Prehospital Thrombolysis Research Articles

047 What are the predictors of not receiving a reperfusion therapy in STEMI patients?

The proportion of pts receiving a reperfusion therapy was fluctuating but relatively stable during the last 16 years ranging from 45.2% in 1995 to 58.2% in 2010 with a peak of 74.2% in 2001. From 1995 to 2000, reperfusion was almost exclusively performed by thrombolysis whereas a dramatic increase of the use of PAMI was observed between 2000 and 2005 followed by a decrease in favor of the use of thrombolysis during the following 5 years probably due to an increase of the use of prehospital thrombolysis that ranged from14.3% in 2001 to 84% in 2009 among the thrombolysed pts.

NSW Pre-hospital Thrombolysis

NSW Pre-hospital Thrombolysis

Ultrasound Enhanced Prehospital Thrombolysis Using Microbubbles Infusion in Patients with Acute ST Elevation Myocardial Infarction: Pilot of the Sonolysis Study

In animal studies, transthoracic ultrasound and microbubbles have shown to dissolve thrombi in ST elevation myocardial infarction (STEMI). To examine this effect in patients, we have initiated the Sonolysis trial. In this pilot study of 10 patients with a first acute STEMI, we investigated the safety and feasibility of this trial. After pretreatment in the ambulance, five patients were randomized to receive microbubbles with three-dimensional (3-D) guided high mechanical index impulses (1.18) for 15 min, whereas the control group received placebo without ultrasound. Subsequently, primary percutaneous coronary intervention (PPCI) was performed, if indicated. All patients successfully underwent study treatment and PPCI. No significant difference between treatment and control group in safety (minor adverse events 2/5 vs. 2/5, p = NS) and outcome (TIMI III flow 3/5 vs. 1/5 respectively, p = 0.23) was recorded. These results demonstrate that the study protocol is feasible in the acute cardiac care setting and safe during treatment and follow-up.

Abstract 17087: Doubled Survival From Out-of-Hospital Cardiac Arrest in a Rural Community in North-Norway Following Implementation of an Aggressive Chest Pain Protocol with Early Prehospital Thrombolysis for STEMI

Introduction Survival from prehospital cardiac arrest (PCA) remains low. Tromsø municipality in rural North-Norway has a mixed urban-rural population of 60.000, good ground and air ambulance systems, short response times, and dispatch centres staffed with nurses and paramedics, all loyal to current guidelines. Hypothesis By changing focus from the onset of ‘ collapse ’ in PCA to the onset of chest pain in acute coronary syndrome, we hypothesized that more PCA-patients could survive by saving time to alarm, dispatch, diagnosis and first defibrillation. We started an aggressive criteria based prehospital chest pain protocol in 2000. Local GPs and ambulance paramedics were trained in symptoms and signs of STEMI, to access and transmit prehospital 12-leads ECG, give MONA as well as early prehospital thrombolysis (PHT) to patients with prehospital diagnosed acute STEMI. We applied defibrillation pads to all chest pain. The population was informed through media stunts. Methods Retrospective study of survival from PCA during two 5-years periods in Tromsø (1999 -2004; 2004-2009). Each PCA patient's Utstein-chart, digital dispatch centre logs, hospital records and non-survivors autopsy reports were analysed. Results Annual incidence of PCA with resuscitation attempts and ambulance dispatched was 45,3 pr. 100.000. During first 5-years, 10,5 % of all patients (18/172) with PCA were discharged alive. During second period, survival to discharge doubled to 22,3 % (31/139, p<0,05). Presence of an initial shockable rhythm (VF/VT) increased significantly. In patients with witnessed PCA of cardial etiology and a shockable first rhythm, survival to discharge was 21,4 % during the first 5-years period, but doubled to 44,2 % (19/43, p<0,05) in the second period. CPR was started by lay bystanders prior to ambulance arrival in 68,2 % of patients during first, increasing to 76,3 % during the second study period (NS). Prehospital ambulance response time was unchanged at 10 min in each period. By moving system attention ‘to the left of cardiac arrest’, survival to discharge doubled.

TCT-355: Does Thrombus Extraction from IRA during Rescue PCI after Pre-Hospital Thrombolysis Improve Early and Mid-Term Follow-Up in STEMI Patients?

TCT-355: Does Thrombus Extraction from IRA during Rescue PCI after Pre-Hospital Thrombolysis Improve Early and Mid-Term Follow-Up in STEMI Patients?

Prehospital Administration of Tenecteplase for ST-segment Elevation Myocardial Infarction in a Rural EMS System

Introduction. In the setting of ST-segment elevation myocardial infarction (STEMI), early reperfusion yields better patient outcomes. Emergency medical services (EMS) is the first medical contact for half of the afflicted population, and prehospital thrombolysis may result in considerably faster reperfusion compared with percutaneous coronary intervention (PCI) in rural settings. However, there are few reports of prehospital thrombolysis in rural EMS systems. Objective. To describe a rural EMS system's experience with tenecteplase in STEMI. Methods. Data were retrospectively abstracted from the medical records of patients receiving tenecteplase using standard chart review guidelines. Primary outcomes included time saved by EMS-initiated thrombolysis, aborted infarctions, serious bleeding events, and in-hospital mortality. Secondary outcomes included reinfarction, rescue angioplasty, and appropriateness of treatment. Time savings was defined as transport time after tenecteplase administration plus 90 minutes, which is the typical door-to-balloon time for PCI laboratories. Aborted infarction was defined as resolution of the cumulative ST-segment elevation to ≤50% of that on the initial electrocardiogram (ECG) within two hours after treatment, and peak creatine kinase (CK)/CK-MB levels less than or equal to twice the upper limit of normal. Results. Seventy-three patients received prehospital tenecteplase; this treatment was determined to be appropriate in 86.4% of cases. The mean patient age was 59 years, and 71.6% of the patients were male. Mean (± standard deviation) scene-arrival-to-drug time was 26.2 (±11.4) minutes, the mean scene-arrival-to-hospital-arrival time was 73.0 (±20.6) minutes, and the mean transport time was 46.0 (± 11.1) minutes. Tenecteplase was administered 35.9 (±25.0) minutes prior to hospital arrival, and the estimated reperfusion time savings over PCI was 125.9 (±25.0) minutes. Aborted infarctions were observed in 24.1% of patients, whereas 9.6% suffered reinfarction, 47.9% underwent rescue angioplasty, and 16.7% required coronary artery bypass grafting (CABG). Serious bleeding events occurred in 15 patients (20.5%), and four (5.5%) died. Conclusion. In this retrospective review of rural STEMI patients, tenecteplase was administered 36 minutes prior to hospital arrival, saving approximately two hours over typical PCI strategies and resulting in aborted infarctions in one-fourth of patients. In a rural setting with lengthy transport times to PCI facilities, tenecteplase appears to be a feasible prehospital intervention. Randomized controlled trials are needed to fully evaluate the safety and effectiveness of this intervention prior to widespread adoption.

Prehospital thrombolysis for STEMI: a strategy for town and country?

Prehospital thrombolysis for STEMI: a strategy for town and country?

Letter to the editors: the potential role for prehospital thrombolysis and time-critical stroke transfers in the northern Norway aeromedical retrieval system; In response to: Norum J, Elsbak TM: Air ambulance services in the Arctic: a Norwegian study. Int J Emerg Med 2011, 4:1.

The role for prehospital thrombolysis for ST-elevation acute myocardial infarction and time-critical stroke transfers in the northern Norway aeromedical retrieval system as well as the aero-evacuation impact of increased Arctic expedition tourism could benefit from further discussion by Norum and Elsbak. Close ECG surveillance for ST elevation and retrieval thrombolysis en route to the accepting hospital could be of benefit for acute coronary syndrome patients in northern Norway who require prolonged aeromedical transfer. For patients who remain within a reasonable time frame for stroke thrombolysis (up to 4.5 h after symptom onset), expedited transfer for neuroimaging to determine eligibility is recommended.

Ting JY: Letter to the Editors: The potential role of prehospital thrombolysis and time-critical stroke transfers in the northern Norway aeromedical retrieval system.

In our study, we reported a lengthy 3 h 33 min one-way transfer time from the Norwegian Arctic to the mainland. However, I fully agree with Ting that we should have focused more on the present system where ECGs may be communicated digitally from the ambulances, district medical centers and local hospitals to cardiologists at the main hospitals. This was however mentioned in our previous article on ambulances. In practice, patients in the Svalbard Islands are now transported to the small hospital unit in Longyearbyen for diagnosis (ECG) and initial treatment. The ECG is then communicated digitally to the cardiologist on duty at the University Hospital of North Norway (UNN) located on the mainland (city of Tromso). The recognition of STEMI can be achieved and advice concerning prehospital thrombolysis given by the cardiologist prior to the lengthy transfer to the mainland. In some settings ECGs may also be communicated from minor bases in the Arctic, but be aware of communication problems this far to the north. I am aware of one case where an ECG was sent by fax from a remotely located base (Jan Mayen) in the Norwegian Arctic to the UNN.

Association of mechanical chest compression and prehospital thrombolysis

Pulmonary embolism (PE) is a common cause of sudden death; the use of prehospital thrombolysis is currently a last-resort option and requires a prolonged cardiopulmonary resuscitation (CPR). Novel mechanical devices have recently been introduced that provides automatic mechanical chest compression (AMCC) according to the guidelines and continually without decrease efficiency throughout prolonged resuscitation. A 54 year-old woman with a history of breast cancer experienced sudden chest pain and severe dyspnea. A mobile intensive care unit was dispatched to her home. During physical examination, she suddenly collapsed with pulseless electrical activity as the initial rhythm. Prehospital thrombolysis during CPR combined with use of AMCC was performed based on a strongly suspected diagnosis of massive PE. After 75 minutes of effective CPR, return of spontaneous circulation was attained. After admission to an intensive care unit, computed tomographic scan confirmed bilateral PE. The patient was discharged 3 weeks after CPR in good neurologic condition. To our knowledge, this is the first case describing combined use of thrombolysis and AMCC in out-ofhospital cardiac arrest. However, for the time being, prehospital thrombolysis in CPR continues to be a measure that should only be performed on a case-by-case basis based on informed decision. Further studies are needed to evaluate the efficacy and safety of AMCC with thrombolysis and thus prolonged CPR.

A simple nomogram for early prediction of myocardial reperfusion after pre-hospital thrombolysis

To discriminate early ST-segment elevation myocardial infarction (STEMI) presenters at a high probability of successful pre-hospital thrombolysis (PHT) using a simple nomogram based on independent predictors of complete ST resolution. OPTIMAL was an observational, prospective study undertaken at 79 medical centres in France in patients with STEMI undergoing pre-hospital thrombolysis (PHT) within six hours of symptom onset and coronary angiography within six hours of thrombolysis. The baseline and pre-coronary angiography ECGs of 800 patients were analysed. The main outcome measure was ST segment resolution ≥ 70%. ST resolution was associated with a significant reduction in mortality (1.8% vs. 4.3%; p=0.05). After multivariable logistic regression analysis, five independent predictors of successful myocardial reperfusion were identified: ≤ 1 h between pain onset and thrombolysis (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.18-2.62); body mass index (BMI) <30 kg/m2 (OR 1.74, CI 1.12-2.72); current/previous smoking (OR 1.71, CI 1.21-2.43); non-anterior infarct territory (OR 1.75, CI 1.27-2.41); and maximum amplitude of ST elevation <3 mm (OR 1.83, CI 1.32-2.54). The C-statistic of the model was 0.71 (95% CI 0.67-0.74). Using these five independent factors, a simple nomogram was developed to assess the probability of ST resolution after PHT. This nomogram allows discrimination of probabilities ranging from 13 to 72%. This simple nomogram can predict the probability of successful myocardial reperfusion after thrombolysis. This may be useful in the triage of STEMI presenters.

Post Cardiac Arrest Syndrome

Out-of-hospital cardiac arrest (OHCA) is a common initial presentation of cardiovascular disease, affecting up to 325 000 people in the United States each year.1 In a recent meta-analysis of >140 000 patients with OHCA, survival to hospital admission was 23.8%, and survival to hospital discharge was only 7.6%.2 In patients who initially achieve return of spontaneous circulation (ROSC) after OHCA, the significant subsequent morbidity and mortality are due largely to the cerebral and cardiac dysfunction that accompanies prolonged whole-body ischemia. This syndrome, called the post cardiac arrest syndrome, comprises anoxic brain injury, post cardiac arrest myocardial dysfunction, systemic ischemia/reperfusion response, and persistent precipitating pathology3,4 (Table 1). The contribution of each of these components in an individual patient depends on various factors, including prearrest comorbidities, duration of the ischemic insult, and cause of the cardiac arrest. This review focuses on therapeutic strategies and recent developments in managing patients who are initially resuscitated from cardiac arrest. View this table: Table 1. Post Cardiac Arrest Syndrome: Pathophysiology and Potential Treatment Strategies There are 3 major aspects that require consideration in the management of the post cardiac arrest patient. After resuscitation, a decision must be made in relation to the appropriate triage of the OHCA patient. The next phase of management concerns the in-hospital treatment, which must address each component of the postarrest syndrome as appropriate for the individual patient. Finally, there are issues relating to prognostication and the deployment of various secondary prevention measures. Our recommended treatment algorithm is summarized in the Figure. This ideally follows from the implementation of basic and advanced life support measures, including effective cardiopulmonary resuscitation and defibrillation when appropriate, which are major determinants of outcome.2 Such an approach to care may be further modified according to the presence of other comorbidities and precipitating factors, which should be assessed …

Therapeutic application of ultrasound: contrast-enhanced thrombolysis in acute ST-elevation myocardial infarction; the Sonolysis study

Contrast enhancement by microbubble infusion has proven its applicability in the field of diagnostic ultrasound. Recent studies also indicate a therapeutic effect of the combined use of ultrasound and microbubbles. Results from animal studies demonstrate that diagnostic ultrasound in combination with intravenous microbubbles can dissolve thrombi. So far, this effect has never been tested in patients with an acute ST-elevation myocardial infarction (STEMI). We recently launched a pilot study in acute STEMI patients to assess safety, feasibility and efficacy of the treatment in this patient group with transthoracic three-dimensional diagnostic ultrasound and intravenous microbubbles immediately after prehospital thrombolysis, but prior to primary percutaneous coronary intervention.

COST-EFFECTIVENESS EVALUATION OF PREHOSPITAL THROMBOLYSIS WITH TENECTEPLASE

Aim. To evaluate clinical and cost effectiveness of different reperfusion strategies in myocardial infarction with ST segment elevation (STEMI), including pre-hospital thrombolysis with tenecteplase. Material and methods. Methods of cost-effectiveness analysis and economic modeling were used to calculate the costs of reperfusion in STEMI, expected number of life gains, the cost of life gains depending on reperfusion strategy (no reperfusion, percutaneous coronary intervention (PCI), prehospital thrombolysis, hospital thrombolysis). Results. In accordance to analysis results and from economic point of view, the most effective strategy is primary PCI in patients within therapeutic window and pre-hospital thrombolysis in the remaining patients with STEMI. More complex strategy of patients flow control with patient division into groups of primary PCI, pre-hospital thrombolysis and hospital thrombolysis lead to decrease in reperfusion costs efficacy. Conclusion. The reperfusion model with primary PCI in the first 120 minutes after STEMI symptoms onset, and pre-hospital thrombolysis with bolus thrombolytic administration, when PCI is not possible in this period, is the most effective economically and in respect on mortality reduction in patients with STEMI.

PRE-HOSPITAL THROMBOLYSIS IN KRASNOYARSK: RESULTS OF A RETROSPECTIVE COMPARATIVE STUDY

Aim. To compare the safety and efficacy of pre-hospital thrombolysis with tenecteplase and hospital thrombolysis with alteplase. Material and Methods. Pre-hospital thrombolytic therapy with tenecteplase (n=15) and hospital thrombolysis with alteplaza (n=60) in patients with acute coronary syndrome and acute ST-segment elevation myocardial infarction were analyzed in retrospective comparative study. Time characteristics of thrombolysis and its efficacy and safety were assessed. Results. The mean time from patients emergency medical service call to pre-hospital thrombolysis was 51.8±1.23 min, whereas to hospital thrombolysis 106.5±2.15 min (p&lt;0.05). The effective hospital thrombolysis was observed in 68.3 and 83.3% of patients according to ECG (&gt;50% resolution of ST-segment elevation) and coronary angiography criteria, respectively. The effective pre-hospital thrombolysis was registered in 93.3% of patients as demonstrated with ECG and coronary angiography. Conclusion. Pre-hospital thrombolysis in patients with acute coronary syndrome was performed by 54.7 min earlier than hospital thrombolysis was. This can improve the patient prognosis.

AToMS: A Ubiquitous Teleconsultation System for Supporting AMI Patients with Prehospital Thrombolysis

The latest population-based studies in the medical literature worldwide indicate that acute myocardial infarction (AMI) patients still experience prolonged delay to be rescued, which often results in morbidity and mortality. This paper reports from a technological standpoint a teleconsultation and monitoring system named AToMS. This system addresses the problem of prehospital delivery of thrombolysis to AMI patients by enabling the remote interaction of the paramedics and a cardiologist available at a Coronary Care Unit (CCU). Such interaction allows the diagnosis of the patient eligibility to the immediate application of thrombolysis, which is meant to reduce the delay between the onset of symptoms and the eventual application of proper treatment. Such delay reduction is meant to increase the AMI patient's chances of survival and decrease the risks of postinfarction sequels. The teleconsultation is held with the support of wireless and mobile technologies, which also allows the cardiologist to monitor the patient while he/she is being taken to the nearest CCU. All exchanged messages among paramedics and cardiologists are recorded to render an auditable system. AToMS has been deployed in a first stage in the city of Rio de Janeiro, where the medical team involved in the project has conducted commissioned tests.

Risk Reduction for Cardiac Events After Primary Coronary Intervention Compared With Thrombolysis for Acute ST-Elevation Myocardial Infarction (Five-Year Results of the Swedish Early Decision Reperfusion Strategy [SWEDES] Trial)

Primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction compares favorably to thrombolysis. In previous studies the benefit has been restricted to the early postinfarction period with no additional risk decrease beyond this period. Long-term outcome after use of third-generation thrombolytics and modern adjunctive pharmaceutics in the 2 treatment arms has not been investigated. This study was conducted to compare 5-year outcome after updated regimens of PPCI or thrombolysis. Patients with ST-elevation myocardial infarction were randomized to enoxaparin and abciximab followed by PPCI (n = 101) or enoxaparin followed by reteplase (n = 104), with prehospital initiation of therapy in 42% of patients. Data on survival and major cardiac events were obtained from Swedish national registries after 5.3 years. PPCI resulted in a better outcome with respect to the composite of death or recurrent myocardial infarction (hazard ratio 0.54, confidence interval 0.31 to 0.95) compared to thrombolysis. This was attributed to a significant decrease in cardiac deaths (hazard ratio 0.16, confidence interval 0.04 to 0.74). The difference evolved continuously over the 5-year follow-up. After adjustment for covariates, a significant benefit remained with respect to cardiac death or recurrent infarction but not for the composite of total survival or recurrent myocardial infarction (p = 0.07). The observed differences were not seen in patients in whom therapy was initiated in the prehospital phase. In conclusion, PPCI in combination with enoxaparin and abciximab compares favorably to thrombolysis in combination with enoxaparin with a risk decrease that stretches beyond the early postinfarction period. Prehospital thrombolysis may, however, match PPCI in long-term outcome.

Bringing the Hospital to the Patient: First Treatment of Stroke Patients at the Emergency Site

BackgroundEarly treatment with rt-PA is critical for favorable outcome of acute stroke. However, only a very small proportion of stroke patients receive this treatment, as most arrive at hospital too late to be eligible for rt-PA therapy.Methods and FindingsWe developed a “Mobile Stroke Unit”, consisting of an ambulance equipped with computed tomography, a point-of-care laboratory system for complete stroke laboratory work-up, and telemedicine capabilities for contact with hospital experts, to achieve delivery of etiology-specific and guideline-adherent stroke treatment at the site of the emergency, well before arrival at the hospital. In a departure from current practice, stroke patients could be differentially treated according to their ischemic or hemorrhagic etiology even in the prehospital phase of stroke management. Immediate diagnosis of cerebral ischemia and exclusion of thrombolysis contraindications enabled us to perform prehospital rt-PA thrombolysis as bridging to later intra-arterial recanalization in one patient. In a complementary patient with cerebral hemorrhage, prehospital diagnosis allowed immediate initiation of hemorrhage-specific blood pressure management and telemedicine consultation regarding surgery. Call-to-therapy-decision times were 35 minutes.ConclusionThis preliminary study proves the feasibility of guideline-adherent, etiology-specific and causal treatment of acute stroke directly at the emergency site.

Prehospital thrombolysis in acute myocardia infarction: A meta-analysis

Objective A meta-analysis of clinical trials of prehospital thrombolysis versus in-hospital thrombolysis or PCI for acute myocardia infarction (AMI). Method We collected the literature on prehospital thrombolysis for AMI published at home and abroad from January 1989 to April 2009. Recanalization rate of infarct-related arter, complication incidence and mortality ( ＜ 30 d) were regarded as result indicators. Software RevMan 4.2.8 was used to process meta-analysis. Results There were only 27 literatures selected. Prehospital thrombolysis was associated with higher recanalization rate of infarct-related arter[OR 2.67,95%CI(1.86 ～ 3.85);P ＜0.01] and lower mortality ( ＜ 30 d ) [OR 0.71,95%CI(0.64 ～ 0.78); P ＜ 0.01] than in-hospital thrombolysis. There was no significant difference in complications between them. Compared with PCI, prehospital thrombolysis was associated with higher complication incidence [OR 2.91,95% CI ( 1.26 ～ 3.80); P = O.005]. There was no significant statistical difference of mortality ( ＜30 d ),but the sensitivity analysis was not good. Conchusions The effect and prognosis of prehospital thrombolytic are superior to that of in-hospital thrombolysis,and the same with PCI,but prehospital thrombolytic has higher incidences of complications,and the sensitivity is not good. Key words: Acute myocardia infarction; Prehospital thrombolysis; Recanalization of infarct-related arter;

Paramedic decision making: prehospital thrombolysis and beyond

BackgroundMortality from acute myocardial infarction is influenced by the speed at which reperfusion therapy is delivered. In the UK, prehospital thrombolysis (PHT), administered by paramedics, has been developed to improve...