Temporal and Provincial Variation in Ambulance Use Among Patients Who Present to Acute Care Hospitals With ST-Elevation Myocardial Infarction

Primary Percutaneous Coronary Intervention and Application of the Pharmacoinvasive Approach Within ST-Elevation Myocardial Infarction Care Networks

The management of acute ST-elevation myocardial infarction (STEMI) has transitioned from observation and reactive treatment of hemodynamic and arrhythmic complications to accelerated reperfusion and application of evidence-based treatment to minimize morbidity and mortality. International research established the importance of timely reperfusion therapy and the application of fibrinolysis, primary percutaneous coronary intervention (PCI), and subsequent development of the pharmacoinvasive approach. Clinician thought leaders developed and investigated comprehensive systems of care to optimize the outcomes of patients with STEMI, with a key focus in Canada being the integration of prehospital paramedics in diagnosis, triage, and treatment. This article will review highlights of these interventions and identify future challenges and opportunities in STEMI patient care.

Prehospital identification of ST-segment elevation myocardial infarction and mortality (ANZACS-QI 61)

BACKGROUND

Early recognition of ST-segment elevation myocardial infarction (STEMI) is needed for timely cardiac monitoring and reperfusion therapy.

METHODS

Three anonymously linked New Zealand national datasets (July 2016-November 2018) were used to assess the utilisation of ambulance transport in STEMI cases, the concordance between ambulance initial clinical impressions and hospital STEMI diagnoses, and the association between initial paramedic clinical impressions and 30-day mortality. The St John Ambulance electronic record captures community call-outs and paramedic initial clinical impressions. The national cardiac (ANZACS-QI) registry and national administrative datasets capture all New Zealand public hospital admission diagnoses and mortality data.

RESULTS

Of 5465 patients with STEMI, 73% were transported to hospital by ambulance. For these patients, the initial paramedic impression was STEMI in 50.7%, another acute coronary syndrome (ACS) diagnosis in 19.9% and non-ACS diagnosis in 29.7%. Only 37% of the 5465 patients with STEMI were both transported by ambulance and clinically suspected of STEMI by paramedics. Compared with patients with paramedic-'suspected STEMI', 30-day mortality was over threefold higher for patients thought to have a non-ACS condition (10.9% and 34.9%, respectively), but after adjustment for available covariates, this was substantially ameliorated (HR 1.48, 95% CI 1.22 to 1.80).

CONCLUSIONS

In this national data linkage study, only 4 out of every 10 patients with STEMI were both transported by ambulance and had STEMI suspected by paramedics. Although patients with STEMI not suspected of an ACS diagnosis by paramedics had the highest mortality rate, this is largely explained by the different risk profile of these patients.

Twelve-Year Temporal Trends in Ambulance Use for Patients Hospitalized With a Primary Diagnosis of Syncope in Canada

Background

Ambulance use is a costly mode of transportation to the emergency department (ED). Syncope is a frequent presentation to the ED; however, no data exist regarding the proportion of hospitalized patients with syncope arriving by ambulance and their outcomes compared with self-presenters.

Methods

The Canadian Institute for Health Information database was used to identify patients aged > 20 years hospitalized with a primary diagnosis of syncope (International Classification of Diseases 10th Revision code R55) in Canada, except Quebec, between April 2004 and March 2016. Logistic regression models (odds ratio and 95% confidence interval) were used to identify demographics, clinical factors, and province associated with ambulance use and whether ambulance use was associated with in-hospital mortality.

Results

Among 108,967 syncope hospitalizations, 64% of patients arrived by ambulance, and use increased from 58.8% to 66.1% over 12 years (P for trend < 0.01). Significant variations existed in ambulance use across provinces (P < 0.01). Predictors associated with higher odds of ambulance use were increasing age, male sex, urban residence, residing in areas with lower annual household income, and higher comorbidity burden. In multivariable-adjusted analysis, ambulance use was associated with a 1.7-fold higher odds of in-hospital mortality.

Conclusions

Approximately two-thirds of patients hospitalized for syncope presented by ambulance, and use has increased over time. Hospitalized patients in syncope who are transported by ambulance have a worse prognosis. Further research on emergency medical services’ risk stratification of patients who are transported by ambulance may help to identify a low-risk population who may obviate the need for transport.

Impact of Patient- and System-Level Delays on Reperfusion Among Patients With ST-Elevation Myocardial Infarction

Background

Patients with ST-elevation myocardial infarction (STEMI) presenting to percutaneous coronary intervention (PCI)-capable hospitals often experience delays for primary PCI (pPCI). We sought to describe the effect of specific delay intervals and patient/system-level factors on STEMI reperfusion times.

Methods

We analyzed all consecutive patients with STEMI who presented to 2 PCI-capable hospital emergency departments (EDs) between June 2007 and March 2016 who received successful pPCI. We excluded patients with prehospital cardiac arrest. We compared specific system delay intervals, patient characteristics, and in-hospital outcomes among patients who received timely (first medical contact-device ≤90/≤120 minutes) vs delayed >90/>120 minutes) pPCI.

Results

Of 1936 patients with STEMI, 1127 (58%) presented directly to a PCI-capable hospital via emergency health services (EHS), 499 (26%) were transferred from the ED of a non-PCI hospital, and 310 (16%) self-presented to the ED of a pPCI-capable hospital. Guideline-recommended reperfusion times were met in 47% of direct-EHS, 42% of transfers, and 33% of self-presenters. Each time interval from first medical contact to device deployment was significantly prolonged in the delayed vs timely reperfusion cohorts across all 3 groups, excepting vascular access time. ED dwell time contributed the most to the difference in median reperfusion time within each group. Time of presentation, comorbidities, and sex were each significantly associated with delayed reperfusion. Within the EHS-direct group, prolonged reperfusion and ED dwell times were significantly associated with increased mortality, major bleeding, and cardiogenic shock.

Conclusion

Ongoing efforts to identify and reduce ED dwell time and other systemic pPCI delays may improve STEMI outcomes, including mortality.

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.

What's the Risk? Older Women Report Fewer Symptoms for Suspected Acute Coronary Syndrome than Younger Women

The purpose of the study was to determine whether older (≥65 years) and younger (<65 years) women presenting to the emergency department (ED) with symptoms suggestive of acute coronary syndrome (ACS) varied on risk factors, comorbid conditions, functional status, and symptoms that have implications for emergent cardiac care. Women admitted to five EDs were enrolled. The ACS Symptom Checklist was used to measure symptoms. Comorbid conditions and functional status were measured with the Charlson Comorbidity Index and Duke Activity Status Index. Logistic regression models were used to evaluate symptom differences in older and younger women adjusting for ACS diagnosis, functional status, body mass index (BMI), and comorbid conditions. Analyses were stratified by age, and interaction of symptom by age was tested. Four hundred women were enrolled. Mean age was 61.3 years (range 21–98). Older women (n = 163) were more likely to have hypertension, hypercholesterolemia, never smoked, lower BMI, more comorbid conditions, and lower functional status. Younger women (n = 237) were more likely to be members of minority groups, be college-educated, and have a non-ACS discharge diagnosis. Younger women had higher odds of experiencing chest discomfort, chest pain, chest pressure, shortness of breath, nausea, sweating, and palpitations. Lack of chest symptoms and shortness of breath (key symptoms triggering a decision to seek emergency care) may cause older women to delay seeking treatment, placing them at risk for poorer outcomes. Younger African American women may require more comprehensive risk reduction strategies and symptom management.

The high cost of critical care unit over-utilization for patients with NSTE ACS

BACKGROUND

There is substantial variability among hospitals in critical care unit (CCU) utilization for patients admitted with non-ST-Segment Elevation Acute Coronary Syndromes (NSTE ACS). We estimated the potential cost saving if all hospitals adopted low CCU utilization practices for patients with NSTE ACS.

METHODS

National hospital claims data were used to identify all patients with a primary diagnosis of NSTE ACS initially admitted to an acute care hospital between 2007 and 2013. Hospital CCU utilization was classified as low (<30%), medium (30-70%), or high (>70%).

RESULTS

Among the 270,564 NSTE ACS hospitalizations (71.6% non-ST-segment elevation myocardial infarction; 28.4% unstable angina) admitted to 261 hospitals, 41.9% (inter-hospital range 0.3%-95.1%) were admitted to a CCU. The proportion of patients admitted to a CCU in low, medium and high utilization hospitals was 16.3%, 49.5%, and high 81.1%, respectively. No differences in adjusted inpatient mortality were observed by hospital CCU utilization. The overall inpatient costs of caring for NSTE ACS were $1.1 billion. CCU care accounted for 45.2% of all hospitalization costs including 22.6%, 49.9%, and 69.0% (P < .001) of costs in low, medium and high utilization centers. The national potential direct cost savings of medium and high CCU utilization centers adopting low NSTE ACS CCU utilization practices was $113.4 million over the study period.

CONCLUSIONS

In a population-based contemporary cohort, CCU utilization for patients with NSTE ACS varied widely and in-hospital mortality was similar between low, medium and high utilization centers. CCU care accounted for 45% of hospitalization costs; thus, implementing policies and admission practices to align hospital resources with patient care needs have the potential to reduce overall health care costs.

Ambulance use, distance and outcomes in patients with suspected cardiovascular disease: a registry-based geographic information system study

BACKGROUND

Despite guideline recommendations, the majority of patients with symptoms suggestive of acute coronary syndrome do not use emergency medical services to reach the emergency department (ED). The aim of this study was to investigate the factors associated with EMS utilisation and subsequent patient outcomes.

METHODS

Using administrative data, all patients who presented to an ED in the metropolitan areas of Edmonton and Calgary in the years of 2007-2013 with main ED diagnosis of acute coronary syndrome, stable angina or chest pain were included. The travel distance was estimated using the geographic information system method to approximate the distance between the ED and patient home. The clinical endpoints were the 7-day and 30-day all-cause events (death, re-hospitalisation and repeat ED visit).

RESULTS

Of 50,881 patients, 30.5% presented by emergency medical services. Patients with older age, female sex, ED diagnosis of acute coronary syndrome, more comorbidities and lower household income were more likely to use emergency medical services to reach the hospital. Longer travel distance was associated with higher emergency medical services use (odds ratio 1.09, 95% confidence interval 1.09-1.10), but it was not a predictor of clinical events. After adjustment for covariates and inverse propensity score weighting, emergency medical services use was associated with a higher risk of 7-day and 30-day clinical events.

CONCLUSION

Several demographic and clinical features were associated with higher emergency medical services use including geographical variation. Although longer travel distance was shown to be linked to higher emergency medical services use, it was not an independent predictor of patient outcome. This has implications for the design of emergency medical services systems, triage and early diagnosis and treatment options.

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.