixed venous oxygen saturation 70±9% 67±10% 30 Day All cause Mortality/Re-Infarction 14 (4%) 15 (11%)*

Resolving inequalities in care? Reduced mortality in the elderly after acute coronary syndromes. The Myocardial Ischaemia National Audit Project 2003-2010

To examine age-dependent in-hospital mortality for hospitalization with acute coronary syndromes (ACS) in England and Wales. Mixed-effects regression analysis using data from 616 011 ACS events at 255 hospitals as recorded in the Myocardial Ischemia National Audit Project (MINAP) 2003-2010; 102 415 (16.7%) patients were aged <55 years and 72 721 (11.9%) ≥85 years. Patients ≥85 years with ST-elevation myocardial infarction (STEMI) were less likely to receive emergency reperfusion therapy than those <55 years (RR = 0.27, 95% CI: 0.25-0.28). Older patients had greater lengths of stay (P< 0.001) and higher in-hospital mortality (P< 0.001). For STEMI and non-ST-elevation myocardial infarction (NSTEMI), there were reductions in in-hospital mortality from 2003 to 2010 across all age groups including the very elderly. For STEMI ≥ 85 years, in-hospital mortality reduced from 30.1% in 2003 to 19.4% in 2010 (RR = 0.54, 95% CI: 0.38-0.75, P< 0.001), and for NSTEMI ≥ 85 years, from 31.5% in 2003 to 20.4% in 2010 (RR = 0.56, 95% CI: 0.42-0.73, P< 0.001). Findings were upheld after multi-level adjustment (base = 2003): male STEMI 2010 OR = 0.60, 95% CI: 0.48-0.75; female STEMI 2010 OR = 0.55, 95% CI: 0.42-0.71; male NSTEMI OR = 0.50, 95% CI: 0.42-0.60; female NSTEMI OR = 0.49, 95% CI: 0.40-0.59. For patients hospitalized with ACS in England and Wales, there have been substantial reductions in in-hospital mortality rates from 2003 to 2010 across all age groups. The temporal improvements in mortality were similar for sex and type of acute myocardial infarction. Age-dependent inequalities in the management of ACS were apparent.