Diversion of ST-elevation myocardial infarction patients for primary angioplasty based on wireless prehospital 12-lead electrocardiographic transmission directly to the cardiologist's handheld computer: a progress report

Early prediction of ventricular fibrillation using electrocardiographic characteristics in prehospital suspected ST-segment elevation myocardial infarction: a case-control study

PURPOSE

Our objective was to determine characteristics of electrocardiograms (ECG) that predict ventricular fibrillation (VF) among prehospital patients with suspected ST-segment elevation myocardial infarction (STEMI) in Québec.

METHODS

We performed a matched case-control study of prehospital adult suspected with STEMI. Patients in case group (STEMI/VF+) were matched with controls (STEMI/VF-) for age and sex and then compared for ECG characteristics, including ST-segment elevations (STE) and depressions (STD), duration of interval complexes, general characteristics, and several calculated variables. Logistic regression was used to measure the association between ECG characteristics and VF development.

RESULTS

Overall, 310 prehospital patients with suspected STEMI were included in the analysis (case group, n = 155; control group, n = 155). We confirmed that the presence of TW-pattern complex (OR 7.0, 95% CI 1.55-31.58), premature ventricular contraction (PVC) (OR 5.5, 95% CI 2.04-14.82), and STE in V2-V6 (OR 3.8, 95% CI 1.21-11.74) were electrocardiographic predictors of VF. We also observed that STD in V3-V5 (OR 6.5, 95% CI 1.42-29.39), atrial fibrillation (AF) ≥ 100 beats per minute (bpm) (OR 6.3, 95% CI 1.80-21.90), the combination of STE in V4 and V5, and STD in II, III and aVF (OR 4.8, 95% CI 1.01-22.35), and the presence of STD in ≥ 6 leads (OR 4.2, 95% CI 1.33-13.13) were also associated with VF development. Finally, simultaneous association of 2 (OR 2.3, 95% CI 1.13-4.06) and 3 (OR 11.6, 95% CI 3.22-41.66) predictors showed significant association with VF.

CONCLUSIONS

In addition to some already known predictors, we have identified several ECG findings associated with the development of VF in patients with suspected STEMI. Early identification of patients with STEMI at increased risk of VF should help EMS providers anticipate adverse events and encourage use of defibrillation pads.

Detection of STEMI Using Prehospital Serial 12-Lead Electrocardiograms

OBJECTIVE

Repeated or serial 12-lead electrocardiograms (ECGs) in the prehospital setting may improve management of patients with subtle ST-segment elevation (STE) or with a ST-segment elevation myocardial infarction (STEMI) that evolves over time. However, there is a minimal amount of scientific evidence available to support the clinical utility of this method. Our objective was to evaluate the use of serial 12-lead ECGs to detect STEMI in patients during transport in a Canadian emergency medical services (EMS) jurisdiction.

METHODS

We performed a retrospective study of suspected STEMI patients transported by EMS in the Chaudière-Appalaches region (Québec, Canada) between August 2006 and December 2013. Patients were monitored by a serial 12-lead ECG system where an averaged ECG was transmitted every 2 minutes. Following review by an emergency physician, ECGs were grouped as having either a persistent STE or a dynamic STE that evolved over time.

RESULTS

A total of 754 suspected STEMI patients were transported by EMS during the study period. Of these, 728 patients met eligibility criteria and were included in the analysis. A persistent STE was observed in 84.3% (614/728) of patients, while the remaining 15.7% (114/728) had a dynamic STE. Among those with dynamic STE, 11.1% (81/728) had 1 ST-segment change (41 no-STEMI to STEMI; 40 STEMI to no-STEMI) and 4.5% (33/728) had ≥ 2 ST-segment changes (17 no-STEMI to STEMI; 16 STEMI to no-STEMI). Overall, in 8.0% (58/728) of the cohort, STEMI was identified on a subsequent ECG following an initial no-STEMI ECG.

CONCLUSIONS

Through recognition of transient ST-segment changes during transport via the prehospital serial 12-lead ECG system, STEMI was identified in 8% of suspected STEMI patients who had an initial no-STEMI ECG. Key words: electrocardiography; emergency medical services; ST-elevation myocardial infarction; prehospital dynamic ECG.

Field triage in the ambulance versus referral via non-percutaneous coronary intervention centre in ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention: A systematic review

AIMS

The purpose of this study was to determine whether direct ambulance transport of ST-elevation myocardial infarction (STEMI) patients to a percutaneous coronary intervention (PCI) hospital (field triage) leads to a lower 30-day mortality compared to transport via a referral non-PCI hospital (referral via a spoke centre) in STEMI patients.

METHODS AND RESULTS

We performed a systematic review of interventions. An experienced librarian searched in PubMed, EMBASE.com and The Cochrane Library (via Wiley) from January 1980-February 2013. Studies that examined field triage and/or referral via a spoke centre in STEMI patients treated with primary or facilitated PCI were included. Two authors independently conducted the study selection and data extraction. Multivariable frequency weighted logistic regression analysis was performed to assess the effect of the type of transfer on the outcome measures. We identified 14 randomised clinical trials (RCTs), including 20 transfer groups and 4474 participants. Thirty-day mortality was lower in patients who underwent field triage (3.0%; 95% confidence interval (CI) 2.2-4.2) compared to patients who were referred via a spoke centre (4.7%; 95% CI 4.0-5.5). In multivariable frequency weighted logistic regression analysis, field triage was independently associated with a lower incidence of 30-day mortality (odds ratio (OR): 0.58; 95% CI 0.37-0.89).

CONCLUSION

Field triage compared to referral via a spoke centre leads to a lower 30-day mortality in STEMI patients. Therefore, direct ambulance transport to a PCI hospital should become the transfer type for STEMI patients.

Computerized interpretation of the prehospital electrocardiogram: predictive value for ST segment elevation myocardial infarction and impact on on-scene time

Introduction:

Computerized interpretation of the prehospital electrocardiogram (ECG) is increasingly being used in the basic life support (BLS) ambulance setting to reduce delays to treatment for patients suspected of ST segment elevation myocardial infarction (STEMI).

Objectives:

To estimate 1) predictive values of computerized prehospital 12-lead ECG interpretation for STEMI and 2) additional on-scene time for 12-lead ECG acquisition.

Methods:

Over a 2-year period, 1,247 ECGs acquired by primary care paramedics for suspected STEMI were collected. ECGs were interpreted in real time by the GEMarquette 12SL ECG analysis program. Predictive values were estimated with a bayesian latent class model incorporating the computerized ECG interpretations, consensus ECG interpretations by study cardiologists, and hospital diagnosis. On-scene time was compared for ambulance-transported patients with (n 5 985) and without (n 5 5,056) prehospital ECGs who received prehospital aspirin and/or nitroglycerin.

Results:

The computer's positive and negative predictive values for STEMI were 74.0% (95% credible interval [CrI] 69.6–75.6) and 98.1% (95% CrI 97.8–98.4), respectively. The sensitivity and specificity were 69.2% (95% CrI 59.0–78.5) and 98.9% (95% CrI 98.1–99.4), respectively. Prehospital ECGs were associated with a mean increase in on-scene time of 5.9 minutes (95% confidence interval 5.5–6.3).

Conclusions:

The predictive values of the computerized prehospital ECG interpretation appear to be adequate for diversion programs that direct patients with a positive result to hospitals with angioplasty facilities. The estimated 26.0% chance that a positive interpretation is false is likely too high for activation of a catheterization laboratory from the field. Acquiring prehospital ECGs does not substantially increase on-scene time in the BLS setting.

The influence of residential distance on time to treatment in ST-elevation myocardial infarction patients

Aims

To evaluate the relation between residential distance and total ischaemic time in patients with acute ST-elevation myocardial infarction (STEMI).

Methods

STEMI patients were transported to the Isala Hospital Zwolle with the intention to perform primary percutaneous coronary intervention PCI (pPCI) from 2004 until 2010 (n = 4149). Of these, 1424 patients (34 %) were referred via a non-PCI ‘spoke' centre (‘spoke’ patients) and 2725 patients (66 %) were referred via field triage in the ambulance (ambulance patients).

Results

A longer residential distance increased median total ischaemic time in ‘spoke’ patients (0–30 km: 228 min, >30-60 km: 235 min, >60-90 km: 264 min, p < 0.001), however not in ambulance patients (0–30 km: 179 min, >30-60 km: 175 min, >60-90 km: 186 min, p = 0.225). After multivariable linear regression analysis, in ‘spoke’ patients residential distance of >30-60 km compared with 0–30 km was not independently associated with ischaemic time; however, a residential distance of >60-90 km (exp (B) = 1.11, 95 % CI 1.01-1.12) compared with 0–30 km was independently related with ischaemic time. In ambulance patients, residential distance of >30-60 and >60-90 km compared with 0–30 km was not independently associated with ischaemic time.

Conclusion

A longer distance from the patient’s residence to a PCI centre was associated with a small but significant increase in time to treatment in ‘spoke’ patients, however not in ambulance patients. Therefore, referral via field triage in the ambulance did not lead to a significant increase in time to treatment, especially at long distances (up to 90 km).

System dynamics modeling in the evaluation of delays of care in ST-segment elevation myocardial infarction patients within a tiered health system

Background

Mortality rates amongst ST segment elevation myocardial infarction (STEMI) patients remain high, especially in developing countries. The aim of this study was to evaluate the factors related with delays in the treatment of STEMI patients to support a strategic plan toward structural and personnel modifications in a primary hospital aligning its process with international guidelines.

Methods and Findings

The study was conducted in a primary hospital localized in Foz do Iguaçu, Brazil. We utilized a qualitative and quantitative integrated analysis including on-site observations, interviews, medical records analysis, Qualitative Comparative Analysis (QCA) and System Dynamics Modeling (SD). Main cause of delays were categorized into three themes: a) professional, b) equipment and c) transportation logistics. QCA analysis confirmed four main stages of delay to STEMI patient’s care in relation to the ‘Door-in-Door-out’ time at the primary hospital. These stages and their average delays in minutes were: a) First Medical Contact (From Door-In to the first contact with the nurse and/or physician): 7 minutes; b) Electrocardiogram acquisition and review by a physician: 28 minutes; c) ECG transmission and Percutaneous Coronary Intervention Center team feedback time: 76 minutes; and d) Patient’s Transfer Waiting Time: 78 minutes. SD baseline model confirmed the system’s behavior with all occurring delays and the need of improvements. Moreover, after model validation and sensitivity analysis, results suggested that an overall improvement of 40% to 50% in each of these identified stages would reduce the delay.

Conclusions

This evaluation suggests that investment in health personnel training, diminution of bureaucracy, and management of guidelines might lead to important improvements decreasing the delay of STEMI patients’ care. In addition, this work provides evidence that SD modeling may highlight areas where health system managers can implement and evaluate the necessary changes in order to improve the process of care.

Update: Innovation in cardiology (II). 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.

Transtelephonic electrocardiography for managing out-of-hospital chest pain emergencies

BACKGROUND

Some healthcare facilities lack professionals qualified to interpret electrocardiograms. We aimed to assess the usefulness of transtelephonic electrocardiography in combination with patients' clinical histories in the diagnosis and management of patients with acute chest pain in out-of-hospital healthcare facilities with personnel without expertise in cardiology or electrocardiography.

METHODS

Data from 506 consecutive patients (53.9 ± 16.2 years old) referred from 55 healthcare facilities without professionals specialized in cardiology or electrocardiography form the basis of analysis. Patients were classified into 2 groups according to the results of transtelephonic electrocardiography: (A) patients without electrocardiographic abnormalities (n = 445) and (B) patients who presented abnormalities suggesting a cardiac origin (n = 61) of the chest pain. The presence of risk factors was evaluated by multivariate analysis.

RESULTS

The following risk factors were independent predictors of electrocardiographic abnormalities: male gender (P = .006), diabetes mellitus (P = .0001), and dyslipidemia (P = .001). The multivariate analysis yielded a high degree of specificity (99.6%). Follow-up visits confirmed the noncardiac origin of pain in 432 patients (97%) in group A and the cardiac origin of pain in 59 patients (97%) in group B.

CONCLUSIONS

Transtelephonic electrocardiography combined with awareness of the risk factors of patients presenting with chest pain is useful for the diagnostic management of these patients in health care facilities without the means to interpret electrocardiograms.

Cellular video-phone assisted transmission and interpretation of prehospital 12-lead electrocardiogram in acute st-segment elevation myocardial infarction

BACKGROUND

Prehospital 12-lead electrocardiogram (ECG) reduces the time to reperfusion in acute ST-segment elevation myocardial infarction (STEMI). However, the reliability of using cellular video-phone (VP) assisted interpretation of ECG is unknown.

METHODS

We studied the interphysician reliability in interpreting the ECG assisted with VP compared to print ECG interpretation. Twenty-seven physicians prospectively interpreted the ECG transmitted from the field in real-time using VP and later using the same printed ECG. The time to completion, accuracy of interpretation, and physician rating of the VP technology were recorded.

RESULTS

Similar high interphysician reliability was observed with both VP assisted and printed ECG interpretation including presence of ST-segment elevation (intraclass correlation coefficient [ICC]= 0.98 [95% CI 0.96-1] vs. 0.99 [95% CI 0.99-1]) and pathologic Q wave (ICC = 0.99 [95% CI 0.98-1] vs. 1 [95% CI 1]), respectively. The mean time to transmit and interpret the ECG with VP versus printed ECG was 3.9 ± 1.9 versus 2.1 ± 0.9 minutes, respectively, P < 0.01. On a scale of 1 to 5 with 5 being the best, the average rating of VP ease of use was 4.4 ± 0.5 and utility to recommend treatment was rated a 5.

CONCLUSION

Cellular VP-assisted transmission and interpretation in real-time of prehospital ECG has high interphysician reliability, similar to the printed ECG interpretation. Future studies testing whether VP decreases the ischemic time and expedites the reperfusion of STEMI patients are needed.

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.

Prehospital triage in the ambulance reduces infarct size and improves clinical outcome

BACKGROUND

We evaluated the effect of prehospital triage (PHT) in the ambulance on infarct size and clinical outcome and studied its relationship to the distance of patient's residence to the nearest percutaneous coronary intervention (PCI) center.

METHODS

All consecutive ST-segment elevation myocardial infarction patients who were transported to the Isala klinieken from 1998 to 2008 were registered in a dedicated database. Of these, 2,288 (45%) were referred via a spoke center and 2.840 (55%) via PHT.

RESULTS

PHT patients were more often treated within 3 hours after symptom onset (46.2% vs 26.8%, P < .001), more often had a post-procedural thrombolysis in myocardial infarction (TIMI) 3 flow (93.0% vs 89.7%, P < .001) had a smaller infarct size (peak creatine kinase 2,188 ± 2,187 vs 2,575 ± 2,259 IU/L, P < .001) and had a lower 1-year mortality (4.9% vs 7.0%, P = .002). After multivariate analysis, PHT was independently associated with ischemic time less than 3 hours (OR 2.45, 95% CI 2.13-2.83), a peak creatine kinase less than the median value (OR 1.19, 95% CI 1.04-1.36) and a lower 1-year mortality (OR 0.67, 95% CI 0.50-0.91). The observed differences between PHT patients and the spoke group were more pronounced in the subgroup of patients living >38 km from the PCI center.

CONCLUSION

PHT in the ambulance is associated with a shorter time to treatment, a smaller infarct size and a more favorable clinical outcome, especially with longer distance from the patient's residence to the nearest PCI center. Therefore, PHT in the ambulance may reduce the negative effect of living at a longer distance from the PCI center.

Health technology assessment review: remote monitoring of vital signs--current status and future challenges

Recent developments in communications technologies and associated computing and digital electronics now permit patient data, including routine vital signs, to be surveyed at a distance. Remote monitoring, or telemonitoring, can be regarded as a subdivision of telemedicine - the use of electronic and telecommunications technologies to provide and support health care when distance separates the participants. Depending on environment and purpose, the patient and the carer/system surveying, analysing or interpreting the data could be separated by as little as a few feet or be on different continents. Most telemonitoring systems will incorporate five components: data acquisition using an appropriate sensor; transmission of data from patient to clinician; integration of data with other data describing the state of the patient; synthesis of an appropriate action, or response or escalation in the care of the patient, and associated decision support; and storage of data. Telemonitoring is currently being used in community-based healthcare, at the scene of medical emergencies, by ambulance services and in hospitals. Current challenges in telemonitoring include: the lack of a full range of appropriate sensors, the bulk weight and size of the whole system or its components, battery life, available bandwidth, network coverage, and the costs of data transmission via public networks. Telemonitoring also has the ability to produce a mass of data - but this requires interpretation to be of clinical use and much necessary research work remains to be done.

Underuse of prehospital strategies to reduce time to reperfusion for ST-elevation myocardial infarction patients in 5 Canadian provinces

OBJECTIVE

Timely reperfusion therapy for ST-elevation myocardial infarction (STEMI) is an important determinant of outcome, yet targets for time to treatment are frequently unmet in North America. Prehospital strategies can reduce time to reperfusion. We sought to determine the extent to which emergency medical services (EMS) use these strategies in Canada.

METHODS

We carried out a cross-sectional survey in 2007 of ground EMS operators in British Columbia, Alberta, Ontario, Quebec and Nova Scotia. We focused on the use of 4 prehospital strategies: 1) 12-lead electrocardiogram (ECG), 2) routine expedited emergency department (ED) transfer of STEMI patients (from a referring ED to a percutaneous coronary intervention [PCI] centre), 3) prehospital bypass (ambulance bypass of local EDs to transport patients directly to PCI centres) and 4) prehospital fibrinolysis.

RESULTS

Ninety-seven ambulance operators were surveyed, representing 15 681 paramedics serving 97% of the combined provincial populations. Of the operators surveyed, 68% (95% confidence interval [CI] 59%-77%) had ambulances equipped with 12-lead ECGs, ranging from 40% in Quebec to 100% in Alberta and Nova Scotia. Overall, 47% (95% CI 46%-48%) of paramedics were trained in ECG acquisition and 40% (95% CI 39%-41%) were trained in ECG interpretation. Only 18% (95% CI 10%-25%) of operators had prehospital bypass protocols; 45% (95% CI 35%-55%) had protocols for expedited ED transfer. Prehospital fibrinolysis was available only in Alberta. All EMS operators in British Columbia, Alberta and Nova Scotia used at least 1 of the 4 prehospital strategies, and one-third of operators in Ontario and Quebec used 0 of 4. In major urban centres, at least 1 of the 3 prehospital strategies 12-lead ECG acquisition, bypass or expedited transfer was used, but there was considerable variation within and across provinces.

CONCLUSION

The implementation of widely recommended prehospital STEMI strategies varies substantially across the 5 provinces studied, and relatively simple existing technologies, such as prehospital ECGs, are underused in many regions. Substantial improvements in prehospital services and better integration with hospital-based care will be necessary in many regions of Canada if optimal times to reperfusion, and associated outcomes, are to be achieved.

An overview of recent health care support systems for eEmergency and mHealth applications

Advances in mobile communications and medical technologies facilitate the development of emerging mobile systems and applications for healthcare. The objective of this paper is to provide an overview and the current status of mobile health care systems (mHealth) and their applications for Emergency healthcare support (eEmergency). Our paper reports on journal papers that use wireless, emergency telemedicine systems that appeared since 2000. The majority of the applications are focused on the transmission of crucial biosignals (mainly ECG) for the support of heart-related healthcare. A limited number of new studies were focused on supporting emergency healthcare for trauma by facilitating both 2D image or video transmission (eg: ultrasound). Alternatively, new studies have focused on integrated systems for specialized emergency scenaria such as stroke. This paper is an extension of work previously published by our group [1].

The impact of mobile handheld technology on hospital physicians' work practices and patient care: a systematic review

The substantial growth in mobile handheld technologies has heralded the opportunity to provide physicians with access to information, resources, and people at the right time and place. But is this technology delivering the benefits to workflow and patient care promised by increased mobility? The authors conducted a systematic review to examine evidence regarding the impact of mobile handheld technology on hospital physicians' work practices and patient care, focusing on quantification of the espoused virtues of mobile technologies. The authors identified thirteen studies that demonstrated the ability of personal digital assistants (PDAs) to positively impact on areas of rapid response, error prevention, and data management and accessibility. The use of PDAs demonstrates the greatest benefits in contexts where time is a critical factor and a rapid response crucial. However, the extent to which these devices improved outcomes and workflow efficiencies because of their mobility was largely absent from the literature. The paucity of evidence calls for much needed future research that asks explicit questions about the impact the mobility of devices has on work practices and outcomes.

The Positive Predictive Value of Paramedic Versus Emergency Physician Interpretation of the Prehospital 12-Lead Electrocardiogram

BACKGROUND

Obtaining a prehospital 12-lead ECG may improve triage and expedite care of patients with acute myocardial infarction (AMI). Whether the ECG should undergo physician review prior to activation of a percutaneous intervention (PCI) team is unclear.

OBJECTIVE

To document the positive predictive value (PPV) of the prehospital 12-lead ECG when interpreted by paramedics versus emergency physicians.

METHODS

This was a prospective, observational study. In November 2003, our local health care and emergency medical services (EMS) systems implemented a prehospital "cardiac alert" program in which patients suspected of having ST-elevation myocardial infarction (STEMI) based on the prehospital 12-lead ECG were diverted away from receiving facilities without emergent PCI capability and the PCI team was mobilized. For the first year, a cardiac alert was activated by paramedics (Phase I). After the first year, the ECG was transmitted to the ED, with the emergency physician (EP) responsible for activation (Phase II). The PPV for cardiac alerts in Phases I and II were compared by using three different "gold standards": cardiologist interpretation of the prehospital 12-lead ECG, disposition to emergent PCI, and coronary lesions on angiography or arrest prior to emergent PCI.

RESULTS

A total of 110 patients were enrolled (54 in Phase I, 56 in Phase II). Cardiologist confirmation of a STEMI on the prehospital 12-lead EKG was 42/54 (78%) in Phase I and 54/56 (96%) in Phase II. Disposition to emergent PCI occurred in 38/54 (70%) Phase I patients and 51/56 (91%) Phase II patients. Lesions at catheterization or arrest prior to emergent PCI were observed in 41/54 (69%) of Phase I patients and 50/56 (89%) of Phase II patients. All of these comparisons achieved statistical significance (p < 0.01).

CONCLUSIONS

Transmission to the ED for EP interpretation improves the PPV of the prehospital 12-lead ECG for triage and therapeutic decision-making.

Direct ambulance admission to the cardiac catheterization laboratory significantly reduces door-to-balloon times in primary percutaneous coronary intervention

BACKGROUND

Primary percutaneous coronary intervention (PCI) is the preferred treatment for ST-segment elevation myocardial infarction (STEMI) provided it can be delivered within 90 minutes of hospital admission. In clinical practice this target is difficult to achieve. We aimed to determine the effect of direct ambulance admission to the cardiac catheterization laboratory on door-to-balloon and call-to-balloon times in primary PCI.

METHODS

We performed a prospective evaluation of a new system of paramedic electrocardiogram diagnosis of STEMI and subsequent direct ambulance admission to the cardiac catheterization laboratory for primary PCI. Door-to-balloon and call-to-balloon times were recorded for all patients. Direct admissions were compared with admissions via the emergency room of the interventional center and of 2 referring hospitals. All times are quoted as medians.

RESULTS

Five hundred and seventy-seven patients (70% male, age 63 +/- 13 years) underwent primary PCI between April 2005 and May 2007. After February 2006, 172 (44%) of 387 patients were admitted directly from the ambulance to the catheterization laboratory. Directly admitted patients had significantly reduced door-to-balloon (58 vs 105 minutes, P < .001) and call-to-balloon times (105 vs 143 minutes, P < .001). The 90-minute target for door-to-balloon time was achieved in 94% of direct admissions compared to 29% of patients referred from the emergency room.

CONCLUSIONS

Direct admission of patients with suspected STEMI from the ambulance service to the catheterization laboratory significantly reduces time to treatment in primary PCI and allows the 90-minute door-to-balloon time target to be reliably achieved.

Facilitated PCI in patients with ST-elevation myocardial infarction

BACKGROUND

We hypothesized that percutaneous coronary intervention (PCI) preceded by early treatment with abciximab plus half-dose reteplase (combination-facilitated PCI) or with abciximab alone (abciximab-facilitated PCI) would improve outcomes in patients with acute ST-segment elevation myocardial infarction, as compared with abciximab administered immediately before the procedure (primary PCI).

METHODS

In this international, double-blind, placebo-controlled study, we randomly assigned patients with ST-segment elevation myocardial infarction who presented 6 hours or less after the onset of symptoms to receive combination-facilitated PCI, abciximab-facilitated PCI, or primary PCI. All patients received unfractionated heparin or enoxaparin before PCI and a 12-hour infusion of abciximab after PCI. The primary end point was the composite of death from all causes, ventricular fibrillation occurring more than 48 hours after randomization, cardiogenic shock, and congestive heart failure during the first 90 days after randomization.

RESULTS

A total of 2452 patients were randomly assigned to a treatment group. Significantly more patients had early ST-segment resolution with combination-facilitated PCI (43.9%) than with abciximab-facilitated PCI (33.1%) or primary PCI (31.0%; P=0.01 and P=0.003, respectively). The primary end point occurred in 9.8%, 10.5%, and 10.7% of the patients in the combination-facilitated PCI group, abciximab-facilitated PCI group, and primary-PCI group, respectively (P=0.55); 90-day mortality rates were 5.2%, 5.5%, and 4.5%, respectively (P=0.49).

CONCLUSIONS

Neither facilitation of PCI with reteplase plus abciximab nor facilitation with abciximab alone significantly improved the clinical outcomes, as compared with abciximab given at the time of PCI, in patients with ST-segment elevation myocardial infarction. (ClinicalTrials.gov number, NCT00046228 [ClinicalTrials.gov].)

The real value of the transtelephonic ECG system in the clinical cardiological practice

A szerzők ismertetik a transztelefonos EKG-rendszer alapelveit és ennek alkalmazási lehetőségeit a kardiológiai klinikai gyakorlatban. A rendszer alapeleme a kisméretű felvevőegység, melynek révén tetszés szerinti telefonrendszeren keresztül lehet a jelet a fogadó- és irányítóközpontba küldeni. A rendszer használata előnyös heveny kardiológiai esetekben, angina pectoris szindrómában, szívritmuszavarokban és a kardiológiai gondozás keretében (rehabilitáció, pacemaker-ellenőrzés). Ismertetik a nemzetközi gyakorlat eddigi legfontosabb eredményeit és bemutatják a hazánkban működő rendszert.

Time to reperfusion in acute myocardial infarction. It is time to reduce it!

BACKGROUND AND OBJECTIVES

Mortality from ST-segment elevation myocardial infarction remains high, with most deaths occurring before hospital admission. Despite effective pre- and in-hospital reperfusion strategies becoming standard over the past 2 decades, time-to-admission and time-to-treatment remain prolonged. We reviewed temporal trends in these times in published clinical trials.

METHODS

All major randomized clinical trials reporting on reperfusion strategies for acute myocardial infarction published between 1993 and 2003 were evaluated. Strategies included pre- and in-hospital thrombolysis, primary percutaneous coronary intervention (pPCI) with or without transfer, and "facilitated" PCI. We generated overall estimates of time-to-admission, time-to-treatment, door-to-balloon (DTB), and door-to-needle (DTN) times and evaluated temporal trends in the length of time-to-admission and time-to-treatment.

RESULTS

In studies that evaluated only in-hospital thrombolysis, the time-to-admission was 149 +/- 45 minutes; the mean time-to-treatment was 181 +/- 29 minutes. In studies that considered only in-hospital pPCI (without transfer), the mean time-to-admission was 153 +/- 41 minutes; the mean time-to-treatment was 234 +/- 43 minutes. In studies that compared in-hospital pPCI with in-hospital thrombolytic therapy, the mean time-to-admission was 155 +/- 47 and 150 +/- 48 minutes, respectively. The DTN time was 65 +/- 10 minutes, whereas DTB time was 81 +/- 39 minutes. In other trials evaluating in-hospital thrombolysis and pPCI with transfer to a referral center, the time-to-admission in subjects treated with thrombolysis (n = 1345) was 127 +/- 32 minutes vs 131 +/- 36 minutes for pPCI (n = 1528). For in-hospital thrombolysis, time-to-treatment was 151 +/- 23 minutes vs 203 +/- 15 minutes for pPCI patients with transfer. The DTN time in the thrombolysis group was 44 +/- 28 minutes as compared with DTB time of 78 +/- 38 minutes in the pPCI group. Throughout the last decade, time-to-admission decreased significantly (P = .02) but time-to-treatment remained unchanged (P = .38) for patients undergoing thrombolysis. In the pPCI arm, time-to-admission remained unchanged (P = .11) but a insignificant trend toward reduction was demonstrated in time-to-treatment (P = .11).

CONCLUSION

Time-to-admission and time-to-treatment for ST-segment elevation myocardial infarction are still prolonged. Resources should be directed to early recognition of the acute myocardial infarction, improved utilization of emergency services for transportation, and prehospital diagnosis and triaging. Ambulances equipped with wireless capability to transmit electrocardiograms to the on-call cardiologist seem to be promising tools to achieve earlier diagnosis and triaging with high diagnostic sensitivity and specificity.