Canadian Cardiovascular Society Working Group: Providing a perspective on the 2007 focused update of the American College of Cardiology and American Heart Association 2004 guidelines for the management of ST elevation myocardial infarction

Issue with Evaluating Costs Over Time in a Context of Medical Guideline Changes: An Example in Myocardial Infarction Care Based on a Longitudinal Study from 1997 to 2018

Background

Cost studies appear sporadically in the scientific literature and are rarely revised unless drastic technological advancements occur. However, health technologies and medical guidelines evolve over time. It is unclear if these changes render obsolete prior estimates. We examined this issue in a cost study in the context of patients' first myocardial infarction (MI), a clinical area prone to such continuous evolution in care.

Methods

We conducted a longitudinal cost analysis based on a Quebec cohort. Quebec health administrative databases were used to identify incident MI cases using diagnostic codes from the international classification of diseases (ICD-9 and ICD-10). Physician fees and hospitalization costs (ie, costs incurred by the hospital center) were derived from administrative databases and a university hospital's finance department. All costs were converted to 2019 Canadian dollars. Nonparametric bootstraps were used to estimate 95% confidence intervals (CI) of the average costs of an episode of care. Generalized linear regressions were used to examine temporal trends of cost.

Results

Our study sample consists of 261 patients hospitalized for a first MI. The average total cost for this first event was estimated at $5782 (95% CI: $5293 - $6373). Though total costs remained stable over time, physician fees increased by 123% ($1240 vs $2761) whereas total hospital length of stay dropped by 17% (6.6 vs 5.5 days) over the 21-year period.

Conclusion

Patients' first MI hospitalization impose an economic burden on the healthcare system. Though overall costs remained stable, our results suggest that some cost components varied over time.

Effect of Real-Time Physician Oversight of Prehospital STEMI Diagnosis on ECG-Inappropriate and False Positive Catheterization Laboratory Activation

Background

ST-elevation myocardial infarction diagnosis at first medical contact (FMC) and prehospital cardiac catheterization laboratory (CCL) activation are associated with reduced total ischemic time and therefore have become the dominant ST-elevation myocardial infarction referral method in primary percutaneous coronary intervention systems. We sought to determine whether physician oversight was associated with improved diagnostic performance in a prehospital CCL activation system and what effect the additional interpretation has on treatment delay.

Methods

Between 2012 and 2015, all patients in 2 greater Montreal catchment areas with a chief symptom of chest paint or dyspnea had an in-the-field electrocardiogram (ECG). A machine diagnosis of "acute myocardial infarction" resulted either in automatic CCL (automated cohort without oversight) or transmission of the ECG to the receiving centre emergency physician for reinterpretation before CCL activation. System performance was assessed in terms of the proportion of false positive and inappropriate activations (IA), as well as the proportion of patients with FMC-to-device times ≤ 90 minutes.

Results

Four hundred twenty-eight (428) activations were analyzed (311 automated; 117 with physician oversight). Physician oversight tended to decrease IAs (7% vs 3%; P = 0.062), but was also associated with a smaller proportion of patients achieving target FMC-to-device (76% vs 60%; P < 0.001). There was no significant effect on the proportion of false positive activation.

Conclusions

Real-time physician oversight might be associated with fewer IAs, but also appears to have a deleterious effect on FMC-to-device performance. Identifying predictors of IA could improve overall performance by selecting ECGs that merit physician oversight and streamlining others. Larger clinical studies are warranted.

Effects of Prehospital Traige and Diagnosis of ST Segment Elevation Myocardial Infarction on Mortality Rate

INTRODUCTION

Adverse outcomes and mortality associated with STEMI (ST segment elevation myocardial infarction) are associated with the management and diagnosis time. The aim of this study is to evaluate the outcomes of prehospital diagnosis of STEMI via emergency medical service (EMS) on mortality, in comparison to the patients who did not receive EMS.

METHODS

This retrospective study included STEMI patients, who underwent primary angioplasty. The patients were categorized as group A: referred without emergency service, group B: patients who did not receive PPCI and group C: patients referred via ambulance and received telecardiology. Medical records of these patients were evaluated for the diagnosis time, door-to-balloon time, in-hospital, six months, one year and three-year mortality, left ventricular ejection fraction and previous history of cardiovascular conditions and surgeries. The data were recorded and statistically analyzed using SPSS v21.

RESULTS

Of 424 patients studied, 79 were referred without emergency service (group A), 52 patients did not receive PPCI (group B) and 293 patients were referred via ambulance with telecardiology (group C). Door-to-balloon time was least in group C (57.78 min) compared to group A (141.70 min). In-hospital, six months, one year and three-year mortality was least in group C, however, the difference was not statistically significant. The left ventricular ejection fraction was significantly greater in group C.

CONCLUSION

The results of our study indicate that prehospital diagnosis and telecardiology significantly reduce door-to-balloon time in STEMI patients referred for percutaneous intervention and might have an influence on short-term and long-term mortality rates.

The effect of prehospital telecardiology on the mortality and morbidity of ST-segment elevated myocardial infarction patients undergoing primary percutaneous coronary intervention: A cross-sectional study

OBJECTIVES

The sooner the primary percutaneous coronary intervention (PPCI) is performed, the better prognosis is expected in patients with acute myocardial infarction. The objective is to evaluate the effect of prehospital triage based on electrocardiogram (ECG) and telecardiology on the mortality and morbidity of ST-segment elevated myocardial infarction (STEMI) patients undergoing PPCI.

METHODS

This cross-sectional study was conducted based on the data extracted from the hospital information system (HIS) of one general hospital, which had the capability of performing PPCI 24 h a day, 7 days a week. All patients with STEMI who undergone PPCI during 1 year, transferred by emergency medical service (EMS) and their data were registered in the HIS were eligible. Besides the baseline characteristics, first medical contact (FMC)-to-balloon time was recorded. Morbidity based on predischarge left ventricular ejection fraction (LVEF) and mortality based on Global Registry of Acute Cardiac Events (GRACE) score were also recorded. Patients who were referred to the hospital by EMS with prehospital ECG and telecardiology were compared with those without prehospital ECG.

RESULTS

Totally, 298 patients with STEMI were enrolled, of whom 183 patients (61.4%) had prehospital ECG (telecardiology), and 115 patients (38.6%) had not. The means of predischarge LVEF of the patients in the first and the second groups were 40.7 ± 10.4 and 40.6 ± 11.2, respectively (P = 0.946). The mean of the probability of 6-month mortality based on GRACE score in the first group was significantly less than that of the second group (P = 0.004). Analyses of multivariable ordinal logistic regression showed that 6-month mortality severity risk in the second group was 1.5 times more than the first group (95% confidence interval 0.8-2.6), although this difference was not statistically significant (P = 0.199).

CONCLUSIONS

It is likely that prehospital telecardiology, with shortening FMC to balloon time result in reducing probability 6-month mortality in STEMI patients who undergone PPCI. However, the process of telecardiology had no effect on predischarge LVEF in the current study.

2019 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology Guidelines on the Acute Management of ST-Elevation Myocardial Infarction: Focused Update on Regionalization and Reperfusion

Rapid reperfusion of the infarct-related artery is the cornerstone of therapy for the management of acute ST-elevation myocardial infarction (STEMI). Canada's geography presents unique challenges for timely delivery of reperfusion therapy for STEMI patients. The Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology STEMI guideline was developed to provide advice regarding the optimal acute management of STEMI patients irrespective of where they are initially identified: in the field, at a non-percutaneous coronary intervention-capable centre or at a percutaneous coronary intervention-capable centre. We had also planned to evaluate and incorporate sex and gender considerations in the development of our recommendations. Unfortunately, inadequate enrollment of women in randomized trials, lack of publication of main outcomes stratified according to sex, and lack of inclusion of gender as a study variable in the available literature limited the feasibility of such an approach. The Grading Recommendations, Assessment, Development, and Evaluation system was used to develop specific evidence-based recommendations for the early identification of STEMI patients, practical aspects of patient transport, regional reperfusion decision-making, adjunctive prehospital interventions (oxygen, opioids, antiplatelet therapy), and procedural aspects of mechanical reperfusion (access site, thrombectomy, antithrombotic therapy, extent of revascularization). Emphasis is placed on integrating these recommendations as part of an organized regional network of STEMI care and the development of appropriate reperfusion and transportation pathways for any given region. It is anticipated that these guidelines will serve as a practical template to develop systems of care capable of providing optimal treatment for a wide range of STEMI patients.

Routine Glycoprotein IIb/IIIa Inhibitor Therapy in ST-Segment Elevation Myocardial Infarction: A Meta-analysis

BACKGROUND

Guidelines recommend adjunct glycoprotein IIb/IIIa inhibitors (GPIs) only in selected patients with acute ST-segment elevation myocardial infarction (STEMI). This study aimed to evaluate routine GPI use in STEMI treated with primary percutaneous coronary intervention.

METHODS

Online databases were searched for randomized controlled trials of routine GPI vs control therapy in STEMI. Data from retrieved studies were abstracted and evaluated in a comprehensive meta-analysis. Twenty-one randomized controlled trials with 8585 patients were included: 10 trials randomized tirofiban, 9 abciximab, 1 trial eptifibatide, and 1 trial used abciximab+tirofiban; only 1 trial used dual antiplatelet therapy with prasugrel/ticagrelor.

RESULTS

Routine GPI use was associated with a significant reduction in all-cause mortality at 30 days (2.4% [GPI] vs 3.2%; risk ratio [RR], 0.72; P = 0.01) and 6 months (3.7% vs 4.8%; RR, 0.76; P = 0.02), and a reduction in recurrent myocardial infarction (1.1% vs 2.1%; RR, 0.55; P = 0.0006), repeat revascularization (2.5% vs 4.1%; RR, 0.63; P = 0.0001), thrombolysis in myocardial infarction flow <3 after percutaneous coronary intervention (5.4% vs 8.2%; RR, 0.61; P < 0.0001), and ischemic stroke (RR, 0.42; P = 0.04). Major (4.7% vs 3.4%; RR, 1.35; P = 0.005) and minor bleedings (7.2% vs 5.1%; RR, 1.39; P = 0.006) but not intracranial bleedings (0.1% vs 0%; RR, 2.7; P = 0.37) were significantly increased under routine GPI.

CONCLUSIONS

Routine GPI administration in STEMI resulted in a reduction in mortality, driven by reductions in recurrent ischemic events-however predominantly in pre-prasugrel/ticagrelor trials. Trials with contemporary STEMI management are needed to confirm these findings.

The Role of Pre-Hospital Telecardiology in Reducing the Coronary Reperfusion Time; a Brief Report

INTRODUCTION

Telecardiology is defined as using telecommunication for remote treatment of cardiac patients. This study aimed to assess the role of pre-hospital triage via telecardiology on coronary reperfusion time of patients with ST segment elevation myocardial infarction (STEMI).

METHODS

This cross-sectional study was conducted from September, 2015 to January, 2018 in six academic referral hospitals, Tehran, Iran. Studied patients were divided into two groups of percutaneous coronary intervention (PCI) following telecardiology or PCI following emergency department (ED) diagnosis of STEMI and time to reperfusion was compared between them.

RESULTS

1205 patients with the mean age of 58.99 ± 12.33 (19-95) years entered the study (82.7% male). 841 (69.8%) cases were transferred directly to the Cath-Lab following telecardiology and 364 (30.2%) cases were first admitted to the ED. There was no significant difference between the groups regarding mean age (p = 0.082) and gender (p = 0.882) of participants. Symptom-to-device interval time in patients who underwent PCI following telecardiology was significantly lower (p < 0.001); however, the difference was not significant in the first medical contact (FMC)-to-device interval time (p = 0.268).

CONCLUSIONS

It is likely that the use of telecardiology in pre-hospital triage plays an important role in reducing time to PCI for patients with STEMI.

Clinical adverse events in prehospital patients with ST-elevation myocardial infarction transported to a percutaneous coronary intervention centre by basic life support paramedics in a rural region

CLINICIAN’S CAPSULE

What is known about the topic?

ST-elevation myocardial infarction (STEMI) patients transported by ambulance are at risk for adverse events.

What did this study ask?

What is the impact of transport time on the occurrence of adverse events in the presence of basic life support paramedics?

What did this study find?

Transport time is not associated with a higher risk of adverse events.

Why does this study matter to clinicians?

Largest investigation of adverse events in a Canadian cohort of STEMI patients transported by ambulance.

Evaluating clinical reason and rationale for not delivering reperfusion therapy in ST elevation myocardial infarction patients: Insights from a comprehensive cohort

BACKGROUND

In ST elevation myocardial infarction (STEMI), reperfusion therapy is lifesaving but is not delivered in approximately one quarter of patients. To address this care gap, we reviewed all STEMI patients that did not receive reperfusion to identify patient characteristics, in-hospital outcomes and the clinical reason or rationale for withholding reperfusion therapy.

METHODS

A prospective chart review identified a consecutive cohort of STEMI patients over one-year within a defined health care region with independent data abstraction. Subsequently a trained nurse completed retrospective chart review and categorized patients by rationale for failure to receive reperfusion.

RESULTS

Of 745 STEMI patients, 181 (24.3%) did not receive reperfusion. Compared to those receiving reperfusion, they were older (67.5 vs. 58.0years, p=0.001) with more comorbidities and higher in-hospital mortality (15.5% vs. 3.5% p=<0.0001). After excluding 35 patients (unavailable data) there were 146 STEMI patients for qualitative determination. Patient delay greater than 12hours from symptom onset accounted for the majority of patients (56/146, 38.4%). In 19.9% (29/146), conservative medical management with documented rationale occurred. Following angiography, primary PCI was attempted but was unsuccessful or no culprit lesion identified in 19.2% (28/146). The diagnosis of STEMI was missed or no rationale for failure to deliver therapy identified in 8.2% (12/146). Death prior to planned reperfusion occurred in 8 (8/146, 5.5%).

CONCLUSIONS

Legitimate rationale exists for the majority of STEMI patients not receiving reperfusion. Ultimately, only 1.6% (12/745) of consecutive STEMI patients failed to receive reperfusion without documented rationale or due to missed diagnosis.

Initial experience with pre-activation of the cardiac catheterization lab and emergency room bypass for patients with ST-elevation myocardial infarction in Halifax, Nova Scotia

BACKGROUND

To determine whether pre-activation of the cardiac catheterization lab by Emergency Health Services (EHS) with a single call system in the field was associated with reduced time to reperfusion in patients with ST-Elevation Myocardial Infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).

METHODS

Consecutive STEMI patients identified by EHS and subsequently taken to the Queen Elizabeth II Health Sciences Center (QEIIHSC) for PPCI between February 1, 2011 and January 30, 2013 were examined. Patients who had pre-activation of the catheterization lab from the field (pre-act group) after the acquisition of the LifeNet® system (Physio Control, Redmond Washington) were compared to those who had usual activation (routine group) prior to the acquisition of the LifeNet® system, for outcomes including treatment timeline data and mortality.

RESULTS

271 patients were included in the analysis, 149 patients in the pre-act group and 122 patients in the routine group. Door-to-device (DTD) times of less than 90min were achieved more frequently in the Pre-act group (91.9% vs. 62.2%; P<0.001). DTD time was shorter in the Pre-act group (48min IQR: 38 to 63min vs. 78min IQR: 64-101min; p=0.001) as was first medical contact-to-device (FMCTD) time (91min IQR: 78 to 106min vs. 115min IQR: 90 to 139min; P<0.001). False activation of the catheterization lab was infrequent (1.3%).

CONCLUSIONS

Implementation of catheterization lab pre-activation using the LifeNet® system was associated with more efficient reperfusion times as measured by reduced FMCTD and DTD times without excess false activation rates.

Unité de Coordination Clinique des Services Préhospitaliers d'Urgence: A clinical telemedicine platform that improves prehospital and community health care for rural citizens

Access to health care in Canada's rural areas is a challenge. The Unité de Coordination Clinique des Services Préhospitaliers d'Urgence (UCCSPU) is a telemedicine program designed to improve health care in the Chaudiere-Appalaches and Quebec City regions of Canada. Remote medical services are provided by nurses and by an emergency physician based in a clinical unit at the Alphonse-Desjardins Community Health and Social Services Center. The interventions were developed to meet two objectives. The first is to enhance access to quality health care. To this end, Basic Life Support paramedics and nurses were taught interventions outside of their field of expertise. Prehospital electrocardiograms were used to remotely diagnose ST segment elevation myocardial infarction and to monitor patients who were en route by ambulance to the nearest catheterization facility or emergency department. Basic Life Support paramedics received extended medical authorization that allowed them to provide opioid analgesia via telemedicine physician orders. Nurses from community health centres without physician coverage were able to request medical assistance via a video telemedicine system. The second objective is to optimize medical resources. To this end, remote death certifications were implemented to avoid unnecessary transport of deceased persons to hospitals. This paper presents the telemedicine program and some results.

The Role of EMS in Regionalized Systems of Care

The parallel advancement of prehospital and in-hospital patient care has provided impetus for the development and implementation of regionalized systems of health care for patients suffering from acute, life-threatening injury and illness. Regardless of the patient's clinical condition, regionalized systems of care revolve around the premise of providing the right care to the right patient at the right time. Current regionalization strategies have shown improvements in the time to patient treatment and in patient outcome, with the incorporation of emergency medical services (EMS) bypass as a key component of the system of care. This article discusses the emerging role of EMS as a critical component of regionalized systems essential to ensure effective and efficient use of resources to improve patient outcome. We also examine some of the benefits and barriers to implementation of regionalized systems of care and avenues for future research.

Information on myocardial ischemia and arrhythmias added by prehospital electrocardiograms

BACKGROUND

The prehospital electrocardiogram (ECG) allows earlier identification of acute ST-segment elevation myocardial infarction (STEMI). Its utility for detection of other acute cardiac events, as well as for transient ST-segment abnormalities no longer present when the first hospital ECG is performed, is not well characterized.

OBJECTIVE

We sought to examine whether the prehospital ECG adds supplemental information to the first ECG obtained in hospital, by comparing data on possible cardiac ischemia and arrhythmias provided by the two ECGs, in ambulance patients later diagnosed as having cardiac disorders, including STEMI.

METHODS

Ambulance personnel acquired 12-lead ECGs for patients suspected of having an acute ischemic event, prior to transport to hospital. The first emergency department 12-lead ECG was provided by medical records at the receiving hospital, and the principal hospital diagnosis for the event was extracted from chart data. Two cardiologists, blinded to the hospital diagnosis, provided their consensus interpretation of 1,209 pairs of ECGs, noting the presence or absence of specific abnormalities on each tracing.

RESULTS

Among the 82 patients who had an eventual hospital diagnosis of STEMI, the study cardiologists identified 71 with ST-segment elevations on the ECGs they examined. The vast majority of these (97%) were observed on both ECGs, but the prehospital ECG showed ST-segment elevation for two additional patients (3%). No additional instances were seen only on the hospital ECG. Among the 116 patients with a hospital diagnosis of non-ST-segment elevation myocardial infarction (NSTEMI), the cardiologists identified 36 with ST-segment depressions: 28 (78%) of these were present on both ECGs, seven (19%) only on the prehospital ECG, and one (3%) only on the hospital ECG. Among the 567 patients with any cardiac hospital diagnosis, the cardiologists identified 87 with arrhythmias: 73 (84%) on both ECGs, 12 (14%) only on the prehospital ECG, and two (2%) only on the hospital ECG.

CONCLUSIONS

Beyond identifying ST-segment elevation earlier, prehospital ECGs detect important transient abnormalities, information not otherwise available from the first emergency department ECG. These data can expedite diagnosis and clinical management decisions among patients suspected of having an acute cardiac event. The prehospital ECG should be fully integrated into emergency medicine practice.

Bridging the gap for nonmetropolitan STEMI patients through implementation of a pharmacoinvasive reperfusion strategy

BACKGROUND

Timely primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy in ST-elevation myocardial infarction (STEMI). However, universal access is limited outside metropolitan centres and portends worse outcomes for rural patients. This study evaluates the outcomes of STEMI patients treated in a metropolitan and nonmetroplitan setting within Vital Heart Response, an integrated reperfusion program developed to reduce reperfusion delay in Central and Northern Alberta.

METHODS

From October 2006 to March 2011, data on consecutive STEMI patients was prospectively recorded. Clinical characteristics, in-hospital management, and outcomes grouped by site of presentation are described.

RESULTS

There were 1990 metropolitan and 1602 nonmetropolitan STEMI patients. Metropolitan were older (62.7 vs 60.4 years; P < 0.001) and had more: angina (21.2% vs 16.5%; P < 0.001), dyslipidemia (45.3% vs 39.6%; P = 0.001), and hypertension (49.9% vs 46.6%; P = 0.047). The reperfusion strategy for metropolitan and nonmetropolitan: primary PCI (57.4% vs 22.9%; P < 0.001), fibrinolysis (26.3% vs 61.2%; P < 0.001), and no reperfusion (16.3% vs 15.9%; P = 0.855). First medical contact to reperfusion was delayed in nonmetropolitan with fibrinolysis and PCI, 8 and 125 minutes. A rescue PCI or coronary angiography within 24 hours was completed in 41.4% and 46.2%, respectively. Nonmetropolitan patients had fewer deaths (4.1% vs 6.8%; P = 0.001) with no difference in the composite outcome (death, reinfraction, congestive heart failure, cardiogenic shock) (16.8% vs 15.1%; P = 0.161) or major bleeding (7.9% vs 8.0%; P = 0.951).

CONCLUSIONS

Systematic application of a pharmacoinvasive strategy appears to be safe and effective for patients in whom a delay in mechanical reperfusion is anticipated.

To transmit or not to transmit: how good are emergency medical personnel in detecting STEMI in patients with chest pain?

BACKGROUND

There is growing use of prehospital electrocardiograms (ECGs) in establishing early diagnosis of ST segment myocardial infarction (STEMI) to facilitate early reperfusion. This study aimed to determine the predictive value of prehospital ECGs interpreted by nonphysician emergency medical services (EMS) in chest pain presentations.

METHODS

In our city of 658,700 people, EMS/paramedics received 21 hours of instruction on STEMI management, ECG acquisition, and interpretation. Suspected STEMI ECGs were wirelessly transmitted to and discussed with a physician for possible therapy. ECGs deemed negative for STEMI by EMS were not transmitted; patients were transported to the closest hospital without prehospital physician involvement.

RESULTS

From July 21, 2008 to July 21, 2010, there were 5426 chest pain calls to EMS, 380 were suspected STEMI cases. The remaining ECGs were deemed negative for STEMI by EMS. To audit the nontransmitted ECGs we analyzed 323 consecutive patients over 2 selected months (January and June 2010) for comparison. Of nontransmitted cases there was 1 missed and 2 STEMIs that developed subsequently. Based on 380 transmitted and 323 nontransmitted cases, the sensitivity and specificity of EMS detecting STEMI were 99.6% and 67.6%, respectively. The positive and negative predictive values for STEMI were 59.5% and 99.7%, respectively.

CONCLUSIONS

Our findings demonstrate nonphysician EMS interpretation of STEMI on prehospital ECG has excellent sensitivity and high negative predictive value. This finding supports the use of prehospital ECGs interpreted by EMS to help identify and facilitate treatment of STEMI. These results may have broad implications on staffing models for first responder/EMS units.

Acute Antiarrhythmic Therapy of Ventricular Tachycardia and Ventricular Fibrillation

Ventricular arrhythmias (ventricular tachycardia and ventricular fibrillation) are often associated with underlying structural heart disease and require prompt assessment and treatment. Acute treatment involves initial hemodynamic stabilization of the patient followed by suppressive treatment with pharmacologic and nonpharmacologic approaches for reducing the risk of recurrence of ventricular arrhythmias and potential development of sudden cardiac death. This article reviews acute antiarrhythmic drug therapy for ventricular arrhythmias based on the clinical presentation.

Myocardial infarction associated with recency of immigration to Ontario

BACKGROUND

New immigrants to North America exhibit lower rates of obesity and hypertension than their native-born counterparts. Whether this is reflected by a lower relative risk of acute myocardial infarction (AMI) is not known.

OBJECTIVE

To determine the risk of AMI among new immigrants compared to long-term residents, and, among those who develop AMI, their short- and long-term mortality rate.

DESIGN

Population-based, matched, retrospective cohort study.

SETTING

Entire province of Ontario, the most populated province in Canada, from 1 April 1995 to 31 March 2007.

PARTICIPANTS

A total of 965,829 new immigrants were matched to 3,272,393 long-term residents by year of birth, sex and geographic location.

MEASUREMENTS

The main study outcome was hospitalization with a most responsible diagnosis of AMI. Secondary study outcomes among those who sustained an AMI were in-hospital, 30-day and 1-year mortality.

RESULTS

The mean age of the participants at study entry was approximately 34 years. The incidence rate of AMI was 4.14 per 10,000 person-years among new immigrants and 6.61 per 10,000 person-years among long-term residents. After adjusting for age, income quintile, urban vs. rural residence, history of hypertension, diabetes mellitus and smoking and number of health insurance claims, the hazard ratio for AMI was 0.66 [95% confidence interval (CI): 0.63-0.69].

CONCLUSION

New immigrants appear to be at lower risk of AMI than long-term residents. This finding does not appear to be explained by the availability of health-care services or income level.

Access to primary percutaneous coronary intervention for ST-segment elevation myocardial infarction in Canada: a geographic analysis

BACKGROUND

Primary percutaneous coronary intervention (PCI) is preferred over fibrinolysis for the treatment of ST-segment elevation myocardial infarction (STEMI). In the United States, nearly 80% of people aged 18 years and older have access to a PCI facility within 60 minutes. We conducted this study to evaluate the areas in Canada and the proportion of the population aged 40 years and older with access to a PCI facility within 60, 90 and 120 minutes.

METHODS

We used geographic information systems to estimate travel times by ground transport to PCI facilities across Canada. Time to dispatch, time to patient and time at the scene were considered in the overall access times. Using 2006 Canadian census data, we extracted the number of adults aged 40 years and older who lived in areas with access to a PCI facility within 60, 90 and 120 minutes. We also examined the effect on these estimates of the hypothetical addition of new PCI facilities in underserved areas.

RESULTS

Only a small proportion of the country's geographic area was within 60 minutes of a PCI facility. Despite this, 63.9% of Canadians aged 40 and older had such access. This proportion varied widely across provinces, from a low of 15.8% in New Brunswick to a high of 72.6% in Ontario. The hypothetical addition of a single facility to each of 4 selected provinces could increase the proportion by 3.2% to 4.3%, depending on the province. About 470 000 adults would gain access in such a scenario of new facilities.

INTERPRETATION

We found that nearly two-thirds of Canada's population aged 40 years and older had timely access to PCI facilities. The proportion varied widely across the country. Such information can inform the development of regionalized STEMI care models.