Value of simultaneous functional assessment in association with acute rest perfusion imaging for predicting short- and long-term outcomes in emergency department patients with chest pain

Background. Rest tomographic myocardial perfusion imaging (MPI) has significant utility for clinical decision making in emergency department chest pain patients. The role of functional data, commonly acquired with perfusion, has not been systematically evaluated. Methods and Results. Low- to moderate-risk patients undergoing rest MPI for risk stratification were included. The patients’ MPI findings were classified as normal (normal perfusion or function), abnormal (perfusion defect with abnormal regional function), or discordant (perfusion defect with normal regional function). Ejection fraction was determined from the gated MPI studies. Events based on perfusion classifications and ejection fraction were evaluated. A total of 2,826 consecutive patients (abnormal MPI results in 40%, normal in 32%, and discordant in 27%) were studied. Outcomes were similar for those with normal MPI results versus those with discordant MPI results (myocardial infarction [MI] based on troponin I [TnI], 3.5% vs 4.0%; MI based on creatine kinase-MB, 1.5% vs 1.7%; revascularization, 5.2% vs 5.5%; and MI/revascularization based on TnI, 7.9% vs 8.1%) (P=not significant for all). Both groups had significantly fewer events (P<.001 for all) when compared with patients with abnormal MPI studies (MI based on TnI, 15%; MI based on creatine kinase-MB, 10%; revascularization, 17%; MI based on TnI or revascularization, 24%). The mortality rate was not different among the 3 groups. Multivariate analysis showed that mild/moderate and severe systolic dysfunction were independent predictors of 30-day and 1-year mortality rates (P=.001). Conclusions. The concurrent evaluation of perfusion and function (regional and global) with MPI provides significant risk/outcome predictive power.     

Differences in diagnostic evaluation and clinical outcomes in the care of patients with chest pain based on admitting service: The benefits of a dedicated chest pain unit

Background  Chest pain is one of the most common complaints of patients presenting at emergency departments. However, the most appropriate diagnostic evaluation for patients with chest pain but without acute coronary syndrome remains controversial, and differs greatly among institutions and physicians. At our institution, patients with chest pain can be admitted to an internist-run hospitalist service, a private attending service, or a cardiologist-run Chest Pain Unit. The goal of the present study was to compare the management and outcomes of patients admitted with chest pain based on admitting service. Methods  The charts of 750 patients (250 consecutive patients per service) with a discharge diagnosis of chest pain were studied retrospectively. Results  Patients admitted to the Chest Pain Unit were younger and had a lower prevalence of known coronary artery disease, hypertension, or diabetes, but a similar prevalence of other risk factors compared with the other groups. Sixty percent of the patients in the Chest Pain Unit underwent stress myocardial perfusion imaging as their primary diagnostic modality (vs 22% and 12% of patients in the hospitalist and private services, respectively; P<.001). In contrast, 35% of the patients admitted to the hospitalist service underwent rest echocardiography (vs 8% and 17% of patients in the Chest Pain Unit and private services, respectively; P<.001). Finally, 47% of the patients in the private service underwent coronary angiography as their primary diagnostic modality (vs 6% and 10% of patients in the Chest Pain Unit and hospitalist services, respectively; P<.001). The length of stay was shortest for patients in the Chest Pain Unit (1.4±1.2 days vs 3.9±3.4 days and 3.5±3.6 days in the hospitalist and private services, respectively; P<.001), even when corrected for patient age and number of risk factors. Readmission within 6 months was lowest for patients in the Chest Pain Unit (4.4% vs 17.6% and 15.2% in the hospitalist and private services, respectively; P<.001). Conclusions  The results of this study demonstrate that a highly protocolized chest pain unit, using myocardial perfusion imaging as primary diagnostic modality, results in a decreased length of stay and readmission rate.     

Esophageal dysfunction in patients with atypical chest pain investigated with esophageal scintigraphy and myocardial perfusion imaging: An outcome study

BACKGROUND: The objectives of this study were to determine the role of esophageal scintigraphy (ES) and myocardial perfusion imaging (MPI) in patients with atypical chest pain investigated for ischemic heart disease (IHD). METHODS AND RESULTS: One hundred five consecutive patients with atypical chest pain were investigated by dual-isotope MPI (1-day rest-stress protocol). Within a 10-day period, each patient also had liquid and semisolid ES performed with dynamic imaging over a 2-minute period for each phase. All patients were risk-stratified, and 28 patients were also investigated by coronary angiography. Patient outcome was assessed with the use of endpoints including cardiac death, myocardial infarction, and coronary revascularization procedures. Of the patients, 53 (50%) had esophageal dysfunction (ED) but no IHD, 41 (39%) had both ED and IHD, 5 (5%) had normal ES and IHD, and 6 (6%) had neither ED nor IHD. On the basis of outcome findings (n = 105) and coronary angiogram results (n = 28), MPI showed sensitivity for the detection of IHD of 92% in this patient population. Of the 94 patients (89%) with ED, 48 (51%) showed esophageal dysmotility, 9 (10%) showed gastroesophageal reflux, 17 (18%) showed esophageal spasm and dysmotility, 17 (18%) showed both reflux and dysmotility, and 3 showed other abnormalities. The median follow-up period after MPI was 20 months (range, 9-30 months). Twenty-one patients had cardiac events. These included 2 cardiac deaths, 2 myocardial infarctions, 6 coronary artery bypass graft surgeries, and 11 angioplasty/stent procedures. All but 2 of these patients had abnormal ES studies, and 7 had no prior history of IHD. MPI detected IHD in all but 2 of these patients. CONCLUSIONS: There is a high incidence of ED in patients with atypical chest pain referred for cardiologic assessment. The low proportion of patients with IHD alone and of those with neither IHD nor ED presenting with atypical chest pain (5%), as well as the high proportion with ED alone (50%), indicates the high likelihood of chest pain derived from ED. However, of the 21 patients with cardiac events, 7 had no prior history of IHD, indicating the importance of the use of MPI in the investigation of patients with atypical chest pain syndromes.     

Comprehensive adenosine stress perfusion MRI defines the etiology of chest pain in the emergency room: Comparison with nuclear stress test

Purpose

To compare standard of care nuclear SPECT imaging with cardiac magnetic resonance imaging (MRI) for emergency room (ER) patients with chest pain and intermediate probability for coronary artery disease.

Materials and Methods

Thirty‐one patients with chest pain, negative electrocardiogram (ECG), and negative cardiac enzymes who underwent cardiac single photon emission tomography (SPECT) within 24 h of ER admission were enrolled. Patients underwent a comprehensive cardiac MRI exam including gated cine imaging, adenosine stress and rest perfusion imaging and delayed enhancement imaging. Patients were followed for 14 ± 4.7 months.

Results

Of 27 patients, 8 (30%) showed subendocardial hypoperfusion on MRI that was not detected on SPECT. These patients had a higher rate of diabetes (P = 0.01) and hypertension (P = 0.01) and a lower global myocardial perfusion reserve (P = 0.01) compared with patients with a normal cardiac MRI (n = 10). Patients with subendocardial hypoperfusion had more risk factors for cardiovascular disease (mean 4.4) compared with patients with a normal MRI (mean 2.5; P = 0.005). During the follow‐up period, patients with subendocardial hypoperfusion on stress MRI were more likely to return to the ER with chest pain compared with patients who had a normal cardiac MRI (P = 0.02). Four patients did not finish the MR exam due to claustrophobia.

Conclusion

In patients with chest pain, diabetes and hypertension, cardiac stress perfusion MRI identified diffuse subendocardial hypoperfusion defects in the ER setting not seen on cardiac SPECT, which is suspected to reflect microvascular disease. J. Magn. Reson. Imaging 2009;30:753–762. © 2009 Wiley‐Liss, Inc.     

Adenosine-stress dynamic real-time myocardial perfusion CT and adenosine-stress first-pass dual-energy myocardial perfusion CT for the assessment of acute chest pain: Initial results

Purpose

Recent innovations in CT enable the evolution from mere morphologic imaging to dynamic and functional testing. We describe our initial experience performing myocardial stress perfusion CT in a clinical population with acute chest pain.

Methods and materials

Myocardial stress perfusion CT was performed on twenty consecutive patients (15 men, 5 women; mean age 65 ± 8 years) who presented with acute chest pain and were clinically referred for stress/rest SPECT and cardiac MRI. Prior to CT each patient was randomly assigned either to Group A or to Group B in a consecutive order (10 patients per group). Group A underwent adenosine-stress dynamic real-time myocardial perfusion CT using a novel “shuttle” mode on a 2nd generation dual-source CT. Group B underwent adenosine-stress first-pass dual-energy myocardial perfusion CT using the same CT scanner in dual-energy mode. Two experienced observers visually analyzed all CT perfusion studies. CT findings were compared with MRI and SPECT.

Results

In Group A 149/170 myocardial segments (88%) could be evaluated. Real-time perfusion CT (versus SPECT) had 86% (84%) sensitivity, 98% (92%) specificity, 94% (88%) positive predictive value, and 96% (92%) negative predictive value in comparison with perfusion MRI for the detection of myocardial perfusion defects. In Group B all myocardial segments were available for analysis. Compared with MRI, dual-energy myocardial perfusion CT (versus SPECT) had 93% (94%) sensitivity, 99% (98%) specificity, 92% (88%) positive predictive value, and 96% (94%) negative predictive value for detecting hypoperfused myocardial segments.

Conclusion

Our results suggest the clinical feasibility of myocardial perfusion CT imaging in patients with acute chest pain. Compared to MRI and SPECT both, dynamic real-time perfusion CT and first-pass dual-energy perfusion CT showed good agreement for the detection of myocardial perfusion defects.     

ECG-gated chest CT angiography with 64-MDCT and tri-phasic IV contrast administration regimen in patients with acute non-specific chest pain

The purpose of this study was to evaluate chest CTA protocol using retrospective ECG-gating and triphasic IV contrast regimen for comprehensive evaluation of patients with acute non-specific chest pain. ECG-triggered dose modulation was used with a 64-MDCT scanner in 56 non-critically ill patients with acute nonspecific chest pain using triphasic IV regimen: 50 ml contrast followed by 50 ml 60% contrast/saline and 30 ml normal saline. Lungs, aorta, pulmonary and coronary arteries were graded on a 5-point scale (5, best). Aorta and pulmonary artery attenuation was measured and three coronary artery groups were evaluated. Comparison with invasive coronary angiography was obtained in nine patients on a per segment (16 total) basis. Dosimetry values were obtained. Studies were satisfactory in all patients (score >3). Aorta and pulmonary artery attenuation was >200 HU in 90.5%. Lung or pleura, non-cardiac vascular and coronary arteries disease were detected in 20, 11 and 16 patients, respectively. Median coronary angiography (grade 5) was significantly higher than acceptable for diagnosis grade 4 (p < 0.001). Per segment, weighted kappa statistic was 0.79 indicating substantial agreement with catheter angiography (p<0.001). Average DLP was 1,490 ± 412 mGy-cm. Gated 64-MDCT angiography with triphasic IV contrast is a robust multipurpose technique for patients with acute non-specific chest pain. An erratum to this article can be found at     

胸痛中心的成立对急性ST段抬高型心肌梗死患者救治的影响

目的 探讨胸痛中心的建立对急性ST段抬高型心肌梗死(STEMI)患者救治的影响.方法 参照国际胸痛中心协会的要求建立胸痛中心及相应的管理制度和救治流程.选取沈阳军区总医院2015年5月-2016年3月收治的急性ST段抬高型心肌梗死(STEMI)患者为观察组,未建立胸痛中心之前2014年1-12月收治的STEMI患者为对照组,共入选患者1088例,观察组576例,对照组512例.采用回顾性非同期队列研究方法,观察组入院后进入胸痛中心,对照组在胸痛中心成立前入院进行常规救治.观察两组STEMI患者的一般情况、入院后首份心电图完成时间以及10min内首份心电图完成份数、经皮冠状动脉介入治疗(PCI)支架置入情况、入门球囊扩张时间(D2B)、住院天数及院内死亡率等.结果 与胸痛中心成立前比较,胸痛中心成立后患者的疾病种类构成以及年龄、性别等差异无统计学意义(P＞0.05),与对照组相比,观察组第一份心电图平均完成时间缩短(P=0.001).观察组PCI支架置入成功率高于对照组,但差异无统计学意义(P=0.222),入门球囊扩张时间(P＜0.001)及住院时间(P=0.005)短于对照组,两组院内死亡率差异无统计学意义(P＞0.05).结论 胸痛中心的建立有效缩短了STEMI患者的救治时间,提高了治疗效率,缩短了住院时间,值得在临床中进一步推广.     

平板运动试验及心肌灌注显像在飞行人员不典型心肌缺血诊断中的对比研究

目的评价活动平板运动试验对飞行人员不典型心肌缺血的诊断价值，并和心肌灌注显像及冠状动脉造影作对比研究，为其医学鉴定提供参考依据。方法不典型胸痛患者38例，均行活动平板运动试验及心肌灌注显像，结果分别与冠状动脉造影相比较。结果38例冠状动脉造影检查中有13例冠状动脉狭窄病变；运动试验阳性15例，阴性23例；心肌灌注显像检出可逆性心肌缺血16例，阴性22例。运动试验、心肌灌注显像诊断冠心病心肌缺血的灵敏度、特异性、准确性分别为53．8％、68．0％、63．2％和92．3％、84．0％、86．8％。结论活动平板运动试验出现异常ST—T改变，对诊断不典型胸痛患者冠心病心肌缺血有一定的意义，对飞行人员群体的冠心病诊断和排除亦有一定的应用价值。心肌灌注显像在飞行人员体检中的应用价值高于平板运动试验。     

Cardiac CT for the assessment of chest pain: Imaging techniques and clinical results

Immediate and efficient risk stratification and management of patients with acute chest pain in the emergency department is challenging. Traditional management of these patients includes serial ECG, laboratory tests and further on radionuclide perfusion imaging or ECG treadmill testing. Due to the advances of multi-detector CT technology, dedicated coronary CT angiography provides the potential to rapidly and reliably diagnose or exclude acute coronary artery disease. Life-threatening causes of chest pain, such as aortic dissection and pulmonary embolism can simultaneously be assessed with a single scan, sometimes referred to as "triple rule out" scan. With appropriate patient selection, cardiac CT can accurately diagnose heart disease or other sources of chest pain, markedly decrease health care costs, and reliably predict clinical outcomes. This article reviews imaging techniques and clinical results for CT been used to evaluate patients with chest pain entering the emergency department.     

Comparison of acute rest myocardial perfusion imaging and serum markers of myocardial injury in patients with chest pain syndromes

BACKGROUND: Newer diagnostic modalities such as serum markers and acute rest myocardial perfusion imaging (MPI) have been evaluated diagnostically in patients with chest pain in the emergency department (ED), but never concurrently. We compared these two modalities in distinguishing patients in the ED with symptomatic myocardial ischemia from those with non-cardiac causes. METHODS: Serum markers and acute technetium-99m sestamibi/tetrofosmin rest MPI were obtained in 75 patients admitted to the ED with chest pain and nondiagnostic electrocardiograms. Venous samples were drawn at admission and 8 to 24 hours later for total creatine kinase, CK-MB fraction, troponin T, troponin I, and myoglobin. Three nuclear cardiologists performed blinded image interpretation. Coronary artery disease (CAD) was confirmed either by diagnostic testing or by the occurrence of myocardial infarction (MI). RESULTS: Acute rest MPI results were abnormal in all 9 patients with MI. An additional 26 patients had objective evidence of CAD confirmed by diagnostic testing. The sensitivity of acute rest MPI for objective evidence of CAD was 73%. Serum troponin T and troponin I were highly specific for acute MI but had low sensitivity at presentation. Individual serum markers had very low sensitivity for symptomatic myocardial ischemia alone. In the multivariate regression model, only acute rest MPI and diabetes were independently predictive of CAD. CONCLUSION: At the time of presentation and 8 to 24 hours later, acute rest MPI has a better sensitivity and similar specificity for patients with objective evidence of CAD when compared with serum markers.     

64层螺旋CT及其联合心肌酶检查用于急性心源性胸痛诊断的价值

目的 探讨64层螺旋CT及其联合心肌酶检查用于诊断急性心源性胸痛的价值.方法 对70例急性心源性胸痛患者及35例正常对照进行64层螺旋CT血管成像(MSCTA)、血清心肌酶检查.结果 MSCTA联合心肌酶检查诊断急性心源性胸痛特异性为100.00％,敏感性为95.71％,均显著高于单用MSCTA时的94.29％和90.00％(P＜0.05);MSCTA在诊断冠状动脉狭窄时发现狭窄数量稍低于冠状动脉造影,但无统计学意义(P＞0.05);MSCT分辨钙化粥样斑块CT值为(341.66士308.43)HU,而非钙化粥样斑块CT值为(59.89士67.94)HU,差异具有统计学意义(P＜0.05).结论 64层螺旋CT联合心肌酶诊断急性心源性胸痛时具有良好的特异性与敏感性,64层螺旋CT还可用于判断冠状动脉狭窄与斑块性质.     

The clinical utility of provocative radionuclide oesophageal transit in the evaluation of non-cardiac chest pain

We combined edrophonium provocative testing with the technique of radionuclide oesophageal transit (RET) in 30 consecutive patients with non-cardiac chest pain (NCCP) and 12 controls. The oesophageal transit time of aqueous technetium-99m sulfur colloid was determined before and after intravenous infusion of 80 g/kg edrophonium chloride (ED). Patient symptoms during provocative RET (P-RET) were recorded. Thirteen (43%) of the patients had abnormal study results, whereas all control subjects had normal results. Three groups considered abnormal were observed: (a) in two patients (6%), the pain was reproduced and transit pre- and post-ED administration was prolonged (>15 s); (b) in six patients (20%), the pain was reproduced, but transit was normal pre- and post-ED; (c) in five patients (17%), transit pre- and post-ED was prolonged, but no pain was reproduced. In five patients (17%), ED prolonged the transit time > 15 s without pain, but the baseline transit was normal. Transit time was measurable in 23 patients. Mean pre-ED transit time was 10.2 ± 7.4 s (mean ± SD) and post-ED, 12.4 ± 8.0 s (P=0.3). We conclude that ED has no significant effect on transit time, and the pain induced by ED rarely correlates with an abnormal transit; P-RET provides additional information to baseline RET, increasing sensitivity, and may be a useful screening method in the evaluation of patients with NCCP.     

Acute chest pain: The role of MR imaging and MR angiography

MR imaging (MRI) and MR angiography (MRA) have gained a high level of diagnostic accuracy in cardiovascular disease. MRI in cardiac disease has been established as the non-invasive standard of reference in many pathologies. However, in acute chest pain the situation is somewhat special since many of the patients presenting in the emergency department suffer from potentially life-threatening disease including acute coronary syndrome, pulmonary embolism, and acute aortic syndrome. Those patients need a fast and definitive evaluation under continuous monitoring of vital parameters. Due to those requirements MRI seems to be less suitable compared to X-ray coronary angiography and multislice computed tomography angiography (CTA). However, MRI allows for a comprehensive assessment of all clinically stable patients providing unique information on the cardiovascular system including ischemia, inflammation and function. Furthermore, MRI and MRA are considered the method of choice in patients with contraindications to CTA and for regular follow-up in known aortic disease. This review addresses specific features of MRI and MRA for different cardiovascular conditions presenting with acute chest pain.     

Establishing a successful coronary CT angiography program in the emergency department: Official writing of the Fellow and Resident Leaders of the Society of Cardiovascular Computed Tomography (FiRST)

Coronary CT angiography is an effective, evidence-based strategy for evaluating acute chest pain in the emergency department for patients at low-to-intermediate risk of acute coronary syndrome. Recent multicenter trials have reported that coronary CT angiography is safe, reduces time to diagnosis, facilitates discharge, and may lower overall cost compared with routine care. Herein, we provide a 10-step approach for establishing a successful coronary CT angiography program in the emergency department. The importance of strategic planning and multidisciplinary collaboration is emphasized. Patient selection and preparation guidelines for coronary CT angiography are reviewed with straightforward protocols that can be adapted and modified to clinical sites, depending on available cardiac imaging capabilities. Technical parameters and patient-specific modifications are also highlighted to maximize the likelihood of diagnostic quality examinations. Practical suggestions for quality control, process monitoring, and standardized reporting are reviewed. Finally, the role of a “triple rule-out” protocol is featured in the context of acute chest pain evaluation in the emergency department.     

Radiology Imaging Volume Changes During Discrete COVID-19 Pandemic Waves: Implications for the Delta Variant of Coronavirus and Future Pandemics

PurposeThe aim of this study was to evaluate radiology imaging volumes at distinct time periods throughout the coronavirus disease 2019 (COVID-19) pandemic as a function of regional COVID-19 hospitalizations.MethodsRadiology imaging volumes and statewide COVID-19 hospitalizations were collected, and four 28-day time periods throughout the COVID-19 pandemic of 2020 were analyzed: pre–COVID-19 in January, the “first wave” of COVID-19 hospitalizations in April, the “recovery” time period in the summer of 2020 with a relative nadir of COVID-19 hospitalizations, and the “third wave” of COVID-19 hospitalizations in November. Imaging studies were categorized as inpatient, outpatient, or emergency department on the basis of patient location at the time of acquisition. A Mann-Whitney U test was performed to compare daily imaging volumes during each discrete 28-day time period.ResultsImaging volumes overall during the first wave of COVID-19 infections were 55% (11,098/20,011; P < .001) of pre–COVID-19 imaging volumes. Overall imaging volumes returned during the recovery time period to 99% (19,915/20,011; P = .725), and third-wave imaging volumes compared with the pre–COVID-19 period were significantly lower in the emergency department at 88.8% (7,951/8,955; P < .001), significantly higher for outpatients at 115.7% (8,818/7,621; P = .008), not significantly different for inpatients at 106% (3,650/3,435; P = .053), and overall unchanged when aggregated together at 102% (20,419/20,011; P = .629).ConclusionsMedical imaging rebounded after the first wave of COVID-19 hospitalizations, with relative stability of utilization over the ensuing phases of the pandemic. As widespread COVID-19 vaccination continues to occur, future surges in COVID-19 hospitalizations will likely have a negligible impact on imaging utilization.     

Coronary CT angiography for acute chest pain in the emergency department

Acute chest pain in the emergency department (ED) is a common and costly public health challenge. The traditional strategy of evaluating acute chest pain by hospital or ED observation over a period of several hours, serial electrocardiography and cardiac biomarkers, and subsequent diagnostic testing such as physiologic stress testing is safe and effective. Yet this approach has been criticized for being time intensive and costly. This review evaluates the current medical evidence which has demonstrated the potential for coronary CT angiography (CTA) assessment of acute chest pain to safely reduce ED cost, time to discharge, and rate of hospital admission. These benefits must be weighed against the risk of ionizing radiation exposure and the influence of ED testing on rates of downstream coronary angiography and revascularization. Efforts at radiation minimization have quickly evolved, implementing technology such as prospective electrocardiographic gating and high pitch acquisition to significantly reduce radiation exposure over just a few years. CTA in the ED has demonstrated accuracy, safety, and the ability to reduce ED cost and crowding although its big-picture effect on total hospital and health care system cost extends far beyond the ED. The net effect of CTA is dependent also on the prevalence of coronary artery disease (CAD) in the population where CTA is used, which significantly influences rates of post-CTA invasive procedures such as angiography and coronary revascularization. These potential costs and benefits will warrant careful consideration and prospective monitoring as additional hospitals continue to implement this important technology into their diagnostic regimen.     

The role of coronary CT angiography for acute chest pain in the era of high-sensitivity troponins

Accurate and efficient diagnostic triage for acute chest pain (ACP) remains one of the most challenging problems in the emergency department (ED). While the proportion of patients that present with myocardial infarction (MI), aortic dissection, or pulmonary embolism is relatively low, a missed diagnosis can be life threatening. Coronary computed tomography angiography (CCTA) has developed into a robust diagnostic tool in the triage of ACP over the past decade, with several trials showing that it can reliably identify patients at low risk of major adverse cardiovascular events, shorten the length of stay in the ED, and reduce cost associated with the triage of patients with undifferentiated chest pain. Recently, however, high-sensitivity troponin assays have been increasingly incorporated as a rapid and efficient diagnostic test in the triage of ACP due to their higher sensitivity and negative predictive value of myocardial infarction. As more EDs adopt high-sensitivity troponin assays into routine clinical practice, the role of CCTA will likely change. In this review, we provide an overview of CCTA and high-sensitivity troponins for evaluation of patients with suspected ACS in the ED. Moreover, we discuss the changing role of CCTA in the era of high-sensitivity troponins.     

A randomized trial of exercise treadmill ECG versus stress SPECT myocardial perfusion imaging as an initial diagnostic strategy in stable patients with chest pain and suspected CAD: Cost analysis

Background  Exercise electrocardiography (ETT) is frequently used in patients with suspected coronary artery disease (CAD). Single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) improves diagnostic stratification. There are no randomized trials comparing ETT and MPI. We hypothesized that first-line MPI would be effective and cost-saving versus ETT. Methods and Results  We randomized 457 outpatients with stable chest pain and suspected CAD to either treadmill electrocardiography or MPI. The post-test likelihood incorporated the pretest likelihood and the test result, with clinically driven testing. The primary endpoint was cost to diagnosis based on institutional and National Institute for Clinical Excellence costs. MPI significantly reduced the intermediate post-test likelihood of CAD (30% for ETT vs 3% for MPI, P<.0001) and further investigations (71% for ETT vs 16% for MPI, P<.0001). Despite the reduction in downstream resource utilization after MPI, mean costs were not different between the 2 initial strategies: ￡490.44 (95% confidence interval, 453.80–527.08) for ETT versus ￡512.41 (95% confidence interval, 481.41–543.41) for MPI. MPI cost was no different from ETT cost in patients with an intermediate or high pretest likelihood (P=not significant). ETT was less expensive in low-risk patients. Conclusions  In this study there was no difference in cost to diagnosis between initial ETT and MPI. In low-likelihood patients ETT was less costly, whereas there was no cost difference in intermediate- or high-likelihood patients. Unrestricted grants for the project were provided by Bristol-Myers Squibb Medical Imaging (London, England) and the Northwick Park Cardiac Research Fund (Harrow, England), as well as a personal research grant for cardiac imaging from Mr Michael Tabor (London, England).     

Usefulness of multislice spiral computed tomography coronary angiography in patients with acute chest pain in the emergency department

Background

Despite reports that multislice spiral computed tomography (MSCT) has high sensitivity and specificity in preselected patient populations, the routine clinical feasibility and utility of MSCT coronary angiography in patients with acute chest pain in the emergency department remains uncertain.

Objectives

We sought to determine whether 16-slice MSCT coronary angiography can provide diagnostically useful images in patients with acute chest pain in the emergency department.

Methods

Ninety-eight patients in the emergency department (41 men, 57 women; mean age ± SD, 48.1 ± 11.9 y) with acute chest pain underwent MSCT coronary angiography. Coronary calcium (Agatston) scoring was performed, followed by contrast-enhanced MSCT. Images were evaluated for mean image quality (MIQ) and for degree of stenosis. These data were correlated with body mass index (BMI; in kg/m²), heart rate, beat-to-beat variation, and calcium score to assess their influence on image quality.

Results

The 28 patients (29%) with nondiagnostic MIQs had significantly higher BMIs (mean ± SD, 32.9 ± 9.1 vs 28.9 ± 6.7; P < 0.05) and heart rates (mean ± SD, 71.0 ± 11.9 beats/min vs 65.6 ± 9.9 beats/min; P < 0.05) than patients with diagnostic MIQs. Forty-five patients (46%) had at least 1 nondiagnostic coronary segment. These patients had significantly higher heart rates (mean ± SD, 70.5 ± 10.3 vs 64.1 ± 13.7; P < 0.05) than patients with only diagnostic-quality scans. Image quality correlated inversely and strongly with BMI and heart rate.

Conclusions

Sixteen-slice MSCT coronary angiography cannot routinely provide diagnostically useful images in patients with acute chest pain in the emergency department.