Maria Sejersten

Effect on Treatment Delay of Prehospital Teletransmission of 12-Lead Electrocardiogram to a Cardiologist for Immediate Triage and Direct Referral of Patients With ST-Segment Elevation Acute Myocardial Infarction to Primary Percutaneous Coronary Intervention

Prehospital electrocardiogram (ECG) transmission to hospitals was shown to reduce time to treatment in patients with acute myocardial infarction. However, new technologies allow transmission directly to a mobile unit so an attending physician can respond irrespective of presence within or outside the hospital. The primary study purpose was to determine whether delays could be decreased in an urban area by transmitting a prehospital 12-lead ECG directly to the attending cardiologists mobile telephone for rapid triage and transport to a primary percutaneous coronary intervention (PCI) center, bypassing local hospitals and emergency departments. A secondary purpose was to describe whether transport would be safe despite longer transport times. During a 2-year period, patients with acute nontraumatic chest pain had their prehospital ECG transmitted directly to a cardiologists mobile telephone. Time to treatment was compared with historic controls. After ECG evaluation, 168 patients (30%) were referred directly for PCI, and 146 of these (87%) underwent emergent catheterization. In referred patients, median time from 911 call to PCI was significantly shorter than in the control group (74 vs 127 minutes; p <0.001). Accordingly, door-to-PCI time was 63 minutes shorter for referred patients versus controls (34 vs 97 minutes; p <0.001). During transport, 7 patients (4%) experienced ventricular fibrillation; 3 patients (2%), ventricular tachycardia; and 1 patient (0.5%), pulseless electrical activity, including 2 deaths (1%) caused by treatment-resistant arrhythmia. In conclusion, transmission of a prehospital 12-lead ECG directly to the attending cardiologists mobile telephone decreased door-to-PCI time by >1 hour when patients were transported directly to PCI centers, bypassing local hospitals. Ambulance transport seems safe despite longer transport times.

Influences of electrocardiographic ischaemia grades and symptom duration on outcomes in patients with acute myocardial infarction treated with thrombolysis versus primary percutaneous coronary intervention: results from the DANAMI‐2 trial

Objective: To determine whether ischaemia grade (GI) on the presenting ECG and duration of symptoms can identify subgroups of patients who would derive more benefit than the general population of patients with ST segment elevation acute myocardium infarction (STEMI) from primary percutaneous coronary intervention (pPCI) over thrombolytic treatment (TT) in reducing mortality or reinfarction. Methods: 1319 DANAMI-2 (Danish trial in Acute Myocardial Infarction-2) patients were classified as having grade 2 ischaemia (GI2; ST segment elevation without terminal QRS distortion) or grade 3 ischaemia (GI3; ST segment elevation with terminal QRS distortion in ⩾ 2 adjacent leads), and were divided into early and late groups split by the median time (3 h) from symptom onset to treatment. Outcomes were 30-day mortality and reinfarction. Results: Mortality was significantly higher for GI3 than for GI2 (9.7% v 4.8%, p < 0.001) and doubled for patients presenting late (GI2: 6.0% v 3.3%, p  =  0.01; GI3: 12.5% v 4.7%, p  =  0.05). Overall mortality did not differ significantly between pPCI and TT; however, a 5.5% absolute mortality reduction was seen in GI3 treated early with pPCI (1.4% v 6.9%, p  =  0.10). Reinfarction rate was particularly high among GI3 patients presenting late and treated with TT (12.2%). pPCI in such patients significantly reduced the rate of reinfarction (0%, p < 0.001). Logistic regression analysis showed that age (odds ratio (OR) 1.09, 95% confidence interval (CI) 1.06 to 1.12, p < 0.001), prior angina (OR 2.56, 95% CI 1.44 to 4.54, p  =  0.001), heart rate (OR 1.03, 95% CI 1.01 to 1.04, p  =  0.001) and GI3 (OR 1.91, 95% CI 1.06 to 3.44, p  =  0.031) were independently associated with mortality, whereas the sum of ST segment elevation was not. Conclusions: GI3 is an independent predictor of mortality among patients with STEMI. Mortality increased significantly with symptom duration in both GI2 and GI3. pPCI may be especially beneficial for patients with GI3 presenting early, whereas patients with GI3 presenting late and treated with TT are at particular risk of reinfarction.

Feasibility and Safety of Prehospital Administration of Bivalirudin in Patients With ST-Elevation Myocardial Infarction

The selective thrombin inhibitor bivalirudin with a provisional glycoprotein IIb/IIIa inhibitor (GPI) has been shown to be comparable to heparin plus GPI in the rates of ischemic events but to significantly reduce the risk of bleeding complications in patients with acute coronary syndromes. The aim of this preliminary study was to describe the feasibility and safety of a switch from prehospital administration of unfractionated heparin to bivalirudin in ST-elevation acute myocardial infarction (STEMI) patients referred for primary percutaneous coronary intervention. Patients with STEMI treated with a 1-mg/kg bivalirudin bolus in the ambulance followed by infusion during angiography/primary percutaneous coronary intervention were compared with a STEMI control group (from the preceding year) treated with 10,000 U unfractionated heparin in the ambulance followed by in-hospital treatment with a GPI. A total of 102 patients (59%) receiving bivalirudin and 72 receiving heparin were followed during hospitalization. The baseline characteristics and prehospital treatment times were comparable between the 2 groups. The thrombolysis in myocardial infarction flow before and after primary percutaneous coronary intervention was similar. Stents were used significantly more often in the heparin-treated patients (90% versus 76%; p = 0.04), with bailout GPI for those receiving bivalirudin occurring in 30% compared with 83% of those receiving heparin (p <0.001). Significant bleeding complications were seen in <10% of all patients undergoing angiography with no difference between groups. Bivalirudin was easy to administer in the prehospital setting and did not affect the prehospital run times. In conclusion, the results suggest that prehospital bivalirudin administration is as safe and effective as heparin in the treatment of patients with STEMI. Prehospital administration seemed to reduce the need for GPI.

Referral of patients with ST-segment elevation acute myocardial infarction directly to the catheterization suite based on prehospital teletransmission of 12-lead electrocardiogram.

BACKGROUND Time from symptom onset to reperfusion is essential in patients with ST-segment elevation acute myocardial infarction. Prior studies have indicated that prehospital 12-lead electrocardiogram (ECG) transmission can reduce time to reperfusion. PURPOSE Determine 12-lead ECG transmission success rates, and time saved by referring patients directly to primary percutaneous coronary intervention (pPCI) bypassing local hospitals and emergency departments. METHODS Prehospital 12-lead ECG was recorded in patients with symptoms suggesting acute coronary syndrome during a 1-year pilot phase and transmitted to the attending cardiologists mobile phone. Transmission success rates were determined, and prehospital and hospital delays were recorded and compared to historic controls. RESULTS Transmission was attempted in 152 patients and was successful in 89%. Twenty-seven patients were referred directly for pPCI. Median hospital arrival to pPCI was 22 vs 94 minutes in the control group (P < .01). CONCLUSIONS Transmission of prehospital ECG is technically feasible and reduces time to pPCI in ST-segment elevation acute myocardial infarction patients.

Pre-hospital diagnosis and transfer of patients with acute myocardial infarction--a decade long experience from one of Europe's largest STEMI networks.

Early reperfusion in patients with ST-segment elevation myocardial infarction (STEMI) is essential. Although primary percutaneous coronary intervention (pPCI) is the preferred revascularization technique, it often involves longer primary transportation or secondary inter-hospital transfers and thus longer system related delays. The current ESC Guidelines state that PCI should be performed within 120 minutes from first medical contact, and door-to-balloon time should be <60 minutes in order to reduce long term mortality. STEMI networks should be established with regionalization of pPCI treatment to address the challenges regarding pre-hospital treatment, triage and transport of STEMI patients and collaborations between hospitals and Emergency Medical Services (EMS). We report on a regional decade long experience from one of Europes largest STEMI networks located in Eastern Denmark, which serves a catchment area of 2.5 million inhabitants by processing ~4000 prehospital ECGs annually transmitted from 4 EMS systems to a single pPCI center treating 1100 patients per year. This organization has led to a significant improvement of the standard of therapy for acute myocardial infarction (MI) patients leading to historically low 30-day mortality for STEMI patients (<6%). About 70-80% of all STEMI patients are being triaged from the field and rerouted to the regional pPCI center. Significant delays are still found among patients who present to local hospitals and for those who are first admitted to a local emergency room and thus subject to inter-hospital transfer. In the directly transferred group, approximately 80% of patients can be treated within the current guideline time window of 120 minutes when triaged within a 185 km (~115 miles) radius. Since 2010, a Helicopter Emergency Medical Service has been implemented for air rescue. Air transfer was associated with a 20-30 minute decrease from first medical contact to pPCI, at distances down to 90 km from the pPCI center and with a trend toward better survival among air transported patients. The pPCI center also serves a small island in the Baltic Sea, where STEMI patients are rescued via air force helicopters. Based on data from more than 100 patients transferred over the past decade, we have found a similar in-hospital and long term mortality rate compared to the main island inhabitants. In conclusion, with the optimal collaboration within a STEMI network including local hospitals, university clinics, EMS and military helicopters using the same telemedicine system and field triage of STEMI patients, most patients can be treated within the time limits suggested by the current guidelines. These organizational changes are likely to contribute to the improved mortality rate for STEMI patients.

Long-Term Prognostic Value of ST-Segment Resolution in Patients Treated With Fibrinolysis or Primary Percutaneous Coronary Intervention: Results From the DANAMI-2 (DANish trial in Acute Myocardial Infarction-2)

OBJECTIVES The purpose of this study was to determine the prognostic value of ST-segment resolution after primary percutaneous coronary intervention (pPCI) versus fibrinolysis. BACKGROUND Resolution of the ST-segment has been used as a surrogate end point in trials evaluating reperfusion in acute myocardial infarction; however, its prognostic significance may be limited to patients treated with fibrinolysis. METHODS In the DANAMI-2 (DANish trial in Acute Myocardial Infarction-2) substudy, including 1,421 patients, the ST-segment elevation at baseline, pre-intervention, 90 min, and 4 h was assessed. The ST-segment resolution was grouped as follows: 1) complete > or =70%; 2) partial 30% to <70%; and 3) no resolution <30%. End points were 30-day and long-term mortality and reinfarction. RESULTS The ST-segment resolution at 90 min was more pronounced after pPCI (median 60% vs. 45%, p < 0.0001), and a catch-up phenomenon was observed at 4 h. In the fibrinolysis group, 30-day and long-term mortality rates were significantly higher among patients without ST-segment resolution, whereas reinfarction rates were higher with complete ST-segment resolution. The ST-segment resolution was not associated with the 2 end points in the pPCI group. By multivariate analysis, ST-segment resolution at 4 h was an independent predictor of lower mortality, but higher reinfarction rates among patients receiving fibrinolytic therapy. CONCLUSIONS The ST-segment resolution at 90 min was more complete after pPCI, suggesting better epicardial and microvascular reperfusion, whereas no difference between treatment strategies was seen at 4 h. The ST-segment resolution at 4 h correlated with decreased mortality, but increased reinfarction rates among patients receiving fibrinolytic therapy, whereas no association was seen for patients receiving pPCI. Consequently, 4-h ST-segment resolution remains an important prognosticator after fibrinolysis, but may be overemphasized as a surrogate end point after pPCI.

Reperfusion delay in patients treated with primary percutaneous coronary intervention: insight from a real world Danish ST-segment elevation myocardial infarction population in the era of telemedicine:

Background: Reperfusion delay in ST-segment elevation myocardial infarction (STEMI) predicts adverse outcome. We evaluated time from alarm call (system delay) and time from first medical contact (PCI-related delay), where fibrinolysis could be initiated, to balloon inflation in a pre-hospital organization with tele-transmitted electrocardiograms, field triage and direct transfer to a 24/7 primary percutaneous coronary intervention (PPCI) center. Methods and results: This was a single center cohort study with long-term follow-up in 472 patients. The PPCI center registry was linked by person identification number to emergency medical services (EMS) and National Board of Health databases in the period of 2005–2008. Patients were stratified according to transfer distances to PPCI into zone 1 (0–25 km), zone 2 (65–100 km) and zone 3 (101–185 km) and according to referral by pre-hospital triage. System delay was 86 minutes (interquartile range (IQR) 72–113) in zone 1, 133 (116–180) in zone 2 and 173 (145–215) in zone 3 (p<0.001). PCI-related delay in directly referred patients was 109 (92–121) minutes in zone 2, but exceeded recommendations in zone 3 (139 (121–160)) and for patients admitted via the local hospital (219 (171–250)). System delay was an independent predictor of mortality (p<0.001). Conclusions: Pre-hospital triage is feasible in 73% of patients. PCI-related delay exceeded European Society of Cardiology (ESC) guidelines for patients living >100 km away and for non-directly referred patients. Sorting the PPCI centers catchment area into geographical zones identifies patients with long reperfusion delays. Possible solutions are pharmaco-invasive regiments, research in early ischemia detection, airborne transfer and EMS personnel education that ensures pre-hospital triage.

A Novel Prehospital Electrocardiogram Score Predicts Myocardial Salvage in Patients with ST-Segment Elevation Myocardial Infarction Evaluated by Cardiac Magnetic Resonance

Objectives: We hypothesized that prehopsital ECG scores can identify ST-segment elevation myocardial infarction (STEMI) patients in whom time delay is particularly important for myocardial salvage. Methods: We evaluated the Anderson-Wilkins (AW) score (which designates the acuteness of ischemia) and grade 3 ischemia (GI3) (which identifies severe ischemia) in the prehospital ECG and compared them to the myocardial salvage index (MSI) assessed by cardiac magnetic resonance. Results: In 150 patients, system delay (alarm to balloon inflation) (β = -0.304, p < 0.001) and AW score (β = 0.364, p < 0.001) correlated with MSI. AW scores ≥3 (p < 0.001) and GI3 (p = 0.002) predicted the MSI. We formed 4 subgroups combining AW scores (<3 or ≥3) and grades of ischemia (<GI3 or =GI3), yielding a prehospital salvage score of 1-4, which predicted the MSI (p < 0.001), left ventricular ejection fraction at 3 months (p = 0.017), infarct size (p < 0.001), and troponin T (p < 0.001). MSI was only dependent on system delay in patients with acute ischemia (AW score = 3) with (β = -0.687, p = 0.005) or without (β = -0.454, p < 0.001) severe ischemia (GI3). Conclusion: In patients with STEMI, the novel prehospital salvage score identifies subgroups in which myocardial salvage is particularly time dependent.

Telemedicine fighting acute coronary syndromes.

INTRODUCTION Telemedicine allows exchange of information and has therefore become an important tool for optimizing patient treatment in the field of cardiology. Transmission of electrocardiograms (ECGs) from the prehospital setting to the receiving hospital is the most widespread technology in the prehospital setting. Providing a diagnostic ECG from patients with acute coronary syndromes to health care professionals with decision-making power has proven pivotal for an early diagnosis, ideal triage, and initiation of reperfusion therapy of the large group of patients presenting with ST-elevation myocardial infarction (STEMI). This urgent triage could be expanded to several diagnosis in cardiology, primarily the non-ST-elevation presenters. PURPOSE The purpose of the present article is to briefly describe the history the teletransmitted ECG and some of the recent results obtained when used in routine practice for acute triage and referral for primary percutaneous coronary intervention. CONCLUSIONS Transmitting 12-lead ECGs from the community directly to attending cardiologists should become routine. Time to reperfusion in STEMI has decreased, explaining much of the observed decrease in STEMI mortality. This technology allows for increasingly complex and individualized prehospital medical care and could be expanded to a broader number of cardiovascular diagnoses.

Telecardiology: Past, Present and Future

Technological advances over the past decades have allowed improved diagnosis and monitoring of patients with acute coronary syndromes as well as patients with advanced heart failure. High-quality digital recordings transmitted wirelessly by cellular telephone networks have augmented the prehospital use of transportable electrocardiogram machines as well as implantable devices for arrhythmia monitoring and therapy. The impact of prehospital electrocardiogram recording and interpretation in patients suspected of acute myocardial infarction should not be underestimated. It enables a more widespread access to rapid reperfusion therapy, thereby reducing treatment delay, morbidity and mortality. Further, continuous electrocardiogram monitoring has improved arrhythmia diagnosis and dynamic ST-segment changes have been shown to provide important prognostic information in patients with acute ST-elevation myocardial infarction. Likewise, remote recording or monitoring of arrhythmias and vital signs seem to improve outcome and reduce the necessity of re-admissions or outpatient contacts in patients with heart failure or arrhythmias. In the future telemonitoring and diagnosis is expected to further impact the way we practice cardiology and provide better care for the patient with cardiovascular disease.