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The frontline of emergency cardiac care in Africa

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Mark Bisanzo at University of Massachusetts Chan Medical School
Mark Bisanzo
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EDITORIAL
The frontline of emergency cardiac care in Africa
While a greater percentage of deaths and disability adjusted
life years (DALYs) in Africa are still due to infectious disease,
ischemic heart disease and acute coronary syndromes (ACS)
are rapidly becoming a noticeable part of the disease burden
in Africa.
1,2
It follows that over time, resources should likewise
become more available to care for patients suffering from car-
diovascular emergencies. A simple internet search revealed the
presence of cardiac catheterization laboratory services already
functioning in Cameroon, Uganda, Kenya, Tanzania and
South Africa. It is likely that this service also exists in other
African countries. However, given the shortage of specialists
in Africa and the tendency of these physicians to cluster
around urban areas, the vast majority of Africans experiencing
ACS or other cardiovascular emergencies are unlikely to see a
cardiologist at any point following a major cardiac event. As a
result much of the acute cardiac care provided in Africa is left
to acute care providers.
This month’s issue of the African Journal of Emergency
Medicine provides examples of sophisticated emergency car-
diac care provided on the continent. Gede et al. describe a
patient with Wellens’ syndrome who they were able to success-
fully stabilize in a moderate resource setting and then transfer
to a high resource setting for successful catheterization. Wach-
ira et al., describe care and outcomes of patients presenting to
an academic hospital in Nairobi with ST elevation myocardial
infarction (STEMI). Osei-Ampofo et al. describe a technique
to confirm the placement of pericardial drainage catheters
under ultrasound guidance and finally Loughborough
describes a technique for performing pericardial drainage
using improvised equipment and bedside ultrasound.
As acute care develops on the continent, it will be impera-
tive for policy makers and educators to acknowledge the
impact acute care providers have on cardiovascular disease
outcomes. While no one in the emergency medicine choir needs
any preaching to in order to be convinced of the value of what
we do, the contribution of emergency care to improve patient
outcomes is clearly not well recognized, even among high level
policy makers and research foundations, which traditionally
have chosen to focus on prevention rather than cure. High
quality research therefore needs to take a central role in deter-
mining how and to what magnitude acute care providers can
improve cardiovascular mortality in a variety of resource
settings. Such research can in turn inform training needs, the
necessary skill sets required for acute care providers and allow
for informed decisions about how to prioritize the introduction
of new resources within a specific resource setting.
Contemporary literature indicates that many of the emer-
gency centre (EC) cardiac interventions employed within high
resource settings have a low number needed to treat (NNT,
Table 1).
3
While the isolated benefit of one of these interven-
tions (e.g. defibrillation) may not nearly be as advantageous
as in a setting where more advanced follow-on care is also
available (e.g. percutaneous coronary interventions or throm-
bolytics), benefit may still exist compared to doing nothing.
Carefully considered use of limited health care resources will
depend not only on the cost of an intervention within a specific
setting, but also on the cost of the burden of disease left
untreated in that same setting. Therefore, while initially it
might seem counter-intuitive to spend money on more expen-
sive interventions in low resource settings, it may in fact be the
most sensible thing to do should the cost of burden of
untreated disease be higher. This concept is referred to as Cost
per DALY averted.
In addition to considering the intervention itself, research
on how it is deployed within various resource and cost settings
is vital. For example, as it seems likely that cardiac catheteri-
zation facilities will remain limited to large urban areas, such
as described in Wachira’s study, other interventions, such as
thrombolytics, would likely have a much wider application.
Since physicians are also a limited resource (emergency
physicians are all but non-existent in most of sub-Saharan
Africa), it follows that use of thrombolytics may have to
involve alternate providers (e.g. nurses, prehospital staff,
etc.). They will have to be sufficiently skilled to accurately
interpret an ECG, determine symptom onset and ensure there
are no contra-indications before thrombolytic administration.
Prehospital workers have been shown in high income countries
to successfully use thrombolytics, but can that be replicated
with non-physician clinicians in Africa?
4
Cost will have to be looked at carefully and interpreted
broadly. Take for instance the costs involved in performing
Peer review under responsibility of African Federation for Emergency
Medicine.
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African Federation for Emergency Medicine
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Please cite this article in press as: Bisanzo M, The frontline of emergency cardiac care in Africa, Afr J Emerg Med (2014), http://dx.doi.org/10.1016/j.afjem.2014.07.001
CPR on a patient in cardiac arrest. For one, CPR training has
costs, which likely are not prohibitive. If no post-resuscitation
care is available, CPR may be just enough to allow the patient
to survive to hospital admission, incur a large hospital bill, but
then die before hospital discharge. In a setting where patients
may very well be paying out of pocket for such care, futile or
near futile interventions may have a significant cost to the
family. Clearly the ethics of all of this become very challenging
very quickly. Again the answer of where the resource line
should be drawn surely lies in the research.
Eventually, a matrix for each intervention can be created
that factors in the NNT, prevalence of disease in a given
country, district or setting and the cost of deploying the
intervention. This will allow policy makers to make informed
decisions about what level of acute cardiac care the country,
district or setting can offer. The paradigm of considering
standard care as a function of local resources available will
be crucial: best practice for STEMI in a rural district hospital
in Kenya will not compare to best practice delivered at Aga
Khan University Hospital in Nairobi. Therefore, answering
these highly pertinent clinical questions within the various
African resource tiers will be critical to developing logical,
effective and sustainable acute care systems. Using robust
research to place appropriate emergency care within the chain
of survival for cardiovascular disease will improve the atten-
tion and resources directed to improving all emergency care
in Africa.
Conflict of interest
None declared.
References
1. Murray CJL, Vos T, Lozano R, et al. Disability-adjusted life years
(DALYs) for 291 diseases and injuries in 21 regions, 1990–2010: a
systematic analysis for the Global Burden of Disease Study 2010.
Lancet 2012;380:2197–223.
2. Lozano Rafael, Naghavi Mohsen, Foreman Kyle, et al. Global and
regional mortality from 235 causes of death for 20 age groups in
1990 and 2010: a systematic analysis for the Global Burden of
Disease Study 2010. Lancet 2012;380:2095–128.
3. http://www.thennt.com/home-nnt/ accessed 28.06.14.
4. Weaver WD, Cerqueira M, Hallstrom AP, et al. Prehospital-
initiated vs hospital-initiated thrombolytic therapy. The Myocar-
dial Infarction Triage and Intervention Trial. JAMA 1993 Sep
8;270(10):1211–6.
Mark Bisanzo
Department of Emergency Medicine,
University of Massachusetts,
Worcester, MA, United States
mbisanzo@gmail.com
Table 1 The Number Needed to Treat for various interventions needed in cardiac emergencies.
3
Intervention NNT Type of benefit
Aspirin for STEMI 42 Life saved
Thrombolytics for STEMI 43 Life saved if given within 6 h
63 Life saved if given between 6–12 h
200 Life saved if given between 12–24 h
Clopidogrel during/after Stenting 27 Non-fatal heart attack or stroke prevented
Defibrillation for ventricular fibrillation 2.5 Life saved (but intervention almost immediately – benefit
was time dependent)
Non-invasive positive pressure ventilation for pulmonary edema 13 Life saved
8 Averted need for intubation
NNT = Number needed to treat to achieve benefit in one patient; STEMI: ST elevation myocardial infraction.
2 Editorial
Please cite this article in press as: Bisanzo M The frontline of emergency cardiac care in Africa, Afr J Emerg Med (2014), http://dx.doi.org/10.1016/j.afjem.2014.07.001
... a b s t r a c t 24 Introduction: The incidence of myocardial infarction is rising in Sub-Saharan Africa. In order to reduce 25 mortality, timely reperfusion by percutaneous coronary intervention (PCI) or thrombolysis followed by 26 PCI is required. South Africa has historically been characterised by inequities in healthcare access based 27 on geographic and socioeconomic status. ...
... These gaps, albeit non-significant, are illustrated in this study 162 by a negative correlation between the amount of private cath labs 163 and those with medical insurance. 164 Africa is no stranger to this inequitable dissemination of 165 resources based on socio-economic status and geographic locale 166 [14,[24][25][26]. Owing to the disarray of the local public transport sys-167 tem [27], the high cost of travel [14] and the unreliable nature of 168 the public EMS system [12,13], even those living in close proximity 169 to the urban concentrated PCI-facilities, might still not be able to 170 access these in a timely manner. ...
Percutaneous coronary intervention still not accessible for many South Africans
Article
Full-text available
  • Apr 2017
Introduction: The incidence of myocardial infarction is rising in Sub-Saharan Africa. In order to reduce mortality, timely reperfusion by percutaneous coronary intervention (PCI) or thrombolysis followed by PCI is required. South Africa has historically been characterised by inequities in healthcare access based on geographic and socioeconomic status. We aimed to determine the coverage of PCI-facilities in South Africa and relate this to access based on population and socio-economic status. Methods: This cross-sectional study obtained data from literature, directories, organisational databases and correspondence with Departments of Health and hospital groups. Data was analysed descriptively while Spearman’s Rho sought correlations between PCI-facility resources, population, poverty and medical insurance status. Results: South Africa has 62 PCI-facilities. Gauteng has the most PCI-facilities (n = 28) while the Northern Cape has none. Most PCI-facilities (n = 48; 77%) are owned by the private sector. A disparity exists between the number of private and state-owned PCI-facilities when compared to the poverty (r = 0.01; p = 0.17) and insurance status of individuals (r = −0.4; p = 0.27). Conclusion: For many South Africans, access to PCI-facilities and primary PCI is still impossible given their socio-economic status or geographical locale. Research is needed to determine the specific PCI-facility needs based on geographic and epidemiological aspects, and to develop a contextualised solution for South Africans suffering a myocardial infarction.
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... The Emergency Centre (EC) acts as a primary access point for entry into the system [5,6], and as outlined by the Collaborative on Enhancing Emergency Care Research in LMICs (CLEER), plays a key role in "population-level improvements in morbidity and amenable mortality" [7]. Patients present with a variety of NCD-related complaints and are from across the age spectrum [8] making this a high-yield population to target. ...
Systematic review on epidemiology, interventions and management of noncommunicable diseases in acute and emergency care settings in Kenya
Article
Full-text available
  • Jun 2021
Introduction Mortality and morbidity from Non-Communicable Diseases (NCDs) in Africa are expected to worsen if the status quo is maintained. Emergency care settings act as a primary point of entry into the health system for a spectrum of NCD-related illnesses, however, there is a dearth of literature on this population. We conducted a systematic review assessing available evidence on epidemiology, interventions and management of NCDs in acute and emergency care settings in Kenya, the largest economy in East Africa and a medical hub for the continent. Methods All searches were run on July 15, 2015 and updated on December 11, 2020, capturing concepts of NCDs, and acute and emergency care. The study is registered at PROSPERO (CRD42018088621). Results We retrieved a total of 461 references, and an additional 23 articles in grey literature. 391 studies were excluded by title or abstract, and 93 articles read in full. We included 10 articles in final thematic analysis. The majority of studies were conducted in tertiary referral or private/mission hospitals. Cancer, diabetes, cardiovascular disease and renal disease were addressed. Majority of the studies were retrospective, cross-sectional in design; no interventions or clinical trials were identified. There was a lack of access to basic diagnostic tools, and management of NCDs and their complications was limited. Conclusion There is a paucity of literature on NCDs in Kenyan emergency care settings, with particular gaps on interventions and management. Opportunities include nationally representative, longitudinal research such as surveillance and registries, as well as clinical trials and implementation science to advance evidence-based, context-specific care.
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... Addressing the NCD epidemic will require efforts across the healthcare system. The Emergency Department (ED) acts as a primary access point for entry into the system (5,6). Patients present with a variety of NCD-related complaints, and are from across the age spectrum (7). ...
SYSTEMATIC REVIEW ON EPIDEMIOLOGY, INTERVENTIONS AND MANAGEMENT OF NONCOMMUNICABLE DISEASES IN ACUTE AND EMERGENCY CARE SETTINGS IN KENYA
Preprint
Full-text available
  • Jun 2020
Introduction: Mortality and morbidity from Non-Communicable Diseases (NCDs) in Africa are expected to worsen if the status quo is maintained. Emergency care settings act as a primary point of entry into the health system for a spectrum of NCD-related illnesses, however, there is a dearth of literature on this population. We conducted a systematic review assessing available evidence on epidemiology, interventions and management of NCDs in acute and emergency care settings in Kenya, the largest economy in East Africa and a medical hub for the continent. Methods: All searches were run on July 15, 2015 capturing concepts of NCDs, and acute and emergency care. The study is registered at PROSPERO (CRD42018088621). Results: We retrieved a total of 461 references, and an additional 23 articles in grey literature. 391 studies were excluded by title or abstract, and 93 articles read in full. We included 10 articles in final thematic analysis. The majority of studies were conducted in tertiary referral or private/mission hospitals. Cancer, diabetes, cardiovascular disease and renal disease were addressed. Majority of the studies were retrospective, cross-sectional in design; no interventions or clinical trials were identified. There was a lack of access to basic diagnostic tools, and management of NCDs and their complications was limited. Conclusion: There is a paucity of literature on NCDs in Kenyan emergency care settings, with particular gaps on interventions and management. Opportunities include nationally representative, longitudinal research such as surveillance and registries, as well as clinical trials and implementation science to advance evidence-based, context-specific care.
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... [12][13][14] Access is not simply a product of proximity, but also of socio-economic status and other demographic factors. 3,15,[20][21][22] Low-income patients living in rural areas and those without medical insurance experience the greatest barriers to accessing healthcare services. 20 In South Africa, 77% of all the PCI facilities are owned by the private healthcare sector and can therefore only be utilised by 18.1% of the population, 15 unless upfront payment of up to $3500 (~R50 000) is made. ...
The proportion of South Africans living within 60 and 120 minutes of a percutaneous coronary intervention facility
Article
  • Mar 2018
Introduction: Timely reperfusion, preferably via percutaneous coronary intervention (PCI) following myocardial infarction, improves mortality rates. Emergency medical services play a pivotal role in recognising and transporting patients with ST-elevation myocardial infarction directly to a PCI facility to avoid delays to reperfusion. Access to PCI is, in part, dependant on the geographic distribution of patients around PCI facilities. The aim of this study was to determine the proportion of South Africans living within 60 and 120 minutes of a PCI facility. Methods: PCI facility and population data were subjected to proximity analysis to determine the average drive times from municipal ward centroids to PCI facilities for each province in South Africa. Thereafter, the population of each ward living within 60 and 120 minutes of a PCI facility was extrapolated. Results: Approximately 53.8 and 71.53% of the South African population live within 60 and 120 minutes of a PCI facility. The median (IQR, range) drive times and distances to a PCI facility are 100 minutes (120.4 min, 0.7-751.8) across 123.6 km (157.6 km, 0.3-940.8). Conclusion: Based on the proximity of South Africans to PCI facilities, it seems possible that most patients could receive timely PCI within 120 minutes of first medical contact. However, this may be unlikely for some due to a lack of medical insurance, under-developed referral networks or other system delays. Coronary care networks should be developed based on the proximity of communities to 12-lead ECG and reperfusion therapies (such as PCI facilities). Public and private healthcare partnerships should be fortified to allow for patients without medical insurance to have equal accesses to PCI facilities.
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Disability-adjusted life years (DALYs) for 291 diseases and injuries in 21 regions, 1990-2010: A systematic analysis for the Global Burden of Disease Study 2010
Article
Full-text available
  • Dec 2012
Background: Measuring disease and injury burden in populations requires a composite metric that captures both premature mortality and the prevalence and severity of ill-health. The 1990 Global Burden of Disease study proposed disability-adjusted life years (DALYs) to measure disease burden. No comprehensive update of disease burden worldwide incorporating a systematic reassessment of disease and injury-specific epidemiology has been done since the 1990 study. We aimed to calculate disease burden worldwide and for 21 regions for 1990, 2005, and 2010 with methods to enable meaningful comparisons over time. Methods: We calculated DALYs as the sum of years of life lost (YLLs) and years lived with disability (YLDs). DALYs were calculated for 291 causes, 20 age groups, both sexes, and for 187 countries, and aggregated to regional and global estimates of disease burden for three points in time with strictly comparable definitions and methods. YLLs were calculated from age-sex-country-time-specific estimates of mortality by cause, with death by standardised lost life expectancy at each age. YLDs were calculated as prevalence of 1160 disabling sequelae, by age, sex, and cause, and weighted by new disability weights for each health state. Neither YLLs nor YLDs were age-weighted or discounted. Uncertainty around cause-specific DALYs was calculated incorporating uncertainty in levels of all-cause mortality, cause-specific mortality, prevalence, and disability weights. Findings: Global DALYs remained stable from 1990 (2·503 billion) to 2010 (2·490 billion). Crude DALYs per 1000 decreased by 23% (472 per 1000 to 361 per 1000). An important shift has occurred in DALY composition with the contribution of deaths and disability among children (younger than 5 years of age) declining from 41% of global DALYs in 1990 to 25% in 2010. YLLs typically account for about half of disease burden in more developed regions (high-income Asia Pacific, western Europe, high-income North America, and Australasia), rising to over 80% of DALYs in sub-Saharan Africa. In 1990, 47% of DALYs worldwide were from communicable, maternal, neonatal, and nutritional disorders, 43% from non-communicable diseases, and 10% from injuries. By 2010, this had shifted to 35%, 54%, and 11%, respectively. Ischaemic heart disease was the leading cause of DALYs worldwide in 2010 (up from fourth rank in 1990, increasing by 29%), followed by lower respiratory infections (top rank in 1990; 44% decline in DALYs), stroke (fifth in 1990; 19% increase), diarrhoeal diseases (second in 1990; 51% decrease), and HIV/AIDS (33rd in 1990; 351% increase). Major depressive disorder increased from 15th to 11th rank (37% increase) and road injury from 12th to 10th rank (34% increase). Substantial heterogeneity exists in rankings of leading causes of disease burden among regions. Interpretation: Global disease burden has continued to shift away from communicable to non-communicable diseases and from premature death to years lived with disability. In sub-Saharan Africa, however, many communicable, maternal, neonatal, and nutritional disorders remain the dominant causes of disease burden. The rising burden from mental and behavioural disorders, musculoskeletal disorders, and diabetes will impose new challenges on health systems. Regional heterogeneity highlights the importance of understanding local burden of disease and setting goals and targets for the post-2015 agenda taking such patterns into account. Because of improved definitions, methods, and data, these results for 1990 and 2010 supersede all previously published Global Burden of Disease results. Funding: Bill & Melinda Gates Foundation.
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Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: A systematic analysis for the Global Burden of Disease Study 2010
Article
Full-text available
  • Dec 2012
Background: Reliable and timely information on the leading causes of death in populations, and how these are changing, is a crucial input into health policy debates. In the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010), we aimed to estimate annual deaths for the world and 21 regions between 1980 and 2010 for 235 causes, with uncertainty intervals (UIs), separately by age and sex. Methods: We attempted to identify all available data on causes of death for 187 countries from 1980 to 2010 from vital registration, verbal autopsy, mortality surveillance, censuses, surveys, hospitals, police records, and mortuaries. We assessed data quality for completeness, diagnostic accuracy, missing data, stochastic variations, and probable causes of death. We applied six different modelling strategies to estimate cause-specific mortality trends depending on the strength of the data. For 133 causes and three special aggregates we used the Cause of Death Ensemble model (CODEm) approach, which uses four families of statistical models testing a large set of different models using different permutations of covariates. Model ensembles were developed from these component models. We assessed model performance with rigorous out-of-sample testing of prediction error and the validity of 95% UIs. For 13 causes with low observed numbers of deaths, we developed negative binomial models with plausible covariates. For 27 causes for which death is rare, we modelled the higher level cause in the cause hierarchy of the GBD 2010 and then allocated deaths across component causes proportionately, estimated from all available data in the database. For selected causes (African trypanosomiasis, congenital syphilis, whooping cough, measles, typhoid and parathyroid, leishmaniasis, acute hepatitis E, and HIV/AIDS), we used natural history models based on information on incidence, prevalence, and case-fatality. We separately estimated cause fractions by aetiology for diarrhoea, lower respiratory infections, and meningitis, as well as disaggregations by subcause for chronic kidney disease, maternal disorders, cirrhosis, and liver cancer. For deaths due to collective violence and natural disasters, we used mortality shock regressions. For every cause, we estimated 95% UIs that captured both parameter estimation uncertainty and uncertainty due to model specification where CODEm was used. We constrained cause-specific fractions within every age-sex group to sum to total mortality based on draws from the uncertainty distributions. Findings: In 2010, there were 52·8 million deaths globally. At the most aggregate level, communicable, maternal, neonatal, and nutritional causes were 24·9% of deaths worldwide in 2010, down from 15·9 million (34·1%) of 46·5 million in 1990. This decrease was largely due to decreases in mortality from diarrhoeal disease (from 2·5 to 1·4 million), lower respiratory infections (from 3·4 to 2·8 million), neonatal disorders (from 3·1 to 2·2 million), measles (from 0·63 to 0·13 million), and tetanus (from 0·27 to 0·06 million). Deaths from HIV/AIDS increased from 0·30 million in 1990 to 1·5 million in 2010, reaching a peak of 1·7 million in 2006. Malaria mortality also rose by an estimated 19·9% since 1990 to 1·17 million deaths in 2010. Tuberculosis killed 1·2 million people in 2010. Deaths from non-communicable diseases rose by just under 8 million between 1990 and 2010, accounting for two of every three deaths (34·5 million) worldwide by 2010. 8 million people died from cancer in 2010, 38% more than two decades ago; of these, 1·5 million (19%) were from trachea, bronchus, and lung cancer. Ischaemic heart disease and stroke collectively killed 12·9 million people in 2010, or one in four deaths worldwide, compared with one in five in 1990; 1·3 million deaths were due to diabetes, twice as many as in 1990. The fraction of global deaths due to injuries (5·1 million deaths) was marginally higher in 2010 (9·6%) compared with two decades earlier (8·8%). This was driven by a 46% rise in deaths worldwide due to road traffic accidents (1·3 million in 2010) and a rise in deaths from falls. Ischaemic heart disease, stroke, chronic obstructive pulmonary disease (COPD), lower respiratory infections, lung cancer, and HIV/AIDS were the leading causes of death in 2010. Ischaemic heart disease, lower respiratory infections, stroke, diarrhoeal disease, malaria, and HIV/AIDS were the leading causes of years of life lost due to premature mortality (YLLs) in 2010, similar to what was estimated for 1990, except for HIV/AIDS and preterm birth complications. YLLs from lower respiratory infections and diarrhoea decreased by 45-54% since 1990; ischaemic heart disease and stroke YLLs increased by 17-28%. Regional variations in leading causes of death were substantial. Communicable, maternal, neonatal, and nutritional causes still accounted for 76% of premature mortality in sub-Saharan Africa in 2010. Age standardised death rates from some key disorders rose (HIV/AIDS, Alzheimer's disease, diabetes mellitus, and chronic kidney disease in particular), but for most diseases, death rates fell in the past two decades; including major vascular diseases, COPD, most forms of cancer, liver cirrhosis, and maternal disorders. For other conditions, notably malaria, prostate cancer, and injuries, little change was noted. Conclusions: Population growth, increased average age of the world's population, and largely decreasing age-specific, sex-specific, and cause-specific death rates combine to drive a broad shift from communicable, maternal, neonatal, and nutritional causes towards non-communicable diseases. Nevertheless, communicable, maternal, neonatal, and nutritional causes remain the dominant causes of YLLs in sub-Saharan Africa. Overlaid on this general pattern of the epidemiological transition, marked regional variation exists in many causes, such as interpersonal violence, suicide, liver cancer, diabetes, cirrhosis, Chagas disease, African trypanosomiasis, melanoma, and others. Regional heterogeneity highlights the importance of sound epidemiological assessments of the causes of death on a regular basis. Funding: Bill & Melinda Gates Foundation.
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Prehospital-initiated vs hospital-initiated thrombolytic therapy. The Myocardial Infarction Triage and Intervention Trial
Article
  • Sep 1993
To determine the effect of prehospital-initiated vs hospital-initiated treatment of myocardial infarction on clinical outcome. Randomized, controlled clinical trial. Multicenter study involving 19 hospitals and all paramedic systems in the Seattle, Wash, metropolitan area. A total of 360 patients with symptoms for 6 hours or less, no risk factors for serious bleeding, and ST-segment elevation were selected by paramedics and a remote physician for inclusion into the trial. They represented 4% of patients with chest pain who were screened and 21% of those with acute infarction. Patients were allocated to have aspirin and alteplase treatment initiated before or after hospital arrival. Intravenous sodium heparin was administered to both groups in the hospital. The primary endpoint was a ranked composite score (combining death, stroke, serious bleeding, and infarct size). The relation between time to treatment and outcome (composite score, infarct size, ejection fraction, and mortality) was also assessed. Initiating treatment before hospital arrival decreased the interval from symptom onset to treatment from 110 to 77 minutes (P < .001). Although more patients whose therapy was initiated before hospital arrival had resolution of pain by admission (23% vs 7%; P < .001), there were no significant differences in the composite score (P = .64), mortality (5.7% vs 8.1%), ejection fraction (53% vs 54%), or infarct size (6.1% vs 6.5%). A secondary analysis of time to treatment and outcome showed that treatment initiated within 70 minutes of symptom onset was associated with better outcome (composite score, P = .009; mortality, 1.2% vs 8.7%, P = .04; infarct size, 4.9% vs 11.2%, P < .001; and ejection fraction, 53% vs 49%, P = .03) than later treatment. Identification of patients eligible for thrombolysis by paramedics reduced the hospital treatment time from 60 minutes (for patients not in the study) to 20 minutes (for study patients allocated to begin treatment in the hospital). There was no improvement in outcome associated with initiating treatment before hospital arrival; however, treatment within 70 minutes of symptom onset--whether in the hospital or in the field--minimized the infarct process and its complications.
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