Outcome from a rapid-assessment chest pain clinic

Chest pain accounts for much of the rising numbers of emergency admissions, but in-patient assessment is not necessarily the best way of dealing with these patients. We ran a 'rapid-assessment chest pain clinic' to provide an alternative route of assessment, and audited its outcome. General practitioners referred patients with recent-onset chest pain, increasing chest pain, chest pain at rest, or other chest pain of concern, on the understanding that they would be seen within 24 h. During 8 1/2 months, 334 patients were referred and 317 patients were seen, most of whom had exercise electrocardiography. A median of 6 months later, 278 patients were personally contacted to determine outcome. Of these, 18% had been admitted immediately with acute coronary syndromes, and 49% had been diagnosed as non-coronary chest pain (none of whom subsequently infarcted or died). Continuing symptoms were infrequent, and satisfaction was high, although 13% of patients had been revascularized. A significant number of patients required immediate admission and/or ultimate revascularization, but many more did not. The majority of these patients had non-coronary chest pain, and this diagnosis was substantiated by their excellent outcome and (in some cases) by further investigation.      

脂蛋白相关磷脂酶A2在冠心病患者严重程度评估中的应用

目的评估脂蛋白相关磷脂酶A2(Lp-PLA2)在冠心病患者严重程度评估及远期心血管事件发生预测中的价值。方法将165例因胸痛行冠状动脉造影的患者按造影结果分为冠心病组98例[其中稳定性心绞痛(SAP)患者59例、急性冠状动脉综合症(ACS)患者39例]和非冠心病组67例。冠心病组按照病变累及的冠状动脉支数分为单支、二支和三支组,同时对每位冠心病患者进行Gensini评分。检测所有患者入院后24 h内的血浆Lp-PLA2及总胆固醇(TC)和低密度脂蛋白胆固醇(LDL-C)水平。随访1～2年,记录主要不良心血管事件。分析不同病例组别、不同病变支数和有、无发生主要不良心血管事件患者的Lp-PLA2水平差异。结果冠心病患者Lp-PLA2水平明显高于非冠心病组(P<0.01),ACS患者Lp-PLA2水平高于SAP患者(P<0.05)。冠心病组TC和LDL-C水平与非冠心病组比较均无差异。冠心病三支病变组Lp-PLA2水平明显高于单支和二支病变组(P<0.01、P<0.05),而单支、二支病变组间无差异(P>0.05)。不良心血管事件阳性患者Lp-PLA2水平明显高于阴性患者(P<0.01)。结论 Lp-PLA2可用于...     

Acute chest pain-a stepwise approach,the challenge of the correct clinical diagnosis

STUDY OBJECTIVE: To assess the safety and the accuracy of a 4 h stepwise diagnostic approach relying on clinical judgement in unselected patients with acute chest pain. DESIGN: Prospective cohort study. SETTING: Emergency department (ED) of a tertiary care university hospital. PATIENTS: 1288 unselected patients presenting with acute chest pain. INTERVENTIONS: After history and physical examination, clinical judgement (step I), governed the need for further patient evaluation: baseline 12 lead electrocardiogramm (ECG) and laboratory examinations (step II), serial 12 lead ECG and laboratory examinations after 4 h (step III), and 4 h troponin T measurement (step IV) to exclude or to confirm a coronary origin of chest pain. Patients were followed clinically for 6 months for future occurrence of cardiac events (myocardial infarction, percutaneous transluminal coronary angioplasty (PTCA), CABG, cardiac death), any death and for accuracy of the ED diagnosis in non-coronary chest pain patients. MEASUREMENTS AND RESULTS: Chest pain was diagnosed to be coronary in origin in 381 and non-coronary in 907 patients, respectively. Cardiac events occurred during follow up in 240 (19%) of 1288 patients, in 233 of 381 (61%) with presumed coronary and seven of 907 (1%) with presumed non-coronary chest pain. Sensitivity, specificity, positive predictive value and negative predictive value for correct detection of coronary chest pain were 97, 86, 61 and 99%, respectively. In non-coronary chest pain patients the agreement between the ED diagnosis and the final diagnosis was good (kappa=0.71, 95% confidence interval (CI) 0.67-0.75). CONCLUSIONS: The 4 h stepwise approach guided by clinical judgement was safe for ruling out impending cardiac events in unselected patients with acute chest pain. However, more extensive evaluation is necessary for accurate rule-in of coronary chest pain.     

Histamine-induced coronary artery spasm: the concept of allergic angina.

Histamine, the main amine released during allergic reactions, can provoke coronary arterial spasm manifested as angina pectoris. This has been shown during clinical and laboratory studies. The effects of histamine on cardiac function are mediated via H1- and H2- receptors situated on the four cardiac chambers and coronary arteries. Coronary arteries of cardiac patients are hyperactive and contain stores of histamine which can initiate coronary artery spasm. Clinical observations indicate that angina pectoris or acute myocardial infarction can be provoked by acute allergic reaction. The coincidental occurrence of chest pain and allergic reaction accompanied by clinical and laboratory findings of classical angina pectoris seems to constitute the syndrome of allergic angina. The clinical symptoms of allergic angina include chest discomfort, dyspnoea, faintness, nausea, pruritus and urticaria. They are accompanied by signs such as hypotension, diaphoresis, pallor and bradycardia. There are also electrocardiographic findings indicating myocardial ischaemia, arrhythmias and conduction defects. Thus, in patients undergoing acute allergic reaction, the development of chest pain could be explained by the mechanism of coronary arterial spasm provoked by the release of histamine, which constitutes the syndrome of allergic angina.     

The effect of elevated serum soluble CD40 ligand on the prognostic value in patients with acute coronary syndromes

BACKGROUND: Increasing evidence shows that high expression of CD40L plays an important role in the pathogenesis of atherosclerosis and coronary artery disease. We evaluated the clinical predictive value of increased serum soluble CD40 ligand (CD40L) in patients with acute coronary syndromes (ACS) and acute chest pain. METHODS: Serum levels of soluble CD40 ligand were measured by ELISA in 128 patients with ACS and in 68 patients with acute chest pain. Platelet activation was assessed by flow cytometry. RESULTS: The levels of soluble CD40 ligand were increased in 57.8% patients with ACS (>8.0 ng/ml) and in 35 patients with acute chest pain (>8.0 ng/ml), respectively. The level of soluble CD40 ligand was slightly correlated with measured levels of troponin T (r=0.21, p<0.05), and the increased soluble CD40L levels (>8.0 ng/ml) were associated with higher risk for AMI, sudden death and recurrent angina. Patients with elevated serum levels of sCD40L and cTnT showed a significantly increased risk of major adverse cardiovascular events (including AMI, sudden death and recurrent angina) in the two groups during 30 days and 6 months of follow-up. CONCLUSION: In patients with unstable coronary artery disease, elevation of serum soluble CD40L levels indicated an independent increased risk of major adverse cardiovascular events.     

The role of angina pectoris in chronic pain after coronary artery bypass graft surgery.

Visceral nociception readily sensitizes the central nervous system, causing referred somatic pain and hyperalgesia via somato-visceral convergence. Hyperalgesia in the perioperative period may increase vulnerability to subsequent development of chronic pain. The study aim is to investigate the role of angina pectoris, an ischemic visceral pain, in long-term pain after coronary artery bypass surgery (CABG). We sent questionnaires to 369 patients who underwent CABG surgery in 2003. Questions were asked about angina pectoris and other pain in the period before surgery, the first week postoperatively (= acute pain), and the period after 3 months after surgery (= chronic pain). We obtained results from 256 patients (response rate = 69%). The point prevalence of chronic pain after CABG was 27% after a mean follow-up of 16 months (SD +/- 3 months). Patients with chronic pain after CABG had more angina pectoris than those without chronic pain: Before surgery (P = .07), early on postoperatively (P = .004), and more than 3 months after surgery (P = .000004). We found cumulative prevalences of chronic pain after CABG at 3 months of 39%, and of 32% after 6 months. Other predictive factors for chronic pain after CABG were acute postoperative pain (P = .00002) and younger age (P = .002). Angina pectoris is associated with chronic pain after CABG surgery. Other predictive factors include acute postoperative pain and younger age. PERSPECTIVE: The influence of postoperative angina pectoris for chronic pain after CABG surgery has not been described in the literature to date. Visceral nociception may play an important role in the development of chronic pain after surgery and should be taken into account in future studies.     

Characteristics of the clinical manifestations of stenocardia in patients with ischemic heart disease, without myocardial infarct, in relation to the state of the coronary bed

Mono- and multifactorial discriminant analyses aided by computer were used in 106 patients with coronary disease to compare the clinical and angiographic findings common to different manifestations of angina pectoris. The relationship was discovered between the clinical form of angina pectoris and the gravity of lesions of the coronary artery. Intracardiac hemodynamics and left ventricular contractility at rest did not differ whatever the patients' group. According to the bicycle ergometry test, the physical exercise tolerance was lower in patients with progressive angina pectoris and depended on the gravity of coronary artery lesions. The outcome of the clinical manifestations of angina pectoris during observation at hospital was mainly influenced by the natural course of coronary disease, primarily stipulated by obstruction in the coronary arteries. Using the multifactorial discriminant analysis aided by computer, the classifying signs were outlined, making it possible to differentiate between the groups of angina pectoris patients depending on the duration of angina pectoris attacks (in minutes), irradiation of pain to the shoulder or to both arms, T wave inversion on the ECG, and the gravity of coronary artery obstruction. The given signs enable one to recognize patients with destabilization of the clinical course of angina pectoris.     

It is safe to manage selected patients with acute coronary syndromes in unmonitored beds

This prospective, observational study evaluated the safety of the Western Hospital admission protocol for patients with suspected acute coronary syndromes. The study included all patients admitted from the Emergency Department with an admission diagnosis of unstable angina, post infarct angina, atypical chest pain, or chest pain for evaluation. Data collected included demographic data, admission diagnosis, location of admission (bed with or without cardiac monitoring), past medical history and presenting chest pain history to determine Agency for Health Care Policy (AHCPR) and Western Hospital (WH) protocol classifications, cardiac enzyme assays, electrocardiogram analysis, adverse outcomes [death, myocardial infarction (MI), dysrhythmia, acute pulmonary edema, recurrent pain], diagnosis at hospital discharge, and length of stay-(LOS). There were 508 patients with a mean age of 63.7 years enrolled in the study. Three hundred nineteen (62.8%) were admitted to beds without any cardiac monitoring. There was one unexpected death in the unmonitored group, an 85 year-old patient who suffered a presumed dysrhythmia and whom the treating physician had decided was not for resuscitation. Twelve patients suffered nonfatal MI, and none suffered pulmonary edema. All MI patients made an uneventful recovery, and none required thrombolysis. If all patients had been admitted to an area of care based on AHCPR guidelines, an additional 310 admissions to monitored beds would have been required. The results of this study suggest that selected patients with suspected acute coronary syndromes can be safely managed in beds without continuous cardiac monitoring.     

Performance and efficacy of 320-row computed tomography coronary angiography in patients presenting with acute chest pain: results from a clinical registry

The purpose of this study was to evaluate the performance of 320-row computed tomography angiography (CTA) in the identification of significant coronary artery disease (CAD) in patients presenting with acute chest pain and to examine the relation to outcome during follow-up. A total of 106 patients with acute chest pain underwent CTA to evaluate presence of CAD. Each CTA was classified as: normal, non-significant CAD (<50% luminal narrowing) and significant CAD (≥50% luminal narrowing). CTA results were compared with quantitative coronary angiography. After discharge, the following cardiovascular events were recorded: cardiac death, non-fatal infarction, and unstable angina requiring revascularization. Among the 106 patients, 23 patients (22%) had a normal CTA, 19 patients (18%) had non-significant CAD on CTA, 59 patients (55%) had significant CAD on CTA, and 5 patients (5%) had non-diagnostic image quality. In total, 16 patients (15%) were immediately discharged after normal CTA and 90 patients (85%) underwent invasive coronary angiography. Sensitivity, specificity, and positive and negative predictive values to detect significant CAD on CTA were 100, 87, 93, and 100%, respectively. During mean follow-up of 13.7?months, no cardiovascular events occurred in patients with a normal CTA examination. In patients with non-significant CAD on CTA, no cardiac death or myocardial infarctions occurred and only 1 patient underwent revascularization due to unstable angina. In patients presenting with acute chest pain, an excellent clinical performance for the non-invasive assessment of significant CAD was demonstrated using CTA. Importantly, normal or non-significant CAD on CTA predicted a low rate of adverse cardiovascular events and favorable outcome during follow-up.     

Diagnosis and risk stratification of patients with anginal pain and non-diagnostic electrocardiograms

Patients with acute chest pain suggestive of myocardial ischaemia, and normal or non-diagnostic electrocardiograms, form a difficult subgroup for diagnosis and early risk stratification. We prospectively evaluated the role of troponin T (cTnT), troponin I (cTnI), CKMB mass and myoglobin, in the diagnosis and risk stratification of 214 patients with acute chest pain of < or = 24 h and non-diagnostic or normal ECGs admitted directly to the Cardiac Unit of the Royal Victoria Hospital Belfast from the Mobile Coronary Care Unit or the Accident/Emergency Department. This was a single-centre prospective study, and follow-up (3 months) was complete for all patients. Blood was assessed for quantitative cTnT, cTnI, CKMB mass and myoglobin, and qualitative cTnT on admission and at 12 h. Diagnosis of index event and incidence of new cardiac events (death, non-fatal myocardial infarction, revascularization, or readmission for unstable angina) over 3 months were assessed. Based on standard criteria, myocardial infarction occurred in 37/214 (17%), and unstable angina in 72/214 (34%). At 12 h from admission, cardiac troponins had higher sensitivity for the diagnosis of acute coronary syndromes (myocardial infarction and unstable angina) than conventional markers (cTnI 48%, cTnT 38%, CKMB mass 30% or myoglobin 27%). At 3 months, a new cardiac event had occurred in 42/214 (20%). Significantly higher event rates occurred when any of the biochemical markers was elevated, but the statistical significance was highest for patients with elevated cTnI (p < 0.0001). Whilst gender, history of ischaemic heart disease (IHD), stress test response, cTnT, cTnI, CKMB mass and myoglobin were univariate predictors, cTnI at 12 h and stress test response were the only two independent significant predictors for a subsequent cardiac event at 3 months. Raised cTnI at 12 h after admission had the highest sensitivity for the diagnosis of acute coronary syndromes, and was independently associated with a 2-3 times increased risk of future cardiac events within 3 months among patients with acute chest pain suggestive of myocardial ischaemia but with normal or non-diagnostic ECGs.     

Suspected angina pectoris: a rapid-access chest pain clinic.

We prospectively evaluated a rapid-access chest pain clinic in terms of clinical diagnoses, outcomes, morbidity and mortality at 3 months follow-up in patients, and cost-effectiveness. All patients seen at the clinic from February 1999 to December 2000 were assessed. Referring doctors indicated the management they would have provided had the clinic been unavailable, to allow a cost-effectiveness analysis. Overall, 709 patients were referred, 471 (66%) from General Practitioners, 212 (30%) from Accident and Emergency doctors and 26 (4%) from other sources. All had recent onset, or increasing frequency of ischaemic-type chest pain (excluding those with suspected myocardial infarction or rest chest pain angina). Fifty-one (7%) had acute coronary syndromes, 119 (17%) had stable ischaemic heart disease, 144 (20%) had possible ischaemic heart disease, and 395 (56%) were considered to have non-ischaemic symptoms. Some 70% of patients were seen within 24 h. Only 57 patients (8%) were admitted. Had the clinic been unavailable, 160 patients would have been admitted. Out-patient cardiology appointments were arranged for 116 patients (16%), and 429 patients (60%) were discharged directly. Follow-up data at 3 months were obtained from 565/567 eligible patients (99.6%). No major cardiac events (death/myocardial infarction) occurred in those with non-ischaemic chest pain. There were five deaths (including one due to cancer) and three patients had a myocardial infarction (event rate 1%). There were eleven readmissions for angina: six were in patients with acute coronary syndromes, and four of these six were awaiting revascularization. The estimated net saving was pound 58/patient. A rapid-access chest pain clinic offers a prompt, safe and cost-effective service in a challenging group of patients.     

Prevalence of acute myocardial infarction and other serious diagnoses in patients presenting to an urban emergency department with chest pain

A retrospective cohort study and chart review were performed to estimate the absolute and relative prevalence of the serious diagnoses that might cause a patient to present to the Emergency Department (ED) with a chief complaint of chest pain. In this study, we queried a database of 347,229 complete visits to the San Francisco General Hospital Emergency Department between July 1, 1993 and June 30, 1998 for visits by patients > 35 years old with a chief complaint of chest pain and no history of trauma. Visits for chest pain that resulted in hospitalization were assigned to one of nine diagnostic groups according to final diagnoses as coded in the database. Manual chart review by trained abstractors using explicit criteria was done when group assignment based on coded diagnoses was unclear and in all diagnoses of pulmonary embolism and aortic dissection. Of 8711 visits (2.5% of all visits) with a chief complaint of non-traumatic chest pain, 3271 (37.6%) resulted in hospitalization. Of the 3078 (94.1% of those hospitalized) assigned a final diagnosis, 329 (10.7% of hospitalizations, 3.8% of all visits) had acute myocardial infarction, 693 (22.5%) had either unstable angina or stable coronary artery disease, and 345 (11.2%) had pulmonary causes (mainly bacterial pneumonia) deemed serious enough to require hospitalization. Pulmonary embolism and aortic dissection were diagnosed in only 12 (0.4%) and 8 (0.3%) patients, respectively. In 905 (29.4%) hospitalizations for chest pain, myocardial infarction was “ruled out” and no cardiac ischemia or other serious etiology for the chest pain was diagnosed. Among patients presenting with chest pain, those in older age groups had dramatically increased risk of acute myocardial infarction. Women presenting with chest pain had a lower risk of acute myocardial infarction than men. In conclusion, the prevalence of acute myocardial infarction in the undifferentiated ED patient with a chief complaint of chest pain is only about 4%. An equal number of patients will have a serious pulmonary cause as the etiology of their pain. Pulmonary embolism and aortic dissection are important but extremely rare causes of a chest pain presentation to the ED.     

Analysis of factors affecting emergency physicians' decisions in the management of chest pain patients.

OBJECTIVE: The aim of this study was to determine the factors most affecting emergency physicians' decisions in the management of chest pain patients. METHODS: This prospective randomized cross-sectional study was carried out between March 2004 and September 2004 in an urban university hospital emergency department. Residents collected data on patients' demographic features, chest pain characteristics, electrocardiography, cardiac enzymes and outcome of patients. RESULTS: Five hundred and sixty-two patients were enrolled in the study; 389 (69.2%) patients were classified as having cardiac chest pain. Of the 389 patients suggested to have cardiac chest pain, 369 (94.4%) were classified as probable acute coronary syndrome; 286 (50.9%) patients were seen by cardiologists and 187 (33.3%) were admitted to the cardiology ward. The logistic regression analysis revealed that angina equivalents (P<0.001), age (P=0.002), history of coronary artery disease (P=0.003), electrocardiography (P=0.001), substernal chest pain (P=0.001), typical chest pain (P=0.000) and radiation of chest pain (P=0.039) were independent factors affecting emergency physicians' decisions. CONCLUSION: The factors affecting emergency physicians' decisions are correlated with guidelines.     

Role of "Ischemia modified albumin", a new biochemical marker of myocardial ischaemia, in the early diagnosis of acute coronary syndromes

Background: Diagnosis of cardiac ischaemia in patients attending emergency departments (ED) with symptoms of acute coronary syndromes is often difficult. Cardiac troponin (cTn) is sensitive and specific for the detection of myocardial damage but may not rise during reversible myocardial ischaemia. Ischemia Modified Albumin (IMA) has recently been shown to be a sensitive and early biochemical marker of ischaemia. Methods and Results: This study evaluated IMA in conjunction with ECG and cTn in 208 patients presenting to the ED within three hours of acute chest pain. At presentation, a 12-lead ECG was recorded and blood taken for IMA and cardiac troponin T (cTnT). Patients underwent standardised triage, diagnostic procedures, and treatment. Results of IMA, ECG, and cTnT, alone and in combination, were correlated with final diagnoses of non-ischaemic chest pain, unstable angina, ST segment elevation, and non-ST segment elevation myocardial infarction. In the whole patient group, sensitivity of IMA at presentation for an ischaemic origin of chest pain was 82%, compared with 45% of ECG and 20% of cTnT. IMA used together with cTnT or ECG, had a sensitivity of 90% and 92%, respectively. All three tests combined identified 95% of patients whose chest pain was attributable to ischaemic heart disease. In patients with unstable angina, sensitivity of IMA used alone was equivalent to that of IMA and ECG combined. Conclusions: IMA is highly sensitive for the diagnosis of myocardial ischaemia in patients presenting with symptoms of acute chest pain.     

颈动脉超声与心型脂肪酸结合蛋白检测对胸痛患者筛查作用的研究

目的通过颈动脉中膜厚度(IMA)测定及血浆心型脂肪酸结合蛋白(H-FABP)水平测定,探讨其对发病早期胸痛患者的筛查作用。方法 60例胸痛患者分为非冠心病组、心绞痛组和急性心肌梗死组,分析IMA结果,并与心电图对比分析,测定并分析各组间血浆H-FABP水平,并与CK-MB做比较。结果冠心病组IMA明显高于对照组和非冠心病组,冠心病组IMA诊断阳性率高于心电图诊断阳性率;血浆H-FABP在冠心病早期即明显升高,其中急性心肌梗死组高于心绞痛组,各组H-FABP诊断阳性率均高于CK-MB诊断阳性率。结论颈动脉中层厚度与心型脂肪酸结合蛋白检测有助于发病早期的胸痛病因识别,尤其对冠心病的识别和危重程度的预测有重要意义。     

Early identification of patients with an acute coronary syndrome as assessed by dispatchers and the ambulance crew

This study was performed to evaluate the possibility of early identification of patients with an acute coronary syndrome who are transported by ambulance. All patients in the community of G?teborg who were transported by ambulance over a period of 3 months owing to symptoms raising any suspicion of an acute coronary syndrome were studied. In all 930 cases that were included in the survey, 130 (14%) had a final diagnosis of acute myocardial infarction (AMI) and 276 (30%) had a final diagnosis of an acute coronary syndrome. Independent risk indicators for development of AMI were: male sex (odds ratio 1.70; 95% confidence limits 1.02-2.84), cold and clammy on admission of the ambulance crew (odds ratio 2.07; 95% confidence limits 1.23-3.49) and showing electrocardiogram (ECG) signs of myocardial ischemia on admission to the emergency department (odds ratio 8.78; 95%confidence limits 5.28-14.61). Independent predictors for development of an acute coronary syndrome were: male sex (odds ratio 1.97; 95% confidence limits 1.30-2.99), a history of angina pectoris (odds ratio 3.41; 95% confidence limits 2.24-5.26), cold and clammy on admission of the ambulance crew (odds ratio 1.95; 95% confidence limits 1.21-3.15), and ECG signs of myocardial ischemia on admission to the emergency department (odds ratio 5.55; 95% confidence limits 3.63-8.58). Among patients seen by the ambulance crew with symptoms raising any suspicion of an acute coronary syndrome, predictors for that diagnosis included male sex, a history of angina pectoris, patients being cold and clammy on admission of the ambulance crew, and ECG signs of myocardial ischemia on admission to the emergency department.     

Observer reproducibility and validity of systems for clinical classification of angina pectoris: comparison with radionuclide imaging and coronary angiography

OBJECTIVE: To assess reproducibility and validity of clinical classification of angina pectoris (AP) patients. DESIGN: Fifty-six patients scheduled for coronary angiography because of stable AP were classified by two independent observers with regard to (i) type and (ii) severity of chest pain (Canadian Cardiovascular Society, CCS) and (iii) cardiac functional status (New York Heart Association, NYHA). Myocardial perfusion imaging (MPI) was performed in 55 including measurement of ejection fraction in 46, angiography was undertaken in 51. RESULTS: Observers agreed 100% on the presence (n = 45) or absence (n = 11) of angina. They agreed in 52 (93%), 48 (86%), and 42 (75%) patients with regard to type of pain, CCS grade, and NYHA class, respectively. In the remaining patients, they disagreed by one class only. The positive and negative predictive values of typical/atypical angina for perfusion abnormalities and coronary disease were 55%/82% and 53%/ 82%, respectively. CONCLUSIONS: Observer agreement was excellent for presence, type, and severity of chest pain but moderate with regard NYHA class. Clinical judgment could not predict with reasonable accuracy abnormal perfusion or coronary artery disease.     

Coronary computed tomography angiography for the assessment of chest pain: current status and future directions

Chest pain is one of the most common presenting symptoms leading to presentation to medical clinics and Emergency Departments worldwide. Defining the nature and etiology of chest pain can pose a diagnostic dilemma for clinicians, despite the availability of several diagnostic algorithms and guidelines to assist them in evaluating these patients. Most investigations in patients with acute chest pain are initially performed to either exclude or diagnose and manage potentially life-threatening conditions such as acute coronary syndrome, pulmonary embolism and aortic dissection. In cases of stable chest pain syndromes, the focus shifts to determining the presence, extent and severity of coronary artery disease. In recent years, coronary computed tomography angiography (CCTA) is being increasingly used worldwide in the assessment of both stable and acute chest pain syndromes. This review evaluates the current evidence regarding the clinical utility of CCTA in the stable and acute chest pain settings and outlines the latest advances in CCTA techniques, including functional assessment of coronary stenoses, and their potential clinical application to improve patient care in a cost-effective manner.     

Coronary CT angiography in emergency department patients with acute chest pain: triple rule-out protocol versus dedicated coronary CT angiography

Immediate coronary catheterization is mandatory for high risk patients with typical chest pain in the emergency department (ED). In contrast, in ED patients with acute chest pain but low to intermediate risk, traditional management protocol includes serial ECG, cardiac troponins and radionuclide perfusion imaging. However, this protocol is time-consuming and expensive, and definite treatment of unstable angina is often delayed. Due to advances of multi-detector CT (MDCT) technology, dedicated coronary CT angiography provides the potential to rapidly and reliably diagnose or exclude acute coronary syndrome in ED patients with acute chest pain. Moreover, major life-threatening causes of ED chest pain (i.e., acute aortic syndrome and pulmonary embolism as well as acute coronary syndrome) can simultaneously be assessed by the so-called “triple rule-out” protocol with a single scan. In ED patients with atypical chest pain and low to intermediate risk, the triple rule-out protocol may be preferred, especially in older patients who have relatively lower risk of lifelong radiation-induced cancer. However, the increased radiation dose resulting from the extended volume coverage with this protocol should be fully considered prior to performing this protocol. Therefore, in ED patients who have a low clinical suspicion of pulmonary embolism and acute aortic syndrome, especially younger patients, dedicated coronary CT angiography accompanied by modifications to reduce radiation dose is recommended.     

缺血修饰性清蛋白的临床应用研究

目的探讨缺血修饰性清蛋白（IMA）在急性冠状动脉综合征（ACS）早期诊断价值。方法将89例ACS患者分别于胸痛发作2、4、6、12h及24h采血检测IMA、肌钙蛋白I（cTnI）和肌酸激酶MB同功酶（CK—MB）。其中急性心肌梗死41例,心绞痛48例。分析IMA对ACS的诊断价值。结果ACS患者IMA水平于胸痛发作2h明显增高,4h达到高峰,6h后降至正常。而cTnI,CK—MB在胸痛发作4h开始增高,6h明显增高,以后逐步递增至24h。在心绞痛、心肌梗死中,IMA水平升高以心绞痛最明显（P〈0．05）。结论IMA是诊断ACS早期敏感指标,是诊断心肌缺血的生化标志物。