Predictors of ambulance use in patients with acute myocardial infarction in Australia

Ability of the Australian general public to identify common emergency medical situations: Results of an online survey of a nationally representative sample

OBJECTIVE

To investigate the Australian general public's ability to identify common medical emergencies as requiring an emergency response.

METHODS

An online survey asked participants to identify likely medical treatment pathways they would take for 17 hypothetical medical scenarios (eight emergency and nine non-emergency). The number and type of emergency scenarios participants correctly suggested warranted an emergency medical response was examined. Participants included Australian residents (aged>18 years; n = 5264) who had never worked as an Australian registered medical doctor, nurse or paramedic.

RESULTS

Most emergencies were predominately correctly classified as requiring emergency responses (e.g. Severe chest pain, 95% correct). However, non-emergency medical responses were often chosen for some emergency scenarios, such as a child suffering from a scalp haematoma (67%), potential meningococcal disease (57%), a box jellyfish sting (40%), a paracetamol overdose (37%), and mild chest pain (26%). Participants identifying as Aboriginal or Torres Strait Islander suggested a non-emergency response to emergency scenarios 29% more often compared with non-indigenous participants.

CONCLUSIONS

Educational interventions targeting specific medical symptoms may work to alleviate delayed emergency medical intervention. This research highlights a particular need for improving symptom identification and healthcare system confidence amongst Aboriginal and Torres Strait Islander populations.

Unscheduled care pathways in patients with myocardial infarction in Scotland

Objective

Treatment of acute myocardial infarction (MI) requires rapid transfer of people with chest pain to hospital, however, unscheduled care pathways vary in their directness (the minimal number of contacts to hospital admission). The aim was to examine unscheduled care pathways and the associations with mortality in people admitted with MI.

Methods

Retrospective population study of all people admitted to Scottish hospitals with a diagnosis of MI between 1 January 2015 and 31 December 2017. Linked data for all National Health Service Scotland unscheduled care services (NHS24 telephone triage service, primary care out of hours, ambulance, emergency department (ED)) was used to define continuous unscheduled care pathways (pathways), which were categorised by initial contact, and whether they were ‘direct’ (had minimum number of contacts between first contact and admission). Analysis estimated ORs and 95% CIs in adjusted models in which all covariates were included.

Results

26 325 people admitted with MI (63.1% men, 61.6% aged 65+ years), of whom 5.6% died from coronary heart disease within 28 days. For 47.0%, the first unscheduled care contact was ambulance, 23.3% attended ED directly and 18.7% called telephone triage. 92.1% of pathways were direct. Pathways starting with telephone triage were more likely to be indirect compared with other initial contacts (adjusted OR (aOR) 1.97, 95% CI 1.61 to 2.40). Compared to direct pathways, indirect pathways starting with telephone triage were associated with higher mortality (aOR 1.97, 95% CI 1.61 to 2.40) as were indirect pathways starting with another service (aOR 1.55, 95% CI 1.19 to 2.01), but not direct pathways starting with telephone triage (aOR 0.87, 95% CI 0.74 to 1.02).

Conclusion

Unscheduled care pathways leading to admission with MI in Scotland are usually direct, but those starting with telephone triage were more commonly indirect. Those indirect pathways were associated with higher mortality.

Association of Socioeconomic Status With Outcomes and Care Quality in Patients Presenting With Undifferentiated Chest Pain in the Setting of Universal Health Care Coverage

BACKGROUND

This study aimed to assess whether there are disparities in incidence rates, care, and outcomes for patients with chest pain attended by emergency medical services according to socioeconomic status (SES) in a universal health coverage setting.

METHODS AND RESULTS

This was a population‐based cohort study of individually linked ambulance, emergency, hospital admission, and mortality data in the state of Victoria, Australia, from January 2015 to June 2019 that included 183 232 consecutive emergency medical services attendances for adults with nontraumatic chest pain (mean age 62 [SD 18] years; 51% women) and excluded out‐of‐hospital cardiac arrest and ST‐segment–elevation myocardial infarction. Age‐standardized incidence of chest pain was higher for patients residing in lower SES areas (lowest SES quintile 1595 versus highest SES quintile 760 per 100 000 person‐years; P<0.001). Patients of lower SES were less likely to attend metropolitan, private, or revascularization‐capable hospitals and had greater comorbidities. In multivariable models adjusted for clinical characteristics and final diagnosis, lower SES quintiles were associated with increased risks of 30‐day and long‐term mortality, readmission for chest pain and acute coronary syndrome, lower acuity emergency department triage categorization, emergency department length of stay >4 hours, and emergency department or emergency medical services discharge without hospital admission and were inversely associated with use of prehospital ECGs and transfer to a revascularization‐capable hospital for patients presenting to non‐percutaneous coronary intervention centers.

CONCLUSIONS

In this study, lower SES was associated with a higher incidence of chest pain presentations to emergency medical services and differences in care and outcomes. These findings suggest that substantial disparities for socioeconomically disadvantaged chest pain cohorts exist, even in the setting of universal health care access.

Prehospital time for patients with acute cardiac complaints: A rural health disparity

OBJECTIVE

Delays in care for patients with acute cardiac complaints are associated with increased morbidity and mortality. The objective of this study was to quantify rural and urban differences in prehospital time intervals for patients with cardiac complaints.

METHODS

The ESO Data Collaborative dataset consisting of records from 1332 EMS agencies was queried for 9-1-1 encounters with acute cardiac problems among adults (age ≥ 18) from 1/1/2013-6/1/2018. Location was classified as rural or urban using the 2010 United States Census. The primary outcome was total prehospital time. Generalized estimating equations evaluated differences in the average times between rural and urban encounters while controlling for age, sex, race, transport mode, loaded mileage, and patient stability.

RESULTS

Among 428,054 encounters, the median age was 62 (IQR 50-75) years with 50.7% female, 75.3% white, and 10.3% rural. The median total prehospital, response, scene, and transport times were 37.0 (IQR 29.0-48.0), 6.0 (IQR 4.0-9.0), 16.0 (IQR 12.0-21.0), and 13.0 (IQR 8.0-21.0) minutes. Rural patients had an average total prehospital time that was 16.76 min (95%CI 15.15-18.38) longer than urban patients. After adjusting for covariates, average total time was 5.08 (95%CI 4.37-5.78) minutes longer for rural patients. Average response and transport time were 4.36 (95%CI 3.83-4.89) and 0.62 (95%CI 0.33-0.90) minutes longer for rural patients. Scene time was similar in rural and urban patients (0.09 min, 95%CI -0.15-0.33).

CONCLUSION

Rural patients with acute cardiac complaints experienced longer prehospital time than urban patients, even after accounting for other key variables, such as loaded mileage.

Prehospital use of a modified HEART Pathway and point-of-care troponin to predict cardiovascular events

The HEART Pathway is a validated risk stratification protocol for Emergency Department patients with chest pain that has yet to be tested in the prehospital setting. This study seeks to test the performance of a prehospital modified HEART Pathway (PMHP). A prospective cohort study of adults with chest pain without ST-segment elevation myocardial infarction was conducted at three EMS agencies between 12/2016-1/2018. To complete a PMHP assessment, paramedics drew blood, measured point-of-care (POC) troponin (i-STAT; Abbott Point of Care) and calculated a HEAR score. Patients were stratified into three groups: high-risk based on an elevated troponin, low-risk based on a HEAR score <4 with a negative troponin, or moderate risk for a HEAR score ≥4 with a negative troponin. Sensitivity, specificity, negative and positive predictive values of the PMHP for detection of major adverse cardiac events (MACE: cardiac death, MI, or coronary revascularization) at 30-days were calculated. A total of 506 patients were accrued, with PMHP completed in 78.1% (395/506). MACE at 30-days occurred in 18.7% (74/395). Among these patients, 7.1% (28/395) were high risk yielding a specificity and PPV for 30-day MACE of 96.6% (95%CI: 94.0–98.3%) and 60.7% (95%CI: 40.6–78.6%) respectively. Low-risk assessments occurred in 31.4% (124/395), which were 90.5% (95%CI: 81.5–96.1%) sensitive for 30-day MACE with a NPV of 94.4% (95%CI: 88.7–97.7%). Moderate-risk assessments occurred in 61.5% (243/395), of which 20.6% had 30-day MACE. The PMHP is able to identify high-risk and low-risk groups with high specificity and negative predictive value for 30-day MACE.

Sub-Daily Exposure to Fine Particulate Matter and Ambulance Dispatches during Wildfire Seasons: A Case-Crossover Study in British Columbia, Canada

BACKGROUND

Exposure to fine particulate matter (PM2.5) during wildfire seasons has been associated with adverse health outcomes. Previous studies have focused on daily exposure, but PM2.5 levels in smoke events can vary considerably within 1 d.

OBJECTIVES

We aimed to assess the immediate and lagged relationship between sub-daily exposure to PM2.5 and acute health outcomes during wildfire seasons in British Columbia.

METHODS

We used a time-stratified case-crossover study design to evaluate the association between modeled hourly PM2.5 and ambulance dispatches during wildfire seasons from 2010 to 2015. Distributed lag nonlinear models were used to estimate the lag-specific and cumulative odds ratios (ORs) at lags from 1 to 48 h. We examined the relationship for all dispatches and dispatches related to respiratory, circulatory, and diabetic conditions, identified by codes for ambulance dispatch (AD), paramedic assessment (PA) or hospital diagnosis (HD).

RESULTS

Increased respiratory health outcomes were observed within 1 h of exposure to a 10-μg/m3 increase in PM2.5. The 48-h cumulative OR [95% confidence interval (CI)] was 1.038 (1.009, 1.067) for the AD code Breathing Problems and 1.098 (1.013, 1.189) for PA code Asthma/COPD. The point estimates were elevated within 1 h for the PA code for Myocardial Infarction and HD codes for Ischemic Heart Disease, which had 24-h cumulative ORs of 1.104 (0.915, 1.331) and 1.069 (0.983, 1.162), respectively. The odds of Diabetic AD and PA codes increased over time to a cumulative 24-h OR of 1.075 (1.001, 1.153) and 1.104 (1.015, 1.202) respectively.

CONCLUSIONS

We found increased PM2.5 during wildfire seasons was associated with some respiratory and cardiovascular outcomes within 1 h following exposure, and its association with diabetic outcomes increased over time. Cumulative effects were consistent with those reported elsewhere in the literature. These results warrant further investigation and may have implications for the appropriate time scale of public health actions. https://doi.org/10.1289/EHP5792.

Pre-hospital delay and emergency medical services in acute myocardial infarction

BACKGROUND/AIMS

Minimising total ischemic time (TIT) is important for improving clinical outcomes in patients with ST-segment elevation myocardial infarction who have undergone percutaneous coronary intervention (PCI). TIT has not shown a significant improvement due to persistent pre-hospital delay. This study aimed to investigate the risk factors associated with pre-hospital delay.

METHODS

Individuals enrolled in the Korea Acute Myocardial Infarction Registry-National Institutes of Health between 2011 and 2015 were included in this study. The study population was analyzed according to the symptom-to-door time (STDT; within 60 or > 60 minutes), and according to the type of hospital visit (emergency medical services [EMS], non-PCI center, or PCI center).

RESULTS

A total of 4,874 patients were included in the analysis, of whom 28.4% arrived at the hospital within 60 minutes of symptom-onset. Old age (> 65 years), female gender, and renewed ischemia were independent predictors of delayed STDT. Utilising EMS was the only factor shown to reduce STDT within 60 minutes, even when cardiogenic shock was evident. The overall frequency of EMS utilisation was low (21.7%). Female gender was associated with not utilising EMS, whereas cardiogenic shock, previous myocardial infarction, familial history of ischemic heart disease, and off-hour visits were associated with utilising EMS.

CONCLUSION

Factors associated with delayed STDT and not utilising EMS could be targets for preventive intervention to improve STDT and TIT.

Diurnal, weekly and seasonal variations of chest pain in patients transported by emergency medical services

OBJECTIVES

Chest pain is among the leading causes for emergency medical services (EMS) activation. Acute myocardial infarction (MI) is not only one of the most critical aetiologies of chest pain, but also one of few conditions encountered by EMS that has been shown to follow a circadian pattern. Understanding the diurnal relationship between the inflow of chest pain patients and the likelihood of acute MI may inform prehospital and emergency department (ED) healthcare providers regarding the prediction, and hence prevention, of dire outcomes.

METHODS

This was a secondary analysis of previously collected data from an observational prospective study that enrolled consecutive chest pain patients transported by a large metropolitan EMS system in the USA. We used the time of EMS call to determine the time-of-day of the indexed encounter. Two independent reviewers examined available medical data to determine our primary outcome, the presence of MI, and our secondary outcomes, infarct size and 30-day major adverse cardiac events (MACE). We estimated infarct size using peak troponin level.

RESULTS

We enrolled 2065 patients (age 56±17, 53% males, 7.5% with MI). Chest pain encounters increased from 9:00 AM to 2:00 PM, with a peak at 1:00 PM and a nadir at 6:00 AM. Acute MI had a bimodal distribution with two peaks: 10 AM in ST-elevation MI, and 10 PM in non-ST-elevation MI. ST-elevation MI with afternoon onset was an independent predictor of infarct size. Acute MI with winter and early spring presentation was an independent predictor of 30-day MACE.

CONCLUSIONS

EMS-attended chest pain calls follow a diurnal pattern, with the most vulnerable patients encountered during afternoons and winter/spring seasons. These data can inform prehospital and ED healthcare providers regarding the time of presentation where patients are more likely to have an underlying MI and subsequently worse outcomes.

Emergency Medical Services Utilization and Outcomes of Patients with ST-Elevation Myocardial Infarction in Lebanon

BACKGROUND

Arrival of patients with ST-elevation myocardial infarction (STEMI) by Emergency Medical Services (EMS) results in shorter reperfusion times and lower mortality in developed countries.

OBJECTIVES

This study examines EMS use by STEMI patients in Lebanon and associated clinical outcomes.

METHODS

A retrospective observational study with chart review was carried out for STEMI patients arriving to the Emergency Department of a tertiary care center in Lebanon between January 1, 2013 and August 31, 2016. A descriptive analysis was done and followed by a bivariate analysis comparing two groups of patients (EMS vs. Non-EMS).

RESULTS

A total of 280 patients were included in the study. They were mostly male (71.8%). Mean age was 65.1 years (95% confidence interval [CI] 63.4-66.9). Only 12.5% (95% CI 8.6-16.4) presented by EMS. Chest pain (81.1%) was the most common presenting symptom. Anterior myocardial infarction was the most common electrocardiogram (ECG) diagnosis (51.4%). Most patients were admitted (98.2%), and 72.0% of these patients were treated with primary percutaneous coronary intervention. Cardiogenic shock was the most frequent in-hospital complication (6.2%). The mortality rate was 7.1%. Mean door-to-ECG and door-to-balloon times were 10.8 (95% CI 7.1-14.4) min and 106.2 (95% CI 95.9-116.6) min, respectively. Patients' characteristics, presenting symptoms, outcomes, and performance metrics were similar between the two groups.

CONCLUSION

EMS is underutilized by STEMI patients in Lebanon and is not associated with improvement in clinical outcomes. Medical oversight and quality initiatives focusing on outcomes of patients with timely sensitive emergencies are needed to advance the prehospital care system in Lebanon.

Characteristics of patients with acute myocardial infarction contacting primary healthcare before hospitalisation: a cross-sectional study

Background

The characteristics of patients with on-going myocardial infarction (MI) contacting the primary healthcare (PHC) centre before hospitalisation are not well known. Prompt diagnosis is crucial in patients with MI, but many patients delay seeking medical care. The aims of this study was to 1) describe background characteristics, symptoms, actions and delay times in patients contacting the PHC before hospitalisation when falling ill with an acute MI, 2) compare those patients with acute MI patients not contacting the PHC, and 3) explore factors associated with a PHC contact in acute MI patients.

Methods

This was a cross-sectional multicentre study, enrolling consecutive patients with MI within 24 hours of admission to hospital from Nov 2012 until Feb 2014.

Results

A total of 688 patients with MI, 519 men and 169 women, were included; the mean age was 66±11 years. One in five people contacted PHC instead of the recommended emergency medical services (EMS), and 94% of these patients experienced cardinal symptoms of an acute MI; i.e., chest pain, and/or radiating pain in the arms, and/or cold sweat. Median delay time from symptom-onset-to-decision-to-seek-care was 2:15 hours in PHC patients and 0:40 hours in non-PHC patients (p<0.01). The probability of utilising the PHC before hospitalisation was associated with fluctuating symptoms (OR 1.74), pain intensity (OR 0.90) symptoms during off-hours (OR 0.42), study hospital (OR 3.49 and 2.52, respectively, for two of the county hospitals) and a final STEMI diagnosis (OR 0.58).

Conclusions

Ambulance services are still underutilized in acute MI patients. A substantial part of the patients contacts their primary healthcare centre before they are diagnosed with MI, although experiencing cardinal symptoms such as chest pain. There is need for better knowledge in the population about symptoms of MI and adequate pathways to qualified care. Knowledge and awareness amongst primary healthcare professionals on the occurrence of MI patients is imperative.

Barriers to the use of emergency medical services for ST-elevation myocardial infarction: Determining why many patients opt for self-transport

RATIONALE, AIMS, AND OBJECTIVES

Access to timely ST-elevation myocardial infarction (STEMI) care is facilitated by paramedics and emergency medical services (EMS). However, a large proportion of STEMI patients do not access care through EMS. This study sought to identify patient-reported factors for their decision to use (or not use) EMS.

METHODS

Semi-structured interviews were conducted with a sample of STEMI patients admitted to a large tertiary care centre between November 2011 and January 2012. Participants were grouped according to mode of transportation to hospital at time of index event (EMS vs self-transport). Participant responses were classified using a published framework (modified for a STEMI population) as barriers or facilitators to EMS use, and compared between groups.

RESULTS

Data were collected on 61 patients (32 EMS, 29 self-transport). Mean age was 60.3 (SD 11.5), and 23% were female. EMS users were more likely to have a Killip Class >1 (25% vs 4%; P = 0.03). Self-transport patients were more likely to perceive EMS as slower (48% vs 0%) and express concerns over resources misuse (34% vs 3%; P = 0.002), when compared to EMS patients. Patients who accessed EMS were more likely to acknowledge the benefits of EMS (44% vs 7%; P = 0.001) and were more likely to have been encouraged by a family member to call EMS (34% vs 4%; P = 0.003).

CONCLUSIONS

STEMI patient perceptions are a key factor in determining EMS use. Health care stakeholders should target the identified barriers to improve utilization of EMS, and develop strategies to optimize care for patients who do not access EMS.

Differences in symptoms and presentation delay times in myocardial infarction patients with and without diabetes: A cross-sectional study in Pakistan

Objective

A short pre-hospital delay, from the onset of symptoms to rapid initiation of reperfusion therapy, is a crucial factor in determining prognosis of myocardial infarction (MI). The purpose of this study was to evaluate symptoms and presentation delay times in MI patients with and without diabetes.

Methods

This cross-sectional study was conducted in 3 tertiary care hospitals of Pakistan over a period of 6 months. The study sample consisted of 280 consenting individuals diagnosed with ST-elevation MI (STEMI) or Non-ST elevation MI (NSTEMI), out of which 130 were diabetic and 150 were non-diabetic. Data was collected using a standardized questionnaire, investigating MI symptoms along with causes and duration of pre-hospital delay within 72 hours of admission.

Results

No significant difference was found in the intensity of chest pain between diabetics and non-diabetics. Atypical symptoms of MI such as anxiety (p < 0.001), cold sweats (p = 0.034) and epigastric pain (p = 0.017) were more frequently reported in diabetics. MI patients with diabetes had a significantly longer presentation delay time with 75% of the patients presenting after elapse of 3 h. Only a few patients reported to the hospital within an hour of onset of symptoms (n = 23, 8.2%), out of which majority were non-diabetics (n = 18). A majority of patients (n = 146, 52%) in both groups did not use emergency medical services.

Conclusion

This study provides an incentive for further research, aiming to reduce pre hospital delay along with investigating the effectiveness of emergency medical services.

Factors influencing choice of pre-hospital transportation of patients with potential acute coronary syndrome: An observational study

OBJECTIVE

To determine factors associated with ambulance use in patients with confirmed and potential acute coronary syndrome presenting to the ED.

METHODS

A convenience sample of patients (n = 247) presenting to the ED from April 2014 to January 2015 with suspected acute coronary syndrome were included in the study. Data on mode of transport and patient demographics were collected from the Emergency Department Information System database. Clinical data were collected from chart records and information systems. A questionnaire assessed reasons for using a chosen method of transport, symptom timing and characteristics, acute coronary syndrome knowledge, and awareness of the National Heart Foundation Early Warning Symptoms campaign.

RESULTS

Approximately half the patients (49.4%) assessed with symptoms of potential acute coronary syndrome used ambulance transport to the ED. Patients who arrived by ambulance were older than those not arriving by ambulance (mean 56.7 years vs 51.7 years, P = 0.01). Risk factors were not associated with ambulance use. Dizziness (P < 0.01), sweating (P = 0.03), nausea (P = 0.03) and vomiting (P = 0.04) were associated with increased ambulance use. Mean systolic blood pressure was lower in the ambulance group (136 mmHg, standard deviation [SD] = 19.8) than in the non-ambulance group (143 mmHg, SD = 25.9). Awareness of the National Heart Foundation Heart Attack Warning Signs campaign was not associated with ambulance use.

CONCLUSIONS

Patients with possible ischaemic symptoms who are at a high risk of cardiac disease do not utilise ambulance services more than low risk patients. In general, transport to hospital using ambulance services by patients with symptoms of possible acute coronary syndrome is low despite community campaigns.

Factors Associated With Emergency Services Use by Patients With Recurrent Myocardial Infarction: From the Monitoring Trends and Determinants in Cardiovascular Disease/Cooperative Health Research in the Region of Augsburg Myocardial Infarction Registry

BACKGROUND

Although emergency medical services (EMS) use is the recommended mode of transport in case of acute coronary symptoms, many people fail to use this service.

OBJECTIVE

The objective of this study was to determine factors associated with EMS use in a population-based sample of German patients with recurrent acute myocardial infarction (AMI).

METHODS

The sample consisted of 998 persons with a first and recurrent AMI, recruited from 1985 to 2011. Logistic regression modeling adjusted for sociodemographic, situational, and clinical variables, previous diseases, and presenting AMI symptoms was applied.

RESULTS

Emergency medical services was used by 48.8% of the patients at first, and 62.6% at recurrent AMI. In first AMI, higher age, history of hyperlipidemia, ST-segment elevation AMI, more than 4 presenting symptoms, symptom onset in daytime, and later year of AMI were significantly related with EMS use. Pain in the upper abdomen and pain between the shoulder blades were significantly less common in EMS users. In recurrent AMI, EMS use at first AMI, presence of any other symptom except chest pain, ST-segment elevation myocardial infarction, and later year of AMI were significantly related with EMS use. Significant predictors of EMS use in recurrent AMI in patients who failed to use EMS at first AMI were unmarried, experience of any symptom except chest symptoms at reinfarction, bundle branch block (first AMI), any in-hospital complication (first AMI), longer duration between first and recurrent AMI, and later year of reinfarction.

CONCLUSIONS

Patients with AMI and their significant others may profit by education about the benefits of EMS use.

Pre-hospital delay in patients with first time myocardial infarction: an observational study in a northern Swedish population

Background

In myocardial infarction (MI), pre-hospital delay is associated with increased mortality and decreased possibility of revascularisation. We assessed pre-hospital delay in patients with first time MI in a northern Swedish population and identified determinants of a pre-hospital delay ≥ 2 h.

Methods

A total of 89 women (mean age 72.6 years) and 176 men (mean age 65.8 years) from a secondary prevention study were enrolled in an observational study after first time MI between November 2009 and March 2012. Total pre-hospital delay was defined as the time from the onset of symptoms suggestive of MI to admission to the hospital. Decision time was defined as the time from the onset of symptoms until the call to Emergency Medical Services (EMS). The time of symptom onset was assessed during the episode of care, and the time of call to EMS and admission to the hospital was based on recorded data. The first medical contact was determined from a mailed questionnaire. Determinants associated with pre-hospital delay ≥ 2 h were identified by multivariable logistic regression.

Results

The median total pre-hospital delay was 5.1 h (IQR 18.1), decision time 3.1 h (IQR 10.4), and transport time 1.2 h (IQR 1.0). The first medical contact was to primary care in 52.3 % of cases (22.3 % as a visit to a general practitioner and 30 % by telephone counselling), 37.3 % called the EMS, and 10.4 % self-referred to the hospital. Determinants of a pre-hospital delay ≥ 2 h were a visit to a general practitioner (OR 10.77, 95 % CI 2.39–48.59), call to primary care telephone counselling (OR 3.82, 95 % CI 1.68–8.68), chest pain as the predominant presenting symptom (OR 0.24, 95 % CI 0.08–0.77), and distance from the hospital (OR 1.03, 95 % CI 1.02–1.04). Among patients with primary care as the first medical contact, 67.0 % had a decision time ≥ 2 h, compared to 44.7 % of patients who called EMS or self-referred (p = 0.002).

Conclusions

Pre-hospital delay in patients with first time MI is prolonged considerably, particularly when primary care is the first medical contact. Actions to shorten decision time and increase the use of EMS are still necessary.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0271-x) contains supplementary material, which is available to authorized users.

Ambulance use in acute coronary syndrome in Ireland: A cross-sectional study

BACKGROUND

As myocardial salvage is time dependent, prompt emergency department attendance is imperative in the presence of unresolved acute coronary syndrome symptoms. Although ambulance use is the recommended mode of transport during an acute coronary syndrome event, people regularly have misperceptions about its role. Consequently, many fail to use this service when warranted.

AIM

To evaluate factors associated with ambulance usage among patients admitted to emergency departments with acute coronary syndrome symptoms in Ireland.

METHODS

Patients (N=1947) diagnosed with acute coronary syndrome were recruited across five hospitals. The ACS Response Index was used to identify mode of transport to access the emergency department, symptom context and experience and the rationale for non-ambulance use. Using logistic regression, predictors of ambulance use were identified.

RESULTS

Only 40.1% of the sample used an ambulance. The primary reason for non-ambulance use was the perception that it was unwarranted (31%). A further 23.8% thought another mode of transportation would be faster. Independent predictors of ambulance usage differed among the three sub-diagnoses of acute coronary syndrome. For each group, visiting the general practitioner with symptoms was associated with a greater likelihood of not using an ambulance.

CONCLUSION

The use of ambulance services is not positively embraced by the public. Furthermore, it appears that general practitioners may not always promote its use, particularly in the early stages of acute coronary syndrome symptom onset. The findings from our study suggest that a public education drive is necessary to promote ambulance usage during an acute coronary syndrome event.

Comparison of outcomes of ambulance users and nonusers in ST elevation myocardial infarction

In a systematic province-wide evaluation of care and outcomes of ST elevation myocardial infarction (STEMI), we sought to examine whether a previously documented association between ambulance use and outcome remains after control for clinical risk factors. All 82 acute care hospitals in Quebec (Canada) that treated at least 30 acute myocardial infarctions annually participated in a 6-month evaluation in 2008 to 2009. Medical record librarians abstracted hospital chart data for consecutive patients with a discharge diagnosis of myocardial infarction who presented with characteristic symptoms and met a priori study criteria for STEMI. Linkage to administrative databases provided outcome data (to 1 year) and co-morbidities. Of 1,956 patients, 1,222 (62.5%) arrived by ambulance. Compared with nonusers of an ambulance, users were older, more often women, and more likely to have co-morbidities, low systolic pressure, abnormal heart rate, and a higher Thrombolysis In Myocardial Infarction risk index at presentation. Ambulance users were less likely to receive fibrinolysis or to be sent for primary angioplasty (78.5% vs 83.2% for nonusers, p = 0.01), although if they did, treatment delays were shorter (p <0.001). The 1-year mortality rate was 18.7% versus 7.1% for nonusers (p <0.001). Greater mortality persisted after adjusting for presenting risk factors, co-morbidities, reperfusion treatment, and symptom duration (hazard ratio 1.56, 95% confidence interval 1.30 to 1.87). In conclusion, ambulance users with STEMI were older and sicker than nonusers. Mortality of users was substantially greater after adjustment for clinical risk factors, although they received faster reperfusion treatment overall.

Treatment-seeking delays in patients with acute myocardial infarction and use of the emergency medical service

OBJECTIVES

To investigate treatment-seeking delays in Chinese patients with acute myocardial infarction (AMI) and to compare sex differences in this behaviour.

METHODS

A descriptive cross-sectional study was undertaken in patients with AMI, admitted to one of three hospitals in Shanghai, China. A treatment-seeking behaviour questionnaire was administered to each patient within 48 h of hospital admission.

RESULTS

In total, 250 patients were included: 159 men and 91 women. The median time for patients with AMI to make a treatment-seeking decision was 130 min. Women took significantly longer to seek treatment than men (240 min versus 120 min). The majority of patients (70.8%) took >1 h to decide to seek treatment. The emergency medical service (EMS) was used by 77 (30.8%) of patients, and these patients had a significantly shorter prehospital delay time than those who transported themselves to hospital. Predictive factors for using the EMS were pain level and rating AMI symptoms as severe.

CONCLUSIONS

Chinese patients with AMI had a significant prehospital delay time and women took longer than men to seek treatment. Public awareness of the importance of seeking immediate medical assistance for AMI via the EMS needs to be increased in China.

Acute heart failure: perspectives from a randomized trial and a simultaneous registry

BACKGROUND

Randomized controlled trials (RCT) are limited by their generalizability to the broader nontrial population. To provide a context for Acute Study of Nesiritide in Decompensated Heart Failure (ASCEND-HF) trial, we designed a complementary registry to characterize clinical characteristics, practice patterns, and in-hospital outcomes of acute heart failure patients.

METHODS AND RESULTS

Eligible patients for the registry included those with a principal diagnosis of acute heart failure (ICD-9-CM 402 and 428; ICD-10 I50.x, I11.0, I13.0, I13.2) from 8 sites participating in ASCEND-HF (n=697 patients, 2007-2010). Baseline characteristics, treatments, and hospital outcomes from the registy were compared with ASCEND-HF RCT patients from 31 Canadian sites (n=465, 2007-2010). Patients in the registry were older, more likely to be female, and have chronic respiratory disease, less likely to have diabetes mellitus: they had a similar incidence of ischemic HF, atrial fibrillation, and similar B-type natriuretic peptide levels. Registry patients had higher systolic blood pressure (registry: median 132 mm Hg [interquartile range 115-151 mm Hg]; RCT: median 120 mm Hg [interquartile range 110-135 mm Hg]) and ejection fraction (registry: median 40% [interquartile range 27-58%]; RCT: median 29% [interquartile range 20-40 mm Hg]) than RCT patients. Registry patients presented more often via ambulance and had a similar total length of stay as RCT patients. In-hospital mortality was significantly higher in the registry compared with the RCT patients (9.3% versus 1.3%,P<0.001), and this remained after multivariable adjustment (odds ratio 6.6, 95% CI 2.6-16.8, P<0.001).

CONCLUSIONS

Patients enrolled in a large RCT of acute heart failure differed significantly based on clinical characteristics, treatments, and inpatient outcomes from contemporaneous patients participating in a registry. These results highlight the need for context of RCTs to evaluate generalizability of results and especially the need to improve clinical outcomes in acute heart failure.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00475852.

Acute myocardial infarction--from territory to definitive treatment in an Italian province

RATIONALE, AIMS AND OBJECTIVES

Early reperfusion is the key to therapeutic success in acute myocardial infarction (AMI). The duration of the process is influenced by various factors which in most of the cases are not easily modifiable. The aim of this study is to analyse AMI treatment process duration to identify determining factors. The objective is to better exploit time intervals imposed by spatial distance from the hospital.

METHOD

One-year data regarding acute coronary syndromes with elevated ST segment for patients presenting to Policlinico teaching hospital (Modena, Italy) have been studied. Patients were divided into two groups for hospital access: A - ambulance access to Policlinico emergency room (ER); B - self-referral to ER.

RESULTS

A total of 141 patients have undergone percutaneous transluminal coronary angioplasty for AMI at Policlinico, 106 males, 35 females (58.1% males in group A, 82.7% in B, P 0.002), with an average age of 66.09 ± 14.30 years in group A and 60.90 ± 13.47 in B (P 0.047). Mean pre-hospital time for group A was 122.54 ± 130.69 minutes and B 171.49 ± 353.60 (P 0.25), mean hospital time in group A was 196.03 ± 67.66 and B 255.14 ± 113.16 (P<0.001), mean total time in group A was 318.56 ± 146.91 and B 426.63 ± 382.01 (P 0.02).

DISCUSSION

Data show that group B suffered on average a 108-minute delay from symptoms insurgence to definitive treatment. The duration of hospital time plays more important role in this finding than distance from the medical facility. In fact, on the ambulance a medical crew starts the diagnostic and therapeutic process relieving ER from initial evaluation.

Utilisation of emergency medical service among Singapore patients presenting with ST-segment elevation myocardial infarction: prevalence and impact on ischaemic time

BACKGROUND

Previous studies in Western countries found that the emergency medical service (EMS) was under-used in patients with myocardial infarction.

AIM

We sought to determine the prevalence of immediate EMS utilisation among Singapore patients presenting with ST-segment elevation myocardial infarction (STEMI), and correlated the use of the EMS with the symptom-to-balloon and door-to-balloon times.

METHODS

We studied 252 patients admitted with STEMI to our institution from August 2008 to September 2009. Information regarding demographic characteristics, whether EMS was used, reperfusion procedural details and mortality rates were collected prospectively.

RESULTS

Among the recruited patients, 89 (35.3%) used the EMS (EMS group) and 163 (64.7%) did not use the EMS (non-EMS group). In the latter group, 98 (60.1%) arrived at our institution through their own transport, 56 (34.4%) first consulted general practitioners, and 9 (5.5%) initially consulted another hospital without acute medical services. Among the 245 (out of 252, 97.2%) patients who received percutaneous coronary intervention (PCI), the EMS group was more likely to undergo primary PCI (P= 0.003) while the non-EMS group was more likely to undergo non-urgent PCI (P= 0.002). In patients who underwent primary PCI, the EMS group had a shorter symptom-to-balloon time (average difference 81.6 min, P= 0.002). The door-to-balloon time was similar for both groups.

CONCLUSION

Despite the availability of a centralised EMS, 64.7% of patients with STEMI did not contact EMS at presentation. These patients were less likely to receive primary PCI and had a significantly longer symptom-to-balloon time.

Hospital type and patient outcomes: an empirical examination using AMI readmission and mortality records

This paper investigates whether there are differences in patient outcomes across different types of hospitals using patient-level data on readmission and mortality associated with acute myocardial infarction (AMI). Hospitals are grouped according to their ownership type (private, public teaching, public non-teaching) and their location (metropolitan, country and remote country). Using data collected from 130 Victorian hospitals on 19,000 patients admitted to a hospital with their first AMI between January 2001 and December 2003, we consider how the likelihood of unplanned re-admission and mortality varies across hospital type. We find that there are significant differences across hospital types in the observed patient outcomes - private hospitals persistently outperform public hospitals.

Use of emergency medical services in patients with acute myocardial infarction in China

BACKGROUND

Although guidelines strongly recommend use of the Emergency Medical Systems (EMS) by patients with acute myocardial infarction (AMI), it remains underutilized in western countries. Information about its current use in China is unclear. The objective of this study was to examine the use of the EMS by patients with AMI in China, and investigate factors affecting its use.

METHODS

A prospective survey study, which included 803 patients with AMI who were admitted to 21 hospitals in China between November 1, 2005 and December 31, 2006.

RESULTS

Only 39.5% of patients called up the EMS at the onset of symptoms (EMS group, n=317), whereas the rest presented to the hospital by some other means (self-transport group, n=486, 60.5%). Predictors of EMS users were older age, symptom onset at evening, unbearable symptoms, having received training and acquired knowledge on heart attack, as well as having a higher income and medical history of heart failure or stroke. Prehospital delay (median 110 min vs. 143 min, p<0.001), door to needle time (median 85 min vs. 93 min, p<0.005) and door-to-balloon time (median 118 min vs. 160 min, p<0.001) were significantly shorter in the EMS group. The early reperfusion rate was also significantly higher in the EMS group (84.8% vs. 78.2%, p=0.019), mainly because of a greater incidence of primary percutaneous coronary intervention (68.1% vs. 61.7%, p=0.046).

CONCLUSIONS

The emergency medical services are underutilized by patients with AMI in China. Use of the EMS may be advantageous in view of greater administration of reperfusion therapy. New public health strategies should be developed to facilitate greater use of the EMS for AMI.