[Chest pain units. Organization and protocol for the diagnosis of acute coronary syndromes]

Factors associated with late presentation to the emergency department in patients complaining of chest pain

OBJECTIVE

We investigated which factors predict late presentation (LP) to the emergency department (ED) in patients with non-traumatic chest pain (CP).

METHODS

All CP cases attended at a single ED (2008-2017) were included. LP was considered if time from CP onset to ED arrival was>6 h. We analyzed associations between 42 patient/CP-related characteristics and LP in the whole cohort and in patients with CP due to acute coronary syndrome (ACS).

RESULTS

The cohort included 25,693 cases (LP=50.6%; ACS=19.0%). Twenty factors were associated with LP, and 8 were also found in patients with ACS: CP of short-duration, aggravated by exertion or breathing/movement, undulating or recurrent CP increased the risk of LP, whereas CP accompanied by diaphoresis, irradiated to the throat, and chronic treatment with nitrates decreased the risk of LP. Exertional and recurrent CP were associated with both, LP and ACS.

CONCLUSION

Some characteristics, mainly CP-related, may lead to LP to the ED. CP aggravated by exercise and recurrent CP were associated with both LP and a final diagnosis of ACS.

PRACTICE IMPLICATIONS

Patient educational initiatives should consider these two features as potential warnings for ACS and thereby encourage patients to seek early medical consultation.

Diagnostic Performance of Point-of-Care Troponin I and Laboratory Troponin T in Patients Presenting to the ED with Chest Pain: A Comparative Study

Background

Chest pain is a common symptom in patients visiting the emergency department (ED). Diagnosing acute coronary syndrome is a challenging task for emergency physicians. Evaluation of chest pain depends on clinical symptoms and signs, ECG, and cardiac enzymes. Here, we aimed to compare the diagnostic performance of the point-of-care troponin I assay with laboratory HsTnT assay in patients presenting to the ED with chest pain.

Methods

A prospective study was done at the ED of Alkhor Hospital, Hamad Medical Corporation, between March 2016 and December 2016. Patients more than 18 years old who presented to the ED with chest pain were enrolled. Patients with renal failure, initial ECG showing ST-elevation MI, or arrhythmias, and hemodynamically unstable patients were excluded. A blood sample was collected at 0 and 3 hours post-admission for POC TnI and laboratory HsTnT assay. The sensitivity, specificity, PPV, NPV, and AUC were determined and compared.

Results

Out of 313 patients enrolled, ten were excluded. At 0 hour, the POC TnI assay had a lower sensitivity (72.5% versus 97.5%) and had almost equal specificity (99.24% versus 93.2%) when compared to lab HsTnT assay. At 3 hours post-admission, the sensitivity increased to 95% versus 100%, and specificity was 100% versus 94.3% when compared to lab HsTnT. The POC TnI assay had a higher PPV than HsTnT, whereas both assays showed a high NPV at 0 and 3 hours.

Conclusion

Although the diagnostic performance of POC TnI was lower than that of Lab HsTnT at 0 hour, at 3 hours post-admission, the diagnostic performance was almost equal to that of HsTnT. Hence we conclude that chest pain in patients with a negative POC TnI at 3 hours post-admission is unlikely to be due to NSTEMI.

Real-time AI prediction for major adverse cardiac events in emergency department patients with chest pain

Background

A big-data-driven and artificial intelligence (AI) with machine learning (ML) approach has never been integrated with the hospital information system (HIS) for predicting major adverse cardiac events (MACE) in patients with chest pain in the emergency department (ED). Therefore, we conducted the present study to clarify it.

Methods

In total, 85,254 ED patients with chest pain in three hospitals between 2009 and 2018 were identified. We randomized the patients into a 70%/30% split for ML model training and testing. We used 14 clinical variables from their electronic health records to construct a random forest model with the synthetic minority oversampling technique preprocessing algorithm to predict acute myocardial infarction (AMI) < 1 month and all-cause mortality < 1 month. Comparisons of the predictive accuracies among random forest, logistic regression, support-vector clustering (SVC), and K-nearest neighbor (KNN) models were also performed.

Results

Predicting MACE using the random forest model produced areas under the curves (AUC) of 0.915 for AMI < 1 month and 0.999 for all-cause mortality < 1 month. The random forest model had better predictive accuracy than logistic regression, SVC, and KNN. We further integrated the AI prediction model with the HIS to assist physicians with decision-making in real time. Validation of the AI prediction model by new patients showed AUCs of 0.907 for AMI < 1 month and 0.888 for all-cause mortality < 1 month.

Conclusions

An AI real-time prediction model is a promising method for assisting physicians in predicting MACE in ED patients with chest pain. Further studies to evaluate the impact on clinical practice are warranted.

External validation of an emergency department triage algorithm for chest pain patients

BACKGROUND

We aimed to externally validate an emergency department triage algorithm including five hierarchical clinical variables developed to identify chest pain patients at low risk of having an acute coronary syndrome justifying delayed rather than immediate evaluation.

METHODS

In a single-centre cohort enrolling 29,269 consecutive patients presenting with chest pain, the performance of the algorithm was compared against the emergency department discharge diagnosis. In an international multicentre study enrolling 4069 patients, central adjudication by two independent cardiologists using all data derived from cardiac work-up including follow-up served as the reference. Triage towards 'low-risk' required absence of all five clinical 'high-risk' variables: history of coronary artery disease, diabetes, pressure-like chest pain, retrosternal chest pain and age above 40 years. Safety (sensitivity and negative predictive value (NPV)) and efficacy (percentage of patients classified as low risk) was tested in this initial proposal (Model A) and in two additional models: omitting age criteria (Model B) and allowing up to one (any) of the five high-risk variables (Model C).

RESULTS

The prevalence of acute coronary syndrome was 9.4% in the single-centre and 28.4% in the multicentre study. The triage algorithm had very high sensitivity/NPV in both cohorts (99.4%/99.1% and 99.9%/99.1%, respectively), but very low efficacy (6.2% and 2.7%, respectively). Model B resulted in sensitivity/NPV of 97.5%/98.3% and 96.1%/89.4%, while efficacy increased to 14.2% and 10.4%, respectively. Model C resulted in sensitivity/NPV of 96.7%/98.6% and 95.2%/91.3%, with a further increase in efficacy to 23.1% and 15.5%, respectively.

CONCLUSION

A triage algorithm for the identification of low-risk chest pain patients exclusively based on simple clinical variables provided reasonable performance characteristics possibly justifying delayed rather than immediate evaluation in the emergency department.

Evaluation of the Manchester triage system for patients with acute coronary syndrome

BACKGROUND

An early diagnosis of acute coronary syndrome (ACS) is crucial for treatment and prognosis. The aim of this study was to evaluate the Manchester triage system (MTS) for patients with ACS, e.g. ST-segment elevation myocardial infarction (STEMI), non-ST elevation myocardial infarction (N-STEMI) and unstable angina pectoris (UAP).

METHODS

Retrospective analysis of patients diagnosed with ACS (STEMI, N‑STEMI and UAP) who were triaged in the emergency department (ED) with the MTS.

RESULTS

In this study 282 patients with ACS (STEMI: 34.0%, N‑STEMI: 61.7%, UAP: 4.3%) were triaged as MTS level 1 (immediate assessment): 0.4%, MTS level 2 (very urgent): 51.4%, MTS level 3 (urgent): 41.5%, MTS level 4 (standard): 6.7%, MTS level 5 (non-urgent): 0%. We observed significantly lower mean MTS levels in males (male: 2.48 ± 0.59, female: 2.68 ± 0.68, p = 0.02) and in patients younger than 80 years (age <80 years: 2.50 ± 0.61, age ≥80 years: 2.70 ± 0.67, p = 0.03). We did not find a significant difference of mean MTS levels in different types of ACS (STEMI: 2.46 ± 0.6, N‑STEMI: 2.59 ± 0.64, STEMI vs N‑STEMI: p = 0.11, UAP: 2.67 ± 0.65, STEMI vs UAP: p = 0.26) and with respect to diabetes (diabetic: 2.47 ± 0.57, non-diabetic: 2.58 ± 0.65, p = 0.13). The in-hospital mortality was 2.5% (MTS level 2: n = 3, MTS level 3: n = 3, MTS level 4: n = 1).

CONCLUSION

The majority of patients with ACS were classified as MTS levels 2 and 3. There was no significant difference of mean MTS levels in patients with STEMI, NSTEMI and UAP. In order to assure an early diagnosis of STEMI, an electrocardiogram (ECG) should be carried out immediately or at least within 10 min after first medical contact in the ED in all patients suspected for ACS, irrespective of the assigned MTS level.

Developing outcome, process and balancing measures for an emergency department longitudinal patient monitoring system using a modified Delphi

BACKGROUND

Early warning score systems have been widely recommended for use to detect clinical deterioration in patients. The Irish National Emergency Medicine Programme has developed and piloted an emergency department specific early warning score system. The objective of this study was to develop a consensus among frontline healthcare staff, quality and safety staff and health systems researchers regarding evaluation measures for an early warning score system in the Emergency Department.

METHODS

Participatory action research including a modified Delphi consensus building technique with frontline hospital staff, quality and safety staff, health systems researchers, local and national emergency medicine stakeholders was the method employed in this study. In Stage One, a workshop was held with the participatory action research team including frontline hospital staff, quality and safety staff and health systems researchers to gather suggestions regarding the evaluation measures. In Stage Two, an electronic modified-Delphi study was undertaken with a panel consisting of the workshop participants, key local and national emergency medicine stakeholders. Descriptive statistics were used to summarise the characteristics of the panellists who completed the questionnaires in each round. The mean Likert rating, standard deviation and 95% bias-corrected bootstrapped confidence interval for each variable was calculated. Bonferroni corrections were applied to take account of multiple testing. Data were analysed using Stata 14.0 SE.

RESULTS

Using the Institute for Healthcare Improvement framework, 12 process, outcome and balancing metrics for measuring the effectiveness of an ED-specific early warning score system were developed.

CONCLUSION

There are currently no published measures for evaluating the effectiveness of an ED early warning score system. It was possible in this study to develop a suite of evaluation measures using a modified Delphi consensus approach. Using the collective expertise of frontline hospital staff, quality and safety staff and health systems researchers to develop and categorise the initial set of potential measures was an innovative and unique element of this study.

Chest pain in the emergency department: risk stratification with Manchester triage system and HEART score

BACKGROUND

Fast and accurate chest pain risk stratification in the emergency department (ED) is critical. The HEART score predicts the short-term incidence of major adverse cardiac events (MACE) in this population, dividing it in three risk categories. We aimed to describe the population with chest pain, to characterize the subgroup of patients with acute coronary syndrome (ACS) and to assess the prognostic value of Manchester triage system and of HEART score.

METHODS

Retrospective observational study including patients admitted to the ED of a tertiary hospital with chest pain as the presenting symptom. The primary outcome was a composite of all-cause mortality, myocardial infarction or unscheduled revascularization at 6 weeks.

RESULTS

We enrolled 233 patients (age 58 ± 19; 55.4 % males). The most common final diagnosis was non-specific chest pain (n = 86, 36.9 %), followed by ACS (n = 22, 9.4 %). Male gender, smoking and chronic kidney disease were associated with higher risk of ACS. According to Manchester triage system, chest pain patients stratified with red or orange priority had a higher incidence of ACS (16.5 % vs. 3.8 %, p = 0.006). The application of HEART score showed that most patients were in low risk category (56.3 %). The six-week incidence of MACE in each category was 2 %, 15.6 % and 76.9 % (p < 0.001). HEART score accurately predicted the short-term incidence of MACE in chest pain patients (c-statistic 0.880; 95 % CI, 0.807-0.950, p < 0.001).

CONCLUSIONS

Chest pain patients have very different levels of severity and the discriminatory power of Manchester triage system should be used in the assessment of this population. The HEART score seems to be an effective tool for risk stratification in the ED.

Troponin elevation in patients without acute coronary syndrome

INTRODUCTION AND OBJECTIVES

Troponins are specific biomarkers of myocardial injury and are implicated in the diagnosis and prognosis of patients with acute coronary syndrome. Our purpose was to determine the clinical characteristics and prognosis of patients with troponin elevation who are not diagnosed with acute coronary syndrome.

METHODS

A total of 1032 patients with an emergency room troponin measurement were studied retrospectively, dividing them into 3 groups: 681 patients with no troponin elevation and without acute coronary syndrome, 139 with acute coronary syndrome, and 212 with troponin elevation and not diagnosed with acute coronary syndrome. The clinical characteristics and in-hospital and 12-month mortality of these 3 groups were compared.

RESULTS

Patients with troponin elevation not diagnosed with acute coronary syndrome were older and had greater comorbidity than patients with acute coronary syndrome or no troponin elevation. The 12-month mortality was 30.2%, compared with 15.1% and 4.7% in the other groups (log rank test, P<.001). In the Cox logistic regression model adjusted for confounding variables, patients with troponin elevation and no diagnosis of acute coronary syndrome had higher mortality compared with patients with negative troponin without acute coronary syndrome (hazard ratio=3.99; 95% confidence interval, 2.36-6.75; P<.001) and similar prognosis as patients with acute coronary syndrome.

CONCLUSIONS

Troponin elevation is an important predictor of mortality, regardless of the patient's final diagnosis.

Exercise echocardiography and multidetector computed tomography for the evaluation of acute chest pain

INTRODUCTION AND OBJECTIVES

Up to 4% of patients with acute chest pain, normal electrocardiogram, and negative troponins present major adverse cardiac events as a result of undiagnosed acute coronary syndrome. Our aim was to compare the diagnostic performance of multidetector computed tomography and exercise echocardiography in patients with a low-to-intermediate probability of coronary artery disease.

METHODS

We prospectively included 69 patients with acute chest pain, normal electrocardiogram, and negative troponins who underwent coronary tomography angiography and exercise echocardiography. Patients with coronary stenosis ≥ 50% or Agatston calcium score ≥ 400 on coronary tomography angiography or positive exercise echocardiography, or with inconclusive results, were admitted to rule out acute coronary syndrome.

RESULTS

An acute coronary syndrome was confirmed in 17 patients (24.6%). This was lower than the suspected 42% based on coronary tomography angiography (P<.05) and not significantly different than the suspected 29% based on the results of exercise echocardiography (P=.56). Exercise echocardiography was normal in up to 37% of patients with pathological findings on coronary tomography angiography. The latter technique provided a higher sensitivity (100% vs 82.3%; P=.21) but lower specificity (76.9% vs 88.4%; P=.12) than exercise echocardiography for the diagnosis of acute coronary syndrome, although without reaching statistical significance. Increasing the stenosis cutoff point to 70% increased the specificity of coronary tomography angiography to 88.4%, while maintaining high sensitivity.

CONCLUSIONS

Coronary tomography angiography offers a valid alternative to exercise echocardiography for the diagnosis of acute coronary syndrome among patients with low-to-intermediate probability of coronary artery disease. A combination of both techniques could improve the diagnosis of acute coronary syndrome.

[Radiologists in the emergency department: when and how to use multislice CT]

Chest pain is a challenging clinical problem in the emergency department. Despite advances in clinical diagnosis, many patients with atypical chest pain are needlessly hospitalized and others are mistakenly discharged. Faced with the specific clinical situation in which a patient has chest pain, an initially normal or inconclusive electrocardiogram, and normal cardiac biomarkers, multislice CT has proven useful for ruling out the conditions that involve the greatest morbidity and mortality and for establishing the cause of pain. This article reviews the current usefulness of multislice CT in the diagnostic workup of patients presenting at the emergency department with chest pain. We review the technique, define the most appropriate population, describe the acquisition protocols, and discuss the advantages and disadvantages of each study protocol.

[Improvement in health care quality for patients from the thoracic/chest pain unit in a regional hospital]

OBJECTIVES

The evaluation of an improvement cycle in patients suffering thoracic/chest pain in hospital emergencies, especially in those who could benefit from the early Bruce Treadmill Test.

MATERIAL AND METHODS

A multidisciplinary group care protocol was designed, which identified improvement opportunities and gave priority to the fact that «an early Bruce Treadmill Test was carried out on fewer occasions than recommended». Causes were analysed (Ishikawa diagram) and six quality criteria were defined. These criteria were evaluated in a random sample of 30 patients out of the total of 180 who used the ergometer at the Hospital in the first six months of 2007, as well as questionnaire for the doctors. Corrective measures were introduced: circulation, accessibility through intranet and explicit information for new employees (doctors). The second evaluation was carried out during the first six-months of 2008 using another random sample of 30 patients from a total of 120.

RESULTS

In the first evaluation, the classification of the risk according to the protocol was very low (100% non-compliance) and patients whose admission to the Chest Pain Unit was recommended and an early Bruce Treadmill Test (74% criteria failure) were referred to cardiology clinics. After implementation of the corrective measures, we obtain a general improvement in all the criteria, but very significant from the previous ones, with non-compliances being reduced to 17% in classification and to the 23% in referrals.

CONCLUSIONS

The structured cycle has helped resolve the priority problem in the short-term. The adopted measures have mainly been organisational, dependent on the professionals involved, and at a very low cost. Simple but organised methodological approaches should be taken into account before the incorporation of higher cost technologies.

Improved outcome in acute coronary syndrome by establishing a chest pain unit

AIMS

Chest pain units (CPUs) have been established to optimize treatment of patients with acute coronary syndrome (ACS) and to early and accurately discharge patients with non-coronary chest pain. The aim of this analysis was to elucidate whether treatment of ACS patients in the CPU versus emergency department (ED) has prognostic implications.

METHODS AND RESULTS

Patients presenting with suspected ACS to either the ED between August 2004 and June 2005 or the CPU between July 2005 and May 2006 were retrospectively analyzed. Of 1,796 included patients, 483 had the discharge diagnosis ACS. When compared to patients with exclusion of ACS they had more cardiovascular risk factors and higher troponin, creatinine and C-reactive protein levels (P < 0.001) at admission. Within 1 year, 37 patients of the ACS group suffered an event. Treatment in the ED compared with the CPU showed a significant increase in hazard ratio of 2.1 (P = 0.034) for the combined endpoint death, myocardial infarction and stroke, remaining unchanged after adjusting for confounders. Event-free 1-year survival was higher in CPU patients for the combined endpoint (P (logrank) = 0.02).

CONCLUSION

These results demonstrate a better 1-year prognosis for ACS patients treated in the CPU instead of the ED, therefore, supporting the idea to establish CPUs in Europe.

[Dual-source computed tomography in inpatients with atypical chest pain]

OBJECTIVE

To evaluate the potential usefulness of dual-source CT (DSCT) in the diagnostic work-up of inpatients with atypical chest pain of unknown etiology.

MATERIAL AND METHODS

Forty-one consecutive inpatients (25 male, 16 female; mean age 55.6+/-17.39 years) with atypical chest pain underwent DSCT to determine the cause of pain. Images were acquired with retrospective ECG gating after the administration of 120ml of iodinated contrast medium at 4ml/s using the bolus tracking technique. Two readers analyzed the images in consensus.

RESULTS

DSCT was diagnostic in all patients. We detected pulmonary embolisms in five patients and aortic disease in two (one aortic ulcer and one sacular aneurysm). Anomalies of the coronary arteries were depicted in 15 patients, two of whom presented luminal stenosis >50%. Extracardiovascular findings at DSCT included pneumonia in eleven patients, sarcoidosis in one, and non-small cell lung carcinoma in one. Pleural effusion was detected in four patients and pericardial effusion in another four. No pathological findings were observed in 22% of subjects. Evolution was favorable in all patients. No patients were readmitted for persistent pain or new onset of acute chest pain during the follow-up period.

CONCLUSION

DSCT can rule out most life-threatening clinical conditions that cause chest pain and is useful in determining the cause of chest pain in inpatients.

[Clinical characteristics, prognosis, and variability in the management of non-ST-segment elevation acute coronary syndromes. Data from the PEPA registry]

OBJECTIVES

To assess the clinical characteristics and inter-hospital variability in the treatment and prognosis of patients with non-ST-segment elevation acute coronary syndromes.

PATIENTS AND METHOD

Data from the PEPA study, a prospective registry that enrolled 4,115 patients in 18 Spanish hospitals, were analyzed.

RESULTS

The mean age of the patients enrolled was 65 years, 33% were women, and 26% had diabetes. Large differences were observed in the clinical profile of patients admitted to different centers, especially relative the history of previous disease, prior coronary revascularization, and co-morbidity. Antiplatelet treatment was used in 93% of patients, heparin in 45%, beta-blockers in 42%, nitrates in 67%, and calcium antagonists in 46%. During hospitalization, exercise stress testing was performed in 37% of patients, coronary angiography in 32%, coronary angioplasty in 9%, and coronary surgery in 4%. Inter-hospital variability was minimal for the use of antiplatelet agents, wide for the use of heparin and beta-blockers, and huge for the use of revascularization procedures. Mortality and the incidence of death or myocardial infarction were 2.6% and 4.4% during hospitalization, and 4.6% and 8% at 3 months, with wide inter-hospital variability. These differences were not significant once adjusted for clinical characteristics and the treatment received at admission.

CONCLUSIONS

Patients with non-ST-segment elevation acute coronary syndromes represent an heterogeneous group with a high incidence of complications. Pharmacologic and, especially, invasive treatment varies widely in different hospitals. These results underline the importance of correct initial risk stratification and uniform treatment following the recommendations of clinical guidelines.

[Applicability of a new definition of myocardial infarction and the opinion of Spanish cardiologists]

INTRODUCTION AND OBJECTIVES

The Working Group on Ischemic Heart Disease and Coronary Care Units of the Spanish Society of Cardiology evaluated the applicability of a new definition of infarction in Spanish hospitals, its current use, and the opinion of Spanish cardiologists.

METHODS

A telephone survey was made (from late 2001 to early 2002) in Spanish hospitals to evaluate the availability of troponin or creatine kinase MB mass determinations. A questionnaire was sent to all members of the Spanish Society of Cardiology to query about the availability of determinations of cardiac necrosis markers at their respective hospitals, use of the new definition, and whether they agreed with the new definition.

RESULTS

An important proportion of Spanish hospitals cannot determine myocardial necrosis markers (troponin or creatine kinase MB mass), mainly due to low-volume activity (fewer than 200 beds). The new definition of myocardial infarction was used by Spanish cardiologists always (24%), frequently (31%), sometimes (17%), seldom (14%), and never (11%). Agreement with the definition was complete in 21%, almost complete in 33%, half and half in 26%, rare in 10%, and absent in 7% of Spanish cardiologists.

CONCLUSIONS

A large percentage of Spanish hospitals cannot use the new definition of myocardial infarction because they cannot determine specific cardiac necrosis markers. Spanish cardiologists are not generally using the new definition and many do not agree with it.

[Chest pain in clinical practice: impact of routine troponin determination on clinical manifestations and care]

INTRODUCTION AND OBJECTIVES. To study the significance of chest pain in the clinical practice of a Spanish hospital and to evaluate the impact of routine troponin determination.

METHODS

In our institution, routine serial measurements of troponins I and T were made in the evaluation of chest pain in 2000. We compared the results obtained in 1999 for all patients who visited the emergency room for chest pain and the patients who were hospitalized. We recorded the diagnosis at discharge, duration of the hospital stay, and associated costs.

RESULTS

In 2000, 1,820 patients with chest pain visited the emergency department, which was equivalent to 1.9% of visits and 7.5 cases per 1,000 people and year: 43% of these patients were hospitalized for suspected acute coronary syndrome as compared to 49% in 1999 (-12%; p > 0.001). Among the patients admitted, 28% were discharged with a diagnosis of non-ischemic chest pain. Troponin determinations were associated with a lower probability of admission due to unstable angina (11.5 vs 16.0%; -28%; p < 0.001) and non-ischemic chest pain (12.1 vs 14.5%; -16%; p < 0.05), and an increase in diagnoses of non-Q wave acute myocardial infarction (3.4% vs 1.8%; +89%; p < 0.01). Non-ST elevation acute coronary syndrome ACS required 3,751 days of hospitalization and 1,003,420 euros of cost, and troponin determinations were associated with a reduction in hospital stays of 832 days (-18.2%) and 185,100 euros (-15.6%).

CONCLUSION

Chest pain had a high incidence, 7.5, and generates high costs in hospital admissions. The routine use of serial troponin determinations was associated with a reduction in hospital admissions due to unstable angina and non-ischemic chest pain, and costs.

[Value of early exercise stress testing in a chest pain unit protocol]

Early exercise testing (first 24 hours) was evaluated in the stratification of patients seen in the emergency room for chest pain. One hundred and forty-two consecutive patients without ischemia in the ECG or troponin I elevation were included. Ninety-two patients were discharged after the exercise testing (group I, 82 negative and 10 inconclusive test results) and 50 patients were hospitalized (group II, 29 positive and 21 inconclusive test results). In group I, cardiac events (unstable angina and non-fatal infarction) occurred in the next 30 days of follow-up in 2 patients with inconclusive test results; no cardiac events occurred in patients with negative test results. In group II, unstable angina was diagnosed in 30 patients and 3 presented recurrent angina. There were no complications during exercise testing. In conclusion, early exercise testing is safe and useful in the stratification of patients seen in the emergency room for chest pain. Only patients with negative test results should be discharged early.

[Chest pain unit: one-year follow-up]

INTRODUCTION AND OBJECTIVES

In Spain there is little information available about chest pain units for the treatment of patients of low-to-medium risk with suspected acute coronary syndrome.

PATIENTS AND METHOD

A prospective study was performed among emergency room patients who complained about acute chest pain and were suspected of suffering an acute coronary syndrome with a normal or unspecific initial evaluation. They underwent an early submaximum stress test to decide on possible hospitalization. The follow-up time was 1 year.

RESULTS

Of 472 emergency room patients with suspected acute coronary syndrome, 179 performed the stress-test during the first hours of the triggering chest pain episode. None met the high-risk criteria for unstable angina. In 78.8% of the cases, the test results were negative and the patients were discharged. The results were positive in 15.1% and inconclusive in 6.1%; there were no complications during the procedure. Patients with a negative stress test had a more favorable outcome than the rest, with fewer following visits to the emergency room (11% vs 22%, p<0.001). One patient with a negative stress test died of a non-cardiovascular complication. None of the patients suffered acute myocardial infarction during follow-up and 89% of the patients with negative stress test had a favorable outcome (in terms of visits to the emergency room, unstable angina, acute myocardial infarction, or cardiovascular death).

CONCLUSIONS

Chest pain units for the care of low-to-medium risk patients with acute chest pain allow a fast and safe hospital release with a favorable mid-term outcome.

[2002 Update of the Guidelines of the Spanish Society of Cardiology for Unstable Angina/Without ST-Segment Elevation Myocardial Infarction]

Since the Spanish Society of Cardiology Clinical Practice Guidelines on Unstable Angina/Non-Q-Wave Myocardial Infarction were released in 1999, the conclusions of several studies that have been published make it advisable to update current clinical recommendations. The main findings are related to the developing role of Chest Pain Units in the management and early risk stratification of acute coronary syndromes in the emergency department; new information concerning the efficacy of glycoprotein IIb/IIIa inhibitors, clopidogrel and low-molecular-weight heparins in the pharmacological treatment of acute coronary syndromes without ST-segment elevation; and the role of early invasive strategy in improving the prognosis of these patients. The published evidence is reviewed and the corresponding clinical recommendations for the management of acute coronary syndromes without persistent ST-segment elevation are updated.