Quantification of the benefit of earlier thrombolytic therapy: five-year results of the Grampian Region Early Anistreplase Trial (GREAT)

Time to thrombolysis and factors contributing to delays in patients presenting with ST-elevation myocardial infarction at Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa

BACKGROUND

Acute coronary syndrome is a public health burden both worldwide and in South Africa (SA). Guidelines recommend thrombolysis within 1 hour of symptom onset and 30 minutes of hospital arrival for patients with ST-elevation myocardial infarction (STEMI) in order to prevent morbidity and mortality. There is a paucity of data pertaining to the time between onset of chest pain and thrombolysis in STEMI patients in SA.

OBJECTIVES

To elucidate the time to thrombolytic therapy, establish the reasons for treatment delays, and calculate the loss of benefit of thrombolysis associated with delays in treatment of patients presenting with STEMI at Chris Hani Baragwanath Academic Hospital (CHBAH), Johannesburg, SA.

METHOD

A prospective observational study of 100 consecutive patients with STEMI was conducted at CHBAH (2021 - 2022).

RESULTS

The mean (standard deviation) age was 55.6 (11.6) years, with a male predominance (78%). Thrombolytic therapy was administered to 51 patients, with a median (interquartile range (IQR)) time to thrombolysis of 360 (258 - 768) minutes; 10 of the patients who received a thrombolytic (19.6%) did so within 30 minutes of arrival at the hospital. The median (IQR) time from symptom onset to calling for help was 60 (30 - 240) minutes, the median time from arrival of help to hospital arrival was 114 (48 - 468) minutes, and the median in-hospital delay to thrombolysis after arrival was 105 (45 - 240) minutes. Numerous reasons that led to delay in treatment were identified, but the most frequent was prehospital delays related to patient factors. Late presentation resulted in 26/49 patients (53.1%) not receiving thrombolytic therapy. Five patients died and 43 suffered from heart failure. Thirty per 1 000 participants could have been saved had they received thrombolytic therapy within 1 hour from the onset of chest pain.

CONCLUSION

Prehospital and hospital-related factors played a significant role in delays to thrombolysis that led to increased morbidity and mortality of patients with STEMI.

Impact of Delayed Pain to Needle and Variable Door to Needle Time On In-Hospital Complications in Patients With ST-Elevation Myocardial Infarction Who Underwent Thrombolysis: A Single-Center Experience

Background Myocardial infarction is a life-threatening event, and timely intervention is essential to improve patient outcomes and mortality. Previous studies have shown that the time to thrombolysis should be less than 30 minutes of the patient's arrival at the emergency room. Pain-to-needle time is a time from onset of chest pain to the initiation of thrombolysis, and door-to-needle time is a time between arrival to the emergency room to initiation of thrombolytic treatment. Ideally, the target for door-to-needle time should be less than 30 minutes; however, it is unclear if the door-to-needle time has a significant impact on patients presenting later than three hours from the onset of pain. As many of the previous studies were conducted in first-world countries, with established emergency medical services (EMS) systems and pre-hospital ST-elevation myocardial infarction (STEMI) triages and protocols, the data is not completely generalizable to developing countries. We, therefore, looked for the impact of the shorter and longer door-to-needle times on patient outcomes who presented to the emergency room (ER) with delayed pain-to-needle times (more than three hours of pain onset).  Objective To determine the impact of delayed pain-to-needle time (PNT) with variable door-to-needle time (DNT) on in-hospital complications (post-infarct angina, heart failure, left ventricular dysfunction, and death) in patients with ST-elevation myocardial infarction (STEMI) who underwent thrombolysis. Methods and results A total of 300 STEMI patients who underwent thrombolysis within 12 hours of symptoms onset were included, which were divided into two groups based on PNT. These groups were further divided into subgroups based on DNT. The primary outcome was in-hospital complications between the two groups and between subgroups within each group. The pain-to-needle time was ≤3 hours in 73 (24.3%) patients and >3 hours in 227 (75.7%) patients. In-hospital complications were higher in group II with PNT >3 hours (p <0.05). On subgroup analysis, in-hospital complications were higher with longer door-to-needle time in group II (p<0.05); however, there was no difference in complications among group I. Conclusion Our study is consistent with the fact that shorter door-to-needle time, even in patients with delayed PNT (>3 hours), has a significant impact on in-hospital complications with no difference in mortality.

Accuracy of Post-thrombolysis ST-segment Reduction as an Adequate Reperfusion Predictor in the Pharmaco-Invasive Approach

Fundamento

A intervenção coronária percutânea primária é considerada o “padrão-ouro” para reperfusão coronária. Entretanto, quando não disponível, a estratégia fármaco-invasiva é método alternativo, e o eletrocardiograma (ECG) tem sido utilizado para identificar sucesso na reperfusão.

Objetivos

Nosso estudo teve como objetivo examinar alterações no segmento-ST pós-lise e seu poder de prever a recanalização, usando os escores angiográficos TIMI e blush miocárdio (MBG) como critério de reperfusão ideal.

Métodos

Foram estudados 2.215 pacientes com infarto agudo do miocárdio com supra-ST submetidos à fibrinólise [(Tenecteplase)-TNK] e encaminhados para angiografia coronária em até 24 h pós-fibrinólise ou imediatamente encaminhados à terapia de resgate. O ECG foi realizado pré-TNK e 60 min-pós. Os pacientes foram categorizados em dois grupos: aqueles com reperfusão ideal (TIMI-3 e MBG-3) e aqueles com reperfusão inadequada (fluxo TIMI <3). Foi definido o critério de reperfusão do ECG pela redução do segmento ST >50%. Consideramos p-valor <0,05 para as análises, com testes bicaudais.

Resultados

O critério de reperfusão pelo ECG apresentou valor preditivo positivo de 56%; valor preditivo negativo de 66%; sensibilidade de 79%; e especificidade de 40%. Houve fraca correlação positiva entre a redução do segmento-ST e os dados angiográficos de reperfusão ideal (r = 0,21; p <0,001) e baixa precisão diagnóstica, com AUC de 0,60 (IC-95%; 0,57-0,62).

Conclusão

Em nossos resultados, a redução do segmento-ST não conseguiu identificar com precisão os pacientes com reperfusão angiográfica apropriada. Portanto, mesmo pacientes com reperfusão aparentemente bem-sucedida devem ser encaminhados à angiografia brevemente, a fim de garantir fluxo coronário macro e microvascular adequados.

Psychological and cognitive factors related to prehospital delay in acute coronary syndrome: A systematic review

BACKGROUND

In acute coronary syndrome the time elapsed between the start of symptoms and the moment the patient receives treatment is an important determinant of survival and subsequent recovery. However, many patients do not receive treatment as quickly as recommended, mostly due to substantial prehospital delays such as waiting to seek medical attention after symptoms have started.

OBJECTIVE

To conduct a systematic review with meta-analysis of the relationship between nine frequently investigated psychological and cognitive factors and prehospital delay.

DESIGN

A protocol was preregistered in PROSPERO [CRD42018094198] and a systematic review was conducted following PRISMA guidelines.

DATA SOURCES

The following databases were searched for quantitative articles published between 1997 and 2019: Medline (PubMed), Web of Science, Scopus, Psych Info, PAIS, and Open grey.

REVIEW METHODS

Study risk of bias was assessed with the NIH Quality Assessment Tool for Observational, Cohort, and Cross-Sectional Studies. A best evidence synthesis was performed to summarize the findings of the included studies.

RESULTS

Forty-eight articles, reporting on 57 studies from 23 countries met the inclusion criteria. Studies used very diverse definitions of prehospital delay and analytical practices, which precluded meta-analysis. The best evidence synthesis indicated that there was evidence that patients who attributed their symptoms to a cardiac event (n = 37), perceived symptoms as serious (n = 24), or felt anxiety in response to symptoms (n = 15) reported shorter prehospital delay, with effect sizes indicating important clinical differences (e.g., 1.5-2 h shorter prehospital delay). In contrast, there was limited evidence for a relationship between prehospital delay and knowledge of symptoms (n = 18), concern for troubling others (n = 18), fear (n = 17), or embarrassment in asking for help (n = 14).

CONCLUSIONS

The current review shows that symptom attribution to cardiac events and some degree of perceived threat are fundamental to speed up help-seeking. In contrast, social concerns and barriers in seeking medical attention (embarrassment or concern for troubling others) may not be as important as initially thought. The current review also shows that the use of very diverse methodological practices strongly limits the integration of evidence into meaningful recommendations. We conclude that there is urgent need for common guidelines for prehospital delay study design and reporting.

Psychosocial markers of pre-hospital decision delay and psychological distress in acute coronary syndrome patients

Objectives Both pre-hospital decision delay - the time patients wait before seeking medical attention after symptoms have started - and high psychological distress after the cardiac episode predict poor prognosis of patients with acute coronary syndromes (ACS). We aimed to identify psychosocial markers of these prognostic factors. Design A cross-sectional study of 102 consecutive, clinically stable ACS survivors. Methods Participants completed a questionnaire measuring pre-hospital decision delay, psychological distress, and several known psychosocial factors related to cardiovascular health: type D personality, resilience, social support, and concerns during the cardiac event. Multiple linear regression and mediation analyses were conducted. Results Type D personality and fewer concerns about the serious consequences of delaying help-seeking were related to more psychological distress post-ACS, and these relationships were mediated by longer pre-hospital decision delay. In contrast, resilience was related to lower psychological distress. Social support and social concerns about help-seeking were not related to the outcome variables. Conclusions Type D personality may be a risk factor for more delayed help-seeking for an ACS and higher psychological distress after the cardiac event. Resilience, in contrast, emerged as a potential protective factor of patients' mental health after the cardiac event. Pre-hospital decision delay was related to thinking about serious consequences (e.g., complications, protecting one's family) but not about social concerns (e.g., wasting other people's time) during the cardiac episode. Statement of Contribution What is already known on this subject? Longer pre-hospital decision delay, that is waiting longer to seek medical attention after symptoms have started, predicts poor prognosis of acute coronary syndrome patients. High psychological distress post-ACS, such as the development of anxiety and/or depression, also predicts poor prognosis of these patients. What does this study adds? This study identifies several psychosocial markers of longer prehospital decision delay and high psychological distress post-ACS. Prehospital decision delay was related to thinking about serious consequences (e.g., complications, protecting one's family) but not about social concerns (e.g., wasting other people's time) during the cardiac episode. Type D personality and fewer concerns about the serious consequences of delaying help-seeking were related to more psychological distress, and these relationships were mediated by longer prehospital decision delay. Resilience was related to lower psychological distress post-ACS.

Door-to-Needle Time in Myocardial Infarction: Small Steps, Huge Dividends

The Himachal Pradesh acute coronary syndrome registry highlighted a prehospital delay of 780 min. Additional door-to-needle time delay by 1 h increases the hazard ratio of death by 20%. We conducted a retrospective (group 1) and a prospective (group 2) analysis of 63 patients each to measure the impact of a fast-track protocol in the emergency department (ED) on the door-to-needle time in ST-elevation myocardial infarction (STEMI). The fast-track protocol involved zero cost to the hospital and saved 63 precious door-to-needle minutes for patients with STEMI. Thrombolysis in ED can save 33 precious minutes wasted in shifting patients to the coronary care unit.

Time to hospital arrival among patients with acute myocardial infarction in China: a report from China PEACE prospective study

Aims

Few contemporary studies have reported the time between acute myocardial infarction (AMI) symptoms onset and hospital arrival, associated factors, and patient perceptions of AMI symptoms and care seeking. We sought to study these issues using data from China, where AMI hospitalizations are increasing.

Methods and results

We used data from the China PEACE prospective AMI study of 53 hospitals across 21 provinces in China. Patients were interviewed during index hospitalization for information of symptom onset, and perceived barriers to accessing care. Regression analyses were conducted to explore factors associated with the time between symptom onset and hospital arrival. The final sample included 3434 patients (mean age 61 years). The median time from symptom onset to hospital arrival was 4 h (interquartile range 2–7.5 h). While 94% of patients reported chest pain or chest discomfort, only 43% perceived symptoms as heart-related. In multivariable analyses, time to hospital arrival was longer by 14% and 39% for patients failing to recognize symptoms as cardiac and those with rural medical insurance, respectively (both P < 0.001). Compared with patients with household income over 100 000 RMB, those with income of 10 000–50 000 RMB, and <10 000 RMB had 16% and 23% longer times, respectively (both P = 0.03).

Conclusion

We reported an average time to hospital arrival of 4 h for AMI in China, with longer time associated with rural medical insurance, failing to recognize symptoms as cardiac, and low household income. Strategies to improve the timeliness of presentation may be essential to improving outcomes for AMI in China.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT01624909.

Trends in clinical outcomes and survival following prehospital thrombolytic therapy given by ambulance clinicians for ST-elevation myocardial infarction in rural sub-arctic Norway

BACKGROUND:

Prehospital thrombolytic therapy given by ambulance emergency medical services to patients with acute ST-segment elevation myocardial infarction (STEMI) may produce earlier reperfusion than percutaneous coronary intervention. Clinical results from prehospital thrombolytic therapy in rural areas are scarce.

METHODS:

We studied outcomes during 11 years of a prehospital thrombolytic therapy system in rural sub-arctic Norway. Ambulance personnel gave protocol basic treatment and transmitted electrocardiograms to hospital physicians who made the decision for prehospital thrombolytic therapy. The study was divided into three time periods; 2000-2003, 2004-2007 and 2008-2011.

RESULTS:

A total of 385 STEMI patients received prehospital thrombolytic therapy, median patient age was 61.2 years, and 77% were men. Time saved by prehospital reperfusion therapy was 131 minutes. The proportion who got prehospital thrombolytic therapy within 2 hours of symptom onset increased from 21% in 2000-2003 to 39% in 2008-2011 ( P=0.003). The proportion who underwent coronary angiography or percutaneous coronary intervention within 24 hours of first medical contact increased from 56.4% to 95.4% ( P<0.001). Post-STEMI systolic heart failure decreased from 19.4% to 8.1% ( P=0.02), while 1-year mortality fell, non-significantly, by 50% over time to reach 5.6%. Thirteen patients suffered acute out-of-hospital cardiac arrest; all were successfully defibrillated. Ten patients had major bleeding events (2.6%).

CONCLUSION:

A decentralised prehospital thrombolytic therapy system based on ambulance personnel, telemetry and centralised 7/24 invasive diagnosis and treatment service, combined with system maturation over time, was associated with earlier reperfusion, improved clinical outcomes and better survival. Prehospital thrombolytic therapy is a feasible and safe intervention used in rural settings with long evacuation lines to percutaneous coronary intervention facilities.

The evolution of recombinant thrombolytics: Current status and future directions

Cardiovascular disorders are on the rise worldwide due to alcohol abuse, obesity, hypertension, raised blood lipids, diabetes and age-related risks. The use of classical antiplatelet and anticoagulant therapies combined with surgical intervention helped to clear blood clots during the inceptive years. However, the discovery of streptokinase and urokinase ushered the way of using these enzymes as thrombolytic agents to degrade the fibrin network with an issue of systemic hemorrhage. The development of second generation plasminogen activators like anistreplase and tissue plasminogen activator partially controlled this problem. The third generation molecules, majorly t-PA variants, showed desirable properties of improved stability, safety and efficacy with enhanced fibrin specificity. Plasmin variants are produced as direct fibrinolytic agents as a futuristic approach with targeted delivery of these drugs using liposome technlogy. The novel molecules from microbial, plant and animal origin present the future of direct thrombolytics due to their safety and ease of administration.

Public Response to Chest Pain in Jordan

Background: Chest pain is one of the main and most frequent manifestations of myocardial infarction (MI). Increased level of public awareness on the optimal response to chest pain due to MI attacks is crucial for minimizing its complications and mortality rate.

Aims: The first aim of this investigation was to assess the level of public awareness on their response to acute chest pain. The second aim was to obtain information about self-reported risk factors for coronary heart disease and acute myocardial infarction.

Settings and design: This survey was conducted in various regions of Jordan during the period of July–September 2004. A total of 4194 adults (out of 4500), 2086 males (49.7%) and 2108 females (50.3%) resident in Jordan were included in the sample. The response rate was 92.3%.

Methods: Each individual of the sample who agreed voluntarily to participate in the investigation was asked to report in a questionnaire his/her possible risk factors for MI. Moreover, each person of the sample was asked “What do you do when you suffer from a severe and crushing chest pain that persists for longer than 15 min and radiates to jaws, neck or left shoulder, with sweating and paleness of the face?” The person was asked to choose one option out of 11.

Statistical analysis: The frequency and percentage were determined for each investigated parameter.

Results and conclusion: The highest percentage of respondents had good response by selecting the option “I go to a doctor” while the lowest percentage of respondents showed poor response by choosing the option “I use an antacid”. The remainder of responses was distributed among other options. Excellent awareness was reported by 47% of the sample. Differences in the type of responses were detected when the results were analyzed according to gender, type of job, level of education and ethnicity. Approximately half of the interviewed individuals of the sample had 2–4 clustering risk factors for developing acute MI attacks. Individuals in more than half of the sample had family history of hypertension and diabetes mellitus.

It is concluded that although the type of response to chest pain in Jordan is good–excellent, more improvement is recommended since the risk to MI is relatively high. Community education campaigns may participate in increasing public health education on the optimal response to chest pain of myocardial origin.

Components and determinants of therapeutic delay in patients with acute ST-elevation myocardial infarction: A tertiary care hospital-based study

Background

Delayed reperfusion is associated with worse outcomes in ST-segment elevation myocardial infarction (STEMI). This study was conducted to assess the components and determinants of therapeutic delay in STEMI patients of our state.

Methods

This study included consecutive patients of STEMI admitted to the coronary care units of two tertiary care hospitals in Srinagar, between 2012 and 2015. Various components of treatment delay including the patient’s decision to delay, referral delay, transportation delay, prehospital delay, and door-to-needle time were calculated. Factors associated with delayed treatment and clinico-demographic correlates of late presentation were identified.

Results

During a period of 3 years, 523 patients (mean age, 57.6 ± 10.5 years) were enrolled in this study. Thrombolysis was administered to 60.2% patients, while 39.8% of patients could not be thrombolysed because of late presentation. The median treatment delay was 250 minutes. Prehospital delay constituted about 83.8% of total treatment delay. Patient’s decision to delay, referral delay, and transport delay constituted 59%, 16%, and 25% of prehospital delay, respectively. Median door-to-needle time was 40 minutes. Residence in rural areas [odds ratio (OR), 2.35; 95% confidence interval (CI), 1.60–3.46], absence of prior coronary artery disease (OR, 1.54; 95% CI, 1.00–2.39), and negative family history of coronary artery disease (OR; 2.76; 95% CI, 1.86–4.10), were identified as independent predictors of delayed presentation (p < 0.001). Interestingly, 44.7% of the patients presented late due to misdiagnosis by local healthcare providers.

Conclusion

The standard of STEMI management in our state is far from ideal, and calls for a lot of improvement. Major efforts to reduce prehospital and in-hospital treatment delays are urgently needed.

Pre-hospital versus in-hospital thrombolysis for ST-elevation myocardial infarction

BACKGROUND

Early thrombolysis for individuals experiencing a myocardial infarction is associated with better mortality and morbidity outcomes. While traditionally thrombolysis is given in hospital, pre-hospital thrombolysis is proposed as an effective intervention to save time and reduce mortality and morbidity in individuals with ST-elevation myocardial infarction (STEMI). Despite some evidence that pre-hospital thrombolysis may be delivered safely, there is a paucity of controlled trial data to indicate whether the timing of delivery can be effective in reducing key clinical outcomes.

OBJECTIVES

To assess the morbidity and mortality of pre-hospital versus in-hospital thrombolysis for STEMI.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OVID), EMBASE (OVID), two citation indexes on Web of Science (Thomson Reuters) and Cumulative Index to Nursing and Allied Health Literature (CINAHL) for randomised controlled trials and grey literature published up to June 2014. We also searched the reference lists of articles identified, clinical trial registries and unpublished thesis sources. We did not contact pharmaceutical companies for any relevant published or unpublished articles. We applied no language, date or publication restrictions. The Cochrane Heart Group conducted the primary electronic search.

SELECTION CRITERIA

We included randomised controlled trials of pre-hospital versus in-hospital thrombolysis in adults with ST-elevation myocardial infarction diagnosed by a healthcare provider.

DATA COLLECTION AND ANALYSIS

Two authors independently screened eligible studies for inclusion and carried out data extraction and 'Risk of bias' assessments, resolving any disagreement by consulting a third author. We contacted authors of potentially suitable studies if we required missing or additional information. We collected efficacy and adverse effect data from the trials.

MAIN RESULTS

We included three trials involving 538 participants. We found low quality of evidence indicating uncertainty whether pre-hopsital thrombolysis reduces all-cause mortality in individuals with STEMI compared to in-hospital thrombolysis (risk ratio 0.73, 95% confidence interval 0.37 to 1.41). We found high-quality evidence (two trials, 438 participants) that pre-hospital thrombolysis reduced the time to receipt of thrombolytic treatment compared with in-hospital thrombolysis. For adverse events, we found moderate-quality evidence that the occurrence of bleeding events was similar between participants receiving in-hospital or pre-hospital thrombolysis (two trials, 438 participants), and low-quality evidence that the occurrence of ventricular fibrillation (two trials, 178 participants), stroke (one trial, 78 participants) and allergic reactions (one trial, 100 participants) was also similar between participants receiving in-hospital or pre-hospital thrombolysis. We considered the included studies to have an overall unclear/high risk of bias.

AUTHORS' CONCLUSIONS

Pre-hospital thrombolysis reduces time to treatment, based on studies conducted in higher income countries. In settings where it can be safely and correctly administered by trained staff, pre-hospital thrombolysis may be an appropriate intervention. Pre-hospital thrombolysis has the potential to reduce the burden of STEMI in lower- and middle-income countries, especially in individuals who have limited access to in-hospital thrombolysis or percutaneous coronary interventions. We found no randomised controlled trials evaluating the efficacy of pre-hospital thrombolysis for STEMI in lower- and middle-income countries. Large high-quality multicentre randomised controlled trials implemented in resource-constrained countries will provide additional evidence for the efficacy and safety of this intervention. Local policy makers should consider their local health infrastructure and population distribution needs. These considerations should be taken into account when developing clinical guidelines for pre-hospital thrombolysis.

Reduction in Door-to-Needle Time after Transfer of Thrombolysis Site from CCU to Emergency Department

Objective. Early restoration of coronary perfusion by thrombolysis or percutaneous coronary intervention is the main modality of treatment to salvage the ischemic myocardium. The earlier the procedure is completed, the greater the benefit is in saving myocardium and restoring its functions. The aim of the study is to compare the door-to-needle time (DNT) in acute ST elevation myocardial infarction (STEMI) in the period prior to December 2008 when the site of thrombolysis was in coronary care unit (CCU) and the period after that when the site was shifted to emergency department (ED). Methods. A retrospective, descriptive study was conducted at Al Khor Hospital, Qatar, in patients with acute STEMI who underwent thrombolysis at CCU and ED from April 2005 until December 2011, to compare the DNT, duration of hospitalization, and mortality. Results. A total of 211 patients with acute STEMI were eligible for thrombolysis; 58 patients were thrombolysed in the CCU and 153 in ED. The median DNT was reduced from 33.5 minutes in the CCU to 17 minutes in the ED representing a reduction of more than 50% with a P value of < 0.0001. Conclusion. The transfer of the thrombolysis site from CCU to the ED was associated with a dramatic and significant reduction in median door-to-needle time by more than half.

An electrocardiogram technician improves in-hospital first medical contact-to-electrocardiogram times: a cluster randomized controlled interventional trial

BACKGROUND

In the case of chest pain, the current guidelines require electrocardiogram (ECG) recording and patient assessment within 10 minutes upon arrival in the emergency department.

METHODS

We investigated the effect of an ECG technician (ECG-T) on in-hospital first medical contact-to-ECG times (iFMC-to-ECG) investigated in a cluster randomized, controlled trial. Allocation of intervention was concealed. Staff satisfaction and feasibility was defined as a secondary outcome. Delays between ECG and the availability of an emergency physician and the assessment of ECG were additionally evaluated.

RESULTS

A total of 163 (44 clusters) and 191 (47 clusters) patients were allocated to control and intervention, respectively. Twenty-seven (17%) of 163 patients in the control group vs 110 (58%) of 191 patients in the intervention group received ECG registration within 10 minutes (risk ratio, 3.40 [2.24-5.15]; P < .001). The iFMC-to-ECG time was 23 (95% confidence interval [CI], 20-27) minutes for the control group vs 9 (95% CI, 8-11) minutes for the intervention group (P < .001). Nursing staff judged the feasibility of intervention with a median of 1 (interquartile range [IQR], 1-1 (on a scale of 1 [best] to 5 [worst]), perceived workload alleviation with a median of 1 (IQR, 1-1), and improvement of quality of care with a median of 1 (IQR, 1-2). The ECG-to-EP time was 78 (95% CI, 64-92) seconds, and diagnosis was made within 17 (95% CI, 16-18) seconds.

CONCLUSIONS

Delays of iFMC-to-ECG can be effectively addressed by implementation of an ECG-T. The service of an ECG-T is feasible and improves staff satisfaction. Both ECG-to-EP time and ECG assessment constitute no relevant delay.

A randomized clinical trial to reduce patient prehospital delay to treatment in acute coronary syndrome

BACKGROUND

Delay from onset of acute coronary syndrome (ACS) symptoms to hospital admission continues to be prolonged. To date, community education campaigns on the topic have had disappointing results. Therefore, we conducted a clinical randomized trial to test whether an intervention tailored specifically for patients with ACS and delivered one-on-one would reduce prehospital delay time.

METHODS AND RESULTS

Participants (n=3522) with documented coronary heart disease were randomized to experimental (n=1777) or control (n=1745) groups. Experimental patients received education and counseling about ACS symptoms and actions required. Patients had a mean age of 67+/-11 years, and 68% were male. Over the 2 years of follow-up, 565 patients (16.0%) were admitted to an emergency department with ACS symptoms a total of 842 times. Neither median prehospital delay time (experimental, 2.20 versus control, 2.25 hours) nor emergency medical system use (experimental, 63.6% versus control, 66.9%) was different between groups, although experimental patients were more likely than control to call the emergency medical system if the symptoms occurred within the first 6 months following the intervention (P=0.036). Experimental patients were significantly more likely to take aspirin after symptom onset than control patients (experimental, 22.3% versus control, 10.1%, P=0.02). The intervention did not result in an increase in emergency department use (experimental, 14.6% versus control, 17.5%).

CONCLUSIONS

The education and counseling intervention did not lead to reduced prehospital delay or increased ambulance use. Reducing the time from onset of ACS symptoms to arrival at the hospital continues to be a significant public health challenge.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov. Identifier NCT00734760.

Phase shift in transmitted electrocardiograms: a cautionary tale of distorted signals

We describe how a routine manufacturer's upgrade of equipment designed to record and transmit electrocardiograms inadvertently introduced the potential for artefact that simulated the ST segment elevation of myocardial infarction. Whilst this type of artefact from a phenomenon known as phase shift is likely to be rare, the possibility should be recognised. Any doubt about the veracity of ST segment elevation from this phenomenon can be tested by introducing test signals from a simple pulse generator.

Predictors of pre-hospital delay among patients with acute myocardial infarction

OBJECTIVE

To evaluate current literature on predictors of pre-hospital delay among patients with acute myocardial infarction (AMI).

METHODS

Medline, CINHAL, and Psych Info databases were searched using keywords: attitude to illness/health, health beliefs, help/health seeking behavior, health behavior, psychosocial factors, treatment delay, socioeconomic factors, time factors, pre-hospital delay, and symptoms. These keywords were combined with AMI to identify literature published during 1995-2008.

RESULTS

Twenty-six data-based research articles were identified. Delay varied across literature and median pre-hospital delay was often reported due to distribution skewness resulting from extremely prolonged values (1.5-15.2h). Six categories of predictors influenced pre-hospital delay; socio-demographic, symptom onset context, cognitive, affective/psychological, behavioral, and clinical factors. Pre-hospital delay was shortest when the decision to seek healthcare was facilitated by family members or coworkers and when symptoms suggestive of heart attack were continuous and severe.

CONCLUSION AND PRACTICE IMPLICATIONS

Developing interventions programs to reduce pre-hospital delay for high-risk patients is warranted. Because decision delay is the only modifiable part by intervention, it is recommended that future investigations and interventions attend to decision time as the primary variable of interest instead of combining it with transportation time. Moreover, content of patient education need to emphasize on symptom awareness and recognition, and prompt and proper patient actions for optimum results. Also, in order to eliminate sampling bias resulting from investigating surviving AMI patients, it is recommended that future studies incorporate data from both surviving and surrogates of non-surviving AMI patients.

Myocardial salvage with early anistreplase treatment

This randomized, double-blind trial in 311 patients with acute myocardial infarction has shown that very early therapy with anistreplase outside the hospital is not only feasible, but provides a major survival advantage. The difference in the median delay to treatment between the group treated in the hospital and those treated earlier was 2 1/4 h. After 30 months, mortality in the early group was less than half that in the later group, so that every hour of delay beyond 2 h resulted in almost 7 additional deaths per 100 patients treated. This is a greater percentage loss of life than would have resulted from a similar delay in the provision of resuscitation for the prehospital cardiac arrest. Multivariate analysis showed that age, treatment delay, and time of presentation were significant risk factors, with patients presenting at 1 h having more than twice the mortality of those presenting at 4 h; the sicker the patient, the earlier the presentation. By 5 years, prehospital administration of anistreplase, by saving 2 h, resulted in an additional 57% of a year's survival per patient. This compares favorably with the projected 14% of a year survival per patient reported with TPA versus streptokinase in GUSTO. Prehospital therapy with anistreplase was highly cost effective when compared with streptokinase given in hospital, and the marginal cost-effectiveness ratio was much lower than that for TPA versus streptokinase derived from GUSTO.

Emergency department triage of acute myocardial infarction patients and the effect on outcomes

STUDY OBJECTIVE

More than half of all acute myocardial infarction patients still do not meet benchmark reperfusion times, and the triage assessment that all patients receive when they arrive at an emergency department (ED) is a hospital-level process that has not been studied as a potential contributor to delays. Our objective was to examine the triage of acute myocardial infarction patients (ST-elevation and non-ST elevation myocardial infarction) and determine whether it is associated with subsequent delays in acute myocardial infarction processes of care.

METHODS

We conducted a retrospective cohort analysis of a population-based cohort of acute myocardial infarction patients admitted to 102 acute care hospitals in Ontario, Canada, from July 2000 to March 2001. Main outcome measures were the rate of low-acuity triage (defined as a Canadian Triage and Acuity Scale score of III, IV, or V) among acute myocardial infarction patients and its association with delays in time from ED arrival to initial ECG (door-to-ECG time) and to administration of fibrinolysis (door-to-needle time).

RESULTS

Among 3,088 acute myocardial infarction patients, the rate of low acuity triage was 50.3%. Median door-to-ECG and door-to-needle time was 12.0 and 40.0 minutes, respectively. In adjusted quantile regression analyses, low-acuity triage was independently associated with a 4.4-minute delay in median door-to-ECG time and a 15.1-minute delay in median door-to-needle time. The adjusted odds of achieving benchmark door-to-ECG and door-to-needle times were 0.54 (95% confidence interval 0.46 to 0.65) and 0.44 (95% confidence interval 0.30 to 0.65), respectively, for acute myocardial infarction patients assigned a low-acuity ED triage score.

CONCLUSION

Half of acute myocardial infarction patients were given a low acuity triage score when they presented to an ED in Ontario, which was independently associated with substantial delays in ECG acquisition and to reperfusion therapy. The quality of ED triage may be an important factor limiting performance on key measures of quality of acute myocardial infarction care.

The cost-effectiveness of thrombolysis administered by paramedics

OBJECTIVE

The objective of this study is to estimate the expected health outcomes, costs and cost-effectiveness of changing from current practice, where thrombolytic therapy is given in hospital, to paramedic practice where thrombolytic therapy is administered by appropriately trained paramedics (pre-hospital) for STEMI patients.

METHODS

A decision-analysis microsimulation model was constructed with a 30-day component and a long-term health state transition component. A brief review of the literature was undertaken to obtain data on time-to-needle to populate the model. The primary health outcome was quality-adjusted life years (QALYs); secondary outcomes included cardiac events, procedures and survival. Costs to the Australian healthcare system for the rest of life were taken as the analytical perspective.

RESULTS

On average, STEMI patients gain 0.13 QALYs at an additional life-time cost of $343. The incremental cost-effectiveness ratios were $3428 per life-year gained and $2601 per QALY gained. These estimates were robust to changes in a range of assumptions and parameter values. The most important factor was the time-to-needle - the greater the difference between current practice times and paramedic practice times, the greater the health benefits and lower the cost per QALY (and life-year) gained. A key factor in the model was the substantially lower incidence of heart failure from earlier time-to-needle. Importantly, there was little change in the cost per QALY gained for a wide range of ages; thus, there is no argument to limit thrombolysis by paramedics to above or below an age threshold.

CONCLUSIONS

Paramedics administering thrombolysis can avert some STEMI deaths and the pre-hospital administration of thrombolysis is good value for money.

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.

Feasibility and long term outcome of home vs hospital initiated thrombolysis

BACKGROUND

Thrombolytic therapy improves mortality in acute myocardial infarction especially in those who receive treatment early. Pre-hospital therapy can reduce the time to treatment.

METHODS

Open, randomized study of patients with acute myocardial infarction of less than six hours duration in a rural community. Pre-hospital thrombolysis was administered using a mobile coronary care unit (MCCU) and all patients received IV streptokinase.

RESULTS

Two-hundred and forty-eight patients were studied, 82 in the MCCU and 166 in the hospital group. The mean delay time to treatment was 136 minutes (MCCU group) and 196 minutes (hospital group) (p < 0.001). Reperfusion time was 116 minutes for the MCCU group and 118 minutes for the hospital group. Mortality at 30 days was 4.9% for the MCCU group and 15.7% for the hospital group (p = 0.014). Mortality at one year was 9.8% for the MCCU group and 23.5% for the hospital group (p = 0.009). Mortality for patients followed up to five years was 17.7% for the MCCU group and 35.2% for the hospital group (p = 0.005). There were no significant adverse events in either treatment group.

CONCLUSION

Pre-hospital thrombolysis by MCCU is feasible and allows significant reduction in the delay time to treatment initiation. There are encouraging improvements in short- and long-term survival with no apparent reduction in safety profile.

Bypassing the emergency room reduces delays and mortality in ST elevation myocardial infarction: the USIC 2000 registry

OBJECTIVE

To study the impact on outcomes of direct admission versus emergency room (ER) admission in patients with ST-segment elevation myocardial infarction (STEMI) DESIGN: Nationwide observational registry of STEMI patients

SETTING

369 intensive care units in France.

INTERVENTIONS

Patients were categorised on the basis of the initial management pathway (direct transfer to the coronary care unit or catheterisation laboratory versus transfer via the ER).

MAIN OUTCOME MEASURES

Delays between symptom onset, admission and reperfusion therapy. Mortality at five days and one year.

RESULTS

Of 1204 patients enrolled, 66.9% were admitted direct and 33.1% via the ER. Bypassing the ER was associated with more frequent use of reperfusion (61.7% v 53.1%; p = 0.001) and shorter delays between symptom onset and admission (244 (interquartile range 158) v 292 (172) min; p < 0.001), thrombolysis (204 (150) v 258 (240) min; p < 0.01), hospital thrombolysis (228 (156) v 256 (227) min, p = 0.22), and primary percutaneous coronary intervention (294 (246) v 402 (312) min; p < 0.005). Five day mortality rates were lower in patients who bypassed the ER (4.9% v 8.6%; p = 0.01), regardless of the use and type of reperfusion therapy. After adjusting for the simplified Thrombolysis in Myocardial Infarction (TIMI) risk score, admission via the ER was an independent predictor of five day mortality (odds ratio 1.67, 95% confidence interval 1.01 to 2.75).

CONCLUSIONS

In this observational analysis, bypassing the ER was associated with more frequent and earlier use of reperfusion therapy, and with an apparent survival benefit compared with admission via the ER.

Thrombolysis: past, present, and future

Management of myocardial infarction evolved because of understanding of underlying disease processes and clinical trials of "chemical" and "mechanical" clot dissolution that reduced in-hospital mortality. Meta-analysis comparing these treatment strategies marginally favours angioplasty. Current European Society of Cardiology guidelines propose primary angioplasty as the preferred therapeutic option but few units in the UK can offer angioplasty on demand as a designated "heart attack centre". Thrombolysis will continue as it is widely available and training needs and costs less than angioplasty. Community thrombolysis should be made available for those patients who do not wish for such aggressive intervention or as a prelude to transfer time to a heart attack centre distant from a triage hospital.

A qualitative study in rural and urban areas on whether--and how--to consult during routine and out of hours

BACKGROUND

Patients vary widely when making decisions to consult primary care. Some present frequently with trivial illness: others delay with serious disease. Differences in health service provision may play a part in this. We aimed to explore whether and how patients' consulting intentions take account of their perceptions of health service provision.

METHODS

Four focus groups and 51 semi-structured interviews with 78 participants (45 to 64 years) in eight urban and rural general practices in Northeast and Southwest Scotland. We used vignettes to stimulate discussion about what to do and why. Inductive analysis identified themes and explored the influence of their perceptions of health service provision on decision-making processes.

RESULTS

Anticipated waiting times for appointments affected consulting intentions, especially when the severity of symptoms was uncertain. Strategies were used to deal with this, however: in cities, these included booking early just in case, being assertive, demanding visits, or calling out-of-hours; in rural areas, participants used relationships with primary care staff, and believed that being perceived as undemanding was advantageous. Out-of-hours, decisions to consult were influenced by opinions regarding out-of-hours services. Some preferred to attend nearby emergency departments or call 999. In rural areas, participants tended to delay until their own doctor was available, or might contact them even when not on call.

CONCLUSION

Perceived barriers to health service access affect decisions to consult, but some patients develop strategies to get round them. Current changes in UK primary care are unlikely to reduce differences in consulting behaviour and may increase delays by some patients, especially in rural areas.

The failure of years of experience with electrocardiographic transmission from paramedics to the hospital emergency department to reduce the delay from door to primary coronary intervention below the 90-minute threshold during acute myocardial infarction

INTRODUCTION

Emergency medical services (EMS), hospital emergency departments, and cardiologists have taken steps to reduce time to reperfusion therapy by implementation of aggressive acute myocardial infarction treatment and triage protocols. Data indicate that significant myocardial salvage requires reperfusion within 2 hours, and the current American College of Cardiology guideline is 90 minutes after hospital emergency department admission.

MATERIALS AND METHODS

To minimize delays in time to reperfusion in an urban-rural North Carolina County, Guilford County EMS and the Moses Cone Hospital have collaborated to implement transmission of EMS electrocardiographs (ECGs) to the emergency department. The study population included 92 patients who were transported by EMS and received primary coronary intervention during the second, third, and fourth years after initiation of this intervention in 1993.

RESULTS

The median time from symptom onset to the initial ECG was 77 minutes. There was an additional 23 minutes between the availability of this ECG and the arrival of the patient at the emergency department. In the first year of the intervention, the time from hospital arrival to percutaneous coronary intervention was 80 minutes. In years 2 through 4, they were 93, 85, and 94 minutes, respectively. In 2003, 10 years after the intervention, the time from hospital arrival to percutaneous coronary intervention was 113 minutes.

CONCLUSION

Initial gains in the time from hospital arrival to percutaneous coronary intervention, attributed to acquisition of the ECG in the prehospital setting, were not sustained over 10 years.

Feasibility of early emergency room notification to improve door-to-balloon times for patients with acute ST segment elevation myocardial infarction

An algorithm to lower time from first contact in the field by EMS personnel to in-hospital mechanical reperfusion is described. ECG tracings were telemetered via cellular phone to an emergency room physician, who then activated the cardiac catheterization call team to bypass usual delays seen during ER triage. Seventy-one ECGs were sent to the ER in the time interval from October 2003 to October 2004. Five ECGs (7.0%) failed to transmit due to failure of the cellular phone to receive an adequate signal. Sixty-six patients (93.0%) had an adequate ECG transmitted to the ER and six patients with ST elevation myocardial infarction were identified. Door-to-balloon times were lowered to 44 +/- 17.4 min, a substantial decrease over historical norms that range from 120 min (25th percentile) to 289 min (75th percentile).

Prehospital 12-lead electrocardiography impact on acute myocardial infarction treatment times and mortality: a systematic review

OBJECTIVES

Prehospital 12-lead electrocardiogram (PHECG) interpretation and advance emergency department (ED) notification may improve time-to-treatment intervals for a variety of treatment strategies to improve outcome in acute myocardial infarction. Despite consensus guidelines recommending this intervention, few emergency medical services (EMS) employ this. The authors systematically reviewed the literature to report whether mortality or treatment time intervals improved when compared with standard care.

METHODS

The authors used the Cochrane strategy to search MEDLINE, EMBASE, Current Contents, Dissertation Abstracts, Cochrane Library, and Index of Scientific and Technical Proceedings. Bibliographies and grant-agency Websites were reviewed, and primary investigators and industry were contacted for published and unpublished studies. Inclusion criteria included PHECG and advance ED notification versus standard EMS care; controlled trials; English only; and evaluation of treatment time intervals, all-cause mortality, or both. Study selection was hierarchical, blinded, and independent. Agreement at each level of review was evaluated by using a kappa statistic. Study quality was measured with a validated scale and was interpreted by two independent reviewers.

RESULTS

A total of 1,283 citations were identified, and five studies met the inclusion criteria. The weighted kappa for selection was 0.61 (standard error [SE], 0.045) for titles, 0.63 (SE, 0.051) for abstracts, and 0.79 (SE, 0.146) for full articles. Mean study quality measures by two independent reviewers were 6.0/15 and 5.5/15 (correlation coefficient, 0.85; p = 0.06). PHECG and advance ED notification increased the weighted mean on-scene time by 1.2 minutes (95% confidence interval [95% CI] = -0.84 to 3.2). The weighted mean door-to-needle interval was shortened by 36.1 minutes (95% CI = 9.3 to 63.0: range of means, 22-48 minutes vs. 50-97 minutes). One study reported all-cause mortality, with a statistically nonsignificant reduction from 15.6% to 8.4%.

CONCLUSIONS

For patients with AMI, the literature would suggest that PHECG and advanced ED notification reduces in hospital time to fibrinolysis. One controlled trial found no difference in mortality with this out-of-hospital intervention.

Prehospital triage of acute myocardial infarction: wireless transmission of electrocardiograms to the on-call cardiologist via a handheld computer

BACKGROUND

Use of intravenous fibrinolytic agents and percutaneous coronary interventions produce the greatest benefit when they are implemented in the first 2 hours after symptom onset. Further delays in the time to treatment typically lead to reduced benefits and poorer outcomes.

METHODS

Cabarrus County Emergency Medical Service personnel complete an acute myocardial infarction case report form and assess a 12-lead electrocardiogram (ECG) to determine if ST elevation of at least 1 mV in at least 2 contiguous leads is present and then to transmit the ECG wirelessly to the emergency department (ED). The ECG is then forwarded wirelessly from the ED to the on-call cardiologist who is carrying the IPAQ handheld computer.

RESULTS

Five representative patients managed using this system during the initial year of its implementation are presented.

CONCLUSION

The examples included in this article illustrate that the system and technology can work if applied in a coordinated fashion using multiple disciplines including emergency medical service, cardiologists, ED personnel, and the hospital cardiac care team, which includes the catheterization laboratory call team, acute coronary care nurses, and clerical support staff.

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

BACKGROUND

Time to reperfusion is critical for outcome in patients with ST-elevation myocardial infarction (STEMI). In our region, patients are routinely treated by primary percutaneous coronary intervention (pPCI), but rerouting patients from the primary receiving hospital to a catheterization center can cause unacceptable delays that may exceed 1 hour in the emergency department. Wireless transmission of prehospital electrocardiograms (ECGs) to receiving stations in hospitals has been shown to reduce time from symptom onset to reperfusion. However, transmission directly to a cardiologist's handheld digital device has not been investigated.

AIM

To report preliminary data from a larger ongoing trial evaluating prehospital 12-lead ECG transmission to a cardiologist's handheld device in patients with symptoms suggesting an acute coronary syndrome.

METHOD

Patients suffering acute, nontraumatic chest pain have their prehospital ECG transmitted by wireless technology directly to a cardiologist's handheld device at an invasive hospital, allowing diversion of STEMI cases to rapid pPCI. Transmission failures are documented. Times for symptom onset, 911 alert, ECG recording, hospital arrival, and pPCI are obtained. All time intervals are summarized as median values and are compared with historic controls from the Danish multicenter study, DANAMI-2.

RESULTS

During the first 15 months of the trial, prehospital ECGs were transmitted for 408 chest pain patients with an overall success rate of 93%. Cardiologist receiving the ECGs recommended that 113 patients (28%) be diverted for pPCI. Mean time from symptom onset to 911 alert was 2 hours 16 minutes (range, 1 minute to 23 hours 15 minutes), and the ambulance response interval was 5 minutes (range, 1-25 minutes). The ambulance on-scene time had increased by 7 minutes compared with historic controls (P<.05). Time from ECG recording to hospital arrival was 25 minutes. The total prehospital time was 2 hours 57 minutes. The hospital treatment time was substantially reduced among diverted patients. Hospital arrival to procedure start was 40 minutes, compared with 94 minutes in the DANAMI-2 historic control group (P<.01).

CONCLUSION

These preliminary data suggest that transmission of prehospital 12-lead ECGs directly to the attending cardiologist using handheld devices is a technologically sound concept without major safety concerns and markedly reducing time to reperfusion in patients with STEMI.

Can the wrong statistic be bad for health? Improving the reporting of door-to-needle time performance in acute myocardial infarction

BACKGROUND

Current acute myocardial infarction (AMI) guidelines call for reperfusion to be given to all eligible patients within a set time interval after hospital arrival, yet current hospital performance benchmarks are based on the median door-to-intervention time among treated patients. Our objective is to compare hospital performance rankings when door-to-needle time (DNT) is measured at the current benchmark (median < or = 30 minutes) versus those obtained with more stringent benchmarks common for other AMI treatments.

METHODS

A secondary analysis of data from the EFFECT study from 52 small, community and teaching hospitals in Ontario. All Ontario hospital corporations that treated > or = 30 patients with AMI from 1999 to 2001 participated. The charts of approximately 125 patients with AMI per hospital were reviewed; median and 85th percentile DNTs were then calculated for patients with ST-elevation AMI given thrombolysis at each site along with the proportion of patients thrombolysed within the recommended time. Hospitals were then ranked according to each indicator.

RESULTS

Data were obtained on 1,578 patients given thrombolytic drugs at 52 hospitals. The median and 85th percentile DNTs were 37 and 82 minutes, respectively; the proportion of patients treated in < or = 30 minutes ranged from 8.5% to 60%. Hospitals that achieved a median DNT of < or = 30 minutes treated 40% to 50% of their patients outside that time frame. The ranks of the top 15 median DNT hospitals changed substantially when re-ranked according to the 85th percentile (average change in rank -16, range +6 to -40). If DNT improved such that a 30-minute median target was achieved, the estimated reduction for the average patient would be 13 minutes versus a 43-minute reduction if the 85th percentile target was achieved.

CONCLUSION

Hospitals that achieve a 30-minute median DNT benchmark still treat 40% to 50% of their patients outside the recommended time, which is not consistent with current AMI treatment guidelines. Door-to-needle time for the average patient would be up to 43 minutes faster if the DNT target was achieved at the 85th percentile.

Limited benefits of ambulance telemetry in delivering early thrombolysis: a randomised controlled trial

OBJECTIVES

To evaluate the potential of a continuous telemetry system linking rural ambulances to a coronary care unit to reduce call to thrombolysis times.

METHODS

This prospective randomised controlled trial recruited patients using the 999 ambulance service in a rural area of the UK with signs or symptoms of coronary heart disease. Subjects were assigned to receive either standard paramedic treatment or transmission of 12 lead ECG, blood pressure, pulse oximetry, and relevant medical history to a general hospital coronary care unit. Cardiology senior house officers then determined each patient's suitability for pre-hospital thrombolysis time, and transmitted this decision back to the ambulance. This was documented as the potential thrombolysis, although no thrombolytic agents were administered by paramedics. The between groups difference in time to potential thrombolysis (intervention group) and actual thrombolysis (controls) was compared. The proportion of intervention group subjects ultimately receiving thrombolysis in hospital was compared with that recommended for pre-hospital thrombolysis.

RESULTS

The potential reduction in call to treatment time for telemetry patients recommended for pre-hospital thrombolysis was 55 minutes (p = 0.022). Following hospital admission,21/213 of the telemetry patients were thrombolysed (10%, 95% confidence interval (CI) 6% to 15%). Of these patients, 3/21 received a recommendation for thrombolysis in the ambulance (14%, 95% CI 3.1% to 36.3%). The sensitivity and specificity of the telemetry system in detecting patients requiring thrombolysis was 13.6 and 99.5% respectively. Errors were made in the pre-hospital treatment recommendations for two patients.

CONCLUSIONS

Continuous telemetry systems may significantly reduce call to treatment times for patients recommended for pre-hospital thrombolysis in a rural setting. However, this benefit must be balanced against the very small proportion of eligible patients identified as suitable for pre-hospital thrombolysis. This limitation may be due to communications problems, the criteria used to identify eligible patients, or the seniority of physicians tasked with making treatment decisions.

Reperfusion treatment of ST-elevation acute myocardial infarction

Reperfusion treatment of ST-segment elevation myocardial infarction (STEMI) is one of the medical interventions with the largest potential for saving human lives, independently of age and gender. An attempt to reopen an acutely occluded coronary artery can be done within a wide array of possibilities, from the simple administration of aspirin to the combination of drugs and complex coronary artery interventions. Fibrinolytic drugs and aspirin represent the easiest way to attempt reperfusion and together offer an acceptable compromise between opportunity for treatment and efficacy. Other drugs and the use of invasive revascularization alternatives yield further advantages, and in some high-risk subgroups may be the most rational treatment approach. Beyond investigator's bias and dedication to either form of reperfusion treatment, interventions and/or drugs should be used as needed (and as possible) to increase the overall impact of reperfusion treatment in the community, taking advantage of the best potential of each approach. Most resources have been directed toward the improvement of reperfusion rates with the combination of fibrinolytic and antiplatelet drugs or with angioplasty. These efforts have certainly raised costs, but have not decisively improved clinical outcome nor have they broadened the impact of reperfusion treatment in the community. Indeed, the main shortcoming of reperfusion therapy is that the cohort of untreated patients is still larger than the cohort of treated patients. At a time when mortality of patients with STEMI reaching the hospital and receiving treatment has decreased significantly, the prehospital diagnosis and treatment of STEMI with the objective of enlarging the treated population and shortening the pretreatment delays is likely the best strategy to further reduce mortality. The need for a population approach to treatment of STEMI is even more obvious when considering the expanding patient load that continuously worsens its clinical risk profile, together with the increasing incidence of diabetes, obesity, hypertension, and smoking habits. The target for improving reperfusion treatment of STEMI in the future, and thereby saving more lives, seems now to involve a cultural change and fulfillment of an organizational mission more than an incremental improvement in the current pharmacologic or interventional approach. These epidemiologic and social aspects of contemporary medicine deserve full attention at a time when researchers, clinicians, and health care providers tend to focus primarily on technological advances.

Emergency department crowding and thrombolysis delays in acute myocardial infarction

STUDY OBJECTIVE

We estimate the effect of emergency department (ED) crowding on door-to-needle time for patients given intravenous thrombolysis for suspected acute myocardial infarction.

METHODS

This was a retrospective observational study of patients thrombolyzed in the ED for suspected acute myocardial infarction in 1998 to 2000 in 25 community and teaching hospital EDs in Ontario. EDs located close together and sharing a common ambulance diversion system were grouped into networks consisting of 2 to 5 hospitals each. At patient registration in an ED, the ambulance diversion status of all EDs in the network was determined. Network crowding was calculated as the percentage of EDs that were diverting ambulances on patient registration, categorized as none (0%), moderate (<60%), and high (> or =60%). Door-to-needle time was defined as time from ED registration to drug administration. Multivariable quantile regression and logistic regression were carried out; covariates included age, sex, ECG characteristics, previous acute myocardial infarction, vital signs, time of presentation, and hospital type.

RESULTS

A total of 3,452 thrombolysis patients were included: mean age was 62.9 years, and 73% were male patients. Overall median door-to-needle time was 43 minutes (interquartile ratio 27 to 80). Median door-to-needle time was 40, 45, and 47 minutes in conditions of none, moderate, and high network crowding, respectively ( P <.001). The adjusted odds ratios for door-to-needle time delay (>30 minutes) and major delay (>60 minutes) were 1.32 (95% confidence interval [CI] 0.98 to 1.79) and 1.40 (95% CI 1.12 to 1.75), respectively, for high network crowding compared with none, and 1.21 (95% CI 0.89 to 1.63) and 1.06 (95% CI 0.86 to 1.29), respectively, for moderate crowding compared with none. In multivariate analyses, moderate and high crowding conditions were associated with increased median door-to-needle time (3.0 minutes [95% CI 0.1 to 6.0] and 5.8 minutes [95% CI 2.7 to 9.0], respectively).

CONCLUSION

ED crowding is associated with increased door-to-needle times for patients with suspected acute myocardial infarction and may represent a barrier to improving cardiac care in EDs.

Differences in care-seeking behavior for acute chest pain in the United States and Japan

BACKGROUND

Delay from onset of acute myocardial infarction symptoms to the delivery of medical care is a major determinant of prognosis. Although studies have explored patient factors for delay in seeking care, there are limited data on international differences in care-seeking behavior.

METHODS

We surveyed 1032 people in the United States and 1422 people in Japan in January 1997 on decision-making responses to a chest pain scenario representing acute MI. Participants were asked about how they would seek initial care and how promptly they would seek care.

RESULTS

The mean age was 43.6 years in the United States and 48.3 years in Japan. For the hypothetical scenario, US respondents were more likely to seek care at an emergency department (22.9% vs 16.2% in Japan) or through emergency medical services/911 (55.9% vs 32.9% in Japan, P =.001). American subjects were also more likely to seek care immediately (83.1% vs 56.4% in Japan, P =.001).

CONCLUSION

Respondents in the United States and Japan differed substantially in their responses to a hypothetical chest pain scenario. Whether these differences result from cultural or health care system factors and whether these apparent attitudes produce gaps in real responses to acute coronary syndromes must be explored in further studies.

Beneficial effects of direct call to emergency medical services in acute myocardial infarction

OBJECTIVES

We investigated the impact of an emergency medical services call on the management of acute myocardial infarction, considering time intervals for intervention and revascularization procedures.

METHODS

Data were prospectively collected from January 2001 to October 2002 from 531 patients hospitalized for myocardial infarction with ST segment elevation and a pre-hospital delay of less than 24 h.

RESULTS

Only 26% of patients called the emergency medical services at the onset of symptoms (n=140). Other patients (n=391, 74%) called another medical contact. Baseline characteristics and cardiovascular history were similar in the two groups, except for the percutaneous coronary intervention history (10% in the emergency medical services group versus 4% in the other medical contact group, P<0.05). Time intervals from the onset of symptoms of myocardial infarction to call or to medical intervention, as well as the time interval from medical intervention to hospital admission were significantly shorter in the emergency medical services group. The early reperfusion rate was also significantly greater in the emergency medical services group (77%) compared with the other medical contact group (64%), mainly because of a greater incidence of primary percutaneous coronary intervention (36 versus 26%, P<0.03, respectively). Multivariate analysis adjusted for sex and age showed that less than three medical care providers [odds ratio (OR) 5.042, P<0.001], percutaneous coronary intervention history (OR 2.462, P<0.05), as well as rhythmic disorders (OR 2.105, P<0.05) and complete atrioventricular block (OR 2.757, P<0.05) were independent predictors of emergency medical services care.

CONCLUSION

This study demonstrated that a call to the emergency medical services is underutilized by patients with symptoms of myocardial infarction, and documented the beneficial effects of an emergency medical services call by reducing pre-hospital delays and increasing early revascularization therapies.