Point-of-Care Diagnosis of Acute Myocardial Infarction in Central Vietnam

International Exchange, Needs Assessment, and Spatial Care Paths

Abstract

Objectives 

Objectives were to (a) advance point-of-care (POC) education, international exchange, and culture; (b) report needs assessment survey results from Thua Thien Hue Province, Central Vietnam; (c) determine diagnostic capabilities in regional health care districts of the small-world network of Hue University Medical Center; and (d) recommend Spatial Care Paths that accelerate the care of acute myocardial infarction (AMI) patients.

Methods 

We organized progressively focused, intensive, and interactive lectures, workshops, and investigative teamwork over a 2-year period. We surveyed hospital staff in person to determine the status of diagnostic testing at 15 hospitals in 7 districts. Questions focused on cardiac rapid response, prediabetes/diabetes, infectious diseases, and other serious challenges, including epidemic preparedness.

Results 

Educational exchange revealed a nationwide shortage of POC coordinators. Throughout the province, ambulances transfer patients primarily between hospitals, rarely picking up from homes. No helicopter rescue was available. Ambulance travel times from distant sites to referral hospitals were excessive, longer in costal and mountainous areas. Most hospitals (92.3%) used electrocardiogram and creatine phosphokinase-MB isoenzyme to diagnose AMI. Cardiac troponin I/T testing was performed only at large referral hospitals.

Conclusions 

Central Vietnam must improve rapid diagnosis and treatment of AMI patients. Early upstream POC cardiac troponin testing on Spatial Care Paths will expedite transfers directly to hospitals capable of intervening, improving outcomes following coronary occlusion. Point-of-care coordinator certification and financial support will enhance standards of care cost-effectively. Training young physicians pivots on high-value evidence-based learning when POC cardiac troponin T/cardiac troponin I biomarkers are in place for rapid decision making, especially in emergency rooms.

The long-term collaborative goal is national development of point-of-care (POC) culture, professional practice, and evidence-based decision making in Vietnam. Specific objectives for this research were (a) to compare needs assessment survey results in Vietnam currently versus 1 decade ago, (b) to determine hospital POC instrument and diagnostic capabilities in the regional districts of Thua Thien Hue Province (TTHP), and (c) to recommend designs, technologies, systems logic, algorithms, and Spatial Care Paths (SCPs) that accelerate the care of patients suspected of having acute myocardial infarction (AMI) in the health care small-world network (SWN) of Hue University Medical Center.

NATIONAL DEVELOPMENT

Following countrywide education programs in 2016 and 2017 (Table 1), our collaborative strategy for advancing point-of-need decision making in Central Vietnam comprised (a) producing an international symposium (Table 2) presented by local and international speakers (Fig. 1) and free for all who wished to attend; (b) conducting full-time field research on site for 1 month; (c) performing POC testing (POCT) needs assessment throughout TTHP; and (d) accelerating diagnosis to improve the care of AMI patients by implementing POC cardiac biomarker testing while optimizing regional SWNs. Surveys also addressed POCT for other medical challenges, such as molecular technologies for infectious diseases, outbreaks, and sepsis; test clusters for diabetes mellitus; and laboratory support of critically ill patients in isolation and intensive care.

TABLE 1: National Educational Program and POC Culture Development in Vietnam

TABLE 2: International Symposium Lectures—MųC LųC

FIGURE 1: International symposium speakers and research team in Hue. This figure can be viewed online in color at www.poctjournal.com.

BACKGROUND

Historical Perspective

Over a decade ago, one author in collaboration with country colleagues in Cambodia and Vietnam performed surveys¹ of POCT sponsored by a Fulbright Scholar Award (to G.J.K.) for the development of POC culture in Association of Southeast Asian Nations (ASEAN) member states. The Fulbright was based out of Chulalongkorn University in Bangkok, Thailand. Upon surveying Cambodia at that time, we found no cardiac biomarker testing whatsoever. In Southern Vietnam, 33% of small hospitals surveyed¹ performed exclusively creatine phosphokinase (CK) or CK-MB isoenzyme (CK-MB) testing in small laboratories to diagnose AMI, whereas none offered cardiac troponin (cTn) testing; 33% of medium-sized hospital laboratories performed qualitative cardiac troponin I (cTnI), and 33%, quantitative cardiac troponin T (cTnT) testing; and 25% of large hospitals performed either qualitative or quantitative cTnI, and 25%, quantitative cTnT testing. None of the sites surveyed offered cardiac biomarker testing at points of care (see Tables 2 and 3 in Kost et al¹).

At the time of the previous survey, Vietnamese health systems lacked systematic means of quickly rescuing, diagnosing, and treating patients living in remote locations. No helicopter transport was available, and ambulance service was inadequate. We concluded, “Cost-effectiveness should be assessed in the context of complete cycles of care from home to hospital and back, for which POCT offers unique advantages in the diagnosis, triage, acute care, intensive care, bedside testing, and after discharge, monitoring at the primary care and home levels.”¹ Further, “Critical care testing and POCT must become prominent components of public health strategies and infrastructures in this low-income country to improve acute care and disaster preparedness.”¹ Now, cardiac deaths are increasing in Vietnam, in part attributed to late diagnosis,² and more fundamentally, to the surprising increase in, and burden of, ischemic heart disease.^3,4

New Mission

In 2014, the World Health Organization produced a Vietnam country profile of noncommunicable disease and associated mortality.⁵ Of approximately 91 million people, 33% of deaths were attributed to cardiovascular diseases alone. Thus, the current new mission for our joint program with Vietnam is (a) to improve the standard of care and outcomes for patients with AMI; (b) to do so with geographic and demographic equity, specifically targeting badly neglected rural regions in need; and (c) to direct diagnostic resources appropriately, efficiently, and cost-effectively.

EDUCATION AND TRAINING

Hypothesis

Our basic hypothesis is that education is fundamental to progress, progress is vital for social equity, and social equity is inherent in sustainable POC culture. We conducted a 2-year national POCT and acute coronary syndrome (ACS) lecture program in 2016 and 2017 comprising collaborative-cooperative instruction and shared experiences in the practice of point-of-need decision making and rapid response diagnostics.

We held lecture and training sessions in 3 key regions—Ho Chi Minh City (HCMC, the South), Hue (Central), and Hanoi (the North). These activities presaged our international exchange organized and supported by the Point-of-Care Testing Center for Teaching and Research (POCT•CTR) at the University of California, Davis (UC Davis), for TTHP, in collaboration with the Faculty of Hue University of Medicine and Pharmacy (HUMP).

International Symposium

Before the needs assessment field survey began, the POCT•CTR sponsored an International Symposium at HUMP with presentations given by (a) the leading Vietnamese POC coordinator, who works at French-Vietnam Hospital in HCMC, (b) guests invited from the United States and Taiwan, and (c) local HUMP expert speakers.

Three undergraduate students (K.N., M.V.S., and A.Z.) from UC Davis, received POCT•CTR travel-research funding, and one (A.Z.), a distinguished UC Davis Student Travel Award, to present at the symposium. Table 2 outlines the international symposium program, which provided a successful platform for launching collaborative regional research investigating the province health care SWN.

Shift to Primary Care

This long-term program was designed to progressively facilitate the implementation of POCT throughout Vietnam in line with recent central government emphasis on redirecting substantial health care funding to smaller community hospitals and primary care sites of first patient contact where diagnostic testing is needed urgently on a daily basis, in order to practice evidence-based medicine.

METHODS

Survey Scope

To determine the status of POCT and other diagnostics at 15 hospitals in 7 districts in TTHP, we surveyed hospital staff on site in both the Vietnamese and English languages. For consistency, we used newly prepared formal survey questionnaires. The province has a tropical monsoon climate, making it rainy and humid throughout the year. It borders Laos to the west. Districts closest to the border are mountainous, with very limited medical resources and extremely constrained access to health care. People living in mountainous regions tend to be culturally distinct and not well integrated with urban styles. To the east is the Bien Deng Sea, also known as the South China Sea. The costal peninsulas and other geographic features of the thin central region of Vietnam present their own challenges for north-south travel over high passes and expeditious cardiac care.

The province is made up of 9 district-level subdivisions comprising 6 districts (A Luoui, Nam Dong, Phong Dien, Phu Loc, Phu Vang, and Quang Dien), 2 towns (Huong Thuy and Huong Tra), and 1 provincial city, Hue, the ninth most populous in Vietnam. Further subdivided administrative units comprise 8 commune-level towns, 105 communes, and 39 wards. We surveyed 6 districts in the time permitted during 1 month on site. This collaborative research was followed by e-mail correspondence, teleconferences, and limited select field visits conducted by Vietnamese students to expand the base of district sites and clarify factual details.

Hospital Levels

Vietnamese hospitals are classified by the government into “levels” (Table 3). The most common is level 4, 1 per commune, with more than 150 in TTHP. These sites, historically and typically the least well equipped and poorest funded, also are known as community health centers. Level 3 hospitals, 1 per district, are commonly known as district hospitals. They are better equipped and funded than level 4 hospitals.

TABLE 3: Hospital Levels in Vietnam

There is 1 level 2 hospital per province, the provincial hospital, even better equipped and funded. Hue University Hospital is level 2. Hue Central Hospital is located in the provincial capitol and is one of the largest in Vietnam. It is 1 of only 3 level 1 hospitals, along with Bach Mai Hospital in Hanoi and Cho Ray Hospital in HCMC, in all of Vietnam. Administration of a level 1 hospital is tightly controlled by the central government. We did not survey the level 1 hospital. Our focus was on the regional health care SWN, mainly rural areas referring patients to higher-level hospitals.

Needs Assessment

We conducted POC needs assessment⁶ according to formal methods and statistical approaches developed during the course of our UC Davis Point-of-Care Testing Center funded by the National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, at the POCT•CTR. We published a series of articles summarized in the first chapter,⁷ “Needs Assessment for Rapid Decision Making in Pandemics, Complex Emergencies, and Disasters: A Global Perspective,” of Global Point of Care: Strategies for Disasters, Emergencies, and Public Health Resilience (Global Point of Care).

In Global Point of Care,⁸ the first Appendix provides an English survey tool that readers can adapt to their own settings and interests. Working from this platform,⁹ we customized a survey for Central Vietnam. The World Health Organization recently emphasized the importance of needs assessment as a first step in relation to determining purpose in “A Guide to Aid the Selection of Diagnostic Tests.”¹⁰ Our new English survey was translated into Vietnamese (Appendix 2, Supplemental Digital Content 2, https://links.lww.com/POC/A17) by 1 coauthor (T.T.B.D.) and piloted to improve fidelity of responses. Both this Vietnamese translation and the English version (Appendix 1, Supplemental Digital Content 1, https://links.lww.com/POC/A16) can be found in the appendices available online.

Geographic Information System, SWNs, and SCPs

Approaches to geographic and topographic analyses are described by Ferguson et al^11,12 based on research conducted at the POCT•CTR. Small-world network theory and application are explained in “Using Small-World Networks to Optimize Preparedness, Response, and Resilience,” Chapter 49 in Global Point of Care.¹³ An SCP is defined as the most efficient route taken by the patient when receiving definitive care in an SWN.¹⁴ Background rationale, detailed explanation, SCP illustrations, and tabular summaries of impact can be found with free access at http://www.ifcc.org/media/332055/eJIFCC2014Vol25No2pp134-153.pdf.

POC Culture

The concept of POC culture (“the future of world medicine for individuals globally”) was created by 1 author (G.J.K.) in 2010 and summarized by Kost et al.¹⁵ Relevant survey questions regarding POC culture were based on Appendix 3¹⁶ of Global Point of Care⁸ and on previous surveys conducted in Cambodia, Indonesia, the Philippines, Thailand, Vietnam, and other ASEAN member states.

Analysis and Statistics

Quantitative methods, associated publications, case illustrations, and needs assessment theory can be found in Chapter 1 of Global Point of Care.⁷ Briefly, survey respondents assigned ranks, R_j, with j = [1, n_r], where n_r is the number of possible ranks for each factor; F_i, where i = [1, n_f]; and n_f = the number of factors given for selection. Scores were calculated using the following equation: S_j = (n_r + 1) − R_j.

We determined the weighted scores by summing the product of each score and the corresponding frequency as follows:

where the frequency, F_ij, is the number of times survey respondents assigned an individual factor a specific rank. When a respondent designated the same rank for 2 or more factors (a “tie”), an average rank was assigned to each factor, and positions of factors with lower ranks were adjusted accordingly. Statistical methods are described by Kost et al.⁷

RESULTS

Tables 1 and 2 present the 2-year educational programs conducted in North, Central, and South Vietnam during 2016 and 2017. In 2017, we focused on Central Vietnam, because the preceding broad diagnostics surveys documented deficiencies of cardiac biomarker testing in this region, both at points of care and in hospital laboratories (Fig. 2). Table 4 and subsequent Tables 5–11 present survey results.

FIGURE 2: Status of POC and clinical laboratory cardiac biomarker testing in Vietnam. The left frame shows the status in 2016, whereas the right frame, 2017. This geographic information systems analysis of trends over the 2-year period of POCT national development shows that Central Vietnam remains deficient in both POC and clinical laboratory cTnT diagnostic resources. During the survey in TTHP, we found no POC cTnI testing, which generally was deficient in central and far north-south regions. This figure can be viewed online in color at www.poctjournal.com.

TABLE 4: Weighted Scores Identifying Needs Priorities for POC Diagnostic Tests*

TABLE 5: Demographics, Critical Care Resources, and Cardiac Biomarker Utilization in Central Vietnam Hospitals

TABLE 6: Site-Specific Deployment of POCT*

TABLE 7: POCT Emergency Medical Staff Should Perform While Transporting Patients in Order to Speed Up Treatment*

TABLE 8: Characterization of Emergency Services

TABLE 9: Strategic Diagnosis, POCT Availability, and Referral Patterns in Central Vietnam

TABLE 10: Acute Coronary Syndromes and Approaches to Patient Care in the Community

TABLE 11: Ambulance Services in TTHP Province

Table 4 reports the results of basic needs assessment. Overall, respondents favored key diagnostic test clusters for urgent care. The Pareto plot (Fig. 3) illustrates the results and indicates statistically significant differences in rankings. Top priorities were attached to hematology, pulse oximetry, chemistry/electrolytes/ionized calcium (Ca²⁺), blood gases, and rapid microbiology test clusters in the emergency room.

FIGURE 3: Pareto plot showing survey respondent priorities for diagnostic test clusters. The Pareto plot presents perceived priorities for diagnostic test clusters based on survey needs assessment. P values approximate levels of significant differences for the labeled test clusters versus hematology, the one ranked highest. Note that this graphic reflects what respondents stated is needed, not necessarily what is in place already. See Table 4 for additional details.

Despite the high prevalence of ACS in the province, cardiac biomarkers came in sixth. Coagulation tests and blood typing received the lowest overall weighted scores. However, cardiac biomarkers placed third after hematology and rapid microbiology tests at level 4 hospitals, which often provide the initial critical contact points for urgent cardiac care. Likewise, the level 2 hospital ranked cardiac biomarkers third, in this case after rapid microbiology and coagulation test clusters.

Table 5 summarizes demographics, critical care resources, and cardiac biomarker utilization in the hospitals surveyed. None of the sites reported vigorous POCT programs. The level 2 hospital offered both cTnT and cTnI testing. Neither cTn test was present in the other hospital levels, which depended mostly on electrocardiogram (ECG) for screening ACS patients. In the level 2 hospital, cTnT is performed on the Cobas 6000 system (Roche Diagnostics) and reimbursed by insurance. Emergency room staff in this hospital rarely ordered cTnI (none in the past year) because it was not covered by insurance. A cardiologist was available to which the other hospitals could refer patients, but we found no POC coordinators.

Table 6 reports site-specific deployment of POCT in community health centers, district hospitals, and the provincial hospital. Prehospital diagnosis of AMI in ambulances could alleviate the problem of obligatory transport of patients through the government-defined chain of different hospitals levels, which causes adverse delays, but none was found. We did find glucose meters in use. Table 7 presents the POC tests emergency medical staff felt should be performed while transporting patients, in order to speed up treatment, along with their rationale for use.

Tables 8 and 9 focus on the challenges of providing rapid response for patients with chest pain, no matter where they are at the time. Table 8 reports responses to specific survey questions. For question 3.2 (see the Appendices, Supplemental Digital Content 1 [https://links.lww.com/POC/A16] and Supplemental Digital Content 2 [https://links.lww.com/POC/A17]), respondents stated that ambulances did not function to rescue patients directly from homes, in some cases because of a shortage of ambulance-type vehicles.

In severe cases, patients could go directly to levels 1 and 2 hospitals with financial support, but for less severe cases, tiered partial payments incentivize patients to engage levels 4 > 3 > 2 > 1. Recently, patients have been allowed to skip level 4 and go to level 3 without financial penalty, but only if within their province of residence. A patient deemed a less severe case is penalized when going directly to level 1 or 2, because in that instance, insurance payment will not cover the full hospital costs.

From a public health standpoint, Table 9 justifies additional funding and the implementation of POC resources for patients with ACS, stroke, and hypertension, which would also facilitate the care of patients who present to the emergency room as a result of motor vehicle accidents, which occur most commonly among the young and middle aged.

Table 10 reflects the community approaches to patients suspected of having an AMI. For example, survey results revealed that severity dictates where patients seek help, as noted previously. However, without reliable ambulance service, the pathway to rescue is chaotic, frustrating, and time consuming. Responding to question 5.5, AMI was identified as the most common condition requiring referral to the larger hospitals in Hue City. Indeed, respondents reported that often AMI was untreated or not treated rapidly enough. For question 3.35, respondents wanted improved transportation systems, ambulances equipped with diagnostic technologies, enhanced screening, and training in resuscitation and cardiopulmonary resuscitation.

DISCUSSION

Past Versus Present Survey Results

Comparison of documented trends starting 12 years ago¹ through 2016–2017 (Fig. 2) with current survey results reveals relatively modest progress in POC cardiac biomarker use throughout Vietnam. Vietnamese health care delivery systems would benefit from improved fundamental resources for the diagnosis, rapid transport, and treatment of critically ill patients, especially those presenting with ACS, in which case POC cTnI or cTnT could help rule in the diagnosis of AMI.

Role of POC Cardiac Biomarkers

Ruling out the diagnosis of AMI is limited by the low sensitivity of POC cTn assays. Therefore, temporal trends in cTn¹⁷ should be followed closely, and as necessary, high-risk patients transferred promptly. In rural areas, Minh¹⁸ recommended, “…evidence-based health interventions for reducing the burden of the cardiovascular disease epidemic in Vietnam….” Further, “Interventions should be comprehensive and integrated, including both primary and secondary approaches, as well as policy-level involvement.” In addition, biomarkers of heart failure, which are rising in importance in Asia, would facilitate differential diagnosis.^19,20

A recent Asia Pacific consensus statement²¹ endorsed cardiac biomarker testing broadly, including high-sensitivity (hs) cTn, and stated, “…where only POCT is available, patients with elevated readings should be considered at high risk, while patients with low/undetectable readings should be retested after 6 hours or sent for laboratory testing… and regular education on the appropriate use of troponin tests is essential.” Contributors included 2 cardiology units in Vietnam, the Department of Cardiology at University Medical Center in HCMC and the National Cardiology Institute in Hanoi.

The consensus authors²¹ failed to point out, however, that current POC cTn tests cannot be used to rule out AMI because of low sensitivity. They focused on cTnI, whereas the POC cTn used commonly throughout Southeast Asia is cTnT. They did not comment on how POC cTnT can be partnered with laboratory-based hs-cTnT. These shortcomings must be rectified by additional work toward agreed practice standards, including for hs-cTnT when it appears in the clinical laboratories of Vietnam.

Technological Progress

Improved cardiac biomarker assays, such as the 9-minute hs-cTnT assay,²² the first hs-cTn test introduced in the United States that meets the International Federation of Clinical Chemistry and Laboratory Medicine guidelines and precision requirements under the third universal definition of AMI,²³ should be implemented in Vietnamese hospital laboratories along with systematic approaches to rescuing rural patients with acute chest pain. Advances in assay speed enable faster therapeutic turnaround time, the time from ordering a test to treating the patient. Accelerated decision making fits one author's (G.J.K.) original vision 12 years ago²⁴ illustrated as a paradigm shift of progressively faster cardiac biomarkers assays driving consensus standards of cardiac care.

As respondents reported, critical care infrastructure in Central Vietnam needs strengthening by simultaneously implementing whole-blood analyzers—handheld, portable, or transportable formats—for patients arriving at smaller hospitals, especially multiplex whole-blood analyzers with test clusters that include free calcium (“ionized calcium,” Ca²⁺) needed when stabilizing critically ill cardiac patients. Eventually, hs-cTn tests will appear on POC devices²⁵ that allow both rule-in and rule-out of AMI, but for now POCT is best suited to ruling in the diagnosis when accompanied by characteristic history, symptoms, and signs, including ECG findings.

Value Proposition

The total costs for performing POCT, quality control, and proficiency testing must be weighed against benefits and alternatives by means of value propositions, as illustrated in Figure 4. Financial assistance can empower physicians and nurses in problem solving, local ownership, and sustainable enterprise. Current human resources and economic constraints, however, will not permit rapid improvement in Central Vietnam without substantial help from the central government, Ministry of Health, and foreign donors. In the United States, emergency rooms are experimenting with direct rapid physician evaluation in lieu of time-consuming triage,²⁶ and in this regard, POC multiplex testing can be pivotal to rapid and efficient diagnosis in Central Vietnam.

FIGURE 4: Risk reduction value proposition for rapid response and improved outcomes. This figure can be viewed online in color at www.poctjournal.com.

Spatial Care Paths

Transport services, equipment, boats, and vehicles in the SWN of Hue University Hospital should be improved substantially, and in particular, coordinated SCPs must be designed and implemented so that the time to diagnosis and treatment is less than 1 hour. Spatial Care Paths help define the most efficient routes in TTHP for rescuing, diagnosing, and treating AMI patients rapidly. Figures 5 and 6 illustrate practical frameworks for solving the problem of limited access and prolonged time to treatment in challenging areas.

FIGURE 5: Spatial Care Path design for mountainous regions in TTHP. This figure can be viewed online in color at www.poctjournal.com.

FIGURE 6: Sequence of AMI patient progress in the coastal region. A, Conventional multistep patient evaluation and serial referrals triage involves serial patient steps in the coastal region near Hue in Central Vietnam. First, the patient travels by motorcycle or taxi from home to the level 4 hospital, then subsequently via boat and taxi to the level 3 hospital. Next, if warranted following evaluation, the patient transfers from the level 3 hospital to level 1 or level 2 hospital via ambulance. The sequential referral process is time consuming. B, Accelerated SCP with prehospital POC cTn diagnosis to reduce the number of steps taken, we recommend an efficient SCP for the coastal region near Hue. Diagnosis by means of POC cTn testing near the home or POCT available on an ambulance, along with telehealth ECG and bidirectional radio communication by a cardiologist, would permit the confirmed patient to skip the sequential steps and be transported directly from home to interventional care in the level 1 or level 2 hospital. Therapeutic turnaround time could be optimized. This figure can be viewed online in color at www.poctjournal.com.

Point-of-care cTn placements in hospitals of different levels and on ambulances can be optimized based on SCP designs explored further by local nurses, physicians, and health care SWN administrators. Table 11 summarizes ambulance services, which need to refocus efforts away from taxi-like functions and instead rescue patients with chest pain, particularly in rural inaccessible areas. Survey respondents stated that most (80%–90%) patients were transported by motorcycle or transported themselves to hospitals, obviously high risk.

Logistics prove as important as test characteristics, such as sensitivity, specificity, and predictive value, when ensuring high quality of diagnostic evidence at points of need in limited-resource settings. In conjunction with designing SCPs for the entire province, we recommend performing further SWN analysis, based on the principles established for limited-resource countries and their rural settings.²⁷ In view of the high prevalence of cardiac disease in this province, rapid access to proven treatment via enhanced ambulance services combined with POC cTn testing will improve patient outcomes, cost-effectiveness, and equity of care for rural patients.

CONCLUSIONS

Needs Assessment

Based on demographic and geographic analyses of survey responses, resources for rapid diagnosis of AMI at points of care and in hospital laboratories performing cTn testing are lacking in Central Vietnam, similar to what appears to be the situation in the far north and far south (Fig. 2). All 3 regions have challenging topology subject to adverse weather encumbered by flooding and other natural disasters.

Lack of POC cardiac biomarker testing in the rural and mountainous areas of TTHP means that patient access and routing to swift interventional care for AMI are compromised even more so when transportation routes are blocked. Systems analysis provides strong indication for implementing POC cTn testing locally for diagnosis, triage, risk stratification, management, and prognosis of patients with suspected myocardial infarction.

International Exchange and Long-term Educational Impact

The 2-year education program was effective in highlighting the importance of cardiac biomarkers and their use at points of decision making. The second year saw direct interactive involvement of key opinion leaders and organizations, including the Center for Standardization & Quality Control in the Medical Laboratory in HCMC, the Vietnamese Association of Clinical Biochemists, and Hue University of Pharmacy and Medicine, where we held the 2017 International Symposium (Table 2). Participants learned how to use cTn assays to shorten visits to the emergency department, reduce the time to final diagnosis, manage non–ST-segment elevation myocardial infarction, and allow earlier safe discharge of low-risk subjects.²⁸

POC Coordinators

Everyone recognized the critical need for training, deployment, and funding of POC coordinators throughout Vietnam, in order to implement POCT, ensure its quality, achieve accreditation (eg, ISO 22870), and facilitate future Ministry of Health policy, guidelines, and funding.

We suggest forming POC coordinator groups, similar to those that arose spontaneously during the early stages of the POC paradigm shift in the United States. These groups now meet regularly in person and/or via the Web (eg, see Internet-based lecture and audio POC coordinator programs at Whitehat Communications [https://whitehatcom.com/]).

Economic Burden and Cost-effectiveness

According to a recent (2017) report by American authors,²⁹ “The HEART (History, ECG, Age, Risk factors, and initial Troponin) Pathway^29–34 can be successfully implemented in a community hospital setting and achieve a meaningful reduction in the rate of admissions to the hospital for patients presenting with chest pain. The use of a simple, clinically meaningful computerized decision support tool was essential for good compliance… use of the pathway was associated with minimal major adverse cardiac events.” Nguyen et al^35–37 stated, “The cost of AMI per hospitalization in Vietnam is higher than GDP per capita… AMI prevention is needed to reduce the burden of disease as well as to avoid catastrophic expenditure and impoverishment problems in Vietnam,” especially among women, who “…experience higher case fatality rates than men.”

Protocol-Based Practice

Current literature offers an international perspective of POC practice. Studies in the United States have demonstrated increasing use of cTnI/T and the 99th percentile threshold for the diagnosis of AMI.³⁸ Others showed the practical utility of POC cTn for patients presenting to the emergency department.^39,40 Japanese authors recently assessed the usefulness of POC cTn in the emergency department.⁴¹ A POC study conducted in an emergency department in Taiwan demonstrated the advantages of using multiple cardiac biomarkers to improve diagnosis of elderly and female patients,⁴² challenging groups for diagnosis, who would benefit in Vietnam.

Therefore, if validated for specific settings in Vietnam, algorithmic protocols, such as the HEART Pathway, with adaptations to merge POC decision making, will prove cost-effective for AMI patients and justify countrywide implementation of hs-cTn in clinical laboratories in partnership with POC cTn in emergency rooms in Vietnam. However, a definitive consensus protocol, with consideration of community settings²⁹ and the potentially adverse impact of low-level cTn cutoffs on resource utilization,⁴³ needs to be established specifically for Vietnam.

Health Care Resources

Health technology advisors recommend POC troponin testing for patients presenting with symptoms of ACS in settings with no immediate access to central laboratory testing.^44–46 Appropriate use of POC assays will prove valuable during any central government redistribution of health care resources and in fact can become one of the primary modalities used to address acute care needs.

Cardiac biomarker testing in smaller hospitals (eg, levels 3 and 4) will serve larger numbers of patients consistent with demography and geography. Point-of-care cTn testing will fill service gaps in mountainous and coastal topographies, while facilitating more equitable cardiac care for diverse rural populations in Vietnam. Elderly ACS patients burdened with higher prevalence of risk factors, such as hypertension and diabetes mellitus,⁴⁷ stand to benefit significantly.

Geographic Optimization

The analysis of travel times, ambulance routes, and telecommunication systems, ideally performed by means of POC geographic information system approaches,^11,12 will reveal optimal sites for the placement of POC cardiac biomarker testing in emergency rooms with simultaneous consideration of routing of patients from homes and primary care sites to definitive intervention for coronary occlusion.

The coastal district represents a unique challenge for topographic analysis and SCP optimization. For example, a time-consuming leg of patient transport typically is by boat (Fig. 6). Helicopter transport would solve the problem. However, that resource generally is not available, so careful placement of POC cTn testing can be used to dynamically diagnosis AMI, that is, follow trends in cTn over the course of the prolonged transport and appropriately redirect to immediate intervention.

Province cardiologists should consider using prehospital diagnosis with POC cTn testing onboard ambulances in conjunction with telemetry of ECG and bidirectional telecommunication with cardiologists at referral sites.^48,49 When relatively stable, patients could bypass intermediate levels 4 and 3 hospitals and be routed directly to levels 1 and 2 sites, where interventional cardiologists and adequate facilities, equipment, and medicinal supplies might be available.

Upstream SCP

Point-of-care testing embedded upstream closer to homes and sites of primary care and as mobile testing in ambulances allows SCPs to shift timely diagnosis and accelerate critical decision making for patients presenting with chest pain. The same principles apply to highly infectious diseases^50–52 and other emergencies at points of need. In conjunction with POC coordinator guidance and oversight, this paradigm shift in accessibility to diagnosis and faster therapeutic response to acute medical challenges improves preparedness, sustainability, and resilience in the community.

Value of Physician Training

In limited-resource settings throughout Asia, we have encountered nurses who demand POC cTn testing to enhance decision making by young physicians assigned to remote emergency rooms and small hospitals, usually for 2 years of payback for government support of their medical education.

Point-of-care cTn provides crucial training, because these young graduates, typically working late hours by themselves, can use actual diagnostic evidence to practice their medical art, rather than guessing what is wrong with patients or placing patients in emergency room holding areas while waiting, too late, for a fatal condition to fully manifest.

Heretofore, the high value of POC cardiac biomarker testing for postgraduate education in remote limited-resource settings has been totally absent from studies of POCT cost-effectiveness. Physician training, per se, represents a critical role for POCT, an indispensible value hidden in plain sight.

FUTURE VISION

POC Culture

The international symposium in Vietnam provided a change agent for POC practice. Now engaged, professional attendees likely will initiate the type of cultural transformation seen in other Southeast Asian nations, such as Thailand. Following initial demonstration projects and symposia,²⁷ POC cTnT was implemented in more than 500 Thai sites using 700 POC devices.

This innovation accelerated evidence-based diagnosis and therapeutic intervention for patients with AMI nationwide. Investigators in Vietnam can improve access, integrate algorithms, decrease overall costs, enhance education, and improve equity of care, especially in rural areas where geographic information systems analysis would prove highly beneficial for consistent deployment of resources.

Systems Logic

The Venn diagram (Fig. 7) captures the logic of future rapid chest pain evaluation by combining the upstream shift in POCT with state-of-the-art cTn assays integrated algorithmically (eg, using the HEART Pathway) to improve medical and economic outcomes in health care SWNs. With future technological progress (eg, see Florescu et al²⁵ and Sarangadharan et al⁵³), hs-cTn eventually will become available on handheld digital POC platforms.

FIGURE 7: Future logic synthesis for rapid intervention for acute chest pain. This figure can be viewed online in color at www.poctjournal.com.

The apparent discontinuity of the clinical laboratory (bottom left) versus points of need (bottom right) in Figure 7 will merge, advancing standards of care holistically throughout limited-resource communities. At the same time, mathematical models and geographic information systems can facilitate ambulance transport within the neglected areas of regional SWNs.⁵⁴

National POCT Policy and Guidelines

We recommend that Vietnam establish national policy and guidelines, not only for the use and deployment of cardiac biomarkers, but also for POCT in general. Near neighbors, first Malaysia in 2012⁵⁵ and then Thailand in 2015,⁵⁶ were successful in implementing suitable policy and guidelines (Figs. 8A, B).

FIGURE 8: National POCT policy and guidelines documents. A, Malaysia, 2012. B, Thailand, 2015. This figure can be viewed online in color at www.poctjournal.com.

One author (G.J.K.) has presented articles and been invited to speak in other countries, such as China, the Philippines, Singapore, South Africa, and Taiwan, to advance national guideline initiatives. Vietnamese government guidelines will provide a solid platform for funding, help harmonize POCT, facilitate collaboration, improve cooperation, and advance the standard of care for ACS patients.

Standards of Care

Policy should address regional cooperation among leading hospitals for cardiovascular care (eg, Ha Noi Heart Hospital, Cho Ray in HCMC, and Hue Central Hospital), satellite hospitals, and referral sites with linkages from home to intervention established through the design of efficient SCPs. Survey tools borrowed from the United States, for example, recently proposed by Hoa et al,⁵⁷ are not adapted for the geography, topography, or settings of limited-resource countries. Adding needs assessment of POC and key test clusters to such survey tools will advance standards of primary care, responsiveness for patients who present with chest pain, and critical care support in Central Vietnam.

ASEAN Leadership

Forming a “critical mass” of countries in Southeast Asia with harmonized POCT policy and guidelines⁵⁸ and avenues for bioinnovation⁵⁹ would help codify the practice of POC cardiac biomarker testing, as well as creative use of POC technologies throughout ASEAN member states, leading to broad assimilation of POC culture.

Resulting direct evidence-based diagnosis will transform the care of patients with AMI, infectious diseases, and other urgent medical problems. Analogous to cTn-initiated improvements in the differential diagnosis of ACS patients historically, POC cTn in Central Vietnam will improve geographic accessibility, fill point-of-service gaps, and propel the quality of equitable care to higher regional standards with added community resilience.⁶⁰