Absence of chest pain and long-term mortality in patients with acute myocardial infarction

Association Between Acute Myocardial Infarction Symptoms and Short- and Long-term Mortality After the Event

BACKGROUND

In this study, we investigated various acute myocardial infarction (AMI) symptoms and their associations with short-term (28 day) and long-term mortality.

METHODS

The analysis was based on 5900 patients, aged 25 to 84 years, with first-time AMI recorded by the population-based Myocardial Infarction Registry Augsburg between 2010 and 2017. Median follow-up time was 3.8 years (interquartile range: 1.1-6.3). As part of a face-to-face interview, the presence (yes/no) of 11 most common AMI symptoms at the acute event was assessed. Using multivariable-adjusted logistic regression and Cox regression models, the association between various symptoms and all-cause mortality was investigated. P values of the regression models were false discovery rate adjusted.

RESULTS

Pain in various body parts (chest pain, left and right shoulder/arm/hand, between shoulder blades), sweating, nausea/vomiting, dizziness and fear of death/feeling of annihilation were significantly associated with a decreased 28-day mortality after AMI. The pain symptoms and sweating were also significantly associated with a decreased long-term mortality. Shortness of breath was significantly associated with a higher long-term mortality.

CONCLUSIONS

The absence of several symptoms, including typical chest discomfort (chest pain or retrosternal pressure/tightness), is associated with unfavourable outcomes after AMI. This finding has implications for patient management and public health measures designed to encourage appropriate and prompt medical consultation of patients with atypical AMI symptoms.

Symptomology, Outcomes and Risk Factors of Acute Coronary Syndrome Presentations without Cardiac Chest Pain: A Scoping Review

For patients experiencing acute coronary syndrome, early symptom recognition is paramount; this is challenging without chest pain presentation. The aims of this scoping review were to collate definitions, proportions, symptoms, risk factors and outcomes for presentations without cardiac chest pain. Full-text peer reviewed articles covering acute coronary syndrome symptoms without cardiac chest pain were included. MEDLINE, CINAHL, Scopus and Embase were systematically searched from 2000 to April 2023 with adult and English limiters; 41 articles were selected from 2,954. Dyspnoea was the most reported (n=39) and most prevalent symptom (11.6-72%). Neurological symptoms, fatigue/weakness, nausea/ vomiting, atypical chest pain and diaphoresis were also common. Advancing age appeared independently associated with presentations without cardiac chest pain; however, findings were mixed regarding other risk factors (sex and diabetes). Patients without cardiac chest pain had worse outcomes: increased mortality, morbidity, greater prehospital and intervention delays and suboptimal use of guideline driven care. There is a need for structured data collection, analysis and interpretation.

The relationship between coronary artery calcium and layer-specific global longitudinal strain in patients with suspected coronary artery disease

PURPOSE

Layer-specific global longitudinal strain (GLS) may provide important insights in patients with suspected coronary artery disease (CAD). We aimed to investigate the association between layer-specific GLS and coronary artery calcium score (CACS) in patients suspected of CAD.

METHODS

We performed a retrospective study of patients suspected of CAD who underwent both an echocardiogram and cardiac computed tomography (median 42 days between). Layer-specific (endocardial-, whole-layer-, and epicardial-) GLS was measured using speckle tracking echocardiography. We assessed the continuous association between layer-specific GLS and CACS by negative binomial regression, and the association with high CACS (≥400) using logistic regression.

RESULTS

Of the 496 patients included (mean age 59 years, 56% male), 64 (13%) had a high CACS. Those with high CACS had reduced GLS in all layers compared to those with CACS < 400 (endocardial GLS: -20.5 vs. -22.7%, whole-layer GLS: -17.7 vs. -19.4%, epicardial GLS: -15.3 vs. -16.9%, p < .001 for all). Negative binomial regression revealed a significant continuous association showing increasing CACS with worsening GLS in all layers, which remained significant after multivariable adjustment including SCORE chart risk factors. All layers of GLS were associated with high CACS in univariable analyses, which was consistent after multivariable adjustment (endocardial GLS: OR = 1.11 (1.03-1.20); whole-layer GLS: OR = 1.14 (1.04-1.24); epicardial GLS: OR = 1.16 (1.05-1.29), per 1% absolute decrease).

CONCLUSION

In this study population with patients suspected of CAD and normal systolic function, impaired layer-specific GLS was continuously associated with increasing CACS, and decreasing GLS in all layers were associated with presence of high CACS.

Chest pain symptoms during myocardial infarction in patients with and without diabetes: a systematic review and meta-analysis

OBJECTIVE

Chest pain (CP) is key in diagnosing myocardial infarction (MI). Patients with diabetes mellitus (DM) are at increased risk of an MI but may experience less CP, leading to delayed treatment and worse outcomes. We compared the prevalence of CP in those with and without DM who had an MI.

METHODS

The study population was people with MI presenting to healthcare services. The outcome measure was the absence of CP during MI, comparing those with and without DM. Medline and Embase databases were searched to 18 October 2021, identifying 9272 records. After initial independent screening, 87 reports were assessed for eligibility against the inclusion criteria, quality and risk of bias assessment (Strengthening the Reporting of Observational Studies in Epidemiology and Newcastle-Ottawa criteria), leaving 22 studies. The meta-analysis followed Meta-analysis Of Observational Studies in Epidemiology criteria and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled ORs, weights and 95% CIs were calculated using a random-effects model.

RESULTS

This meta-analysis included 232 519 participants from 22 studies and showed an increased likelihood of no CP during an MI for those with DM, compared with those without. This was 43% higher in patients with DM in the cohort and cross-sectional studies (OR: 1.43; 95% CI: 1.26 to 1.62), and 44% higher in case-control studies (OR: 1.44; 95% CI: 1.11 to 1.87).

CONCLUSION

In patients with an MI, patients with DM are less likely than those without to have presentations with CP recorded. Clinicians should consider an MI diagnosis when patients with DM present with atypical symptoms and treatment protocols should reflect this, alongside an increased patient awareness on this issue.

PROSPERO REGISTRATION NUMBER

CRD42017058223.

Hypothetical interventions on emergency ambulance and prehospital acetylsalicylic acid administration in myocardial infarction patients presenting without chest pain

BACKGROUND

Myocardial infarction (MI) patients presenting without chest pain are a diagnostic challenge. They receive suboptimal prehospital management and have high mortality. To elucidate potential benefits of improved management, we analysed expected outcome among non-chest pain MI patients if hypothetically they (1) received emergency ambulances/acetylsalicylic acid (ASA) as often as observed for chest pain patients, and (2) all received emergency ambulance/ASA.

METHODS

We sampled calls to emergency and non-emergency medical services for patients hospitalized with MI within 24 h and categorized calls as chest pain/non-chest pain. Outcomes were 30-day mortality and a 1-year combined outcome of re-infarction, heart failure admission, and mortality. Targeted minimum loss-based estimation was used for all statistical analyses.

RESULTS

Among 5418 calls regarding MI patients, 24% (1309) were recorded with non-chest pain. In total, 90% (3689/4109) of chest pain and 40% (525/1309) of non-chest pain patients received an emergency ambulance, and 73% (2668/3632) and 37% (192/518) of chest pain and non-chest pain patients received prehospital ASA. Providing ambulances to all non-chest pain patients was not associated with improved survival. Prehospital administration of ASA to all emergency ambulance transports of non-chest pain MI patients was expected to reduce 30-day mortality by 5.3% (CI 95%: [1.7%;9%]) from 12.8% to 7.4%. No significant reduction was found for the 1-year combined outcome (2.6% CI 95% [- 2.9%;8.1%]). In comparison, the observed 30-day mortality was 3% among ambulance-transported chest pain MI patients.

CONCLUSIONS

Our study found large differences in the prehospital management of MI patients with and without chest pain. Improved prehospital ASA administration to non-chest pain MI patients could possibly reduce 30-day mortality, but long-term effects appear limited. Non-chest pain MI patients are difficult to identify prehospital and possible unintended effects of ASA might outweigh the potential benefits of improving the prehospital management. Future research should investigate ways to improve the prehospital recognition of MI in the absence of chest pain.

Does a Code for Acute Myocardial Infarction Mean the Same in All Norwegian Hospitals? A Likelihood Approach to a Medical Record Review

Objective

Health registries are important data sources for epidemiology, quality monitoring, and improvement. Acute myocardial infarction (AMI) is a common, serious condition. Little is known about variation in the positive predictive value (PPV) of a coded AMI diagnosis and its association with hospital quality indicators. The present study aimed to investigate the relationship between PPV and registry-based 30-day mortality after AMI admission and between-hospital variation in PPV.

Study Design and Setting

An electronic record review was performed in a nationwide sample of Norwegian hospitals. Clinical signs and cardiac troponin measurements were abstracted and analyzed using a mixture model for likelihood ratios and parametric bootstrapping.

Results

The overall PPV was estimated to be 97%. We found no statistically significant association between hospital PPV and the classification of hospitals into low, intermediate, and high registry-based 30-day mortality. There was significant variation between hospitals, with a PPV range of 91–100%.

Conclusion

We found no evidence that variation in PPV of AMI diagnosis can explain variation between hospitals in registry-based 30-day mortality after admission. However, PPV varied significantly between hospitals. We were able to use a very efficient statistical approach to the analysis and handling of various sources of uncertainty.

Comparisons of Prehospital Delay and Related Factors Between Acute Ischemic Stroke and Acute Myocardial Infarction

Background

Prehospital delay is an important contributor to poor outcomes in both acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We aimed to compare the prehospital delay and related factors between AIS and AMI.

Methods and Results

We identified patients with AIS and AMI who were admitted to the 11 Korean Regional Cardiocerebrovascular Centers via the emergency room between July 2016 and December 2018. Delayed arrival was defined as a prehospital delay of >3 hours, and the generalized linear mixed‐effects model was applied to explore the effects of potential predictors on delayed arrival. This study included 17 895 and 8322 patients with AIS and AMI, respectively. The median value of prehospital delay was 6.05 hours in AIS and 3.00 hours in AMI. The use of emergency medical services was the key determinant of delayed arrival in both groups. Previous history, 1‐person household, weekday presentation, and interhospital transfer had higher odds of delayed arrival in both groups. Age and sex had no or minimal effects on delayed arrival in AIS; however, age and female sex were associated with higher odds of delayed arrival in AMI. More severe symptoms had lower odds of delayed arrival in AIS, whereas no significant effect was observed in AMI. Off‐hour presentation had higher and prehospital awareness had lower odds of delayed arrival; however, the magnitude of their effects differed quantitatively between AIS and AMI.

Conclusions

The effects of some nonmodifiable and modifiable factors on prehospital delay differed between AIS and AMI. A differentiated strategy might be required to reduce prehospital delay.

Clinical Profile of Acute Coronary Syndrome Presentation to the Ladysmith Provincial Hospital: High Prevalence Among the Minority Indian Population

Background

Cardiovascular diseases were responsible for 17% of the 460236 natural deaths in South Africa in 2015. Previous studies have reported a disproportionately higher incidence of ischemic heart disease (IHD) and its risk factors among individuals of Indian descent residing in South Africa. The aim of this study was to explore the clinical profile of patients presenting with a diagnosis of acute coronary syndrome (ACS) and to compare the characteristics of patients of Indian descent to those of non-Indian descent.

Methods

Retrospective data were derived from the medical charts of 160 consecutive patients presenting to the Ladysmith Provincial Hospital over a 44-month period with a diagnosis of ACS. Findings were described and compared.

Results

The mean (SD) age of study patients was 55.8 (±12.8) years. The majority of subjects were male (n=90, 56.3%) and unemployed (n=98, 62.3%). The racial distribution of the study sample comprised 103 (64.4%) Indian, 36 (22.5%) Black, and 21 (13.1%) White subjects. Compared to non-Indian subjects, a significantly higher proportion (p<0.05) of Indian subjects were male (64.7% vs 41.4%), cigarette smokers (52.0% vs 32.8%), had a previous history of ACS (37.3% vs 10.3%), were diabetic (33.3% vs 17.2%), and were hypertensive (58.8% vs 29.3%).

Conclusion

The disproportionately high frequency of ACS among the minority Indian population of Ladysmith is concerning. There is a need for rigorous public health interventions to create local awareness, encourage lifestyle modification, and thereby improve control of cardiovascular risk factors, especially among high-risk population groups.

Misdiagnosis of Acute Myocardial Infarction: A Systematic Review of the Literature

BACKGROUND

Despite the availability of tests to diagnose acute myocardial infarction (AMI), cases are still missed.

METHODS

We systematically reviewed the literature to determine how missed AMI has been defined, the reported rates of misdiagnosed AMI, the outcomes patients with misdiagnosed AMI have, what diagnosis was initially suspected in missed AMI cases, and what factors are associated with misdiagnosed AMI. We searched MEDLINE and EMBASE in September 2020 for studies that evaluated missed AMI. Data were extracted from studies that met the inclusion criteria and the results were narratively synthesized.

RESULTS

A total of 15 studies were included in this review. The number of patients with missed AMI in individual studies ranged from 64 to 4707. There was no consistently used definition for misdiagnosed AMI, but most studies reported rates of approximately 1%-2%. Compared with AMI that was recognized, 1 study found no difference in mortality for misdiagnosed AMI at 30 days and 1 year. The common initial misdiagnoses that subsequently had AMI were ischemic heart disease, nonspecific chest pain, gastrointestinal disease, musculoskeletal pain, and arrhythmias. Reasons for missed AMI include incorrect electrocardiogram interpretation and failure to order appropriate diagnostic tests. Hospitals in rural areas and those with a low proportion of classical chest pain patients that turned out to have AMI were at greater risk of missed AMI.

CONCLUSIONS

Misdiagnosed AMI is an unfortunate part of everyday clinical practice and better training in electrocardiogram interpretation, and education about atypical presentations of AMI may reduce the number of misdiagnosed AMIs.

Missed acute myocardial infarction: an underrecognized problem that contributes to poor patient outcomes

Ischemic heart disease is the number one killer in the world. While improvements in the management of acute myocardial infarction (AMI) have resulted in lower mortality rates, there are still cases where AMI is missed with rates varying depending on the setting where the evaluation took place, the population sample, the definition of missed AMI and timing of evaluation. There is consistent evidence that missed AMI is associated with increased risk of complications and mortality. Many factors contribute to missed AMI which include patient factors, clinician factors and institutional factors. While several studies have been conducted to evaluate missed AMI, there is considerable heterogeneity in methodology, which has resulted in variable rates of missed AMI and the factors associated with missed AMI. In this review, we provide an overview on missed AMI discussing rates reported in the literature, why it is important, reasons why it occurs, some of the challenges in evaluating missed AMI and what could potentially be done to reduce these undesirable outcomes for patients.

Impact of myocardial infarction symptom presentation on emergency response and survival

AIMS

We examined associations between symptom presentation and chance of receiving an emergency dispatch and 30-day mortality among patients with acute myocardial infarction (MI).

METHODS AND RESULTS

Copenhagen, Denmark has a 24-h non-emergency medical helpline and an emergency number 1-1-2 (equivalent to 9-1-1). Both services register symptoms/purpose of calls. Among patients with MI as either hospital diagnosis or cause of death within 72 h after a call, the primary symptom was categorized as chest pain, atypical symptoms (breathing problems, unclear problem, central nervous system symptoms, abdominal/back/urinary, other cardiac symptoms, and other atypical symptoms), unconsciousness, non-informative symptoms, and no recorded symptoms. We identified 4880 emergency and 3456 non-emergency calls from patients with MI. The most common symptom was chest pain (N = 5219) followed by breathing problems (N = 556). Among patients with chest pain, 95% (3337/3508) of emergency calls and 76% (1306/1711) of non-emergency calls received emergency dispatch. Mortality was 5% (163/3508) and 3% (49/1711) for emergency/non-emergency calls, respectively. For atypical symptoms 62% (554/900) and 17% (137/813) of emergency/non-emergency calls received emergency dispatch and mortality was 23% (206/900) and 15% (125/813). Among unconscious, patients 99%/100% received emergency dispatch and mortality was 71%/75% for emergency/non-emergency calls. Standardized 30-day mortality was 4.3% for chest pain and 15.6% for atypical symptoms, and associations between symptoms and emergency dispatch remained in subgroups of age and sex.

CONCLUSION

Myocardial infarction patients presenting with atypical symptoms when calling for help have a reduced chance of receiving an emergency dispatch and increased 30-day mortality compared to MI patients with chest pain.

A modified cardiac triage strategy reduces door to ECG time in patients with ST elevation myocardial infarction

Timely performing electrocardiography (ECG) is crucial for early detection of ST-elevation myocardial infarction (STEMI). For shortening door-to-ECG time, a chief complaint-based “cardiac triage” protocol comprising (1) raising alert among medical staff with bedside triage tags, and (2) immediate bedside ECG after focused history-taking was implemented at the emergency department (ED) in a single tertiary referral center. All patients diagnosed with STEMI visiting the ED between November 2017 and January 2020 were retrospectively reviewed to investigate the effectiveness of strategy before and after implantation. Analysis of a total of 117 ED patients with STEMI (pre-intervention group, n = 57; post-intervention group, n = 60) showed significant overall improvements in median door-to-ECG time from 5 to 4 min (p = 0.02), achievement rate of door-to-ECG time < 10 min from 45 to 57% (p = 0.01), median door-to-balloon time from 81 to 70 min (p < 0.01). Significant trends of increase in achievement rates for door-to-ECG and door-to-balloon times (p = 0.032 and p = 0.002, respectively) was noted after strategy implementation. The incidences of door-to-ECG time > 10 min for those with initially underestimated disease severity (from 90 to 10%, p < 0.01) and walk-in (from 29.2 to 8.8%, p = 0.04) were both reduced. In conclusion, a chief complaint-based “cardiac triage” strategy successfully improved the quality of emergency care for STEMI patients through reducing delays in diagnosis and treatment.

Age Differences in the Chief Complaint Associated With a First Acute Myocardial Infarction and Patient's Care-Seeking Behavior

BACKGROUND

This study set out to describe age differences in patient's chief complaint related to a first myocardial infarction and how the "typicality" of patient's acute symptoms relates to extent of prehospital delay.

METHODS

The medical records of 2586 residents of central Massachusetts hospitalized at 11 greater Worcester medical centers with a first myocardial infarction on a biennial basis between 2001 and 2011 were reviewed.

RESULTS

The average age of the study population was 66.4 years, 39.6% were women, 40.2% were diagnosed with a ST-elevation myocardial infarction (STEMI), and 72.0 % presented with typical symptoms of myocardial infarction, namely acute chest pain or pressure. Patients were categorized into 5 age strata: >55 years (23%), 55-64 years (20%), 65-74 years (19%), 75-84 years (22%), and ≥85 years (16%). The lowest proportion (11%) of atypical symptoms of myocardial infarction was observed in patients <55 years, increasing to 17%, 28%, 40%, and 51% across the respective age groups. The most prevalent chief complaint reported at the time of hospitalization was chest pain, but the proportion of patients reporting this symptom decreased from the youngest (83%) to the oldest patient groups (45%). There was a slightly increased risk of prehospital delay across the different age groups (higher in the oldest old) in those who presented with atypical, rather than typical, symptoms of myocardial infarction.

CONCLUSIONS

The present results provide insights to the presenting chief complaint of patients hospitalized with a first myocardial infarction according to age and the relation of symptom presentation to patient's care-seeking behavior.

Mortality at 5 Years Among Very Elderly Patients Undergoing High Sensitivity Troponin T Testing for Suspected Acute Coronary Syndromes

BACKGROUND

Patients aged ≥80 years old often present to Emergency Departments (ED) with symptoms potentially due to an acute coronary syndrome (ACS). This study aimed to evaluate associations between baseline level(s) of high sensitivity troponin T (HsTnT), adjudicated diagnoses and outcomes.

METHODS

Consecutive patients aged ≥80 years were studied, who presented to the ED at Liverpool Hospital, NSW, Australia during the 4 months period March to June 2014 (inclusive) with symptoms suggestive of an ACS, and who had at least one HsTnT assay performed. Diagnoses were based on the fourth universal definition of MI (myocardial infarction) including type-1 MI, type-2 MI, acute myocardial injury, chronic myocardial injury; the rest were termed "other diagnoses". Patients were categorised by baseline HsTnT levels 1) ≤14 ng/L, 2) 15-29 ng/L, 3) 30-49 ng/L and 4) ≥50 ng/L.

RESULTS

Of 2,773 patients screened, 545 were aged ≥80 years (median age 85 [IQR 82-88]); median follow-up was 32 months (IQR 5-56). The respective rates of adjudicated diagnoses were type-I MI 3.1%, type-2 MI 13%, acute myocardial injury 9.5%, chronic myocardial injury 56% and 18.6% had other diagnoses. Mortality rates increased, irrespective of adjudicated diagnoses with increasing HsTnT levels (ng/L): 17% (16/96) for ≤14; 35% (67/194) for 15-29; 51% (65/127) for 30-49; and 64% (82/128) for ≥50 ng/L; log rank p≤0.001. On multi-variable analyses, after adjusting for potential confounding factors including age, hypertension, chronic kidney disease (CKD) and chronic obstructive pulmonary disease (COPD), MI type was not associated with late mortality.

CONCLUSIONS

Among patients aged ≥80 years higher HsTnT levels, irrespective of adjudicated diagnoses, were associated with increased mortality. Most very elderly patients presenting with symptoms suggestive of an ACS undergoing HsTnT testing in EDs had elevated levels most commonly due to chronic myocardial injury. Whether any interventions can modify outcomes require prospective evaluation.

Angiographic characteristics and in-hospital mortality among patients with ST-segment elevation myocardial infarction presenting without typical chest pain: an analysis of China Acute Myocardial Infarction registry

Background:

Patients with ST-segment elevation myocardial infarction (STEMI) who present without typical chest pain are associated with a poor outcome. However, whether angiographic characteristics are related to a higher risk of mortality in this population is unclear. This study aimed to investigate whether the higher mortality risk in patients with STEMI without chest pain could be explained by their “high-risk” angiographic characteristics.

Methods:

We used data of 12,145 patients with STEMI who was registered in China Acute Myocardial Infarction registry from January 2013 to September 2014. We compared the infarct-related artery (IRA), thrombolysis in myocardial infarction (TIMI) flow grade in the IRA, and other angiographic characteristics between patients without and those with chest pain. Multivariable logistic regression model was used to identify independent risk factor of in-hospital mortality.

Results:

The 2922 (24.1%) patients with STEMI presented without typical chest pain. These patients had a higher TIMI flow grade (mean TIMI flow grade: 1.00 vs. 0.94, P = 0.02) and a lower rate of IRA disease of the left anterior descending artery (44.6% vs. 51.2%, χ² = 35.63, P < 0.01) than did those with typical chest pain. Patients without chest pain were older, more likely to have diabetes, longer time to hospital and higher Killip classification, and less likely to receive optimal medication treatment and primary percutaneous coronary intervention and higher In-hospital mortality (3.3% vs. 2.2%, χ² = 10.57, P < 0.01). After adjusting for multi-variables, presentation without chest pain was still an independent predictor of in-hospital death among patients with STEMI (adjusted odds ratio: 1.36, 95% confidence interval: 1.02–1.83).

Conclusions:

Presentation without chest pain is common and associated with a higher in-hospital mortality risk in patients with acute myocardial infarction. Our results indicate that their poor prognosis is associated with baseline patient characteristics and delayed treatment, but not angiographic lesion characteristics.

Clinical trial registration:

NCT01874691, https://clinicaltrials.gov.

Clinical Impact of Atypical Chest Pain and Diabetes Mellitus in Patients with Acute Myocardial Infarction from Prospective KAMIR-NIH Registry

Atypical chest pain and diabetic autonomic neuropathy attract less clinical attention, leading to underdiagnosis and delayed treatment. To evaluate the long-term clinical impact of atypical chest pain and diabetes mellitus (DM), we categorized 11,159 patients with acute myocardial infarction (AMI) from the Korea AMI-National Institutes of Health between November 2011 and December 2015 into four groups (atypical DM, atypical non-DM, typical DM, and typical non-DM). The primary endpoint was defined as patient-oriented composite endpoint (POCE) at 2 years including all-cause death, any myocardial infarction (MI), and any revascularization. Patients with atypical chest pain showed higher 2-year mortality than those with typical chest pain in both DM (29.5% vs. 11.4%, p < 0.0001) and non-DM (20.4% vs. 6.3%, p < 0.0001) groups. The atypical DM group had the highest risks of POCE (hazard ratio (HR) 1.76, 95% confidence interval (CI) 1.48-2.10), all-cause death (HR 2.23, 95% CI 1.80-2.76) and any MI (HR 2.34, 95% CI 1.51-3.64) in the adjusted model. In conclusion, atypical chest pain was significantly associated with mortality in patients with AMI. Among four groups, the atypical DM group showed the worst clinical outcomes at 2 years. Application of rapid rule in/out AMI protocols would be beneficial to improve clinical outcomes.

Evaluation of Molecularly Imprinted Polymers for Point-of-Care Testing for Cardiovascular Disease

Molecular imprinting is a rapidly growing area of interest involving the synthesis of artificial recognition elements that enable the separation of analyte from a sample matrix and its determination. Traditionally, this approach can be successfully applied to small analyte (<1.5 kDa) separation/ extraction, but, more recently it is finding utility in biomimetic sensors. These sensors consist of a recognition element and a transducer similar to their biosensor counterparts, however, the fundamental distinction is that biomimetic sensors employ an artificial recognition element. Molecularly imprinted polymers (MIPs) employed as the recognition elements in biomimetic sensors contain binding sites complementary in shape and functionality to their target analyte. Despite the growing interest in molecularly imprinting techniques, the commercial adoption of this technology is yet to be widely realised for blood sample analysis. This review aims to assess the applicability of this technology for the point-of-care testing (POCT) of cardiovascular disease-related biomarkers. More specifically, molecular imprinting is critically evaluated with respect to the detection of cardiac biomarkers indicative of acute coronary syndrome (ACS), such as the cardiac troponins (cTns). The challenges associated with the synthesis of MIPs for protein detection are outlined, in addition to enhancement techniques that ultimately improve the analytical performance of biomimetic sensors. The mechanism of detection employed to convert the analyte concentration into a measurable signal in biomimetic sensors will be discussed. Furthermore, the analytical performance of these sensors will be compared with biosensors and their potential implementation within clinical settings will be considered. In addition, the most suitable application of these sensors for cardiovascular assessment will be presented.