Evaluation of the patient with acute chest pain

Unexpected mortality in patients discharged from the emergency department following an episode of nontraumatic chest pain

BACKGROUND

Chest pain is the second most common presenting complaint seen in the emergency department. Following evaluation in the emergency department, many of these patients are discharged with a diagnosis of nonspecific chest pain. Our hypothesis is that this group of patients has a high prevalence of ischaemic heart disease.

METHODS

This was a prospective follow-up study of mortality in 786 patients who presented to an emergency department in the UK with an episode of nontraumatic chest pain and were discharged without further inpatient assessment. Observed mortality was compared with expected mortality in age-matched and sex-matched local population.

RESULTS

The observed mortality of the study group was consistently higher than expected throughout the study period. The 5-year mortality rates for men and women under the age of 65 years were more than double the expected rates for the local population [relative risk of 2.1 (95% confidence interval: 1.4-2.8) and 2.6 (1.4-3.8), respectively]. This increase was less marked in male and female patients aged 65 years or more [relative risk of 1.2 (0.9-1.5) and 1.5 (1.2-1.8), respectively]. Ischaemic heart disease accounted for almost 50% of male deaths in the study group. This compared with an expected rate of less than 30% of male deaths in the local population. An excess of cardiac deaths was not seen in women.

INTERPRETATION

Patients discharged from the emergency department following an episode of acute chest pain have significantly reduced 5-year survival. We conclude that further evaluation of this group to establish the prevalence of risk factors is important to support the strategic implementation of appropriate prevention programmes.

Impact of 64-slice cardiac computed tomographic angiography on clinical decision-making in emergency department patients with chest pain of possible myocardial ischemic origin

To examine the impact of contrast enhanced multidetector computed tomography (MDCT) on clinical decision-making in patients who present to the emergency department (ED) with chest pain of possible ischemic origin, we studied 58 consecutive patients (age 56 +/- 10 years, 36% female) with chest pain, intermediate risk, and no ischemic electrocardiographic changes or increased biomarker measurements. After standard ED patient assessment including cardiology consultation, a diagnosis of acute coronary syndrome was made in 41 patients (71%), hospitalization was recommended in 47 (81%), and 32 (55%) were scheduled for an early invasive strategy. Patients underwent 64-slice contrast agent-enhanced MDCT with image reconstruction in multiple formats using retrospective electrocardiographic gating, which revealed normal (no or trivial atheroma) coronary vasculature in 15 patients, nonobstructive atheroma in 20 patients, and obstructive coronary disease (> or =1 luminal narrowing of > or =50%) in 23 patients. After MDCT, the diagnosis of acute coronary syndrome was revised in 18 of 41 patients (44%; 16 normal MDCT/widely patent stents, 2 alternative diagnoses), planned hospitalization canceled in 21 of 47 patients (45%; 13 normal MDCT/patent stent, 8 minor branch vessel disease), and planned early invasive strategy altered in 25 of 58 patients (43%; unnecessary in 20 of 32, advisable in 5 of 26 others). Effect of MDCT on clinical decisions was greater in the 36 patients without known preceding coronary disease. In 32 patients discharged from the ED (11 after initial triage, 21 patients after MDCT), there were no major adverse cardiac events (e.g., death, myocardial infarction, unplanned revascularization) during a 12-month follow-up period. In conclusion, contrast agent-enhanced 64-slice cardiac MDCT was a valuable diagnostic tool in the ED triage of patients with chest pain of possible ischemic origin and decreased the need for hospitalization by almost half in this patient cohort.

Patient-dependent variables affecting treatment and prediction of acute coronary syndrome are age-related

BACKGROUND

Acute coronary syndrome (ACS) prevails in older patients and is associated with higher morbidity and mortality. Little is known about patient-related variables that may affect course and treatment of ACS in older vs. younger with acute chest pain.

METHODS

Situational, circumstantial, and other patient-related variables were assessed in 1000 unselected consecutive older (> or =70 years) and younger (<70 years) patients admitted with chest pain and possible ACS.

RESULTS

In 182 older vs. 818 younger patients, prevalence of females, those not speaking the local language, living alone, lower education level, non-smokers, diabetes, hypertension, preexisting coronary artery disease, and attempting some form of self-treatment before seeking medical help were significantly greater (P<0.001). Interval from chest pain onset to emergency department arrival was longer (P=0.05), and a higher proportion of the older considered hospitalization mandatory, suspecting ACS (P<0.001). ACS eventually developed in 19.1% of younger and 39% of older patients (P<0.001). On multivariate analysis, most predictive of ACS in the younger group were: preexisting coronary artery disease (OR 5.27; 95% CI 3.44-8.07, P<0.001), current smoking (OR 1.78; 95% CI 1.16-2.75, P=0.002), male sex (OR 1.57; 95% CI 1.0-2.59, P=0.07), and older age (OR 1.25; 95% CI 1.11-1.42, P=0.005). In the older group, these were: not speaking the local language (OR 2.39; 95% CI 1.19-4.79, P=0.005), preexisting coronary artery disease (OR 1.95; 95% CI 1.0-3.87, P=0.026), direct emergency department arrival (OR 1.9; 95% CI 1.0-3.77, P=0.066), and diabetes (OR 1.84; 95% CI 1.0-3.56, P=0.079).

CONCLUSIONS

We defined age-associated differences in patient-related variables that may predict ACS and affect treatment negatively. These variables might improve risk stratification upon hospitalization.

Noncardiac chest pain in the emergency department: the role of cardiac history, anxiety or depression and Type D personality

BACKGROUND

Noncardiac chest pain is common in patients presenting to emergency departments and is frequently associated with panic disorder. This can represent a major burden for patients and the healthcare system. Little is known about the patient characteristics that increase the risk of noncardiac chest pain. We examined whether cardiac history or Type D personality was associated with panic disorder and/or depression-driven noncardiac chest pain.

METHODS AND RESULTS

Patients presenting with noncardiac chest pain to the emergency department of the University Hospital Maastricht were screened using the Hospital Anxiety and Depression Scale (HADS). Patients scoring > or =8 on the HADS subscale were invited for a psychiatric interview; a consecutive sample of patients scoring <8 on the HADS was included as a reference group. Type D personality (tendency to experience emotional distress) was assessed with the DS14. Among the 304 HADS-positive patients, 89% were diagnosed with panic disorder/depression as compared with 8% of the 106 HADS-negative patients. Previous cardiac history was not associated with psychiatric diagnosis. Type D patients reported more anxiety symptoms (12.4+/-4.0 vs. 8.1+/-4.9) and depression symptoms on the HADS (10.2+/-4.7 vs. 5.8+/-4.9) and more often had comorbid panic disorder/depression (91/157=58% vs. 57/253=23%) than non-Type D patients (P<0.0001). Type D personality (odds ratio =8.67, 95% confidence interval 4.69-16.02), younger age and male sex were independently associated with increased risk of panic disorder or depression. Type D was independently associated with comorbid panic disorder/depression (odds ratio=14.49).

CONCLUSION

Type D personality, but not cardiac history, is independently associated with the presence of psychopathology in noncardiac chest pain. Type D is associated with a substantially increased risk of co-occurring PD/depression in these patients.

Dual-source computed tomography in patients with acute chest pain: feasibility and image quality

The aim of this study was to determine the feasibility and image quality of dual-source computed tomography angiography (DSCTA) in patients with acute chest pain for the assessment of the lung, thoracic aorta, and for pulmonary and coronary arteries. Sixty consecutive patients (32 female, 28 male, mean age 58.1±16.3 years) with acute chest pain underwent contrast-enhanced electrocardiography-gated DSCTA without prior beta-blocker administration. Vessel attenuation of different thoracic vascular territories was measured, and image quality was semi-quantitatively analyzed by two independent readers. Image quality of the thoracic aorta was diagnostic in all 60 patients, image quality of pulmonary arteries was diagnostic in 59, and image quality of coronary arteries was diagnostic in 58 patients. Pairwise intraindividual comparisons of attenuation values were small and ranged between 1±6 HU comparing right and left coronary artery and 56±9 HU comparing the pulmonary trunk and left ventricle. Mean attenuation was 291±65 HU in the ascending aorta, 334±93 HU in the pulmonary trunk, and 285±66 HU and 268±67 HU in the right and left coronary artery, respectively. DSCTA is feasible and provides diagnostic image quality of the thoracic aorta, pulmonary and coronary arteries in patients with acute chest pain.

The provision of emergency radiology services and potential radiologist workforce crisis: is there a role for the emergency-dedicated radiologist?

One of the greatest challenges facing the specialty of radiology over the next several years will involve the provision of emergency radiology services. The demand for medical imaging--especially computed tomography and magnetic resonance imaging--continues to explode in the emergency setting and threatens to overwhelm the resources of many radiology practices. How our specialty decides ultimately to respond is critical, as it will have far-reaching implications, which will define the role and perceived value of the radiologist in all settings for years to come.

Improvement of the detection of myocardial ischemia thanks to information technologies

BACKGROUND

The standard 12-lead ECG remains one of the basic investigations for the early detection and assessment of acute coronary syndromes. It is easy to perform, anywhere and anytime, and can be digitally transmitted within minutes to an emergency medical service for remote advice and triage. But the conventional ST-segment deviation criteria are of limited diagnostic accuracy. The purpose of this study is to investigate how much the use of computerized ECG techniques based on the measurement of the serial spatiotemporal ECG changes could improve the detection accuracy of transmural myocardial ischemia.

METHODS

We considered the serial changes of continuous 12-lead ECGs of 90 patients undergoing elective percutaneous coronary angioplasty (PTCA) recorded during balloon inflation as an experimental model of ECG changes induced by coronary artery occlusion. The spatiotemporal ECG changes were measured according to the CAVIAR method and assessed by multivariate discriminant analysis in reference to serial changes of control recordings and standard ECG criteria.

RESULTS

The diagnostic accuracy of the CAVIAR criteria for ischemia detection was 97%, with sensitivity of 98% and specificity of 96%, whereas the diagnostic accuracy of the conventional ST-segment criteria was 74%, with sensitivity of 60% and specificity of 88%. The increase of overall performance was obtained for all the occlusion locations.

CONCLUSIONS

Computer-assisted quantitative serial ECG analysis, taking into account the spatiotemporal changes of the QRS and T waves, would provide the physician with additional information for significantly improving the detection of transmural myocardial ischemia.

The risk for acute coronary syndrome associated with atrial fibrillation among ED patients with chest pain syndromes

OBJECTIVE

We sought to determine if atrial fibrillation is associated with an increased risk for an acute coronary syndrome (ACS) among emergency department (ED) patients with chest pain syndromes.

METHODS

We performed a retrospective analysis of a prospectively collected database on ED patients with chest pain by selecting patients with atrial fibrillation and frequency-matched control subjects without atrial fibrillation. Measured outcomes were acute myocardial infarction (AMI), ACS, and unstable angina (UA). The relative risks of AMI, ACS, and UA associated with atrial fibrillation were calculated.

RESULTS

One hundred forty patients with atrial fibrillation and 683 matched control subjects were identified. The rates of AMI for the atrial fibrillation and control groups were 11.4% and 10.8%, respectively; those of ACS were 27.9% and 26.7%, respectively; and those of UA were 16.4% and 15.8%, respectively. The relative risks of AMI and ACS did not increase in patients with atrial fibrillation: AMI, 1.05 (95% confidence interval [CI] = 0.63-1.75); ACS, 1.05 (95% CI = 0.78-1.40); and UA, 1.05 (95% CI = 0.6-1.7).

CONCLUSION

Among patients presenting to the ED with chest pain syndromes, atrial fibrillation is not associated with an increased risk for AMI, ACS, and UA.

Dual-source-CT in der Diagnostik des Thoraxschmerzes

BACKGROUND

With the depiction of pulmonary arteries, coronary arteries, and the aorta, CT angiography of the chest offers a comprehensive diagnostic work-up of unclear chest pain. The aim of this study was to assess the diagnostic accuracy of dual-source CT in this patient group.

MATERIALS AND METHODS

A total of 47 patients suffering from unclear chest pain were examined with a Siemens Somatom Definition. Volume and flow of contrast media (Ultravist, Schering) were adapted to the body weight. The examinations were evaluated with regard to image quality and contrast opacification and to the diagnostic accuracy with reference to the final clinical diagnosis.

RESULTS

Adequate contrast opacification was achieved in all examinations. The depiction of the coronary arteries was diagnostic in all cases. The cause of chest pain could be identified in 41 cases. Among the diagnoses were coronary and myocardial pathologies, valvular disease, aortic aneurysms and dissections, pulmonary embolism, and pneumonic consolidation.

CONCLUSION

DSCT angiography of the chest offers a very good image quality even at high heart rates so that a high diagnostic accuracy is achieved in patients with acute chest pain.

A comprehensive view of sex-specific issues related to cardiovascular disease

Cardiovascular disease (CVD) is the leading cause of mortality in women. In fact, CVD is responsible for a third of all deaths of women worldwide and half of all deaths of women over 50 years of age in developing countries. The prevalence of CVD risk factor precursors is increasing in children. Retrospective analyses suggest that there are some clinically relevant differences between women and men in terms of prevalence, presentation, management and outcomes of the disease, but little is known about why CVD affects women and men differently. For instance, women with diabetes have a significantly higher CVD mortality rate than men with diabetes. Similarly, women with atrial fibrillation are at greater risk of stroke than men with atrial fibrillation. Historically, women have been underrepresented in clinical trials. The lack of good trial evidence concerning sex-specific outcomes has led to assumptions about CVD treatment in women, which in turn may have resulted in inadequate diagnoses and suboptimal management, greatly affecting outcomes. This knowledge gap may also explain why cardiovascular health in women is not improving as fast as that of men. Over the last decades, mortality rates in men have steadily declined, while those in women remained stable. It is also becoming increasingly evident that gender differences in cultural, behavioural, psychosocial and socioeconomic status are responsible, to various degrees, for the observed differences between women and men. However, the interaction between sex-and gender-related factors and CVD outcomes in women remains largely unknown.

Usefulness of 64-slice cardiac computed tomographic angiography for diagnosing acute coronary syndromes and predicting clinical outcome in emergency department patients with chest pain of uncertain origin

BACKGROUND

Multidetector computed tomography (MDCT) has high diagnostic value for detecting or excluding coronary artery stenosis. We examined performance characteristics of MDCT for diagnosing or excluding an acute coronary syndrome in patients presenting to the emergency department (ED) with possible ischemic chest pain and examined relation to clinical outcome during a 15-month follow-up period.

METHODS AND RESULTS

We prospectively studied 58 patients (56+/-10 years of age, 36% female) with chest pain possibly ischemic in origin and no new ECG changes or elevated biomarkers. The patients underwent 64-slice contrast-enhanced MDCT, which showed normal coronary vessels (no or trivial atheroma) in 15 patients, nonobstructive plaque in 20 (MDCT-negative patients), and obstructive coronary disease (> or = 50% luminal narrowing) in 23 (MDCT-positive group). By further investigation (new elevation of cardiac biomarkers, abnormal myocardial perfusion scintigraphy and/or invasive angiography), acute coronary syndrome was diagnosed in 20 of the 23 MDCT-positive patients (ED MDCT sensitivity 100% [20/20], specificity 92% [35/38], positive predictive value 87% [20/23], negative predictive value 100% [35/35]). During a 15-month follow-up period, no deaths or myocardial infarctions occurred in the 35 patients discharged from the ED after initial triage and MDCT findings. One patient underwent late percutaneous coronary intervention (late major adverse cardiovascular events rate, 2.8%). Overall, ED MDCT sensitivity for predicting major adverse cardiovascular events (death, myocardial infarction, or revascularization) during hospitalization and follow-up was 92% (12/13), specificity was 76% (34/45), positive predictive value was 52% (12/23), and negative predictive value was 97% (34/35).

CONCLUSIONS

We found that 64-slice cardiac MDCT is a potentially valuable diagnostic tool in ED patients with chest pain of uncertain origin, providing early direct noninvasive visualization of coronary anatomy. ED MDCT had high positive predictive value for diagnosing acute coronary syndrome, whereas a negative MDCT study predicted a low rate of major adverse cardiovascular events and favorable outcome during follow-up.

Clinical risk scoring beyond initial troponin values: results from a large, prospective, unselected acute chest pain population

BACKGROUND

Risk stratifying the diverse group of patients who present to hospital with chest discomfort remains challenging. Current clinical risk models, typically derived from selected populations, are limited by their relative complexity and the absence of a well-defined role of troponin.

OBJECTIVE

To derive a simple clinical risk score from a large, unselected population of patients with chest discomfort and to delineate the prognostic value of an initial troponin measurement.

METHODS

Prospective, consecutive data were collected from patients who presented to a tertiary care hospital. Multivariate analysis was used to identify variables predictive of the primary end point: death, nonfatal myocardial infarction or revascularization at 30 days. Integer values were assigned, generating a risk score to quantify individual patient risk.

RESULTS

Among 1054 patients, predictor variables included ST-segment deviation (strongest predictor -- assigned two points), male sex, prior congestive heart failure, three or more cardiac risk factors and prior acetylsalicylic acid use (one point each). There was a progressive increase in events with increasing total score (P<0.0001), with a 15-fold gradient from scores of 0 to 4 and greater. Although a negative troponin measurement was associated with fewer events for all scores, patients with higher scores remained exposed to substantial risk. A negative initial troponin measurement conferred a negative predictive value of 97.3% (95% CI 93.7% to 99.1%) among patients with a risk score of 0.

CONCLUSION

Significant 30-day events occurred in patients with elevated risk scores, despite negative initial troponin measurements, emphasizing the importance of clinical risk stratification. This simple clinical risk score, in conjunction with a single troponin I measurement, facilitates triage of patients who present to hospital with chest discomfort.

Reimbursement for chest-pain CT: estimates based on current imaging strategies

The purpose of this study was to estimate reimbursement for chest pain CT, assuming no cost increase for current emergent chest pain imaging. Using reported imaging test characteristics, prevalence and risk of coronary heart disease, and Medicare reimbursement schedules, 10,000 simulated patients were evaluated with three chest pain imaging algorithms. The main difference among the algorithms was the initial imaging tool: stress echocardiography, single photon emission computed tomography (SPECT) and chest pain CT. Outcome analysis included deaths, intra- and extra-hospital myocardial infraction, number of tests performed, time utilization, and the cost per patient. The chest pain CT algorithm was assessed with its reimbursement as an unknown to determine a maximum reimbursement that would not increase overall healthcare costs. Stress echocardiography costs $856.5 per patient with 8.4 observation hours and 646 (27%) negative catheterizations. When SPECT replaces stress echocardiography, the cost increases to $1,413.7 with average observation of 9.05 hours and 1,060 (36%) negative catheterizations. Chest pain CT minimizes observation (by 8.4 and 9.1 compared to echocardiography and SPECT, respectively); negative catheterizations drop to 266 (12%). Solving for chest pain CT reimbursement as an unkown yields $433.1 and $990.3 when compared to echocardiography and SPECT, respectively. Under the assumption that new technology should not increase overall imaging costs, reimbursement for chest pain CT is compatible with current reimbursement for pulmonary embolism and aortic dissection CTA. Reimbursements must be weighed against the complexity and patient benefits of the examination.

The utility of gestures in patients with chest discomfort

PURPOSE

Patient gestures are thought to be useful in determining the etiology of chest discomfort. We sought to determine the utility of certain patient gestures in the diagnosis of ischemic chest discomfort or myocardial infarction.

METHODS

We performed a prospective observational study of 202 patients admitted with chest discomfort. Patients were observed for the Levine Sign (clenched fist to the chest), the Palm Sign (palm of the hand to the chest), the Arm Sign (touching the left arm), and, as an indicator of nonischemic chest discomfort, the Pointing Sign (pointing with 1 finger).

RESULTS

Prevalences of the Levine, Palm, Arm, and Pointing Signs were 11%, 35%, 16%, and 4%, respectively. Using troponin levels and results of functional studies and coronary angiograms as reference standards, none of the sensitivities of the signs exceeded 38%. Specificities of the Levine and Arm Signs ranged between 78% and 86%, but the positive predictive values did not exceed 55%. The Pointing Sign had a specificity of 98% for evidence of nonischemic chest discomfort, and the positive predictive value of a negative troponin was 88%. The diameter of discomfort significantly correlated with certain gestures. Larger chest pain diameters were associated with evidence of myocardial ischemia.

CONCLUSIONS

Although certain gestures are exhibited by patients presenting with chest discomfort, they generally have poor test characteristics. The Pointing Sign has a high specificity for nonischemic chest discomfort, but a low prevalence. The gestures may communicate the size of the chest discomfort, with larger areas suggestive of ischemia.

Transferring Images via the Wireless Messaging Network Using Camera Phones Shortens the Time Required to Diagnose Acute Coronary Syndrome

BACKGROUND

Clear images can be sent via e-mail using camera phones. We examined whether camera phones are useful to transmit electrocardiogram (ECG) images.

METHODS AND RESULTS

ECG images were taken of 20 patients suspected to have acute coronary syndrome. Ten images were sent to a cardiologist by fax. The other 10 images were transmitted using a camera phone. The total time elapsed between image transmission to diagnosis by cardiologists was shorter in the camera phone group than in the fax group.

CONCLUSIONS

ECG image transmission by camera phone can be efficiently used in the diagnosis of acute coronary syndrome.

ECG-Gated 64-MDCT Angiography in the Differential Diagnosis of Acute Chest Pain

OBJECTIVE

The most important differential diagnoses of acute chest pain include myocardial infarction, aortic dissection, and pulmonary embolism. The purpose of this study was to evaluate the diagnostic value of an ECG-gated 64-MDCT angiography protocol for simultaneous assessment of the pulmonary arteries, coronary arteries, and aorta within a single breath-hold.

SUBJECTS AND METHODS

In 55 patients with acute chest pain, ECG-gated CT angiography was performed with a CT system in which 64 slices per gantry rotation were acquired. Density measurement and visual assessment of motion artifacts were performed to evaluate image quality. CT findings were correlated with results of laboratory tests and clinical follow-up. For 20 patients, two independent blinded reviewers compared findings on CT angiography with those on X-ray coronary angiography.

RESULTS

Adequate contrast enhancement of the pulmonary vessels, coronary arteries, and aorta was achieved in all cases. Regarding image quality of the coronary arteries, there was minor blurring in seven patients, and in one examination the images did not provide enough information for diagnosis. The average image quality rating was 1.2 on a scale in which 1 indicated no artifacts; 2, minor motion artifacts; and 3, image insufficient for diagnosis. The cause of chest pain was correctly identified with MDCT in 37 patients. The diagnoses included pulmonary embolism (n = 10), coronary stenosis (n = 9), and aortic dissection (n = 1). In four patients, additional diagnoses were found with other examinations.

CONCLUSION

With current techniques, ECG-gated CT angiography of the entire chest has very good image quality. The protocol proved helpful in the differential diagnosis of acute chest pain.

MDCT in Early Triage of Patients with Acute Chest Pain

OBJECTIVE

Current risk stratification of patients with acute chest pain but normal initial cardiac enzymes and nondiagnostic ECG is inefficient. We sought to determine whether contrast-enhanced MDCT-based detection of stenosis is feasible and improves early and accurate triage of patients with acute chest pain.

SUBJECTS AND METHODS

We studied 40 patients (53% men; mean age, 57 +/- 13 years) with chest pain who were awaiting hospital admission to rule out an acute coronary syndrome (ACS) despite the absence of diagnostic ECG changes and normal cardiac enzymes on emergency department presentation. Patients underwent contrast-enhanced MDCT before hospital admission. Afterward, patients received standard clinical care. All physicians involved in the patients' care were blinded to the results of MDCT. An expert panel established the presence or absence of ACS based on American Heart Association (AHA) guidelines. The MDCT images were evaluated for the presence of significant coronary artery stenosis (diameter reduction > 50%) and were used to make a triage decision.

RESULTS

All five patients (12.5%) with ACS (one with non-ST elevation myocardial infarction, four with unstable angina pectoris) had at least one significant coronary stenosis on MDCT (sensitivity, 100% [95% CI, 49-100%)]. ACS was ruled out in 35 patients (87.5%). Significant coronary stenosis was excluded in 26 of the 35 patients without ACS by MDCT (specificity, 74% [CI, 75-88%]), potentially saving 70% of unnecessary hospital admissions.

CONCLUSION

MDCT-based detection of significant coronary stenoses has tremendous potential to decrease the number of unnecessary hospital admissions, without reducing appropriate admission rates, in patients with chest pain who have nondiagnostic ECG results and normal cardiac enzymes. These results are likely to further improve with advances in MDCT technology.

Coronary multidetector computed tomography in the assessment of patients with acute chest pain

BACKGROUND

Noninvasive assessment of coronary atherosclerotic plaque and significant stenosis by coronary multidetector computed tomography (MDCT) may improve early and accurate triage of patients presenting with acute chest pain to the emergency department.

METHODS AND RESULTS

We conducted a blinded, prospective study in patients presenting with acute chest pain to the emergency department between May and July 2005 who were admitted to the hospital to rule out acute coronary syndrome (ACS) with no ischemic ECG changes and negative initial biomarkers. Contrast-enhanced 64-slice MDCT coronary angiography was performed immediately before admission, and data sets were evaluated for the presence of coronary atherosclerotic plaque and significant coronary artery stenosis. All providers were blinded to MDCT results. An expert panel, blinded to the MDCT data, determined the presence or absence of ACS on the basis of all data accrued during the index hospitalization and 5-month follow-up. Among 103 consecutive patients (40% female; mean age, 54+/-12 years), 14 patients had ACS. Both the absence of significant coronary artery stenosis (73 of 103 patients) and nonsignificant coronary atherosclerotic plaque (41 of 103 patients) accurately predicted the absence of ACS (negative predictive values, 100%). Multivariate logistic regression analyses demonstrated that adding the extent of plaque significantly improved the initial models containing only traditional risk factors or clinical estimates of the probability of ACS (c statistic, 0.73 to 0.89 and 0.61 to 0.86, respectively).

CONCLUSIONS

Noninvasive assessment of coronary artery disease by MDCT has good performance characteristics for ruling out ACS in subjects presenting with possible myocardial ischemia to the emergency department and may be useful for improving early triage.

Cardiac CT in emergency department patients with acute chest pain

Current strategies for the triage of patients who have chest pain but normal initial cardiac enzyme levels and nondiagnostic electrocardiograms do not permit efficient risk stratification. The potentially fatal consequences and high malpractice costs of missed acute coronary syndromes lead every year to the unnecessary hospital admission of about 2.8 million patients who present with acute chest pain in emergency departments in the United States. Most of these patients are at very low risk for an acute coronary syndrome. However, the standard clinical work-up does not provide information about the presence and extent of coronary artery disease. In most patients (80%-94%) with an acute coronary syndrome, a significant coronary artery stenosis can be detected with selective coronary angiography. High levels of diagnostic accuracy also have been established for the detection of significant coronary artery stenosis with the use of 16- and 64-section multidetector computed tomography (CT) in patients with stable angina. Preliminary data indicate that multidetector CT also can help quantify and characterize coronary atherosclerotic plaque and that the CT findings are in good agreement with those at intravascular ultrasonography. Although multidetector CT provides accurate information about the presence of coronary artery disease, large blinded observational studies are warranted to identify CT characteristics with high accuracy for diagnosis of acute coronary syndromes. Such information would enable the conduct of randomized controlled trials to determine whether the detection of coronary stenosis and plaque with multidetector CT improves triage and reduces the costs or increases the cost-effectiveness of management of acute chest pain.

Identifying Chest Pain Emergencies in the Primary Care Setting

The majority of patients presenting to a primary care physician with acute chest pain will have non-life-threatening etiologies. Nevertheless, catastrophic cause of chest pain such as ACS, AD, PE, esophageal perforation, and pericarditis must be considered in the differential diagnosis. Often, these deadly conditions have atypical clinical presentations that must be recognized. Furthermore, the physical examination can be deceptively benign in patients harboring a catastrophic etiology of chest pain. By identifying these atypical presentations, recognizing the utility of the physical examination, and understanding of the limitations of traditional diagnostic imaging, primary care physicians can effectively diagnose patients who have life-threatening cause of acute chest pain.

Myocardial infarction redefined: impact on case-load and outcome of patients with suspected acute coronary syndrome and nondiagnostic ECG at presentation

Risk stratification of chest pain (CP) is still debated. Objective of this study was to evaluate the performance of a risk stratification model for patients with suspected acute coronary syndrome (ACS) and nondiagnostic ECG at presentation, in whom the occurrence of myocardial infarction was either diagnosed following traditional (t-MI) or the recently redefined (r-MI) criteria. First-line 6-h work-up categorized 3068 patients with suspected ACS and nondiagnostic ECG into low-risk for short-term coronary events, intermediate-risk who entered second-line work-up, and high-risk. Intermediate-risk patients with positive second-line work-up and high-risk patients were considered for urgent coronary angiography. Angina, non-fatal MI, sudden death, and revascularization constituted composite end-point (CE) for in-hospital and 6-month outcome. ACS incidence was 16%; r-MI increased by 62% the diagnosis of MI over t-MI. Among 2024 discharged low-risk patients, 12 (0.6%) had non-fatal CE at 6 months. ACS was diagnosed in 19% of 503 intermediate-risk and 96% of 389 high-risk patients. Among ACS patients, in-hospital CE occurred in 14% of t-MI, 7% of r-MI, and 9% of unstable angina (UA) patients (t-MI vs. r-MI and t-MI vs. UA: p<0.05, for both); 6-month CE occurred in 23%, 16% and 12% of t-MI, r-MI and UA, respectively (t-MI vs. UA: p<005). Sensitivity, specificity and accuracy were high both for diagnostic (97%, 98%, 99%, respectively) and treatment (83%, 98%, 97%, respectively) strategy. Risk stratification, and categorization according to traditional or redefined MI and UA criteria allow safe allocation of resources in CP patients with suspected ACS and nondiagnostic ECG at presentation because outcome is accurately predicted.

A simple statistical model for prediction of acute coronary syndrome in chest pain patients in the emergency department

BACKGROUND

Several models for prediction of acute coronary syndrome (ACS) among chest pain patients in the emergency department (ED) have been presented, but many models predict only the likelihood of acute myocardial infarction, or include a large number of variables, which make them less than optimal for implementation at a busy ED. We report here a simple statistical model for ACS prediction that could be used in routine care at a busy ED.

METHODS

Multivariable analysis and logistic regression were used on data from 634 ED visits for chest pain. Only data immediately available at patient presentation were used. To make ACS prediction stable and the model useful for personnel inexperienced in electrocardiogram (ECG) reading, simple ECG data suitable for computerized reading were included.

RESULTS

Besides ECG, eight variables were found to be important for ACS prediction, and included in the model: age, chest discomfort at presentation, symptom duration and previous hypertension, angina pectoris, AMI, congestive heart failure or PCI/CABG. At an ACS prevalence of 21% and a set sensitivity of 95%, the negative predictive value of the model was 96%.

CONCLUSION

The present prediction model, combined with the clinical judgment of ED personnel, could be useful for the early discharge of chest pain patients in populations with a low prevalence of ACS.

Artificial neural network algorithms for early diagnosis of acute myocardial infarction and prediction of infarct size in chest pain patients

BACKGROUND

To prospectively validate artificial neural network (ANN)-algorithms for early diagnosis of myocardial infarction (AMI) and prediction of 'major infarct' size in patients with chest pain and without ECG changes diagnostic for AMI.

METHODS

Results of early and frequent Stratus CS measurements of troponin I (TnI) and myoglobin in 310 patients were used to validate four prespecified ANN-algorithms with use of cross-validation techniques. Two separate biochemical criteria for diagnosis of AMI were applied: TnI > or = 0.1 microg/L within 24 h ('TnI 0.1 AMI') and TnI > or = 0.4 microg/L within 24 h ('TnI 0.4 AMI'). To be considered clinically useful, the ANN-indications of AMI had to achieve a predefined positive predictive value (PPV) > or = 78% and a negative predictive value (NPV) > or = 94% at 2 h after admission. 'Major infarct' size was defined by peak levels of CK-MB within 24 h.

RESULTS

For the best performing ANN-algorithms, the PPV and NPV for the indication of 'TnI 0.1 AMI' were 87% (p=0.009) and 99% (p=0.0001) at 2 h, respectively. For the indication of 'TnI 0.4 AMI', the PPV and NPV were 90% (p=0.006) and 99% (p=0.0004), respectively. Another ANN-algorithm predicted 'major AMI' at 2 h with a sensitivity of 96% and a specificity of 78%. Corresponding PPV and NPV were 73% and 97%, respectively.

CONCLUSIONS

Specially designed ANN-algorithms allow diagnosis of AMI within 2 h of monitoring. These algorithms also allow early prediction of 'major AMI' size and could thus, be used as a valuable instrument for rapid assessment of chest pain patients.

[Predictive value of chest pain score for the diagnosis of acute coronary syndromes]

BACKGROUND AND OBJECTIVE

We analyzed the diagnostic utility of a chest pain score in patients evaluated for chest pain of possible coronary origin.

PATIENTS AND METHOD

We studied 1,068 consecutive patients coming to the emergency room with acute chest pain of possible coronary origin without ST-segment elevation, using a chest pain unit protocol. Chest pain was quantified by validated score (0-20 points). The diagnostic value of the chest pain score was analyzed for the diagnosis of acute myocardial infarction (AMI), unstable angina (UA) and acute coronary syndrome (ACS; AMI or UA).

RESULTS

The diagnosis of ACS was established in 651 patients (61%), AMI in 439 (41%) and UA in 212 (20%). In the multivariate analysis a chest pain score > or = 10 was an independent predictor of ACS (odds ratio [OR] = 2.9; 95% confidence interval [CI] 2.1-4; p = 0.0001), along with an age older than 70 years (OR = 2.6; 95% CI,1.8-3.7; p = 0.0001), male gender (OR = 2; 95% CI, 1.4-2.8; p = 0.0001); insulin-dependent diabetes (OR = 2.3; 95% CI, 1.2-4.6; p = 0.016); previous myocardial infarction (OR = 1.6; 95% CI, 1.1-2.4; p = 0.022), ST depression (OR = 9.3; 95% CI, 5.2-16.7; p = 0.0001) and T wave inversion (OR = 2.5; 95% CI, 1.4-4.3; p = 0.0001). The chest pain score was associated with the diagnosis of both AMI (OR = 1.4; 95% CI, 1.1-1.9; p < 0.02) and UA (OR = 2.8; 95% CI, 1.8-4.2; p < 0.0001).

CONCLUSIONS

The chest pain score allows independent information for the early diagnosis of patients coming to the emergency department with acute chest pain of possible coronary origin.

A computer protocol to evaluate subjects with chest pain in the emergency department: a multicenter study

OBJECTIVE

Chest pain is a frequent cause of medical admission to the emergency department and the main differential diagnosis is between coronary and non-coronary chest pain. We elaborated a computer protocol for the management of patients with chest pain.

METHODS

The computer protocol was made of three sections according to clinical, electrocardiographic and biochemical data. Each section was coded by a letter indicating the probability of coronary chest pain for each section. The combination of the three letters formed a score string used to assign patients to four subgroups of overall probability of coronary chest pain (low, medium-low, medium-high, and high). Low-probability patients were discharged from the emergency department, whereas high-probability patients were admitted to the coronary care unit. The medium-probability patients underwent further evaluation by means of a stress test and were re-classified as having a final low probability (negative test) or high probability (positive test).

RESULTS

We evaluated 472 patients (mean age 64 years, range 18-97 years; 47% female). The incidence of coronary events in patients with low, medium-low, medium-high and high overall probability was 1.9, 12.8,13.5 and 68.0%, respectively (P < 0.05). The positive and negative predictive values of the protocol were 64.7 and 97.1%, respectively.

CONCLUSIONS

Our computer protocol represents a reliable method for the management of patients with chest pain and a non-diagnostic electrocardiogram.

The diagnostic value of troponin T testing in the community setting

BACKGROUND

Many patients presenting with chest pain to their family physician are referred to the emergency room, in part, due to lack of accurate objective diagnostic tools. This study aimed to assess the diagnostic value of bedside troponin T kit testing in patients presenting with chest pain to their family physician.

DESIGN

Prospective, multi-center study.

METHODS

Consecutive subjects with chest pain were recruited from 44 community clinics in Jerusalem. Following clinical assessment by the family physician, qualitative troponin kit testing was performed. Patients with a negative clinical assessment and negative troponin kit were sent home and all others were referred to the emergency room. The final diagnosis at the time of hospital discharge was recorded and telephone follow up was performed after 60 days. Positive predictive value, negative predictive value, sensitivity and specificity of troponin kit for myocardial infarction diagnosis and of family physician for hospitalization, were assessed.

RESULTS

Of 392 patients enrolled, 349 (89%) were included in the final analysis. The prevalence of myocardial infarction was 1.7%. The positive and negative predictive values of the troponin kit for myocardial infarction diagnosis were 100% and 99.7%, respectively. The positive and negative predictive values of the family physician's assessment to predict hospitalization were 41.4% and 94.1%, respectively.

CONCLUSIONS

Troponin kit testing is an important tool to assist the family physician in the assessment of patients with chest pain in the community setting. Troponin kit testing may identify otherwise undiagnosed cases of myocardial infarctions, and reduce unnecessary referrals to the emergency room.

Exercise testing in chest pain units: rationale, implementation, and results

Chest pain units are now established centers for assessment of low-risk patients presenting to the emergency department with symptoms suggestive of acute coronary syndrome. Accelerated diagnostic protocols, of which treadmill testing is a key component, have been developed within these units for efficient evaluation of these patients. Studies of the last decade have established the utility of early exercise testing,which has been safe, accurate, and cost-effective in this setting. Specific diagnostic protocols vary, but most require 6 to 12 hours of observation by serial electrocardiography and cardiac injury markers to exclude infarction and high-risk unstable angina before proceeding to exercise testing. However, in the chest pain unit at UC Davis Medical Center,the approach includes "immediate" treadmill testing without a traditional process to rule out myocardial infarction. Extensive experience has validated this approach in a large, heterogeneous population. The optimal strategy for evaluating low-risk patients presenting to the emergency department with chest pain will continue to evolve based on current research and the development of new methods.

Imaging in the evaluation of the patient with suspected acute coronary syndrome

Over the last decade, major advances have been made in the treatment of acute coronary syndromes (ACSs). However, effective implementation of these treatments requires timely and accurate identification of the high-risk patient among all those presenting to the emergency department (ED) with symptoms suggestive of ACS. The opportunity for improving outcomes is time-dependent, so that early identification of the patient who has true ACS is essential. This necessity further increases the need for rapid triage tools, especially in the current setting of ED and hospital overcrowding that has become the norm in large urban centers.

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 8,711 visits (2.5% of all visits) with a chief complaint of non-traumatic chest pain, 3,271 (37.6%) resulted in hospitalization. Of the 3,078 (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.

Patient-related variables predicting acute coronary syndrome following admission for chest pain of possible coronary origin

OBJECTIVE

Improving risk stratification of patients experiencing acute chest pain with non-revealing electrocardiogram and cardiac biomarkers could reduce missed acute coronary syndrome and avoid unnecessary hospitalization.

METHODS

We assessed the ability of situational, circumstantial, and other patient-related variables in predicting acute coronary syndrome in 921 consecutive patients randomly admitted to this medical department with chest pain of possible coronary origin. A reference group comprised 107 patients referred promptly to the coronary care unit with acute myocardial infarction.

RESULTS

Acute coronary syndrome eventually developed in 219 (23.7%) patients. Age and proportions of male patients and those with diabetes, which were significantly lower in the heterogeneous chest pain group than in the reference group, did not differ when re-evaluation was performed between the latter group and the subgroup of patients who eventually developed acute coronary syndrome. Overweight and a family history of premature coronary artery disease remained significantly higher in the reference group, while prevalence of pre-existing coronary artery disease, previous coronary angiography, and coronary intervention remained significantly lower. Variables most significantly predictive of acute coronary syndrome resulted: pre-existing coronary artery disease [odds ratio (OR) 3.2; 95% confidence interval (CI) 2.17-4.71; P<0.001), older age (OR 1.35; 95% CI 1.17-1.57; P<0.001), male sex (OR 1.77; 95% CI 1.19-2.61; P=0.004), diabetes (OR 1.6; 95% CI 1.11-2.32; P=0.01), self-initiation of pain relief treatment before seeking medical help (OR 1.54; 95% CI 1.07-2.23; P=0.02), and conviction that hospitalization for acute coronary disease was mandatory (OR 1.46; 95% CI 1.03-2.07; P=0.03).

CONCLUSIONS

Easily obtainable patient-related variables might improve risk stratification and assist physicians to decide on policy in the emergency department and upon hospitalization.

Cardiac markers in the low-risk chest pain patient

With the arrival of point-of-care cardiac marker determination, emergency physicians may be able to arrive at the diagnosis of cardiac ischemia faster than ever before. However, these tests must be used with care, as a lack of understanding about when and how they should be obtained is important both for good patient care and to avoid medicolegal pitfalls. This report reviews risk stratification of patients who present with chest pain, provides an overview of cardiac markers and literature supporting their use, and concludes with a practice guideline for the utilization of cardiac markers in the emergency department.

Stress testing and troponin in unstable coronary syndromes: the status trial-clinical outcomes and resource use

Cardiac troponins are markers used to diagnose acute myocardial infarction, but their value in guiding management in low- to intermediate-risk patients is not well established. Using a randomized design, the authors compared a strategy using stress testing with blinded troponins vs a troponin I-guided strategy for risk stratification and management of 241 patients with intermediate-risk unstable angina. Fewer stress-tested patients required coronary care unit admission and repeat hospitalization for acute coronary syndrome, at a lower cost. There was no significant difference in rates of death and myocardial infarction due to acute coronary syndrome at 6 months' follow-up. For patients with intermediate-risk acute coronary syndrome, stress testing is as safe as, and more cost-effective than, a troponin I-guided strategy. Patients with marginal troponin I elevations can safely undergo stress testing. Further studies combining stress testing and a troponin I-guided strategy are warranted.

Initial Evaluation of Chest Pain

Chest pain is among the most frequently evaluated presenting complaints in the emergency department (ED). Diagnostic etiologies range from benign to life-threatening. Failure to diagnose the life-threatening chest emergencies-specifically acute coronary syndrome, aortic dissection, and pulmonary embolism-can lead to catastrophic medical and legal outcomes for the patient and physician respectively. This article focuses on clinical and risk management strategies to minimize misdiagnosis and produce favorable medical and medicolegal outcomes.

Relationship between heart-type fatty acid-binding protein levels and the risk of death in patients with serious condition on arrival at the emergency department

OBJECTIVE

Although heart-type fatty acid-binding protein (H-FABP) is a cardiac marker useful for early diagnosis of acute myocardial infarction (AMI), few data are available on its prognostic value. The objective of this study is to clarify the prognostic value of H-FABP in patients with a serious condition.

METHODS AND PATIENTS

We conducted a prospective study of 617 patients who presented to the emergency department with a serious condition. The H-FABP levels on arrival at the emergency department were divided into four groups using their quartiles. The endpoint was death from any causes in-hospital.

RESULTS

H-FABP ranged from 1.2 to 2,300 ng/ml, with a median of 19.9 ng/ml, a 25%-value of 6.7 ng/ml and 75%-value of 54.0 ng/ml. The unadjusted rate of the mortality increased progressively with increasing H-FABP quartile point (11% for quartile-I, 22% for quartile-II, 36% for quartile-III, and 38% for quartile-IV; p<0.001). After adjustment for age, gender, systolic blood pressure and the presence or absence of cardiovascular disease, H-FABP was the independent factor to predict the mortality.

CONCLUSION

H-FABP has proven to be an independent factor for prognosis in patients with a serious condition on arrival at the emergency department.

How to promote, improve and test adherence to scientific evidence in clinical practice

BACKGROUND

Negative variation in the management of patients with the same clinical condition is frequent, and affects quality of care. Recent studies indicate that single interventions are not an effective solution. We aim to demonstrate that a multifaceted strategy can favor the introduction of research into practice, and to assess its long-term effects on a set of common medical conditions exhibiting significant negative variation at our institution.

METHODS

The strategy, devised and agreed upon by a multidisciplinary group, was first applied to one relevant medical condition--cerebral ischemic stroke. To test its effectiveness a quasi-experimental study was conducted, comparing an intervention group with historical controls. After validation the strategy was extended to other pathologies, and its long-term effect measured using evidence-based quality indicators. Adherence to each indicator was determined prospectively on a six-month basis for a period of at least two consecutive years. Measures are expressed as proportions with 95% confidence intervals.

RESULTS

Validation findings demonstrated that the strategy improved compliance with scientific evidence: the percentage of patients who received a CT scan within 24 hours of hospital presentation rose from 56% to 75%, (chi2 = 7.43 p < 0.01); admissions to selected wards increased from 45% to 64%, (chi2 = 7.81 p < 0.01); the number of physical medicine visits within 24 hours of the request grew from 59% to 91% (chi2 = 14,40 p < 0.001). Over a four-year period the program was gradually applied to 14 medical conditions. Except for 3 cases, compliance with the pathway, i.e. number of eligible patients for whom data on the care process is collected, was above the minimum requirement of 75%. Indicator adherence generally exhibited a positive trend, though variability was observed both among different conditions and between different semesters for the same pathology.

CONCLUSION

According to our experience, incorporation of research into practice can be favored by systematically applying a shared, multifaceted strategy, involving multidisciplinary teams supported by central coordination. Institutions should device a tailor-made approach, should train personnel on implementation strategies, and create cultural acceptance of change. Just like for experimental trials, human and economic resources should be allocated within health care services to allow the achievement of this objective.

Assessment of patients with low-risk chest pain in the emergency department: Head-to-head comparison of exercise stress echocardiography and exercise myocardial SPECT

OBJECTIVES

The aim of the study was to compare head-to-head the performance of exercise tolerance test-stress echocardiography (ex-Echo) and exercise stress-perfusion nuclear imaging (exercise-single-photon emission computed tomography [ex-SPECT]) for the diagnosis of coronary artery disease (CAD) in patients evaluated at the chest pain unit with delay from chest pain (CP) onset.

BACKGROUND

As an early triage strategy for CAD in emergency medicine, ex-Echo could have the advantage of widespread availability and low costs.

METHODS

In the years 2000-2002, 503 consecutive patients (mean age 60 years) with recent (<24 hours) CP and nonischemic electrocardiogram (ECG), in whom CAD remained undiagnosed after first line 6-hour work-up including serum markers of myocardial injury and resting echocardiogram, underwent ex-Echo and ex-SPECT within 24 hours. Patients with (+)ex-Echo or (+)ex-SPECT or (+)ex-ECG or abnormal troponin I were referred to coronary angiography; otherwise, they were discharged and followed up. End points were coronary stenosis > or =50% and cardiovascular events at 6-month follow-up.

RESULTS

Ninety-nine patients (20%) had (+)ex-Echo and 121 (24%) (+)ex-SPECT; CAD was diagnosed in 81% and 67%, respectively; positive tests were concordant in 69%. In negative ex-Echo and ex-SPECT, final evidence of CAD emerged in 14 and 13, respectively. Ex-Echo demonstrated higher accuracy than ex-SPECT (93% +/- 1% vs 89% +/- 1%), optimal specificity (95% +/- 5% vs 90% +/- 5%), and positive predictive value (81% +/- 4% vs 67% +/- 4%); moreover, in the case of (-)ex-ECG, observed effective likelihood ratio indicates a (+)synergy between ex-ECG and ex-Echo.

CONCLUSIONS

Ex-Echo can be an effective diagnostic strategy in the early triage of CP patients, improving diagnosis in case of (-)ex-ECG and reducing unnecessary angiography number. Its drawback is represented by the 5% of missed diagnosis.

Molecular magnetic resonance imaging of coronary thrombosis and pulmonary emboli with a novel fibrin-targeted contrast agent

BACKGROUND

The differential diagnosis of acute chest pain is challenging, especially in patients with normal ECG findings, and may include coronary thrombosis or pulmonary emboli. The aim of this study was to investigate the novel fibrin-specific contrast agent EP-2104R for molecular targeted MR imaging of coronary thrombosis and pulmonary emboli.

METHODS AND RESULTS

Fresh clots were engineered ex vivo from human blood and delivered in the lungs and coronary arteries of 7 swine. Subsequent molecular MR imaging was performed with a navigator-gated free-breathing and cardiac-triggered 3D inversion-recovery black-blood gradient-echo sequence before and after systemic administration of 7.5 micromol/kg EP-2104R. Two swine served as the control group. MR images were analyzed by 2 investigators, and contrast-to-noise ratio and gadolinium concentration in the clots were assessed. Before contrast media application, no thrombi were visible. After contrast administration, all 32 pulmonary emboli, 3 emboli in the right heart, and 5 coronary thrombi were selectively visualized as white spots with a mean contrast-to-noise ratio of 32+/-19. The average gadolinium concentration from all 3 types of thrombi was 144+/-79 micromol/L.

CONCLUSIONS

Molecular MR imaging with the fibrin-targeted contrast-agent EP-2104R allows selective visualization of acute coronary, cardiac, and pulmonary thrombi.

Hand-held echocardiographic examination of patients with symptoms of acute coronary syndromes in the emergency department: the 30-day outcome associated with normal left ventricular wall motion

BACKGROUND

Acute chest pain is a common complaint for patients presenting to emergency departments. Electrocardiography (ECG) results and biochemical markers have strong positive predictive value, but an equally available, inexpensive, and non-invasive test with strong negative predictive value is needed. Hand-held echocardiography (HHE) might serve this purpose. The objective of this study was to test the hypothesis that in patients with symptoms suggestive of acute coronary syndrome, non-diagnostic ECG, and normal biochemical markers, HHE-documented normal left ventricular function is not associated with a clinical diagnosis of acute myocardial ischemia or infarction, nor an ischemic event within 30 days of follow-up.

METHODS

Assessment of left ventricular systolic function was performed in 150 patients with the HHE device. The incidences of the clinical end points of death, myocardial infarction, and ischemia were determined during the 30-day follow-up period. Data analysis included evaluation of specificity, sensitivity, and positive and negative predictive values.

RESULTS

The incidence of acute myocardial infarction was 2.5% (2/78) in the normal HHE group and 20% (6/30) in the abnormal HHE group (P = .002). The incidence of either acute myocardial infarction or ischemia was 7.6% (6/78) in the normal HHE group and 14.6% (6/30) in the abnormal HHE group (P = .11). The negative predictive value of HHE was 91%.

CONCLUSIONS

These results suggest a possible role for HHE in providing additional diagnostic and prognostic information in the examination of patients with a low likelihood of myocardial ischemia or infarction and symptoms suggestive of acute coronary syndrome.

Circulating endothelial cell count as a diagnostic marker for non-ST-elevation acute coronary syndromes

BACKGROUND

Shedding of endothelial cells from damaged endothelium into the blood occurs in a variety of vascular disorders. The purpose of this study was to evaluate the utility of circulating endothelial cell (CEC) count as a diagnostic marker of non-ST-elevation acute coronary syndromes (ACSs).

METHODS AND RESULTS

CEC counts were determined immediately (H0), 4 hours (H4), and 8 hours (H8) after admission in 60 patients with documented non-ST-elevation ACS and 40 control patients with no evidence of coronary artery disease. A total of 32 patients in the ACS group had elevated CEC counts (>3 cells/mL) in relation to early admission and single-episode chest pain. Patients from the control group had normal CEC counts. The interval between the chest pain episode and elevation was significantly shorter for CEC than troponin I. No correlation was found between the 2 markers. Interestingly, a subgroup of ACS patients with initially normal troponin I levels had high CEC counts, thus allowing early diagnosis in 30% more cases. At H0, the mean area under the receiver operating characteristic curve was significantly higher with the CEC count than with the troponin I level. At H4 and H8, the combined use of CEC and troponin was significantly better as a marker of ACS than CEC alone or troponin I alone.

CONCLUSIONS

This study demonstrates that CEC count can be used as an early, specific, independent diagnostic marker for non-ST-elevation ACS. A combined strategy using CEC count and troponin I level could provide an effective diagnostic tool.