Acute chest pain imaging in the outpatient setting

Acute SPECT imaging with Tc-99m sestamibi is an emerging, cost-effective stratagem for selected patients arriving at the emergency department with chest pain. To date, the cohort of patients studied have included those who arrive at the emergency department with typical chest pain and a normal or nondiagnostic electrocardiogram. This application could be extended to other clinical settings. The current case demonstrates that in an outpatient setting, a severe rest SPECT perfusion defect in a symptomatic patient with a nondiagnostic electrocardiogram prompted timely hospitalization and revascularization. The resting defect was consistent with jeopardized, viable myocardium as it normalized after revascularization.     

Focal breast pain: imaging evaluation and outcomes

ObjectivesTo determine the number and characteristics of cancers detected and the optimal imaging evaluation in women presenting with focal breast pain (FBP).Materials and methodsWe performed a retrospective review of 4720 women who underwent imaging for FBP from 2001 to 2013. Women 18 and over with one or two foci of breast pain and no concurrent breast symptoms were included. 944 patients met criteria.We recorded the imaging work-up, presence and type of finding at the site of pain, BI-RADS® assessment, and pathological outcomes. Subsequent imaging and clinical follow up was recorded.ResultsImaging evaluation consisted of sonogram alone in 286 women, mammogram alone in 231 women, and both in 427 women. 113 women had an imaging finding at the site of pain; 103 were designated benign or probably benign. 12 biopsies of corresponding findings were performed: 9 benign, 1 invasive lobular carcinoma, 1 invasive ductal carcinoma, 1 ductal carcinoma in situ. All three malignancies were seen mammographically; 2 had an ultrasound correlate.At initial evaluation, 4 incidental breast cancers were diagnosed remote from the site of FBP. All were seen on mammogram and 2 of 4 had an ultrasound correlate. On follow up evaluation, 9 cancers were diagnosed at the site of pain and 13 incidental cancers were diagnosed.ConclusionFBP is rarely associated with malignancy. Targeted ultrasound may be deferred in women 40 and older with FBP, no other clinical findings, and a negative mammogram.     

Impact of acute chest pain Tc-99m sestamibi myocardial perfusion imaging on clinical management

BACKGROUND: Previous studies have demonstrated the high sensitivity and specificity of technetium 99m sestamibi scintigraphy during acute chest pain myocardial perfusion imaging. However, no study has shown that this technique would alter clinical management in practice. METHODS AND RESULTS: One hundred twenty consecutive patients were injected with Tc-99m sestamibi (22 mCi) during pain; single photon emission computed tomography was performed 1 to 6 hours later. The population included inpatients and those who arrived at the emergency department with chest pain deemed to be at intermediate risk for myocardial ischemia. The requesting physician completed a questionnaire before the study, indicating the likelihood of cardiac disease and proposed management had the test not been available. Follow-up management was evaluated from medical records. There was a 34% reduction in total admissions and 59% in planned admissions to the coronary care unit (P <.001). Conversely, 7 patients had discharge cancelled and 17 required coronary care purely because of abnormal acute rest myocardial perfusion imaging results. Coronary angiography was reduced by 40% in a selected subgroup. CONCLUSIONS: In our population, acute rest myocardial perfusion imaging reduced total admissions and altered resource utilization. This may result in more appropriate triage of individual patients in the management algorithm, as well as potential cost savings.     

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.     

Predictors of image quality of coronary computed tomography in the acute care setting of patients with chest pain

Objective

We aimed to determine predictors of image quality in consecutive patients who underwent coronary computed tomography (CT) for the evaluation of acute chest pain.

Method and materials

We prospectively enrolled patients who presented with chest pain to the emergency department. All subjects underwent contrast-enhanced 64-slice coronary multi-detector CT. Two experienced readers determined overall image quality on a per-patient basis and the prevalence and characteristics of non-evaluable coronary segments on a per-segment basis.

Results

Among 378 subjects (143 women, age: 52.9 ± 11.8 years), 345 (91%) had acceptable overall image quality, while 33 (9%) had poor image quality or were unreadable. In adjusted analysis, patients with diabetes, hypertension and a higher heart rate during the scan were more likely to have exams graded as poor or unreadable (odds ratio [OR]: 2.94, p = 0.02; OR: 2.62, p = 0.03; OR: 1.43, p = 0.02; respectively). Of 6253 coronary segments, 257 (4%) were non-evaluable, most due to severe calcification in combination with motion (35%). The presence of non-evaluable coronary segments was associated with age (OR: 1.08 annually, 95%-confidence interval [CI]: 1.05-1.12, p < 0.001), baseline heart rate (OR: 1.35 per 10 beats/min, 95%-CI: 1.11-1.67, p = 0.003), diabetes, hypertension, and history of coronary artery disease (OR: 4.43, 95%-CI: 1.93-10.17, p < 0.001; OR: 2.27, 95-CI: 1.01-4.73, p = 0.03; OR: 5.12, 95%-CI: 2.0-13.06, p < 0.001; respectively).

Conclusion

Coronary CT permits acceptable image quality in more than 90% of patients with chest pain. Patients with multiple risk factors are more likely to have impaired image quality or non-evaluable coronary segments. These patients may require careful patient preparation and optimization of CT scanning protocols.     

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.     

Assessing risk in acute chest pain: The value of stress myocardial perfusion imaging in patients admitted through the emergency department

Background  

To prospectively assess the clinical value of stress-gated myocardial single photon emission computed tomography (SPECT) for triaging patients admitted through the emergency department (ED) with acute chest pain (ACP).     

Clinical assessment of chest pain and guidelines for imaging

For many emergency facilities, risk assessment of patients with diffuse chest pain still poses a major challenge. In their currently valid recommendations, the international cardiological societies have defined a standardized assessment of the prognostically relevant cardiac risk criteria. Here the classic sequence of basic cardiac diagnostics including case history (cardiac risk factors), physical examination (haemodynamic and respiratory vital parameters), ECG (ST segment analysis) and laboratory risk markers (troponin levels) is paramount. The focus is, on the one hand, on timely indication for percutaneous catheterization, especially in patients at high cardiac risk with or without ST-segment elevation in the ECG, and, on the other hand, on the possibility of safely discharging patients with intermediate or low cardiac risk after non-invasive exclusion of a coronary syndrome. For patients in the intermediate or low risk group, physical or pharmacological stress testing in combination with scintigraphy, echocardiography or magnetic resonance imaging is recommended in addition to basic diagnostics. Moreover, the importance of non-invasive coronary imaging, primarily cardiac CT angiography (CCTA), is increasing. Current data show that in intermediate or low risk patients this method is suitable to reliably rule out coronary heart disease. In addition, attention is paid to the major differential diagnoses of acute coronary syndrome, particularly pulmonary embolism and aortic dissection. Here the diagnostic method of choice is thoracic CT, possibly also in combination with CCTA aiming at a triple rule-out.     

Myocardial perfusion imaging versus biochemical markers in acute coronary syndromes

The assessment and appropriate clinical management of patients with acute chest pain and non-diagnostic electrocardiograms remain a continuing clinical problem. Accordingly, there is considerable interest in evaluating new strategies to improve early diagnostic accuracy in patients with possible acute myocardial ischaemia. Cardiac troponins (T and I) and acute rest myocardial perfusion imaging have similar sensitivities for detecting acute myocardial infarction. Whereas cardiac markers require 6-12 h to become positive, acute rest myocardial perfusion imaging immediately reflects the status of regional myocardial blood flow at the time of radiopharmaceutical injection. The measurement of cardiac troponins is particularly useful in the diagnosis and estimation of the degree of myocardial injury in those patients with a high likelihood of coronary artery disease and myocardial necrosis and for prognostication of adverse cardiac events in those patients with unstable angina. In contrast, the most appropriate use of acute rest myocardial perfusion imaging is in the setting of patients with acute ischaemic symptoms, non-diagnostic electrocardiogram and a low likelihood of myocardial necrosis, in which early imaging will assist in effective triage decisions.     

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.     

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。     

Myocardial perfusion imaging in the elderly: a review

Coronary artery disease is a major cause of morbidity and mortality in the elderly population. As a result of ageing of the population and better medical, interventional and surgical treatment of patients with coronary artery disease, more and more elderly patients are referred to the cardiology department for diagnostic work-up. Stress testing, in combination with myocardial perfusion imaging, is routinely used in elderly patients, a population in which the diagnosis of significant coronary artery disease is often challenging because of atypical symptomatology. Since the introduction of technetium-99m ligands for myocardial perfusion imaging, it is possible to perform electrocardiogram-gated perfusion imaging. This not only improves the specificity of the test for coronary artery disease detection, but also enables the simultaneous assessment of left ventricular functional parameters. This article briefly overviews the possible stress modalities, diagnostic accuracy and prognostic value of myocardial perfusion imaging in elderly patients.