Detection of chest pain of non-cardiac origin at the emergency room by a new non-invasive device avoiding unnecessary admission to hospital

Improved prehospital triage for acute cardiac care: results from HART-c, a multicentre prospective study

BACKGROUND

Cardiac symptoms are one of the most prevalent reasons for emergency department visits. However, over 80% of patients with such symptoms are sent home after acute cardiovascular disease has been ruled out.

OBJECTIVE

The Hollands-Midden Acute Regional Triage-cardiology (HART-c) study aimed to investigate whether a novel prehospital triage method, combining prehospital and hospital data with expert consultation, could increase the number of patients who could safely stay at home after emergency medical service (EMS) consultation.

METHODS

The triage method combined prehospital EMS data, such as electrocardiographic and vital parameters in real time, and data from regional hospitals (including previous medical records and admission capacity) with expert consultation. During the 6‑month intervention and control periods 1536 and 1376 patients, respectively, were consulted by the EMS. The primary endpoint was the percentage change of patients who could stay at home after EMS consultation.

RESULTS

The novel triage method led to a significant increase in patients who could safely stay at home, 11.8% in the intervention group versus 5.9% in the control group: odds ratio 2.31 (95% confidence interval (CI) 1.74-3.05). Of 181 patients staying at home, only 1 (< 1%) was later diagnosed with ACS; no patients died. Furthermore the number of interhospital transfers decreased: relative risk 0.81 (95% CI 0.67-0.97).

CONCLUSION

The HART‑c triage method led to a significant decrease in interhospital transfers and an increase in patients with cardiac symptoms who could safely stay at home. The presented method thereby reduced overcrowding and, if implemented throughout the country and for other medical specialties, could potentially reduce the number of cardiac and non-cardiac hospital visits even further.

H-FABP as a diagnostic marker for early detection of young myocardial infarction among Indians

It is of interest to document the point-of-care test using heart-type fatty-acid binding protein (H-FABP) in comparison with CK-MB, Troponin T and hsCRP. This is a more sensitive and specific cardiac biomarker than cTnT and CK-MB, and it has a higher diagnostic effectiveness for detecting early acute myocardial infarction (AMI). The case-control study enrolled 220 participants (110 myocardial infarction patients as cases and 110 healthy subjects as control) > 18 years of either sex after ethical clearance and informed consent form. The study conducted was conducted in the OPD and IPD of Medicine and Biochemistry Department at Moti Lal Nehru Medical College and Swaroop Rani Nehru Hospital Prayagraj, Uttar Pradesh; Index Medical College & Hospital, Malwanchal University, India. The amount of H-FABP, CKMB and cTnT was measured using the Sandwich ELISA method and hs-CRP was evaluated using the immune-turbidimetry method. H-FABP correlation with selected markers (CK-MB, hs CRP and TnT) and CK-MB was significant. A positive correlation (r=0.2 to 0.29) was found when H-FABP was compared with CK-MB (p<0.05). Similar positive correlation was found in CK-MB with cTnT. H-FABP is a useful cardiac marker for the early diagnosis of young AMI and thus prediction of myocardial injury is possible. H-FABP compared with CK-MB showed positive correlation. CK-MB with cTnT also showed statistically significant relation. Thus, H-FABP and CK-MB, as well as the correlation between CK-MB and TnT, reflects utility in early-stage diagnosis of myocardial injury.

Prehospital triage of patients with acute cardiac complaints: study protocol of HART-c, a multicentre prospective study

INTRODUCTION

Emergency department (ED) overcrowding is a major healthcare problem associated with worse patient outcomes and increased costs. Attempts to reduce ED overcrowding of patients with cardiac complaints have so far focused on in-hospital triage and rapid risk stratification of patients with chest pain at the ED. The Hollands-Midden Acute Regional Triage-Cardiology (HART-c) study aimed to assess the amount of patients left at home in usual ambulance care as compared with the new prehospital triage method. This method combines paramedic assessment and expert cardiologist consultation using live monitoring, hospital data and real-time admission capacity.

METHODS AND ANALYSIS

Patients visited by the emergency medical services (EMS) for cardiac complaints are included. EMS consultation consists of medical history, physical examination and vital signs, and ECG measurements. All data are transferred to a newly developed platform for the triage cardiologist. Prehospital data, in-hospital medical records and real-time admission capacity are evaluated. Then a shared decision is made whether admission is necessary and, if so, which hospital is most appropriate. To evaluate safety, all patients left at home and their general practitioners (GPs) are contacted for 30-day adverse events.

ETHICS AND DISSEMINATION

The study is approved by the LUMC's Medical Ethics Committee. Patients are asked for consent for contacting their GPs. The main results of this trial will be disseminated in one paper.

DISCUSSION

The HART-c study evaluates the efficacy and feasibility of a prehospital triage method that combines prehospital patient assessment and direct consultation of a cardiologist who has access to live-monitored data, hospital data and real-time hospital admission capacity. We expect this triage method to substantially reduce unnecessary ED visits.

Heart-Type Fatty Acid Binding Protein: A Better Cardiac Biomarker than CK-MB and Myoglobin in the Early Diagnosis of Acute Myocardial Infarction

BACKGROUND

Early diagnosis and therapeutic intervention can improve the outcome of acute myocardial infarction (AMI). However, there are no satisfactory cardiac biomarkers for the diagnosis of AMI within 6 hours of onset of symptoms. Among novel biochemical markers of AMI, heart-type fatty acid binding protein (H-FABP) is of particular interest.

AIM

To compare the diagnostic value of H-FABP with that of CK-MB and myoglobin in suspected AMI patients within first 6 hours after the onset of symptoms.

SETTINGS AND DESIGN

The study includes 40 AMI cases and 40 non-cardiac chest pain otherwise healthy controls. The cases and controls were further divided into 2 groups depending on the time since chest pain as those subjects within 3 hours and those between 3-6 hours of onset of chest pain.

MATERIALS AND METHODS

In all the cases and controls, serum H-FABP, CK-MB and myoglobin concentrations were measured by Immunoturbidimetric method, immuno-inhibition method and Chemiluminescence immunoassay respectively.

STATISTICAL ANALYSIS

Data is presented as mean ± SD values. Differences between means of two groups were assessed by Student t-test. Sensitivity, Specificity, Positive predictive value, Negative predictive values were calculated and ROC curve analysis was done to assess the diagnostic validity of each study parameter.

RESULTS

The sensitivity, specificity, PPV, NPV of H-FABP were greater than CK-MB and myoglobin and ROC curve analysis demonstrated highest area under curve for H-FABP followed by myoglobin and CK-MB in patients with suspected AMI both within 3 hours and 3-6 hours after the onset of chest pain.

CONCLUSION

The diagnostic efficiency of H-FABP is greater than CK-MB and myoglobin for the early diagnosis of AMI within first 6 hours of chest pain. H-FABP can be used as an additional diagnostic tool for the early diagnosis of AMI.

A new noninvasive device for measuring central ejection dP/dt mathematical foundation of cardiac dP/dt measurement using a model for a collapsible artery

We have developed a novel non-invasive device for the measurement of one of the most sensitive indices of myocardial contractility as represented by the rate of increase of intraventricular pressure (left ventricular dP/dt and arterial dP/dt performance index (dP/dt(ejc)). Up till now, these parameters could be obtained only by invasive catheterization methods. The new technique is based on the concept of applying multiple successive occlusive pressures on the brachial artery from peak systole to diastole using a inflatable cuff and plotting the values against time intervals that leads to the reconstruction of the central aortic pressure noninvasively. The following describes the computer simulator developed for providing a mathematical foundation of the new sensor. At the core of the simulator lies a hemodynamic model of the blood flow on an artery under externally applied pressure. The purpose of the model is to reproduce the experimental results obtained in studies on patients (Gorenberg et al. in Cardiovasc Eng: 305-311, 2004; Gorenberg et al. in Emerg med J 22 (7): 486-489, 2005) and a animal model where ischemia resulted from balloon inflation during coronary catheterization (Gorenberg and Marmor in J Med Eng Technol, 2006) and to describe correlations between the dP/dt(ejc) and other hemodynamic variables. The model has successfully reproduced the trends observed experimentally, providing a solid in-depth understanding of the hemodynamics involved in the new measurement. A high correlation between the dP/dt(ejc) and the rate of pressure rise in the aorta during the ejection phase was observed. dP/dt(ejc) dependence on other hemodynamic parameters was also investigated.

Validation of a novel method to determine non-invasively the rate of central aortic pressure changes

INTRODUCTION

One of the most sensitive indices of myocardial contractility is represented by the rate of increase of intraventricular pressure during isovolumetric contraction (dP/dt) and (dP/dt(ejc)), which represents the rate of change of pressure during ejection. Today these parameters can be obtained only by invasive catheterization methods. We developed a novel technique that leads to the non-invasive reconstruction of the central aortic pressure. The technique is based on the concept of applying multiple successive occlusive pressures on the brachial artery from peak systole to diastole using an inflatable cuff and plotting the values against time intervals. The hypothesis is that the time intervals required for the aortic pressure wave to overcome a given occlusive brachial pressure applied by a sphyngomanometer on the arm are equal to time needed to reach the same pressure in the central aorta plus the propagation time to the brachial point, which is constant in the same patient throughout the measurements.

METHODS AND RESULTS

We tested the hypothesis using an animal experiment. The new non-invasive device was mounted on the left forelimb of the animal. A Millar pressure transducer catheter was inserted to the aorta and the aorta pressure was recorded at time intervals of 1 ms. A second catheter was inserted into the coronary arteries and used to create controlled occlusion of the arteries using a balloon inflated to 10 atm. Measurements were obtained before the intervention was started, and throughout the sequence of repeated occlusions and deflations. At the end of the sequence, IV dobutamine was administered and results were monitored for 10 min while the heart rate and blood pressure were rising. Non-invasive dP/dt(ejc) was reduced typically by 20% in response to balloon inflation. In long occlusion periods, stabilization and sometimes recovery of dP/dt(ejc) is observed. By plotting dP/dt(ejc) measured by the new non-invasive device versus catheter measurements a correlation factor of 0.843 was found.

CONCLUSION

A newly developed method of non-invasive measurement of central dP/dt has been found to correlate to invasive measurements in an animal model.

Acute coronary syndromes in the emergency department: diagnostic characteristics, tests, and challenges

Failure to diagnose patients who have acute coronary syndromes (ACSs)-either acute myocardial infarction (AMI) or unstable angina pectoris (UAP)-who present to the emergency department (ED) remains a serious public health issue. Better understanding of the pathophysiology of coronary artery disease has allowed the adoption of a unifying hypothesis for the cause of ACSs: the conversion of a stable atherosclerotic lesion to a plaque rupture with thrombosis. Thus, physicians have come to appreciate UAP and AMI as parts of a continuum of ACSs. This article reviews the state of the art regarding the diagnosis of ACSs in the emergency setting and suggests reasons why missed diagnosis continues to occur, albeit infrequently.