Trends in non-focal neurological chief complaints and CT angiography utilization among adults in the emergency department

Prudent imaging use is essential for cost reduction and efficient patient triage. Recent efforts have focused on head and neck CTA in patients with emergent concerns for non-focal neurological complaints, but have failed to demonstrate whether increases in utilization have resulted in better care. The objective of this study was to examine trends in head and neck CTA ordering and determine whether a correlation exists between imaging utilization and positivity rates. This is a single-center retrospective observational study at a quaternary referral center. This study includes patients presenting with headache and/or dizziness to the emergency department between January 2017 and December 2021. Patients who received a head and neck CTA were compared to those who did not. The main outcomes included annual head and neck CTA utilization and positivity rates, defined as the percent of scans with attributable acute pathologies. Among 24,892 emergency department visits, 2264 (9.1%) underwent head and neck CTA imaging. The percentage of patients who received a scan over the study period increased from 7.89% (422/5351) in 2017 to 13.24% (662/5001) in 2021, representing a 67.4% increase from baseline (OR, 1.14; 95% CI 1.11-1.18; P < .001). The positivity rate, or the percentage of scans ordered that revealed attributable acute pathology, dropped from 16.8% (71/422) in 2017 to 10.4% (69/662) in 2021 (OR, 0.86; 95% CI 0.79-0.94; P = .001), a 38% reduction in positive examinations. Throughout the study period, there was a 67.4% increase in head and neck CTA ordering with a concomitant 38.1% decrease in positivity rate.

Impact of HEART Score Decision Aid on Coronary Computed Tomography Angiography Utilization and Diagnostic Yield in the Emergency Department

OBJECTIVE

Emergency physicians are challenged to efficiently and reliably risk stratify patients presenting with chest pain (CP) to optimize diagnostic testing and avoid unnecessary hospital admissions. The objective of our study was to evaluate the impact of a HEART score-based decision aid (HSDA) integrated in the electronic health record on coronary computed tomography angiography (CCTA) utilization and diagnostic yield in adult emergency department (ED) CP patients with suspected acute coronary syndrome.

METHODS

We conducted a before and after study to determine whether implementation of a mandatory computerized HSDA would reduce CCTA utilization in ED CP patients and improve the diagnostic yield of obstructive coronary artery disease (CAD) (≥50%). We included all adult ED CP patients with suspected acute coronary syndrome during the first 6 months of 2018 (before) and 2020 (after) at a large academic center. CCTA utilization and obstructive CAD yield were compared in patients before and after implementing the HSDA using χ2 tests. Secondarily, we assessed the association of HEART scores and CCTA results.

RESULTS

Of the 3095 CP patients during the before study period, 733 underwent CCTA. Of the 2692 CP patients during the after study period, 339 underwent CCTA. CCTA utilization before and after HSDA was 23.4% [95% confidence interval (95% CI), 22.2-25.2] and 12.6% (95% CI, 11.4-13.0), respectively; mean difference was 11.1% (95% CI, 0.9-13.0). Among 1072 patients undergoing CCTA, mean (SD) age and percent females before versus after HSDA were 54 (11) versus 56 (11) years and 50% versus 49%, respectively. We included 1014 patients (686 before and 328 after) for the yield analysis. Obstructive CAD was present in 15% (95% CI, 12.7-17.9) and 20.1% (95% CI, 16.1-24.7) before and after HSDA, respectively; mean difference was 4.9% (95% CI, 0.1-10.1).

CONCLUSIONS

Implementation of a mandatory electronic health record HSDA aid reduced ED CCTA utilization by half and improved the diagnostic yield.

Trends in coronary calcium score and coronary CT angiography imaging volume during the COVID-19 pandemic

OBJECTIVES

The COVID-19 pandemic disrupted the delivery of preventative care and management of acute diseases. This study assesses the effect of the COVID-19 pandemic on coronary calcium score and coronary CT angiography imaging volume.

MATERIALS AND METHODS

A single institution retrospective review of consecutive patients presenting for coronary calcium score or coronary CT angiography examinations between January 1, 2020 to January 4, 2022 was performed. The weekly volume of calcium score and coronary CT angiogram exams were compared.

RESULTS

In total, 1,817 coronary calcium score CT and 5,895 coronary CT angiogram examinations were performed. The average weekly volume of coronary CTA and coronary calcium score CT exams decreased by up to 83% and 100%, respectively, during the COVID-19 peak period compared to baseline (P < 0.0001). The post-COVID recovery through 2020 saw weekly coronary CTA volumes rebound to 86% of baseline (P = 0.024), while coronary calcium score CT volumes remained muted at only a 53% recovery (P < 0.001). In 2021, coronary CTA imaging eclipsed pre-COVID rates (P = 0.012), however coronary calcium score CT volume only reached 67% of baseline (P < 0.001).

CONCLUSIONS

A significant decrease in both coronary CTA and coronary calcium score CT volume occurred during the peak-COVID-19 period. In 2020 and 2021, coronary CTA imaging eventually superseded baseline rates, while coronary calcium score CT volumes only reached two thirds of baseline. These findings highlight the importance of resumption of screening exams and should prompt clinicians to be aware of potential undertreatment of patients with coronary artery disease.

The Impact of Implementing 24/7 Cardiac CTA Interpretation in the Emergency Department on Patient Care: Retrospective Analysis of a Single-Center Experience

OBJECTIVE. The objective of our study was to provide insight on the diagnostic validity of cardiac CTA (CCTA) to identify obstructive coronary artery disease (CAD) and patients who require urgent intervention, compared with those who require same-admission coronary catheterization (CC), and to help elucidate the necessity of a 24/7 CCTA service. MATERIALS AND METHODS. We retrospectively reviewed 658 consecutive CCTA examinations performed of emergency department (ED) patients who presented with acute chest pain from October 1, 2013, to February 28, 2018. Patients were categorized by CAD severity on CCTA. Using same-admission CC as the reference standard, we assessed CCTA's validity to identify obstructive disease using PPV, NPV, sensitivity, and specificity and CCTA's validity to identify patients who require urgent intervention. The added value of the CCTA findings of subendocardial hypoattenuation and wall motion abnormality was evaluated. CCTA examinations were categorized on the basis of the time of day when scanning was performed. RESULTS. The PPV, NPV, and sensitivity of CCTA to diagnose obstructive CAD were 0.87, 0.79, and 0.95, respectively. Nine percent of the scanned patients underwent percutaneous coronary intervention (PCI) or were referred for urgent coronary artery bypass grafting (CABG). The presence of obstructive CAD on CCTA has a PPV of 0.73 to identify patients deemed to be at higher acute coronary syndrome (ACS) risk to warrant urgent PCI or CABG. Wall motion abnormality increased the PPV to 1.0; subendocardial attenuation increased the PPV to 0.9. The NPV and sensitivity were 0.89 and 0.97, respectively. Of the CCTA examinations, 54% were performed outside regular working hours. Of the patients who received urgent interventions, 62% underwent CCTA examinations performed outside regular working hours. CONCLUSION. CCTA provides high correlation with CC, helps identify individuals with high ACS risk, and is further strengthened by functional analysis; 24/7 CCTA service is warranted.

Combined stress myocardial CT perfusion and coronary CT angiography as a feasible strategy among patients presenting with acute chest pain to the emergency department

BACKGROUND

A combined approach of myocardial CT perfusion (CTP) with coronary CT angiography (CTA) was shown to have better diagnostic accuracy than coronary CTA alone. However, data on cost benefits and length of stay when compared to other perfusion imaging modalities has not been evaluated. Therefore, we aim to perform a feasibility study to assess direct costs and length of stay of a combined stress CTP/CTA and use SPECT myocardial perfusion imaging (SPECT-MPI) as a benchmark, among chest pain patients at intermediate-risk for acute coronary syndrome (ACS) presenting to the emergency department (ED).

METHODS

This is a prospective two-arm clinical trial (NCT02538861) with 43 patients enrolled in stress CTP/CTA arm (General Electric Revolution CT) and 102 in SPECT-MPI arm. Mean age of the study population was 65 ​± ​12 years; 56% were men. We used multivariable linear regression analysis to compare length of stay and direct costs between the two modalities.

RESULTS

Overall, 9 out of the 43 patients (21%) with CTP/CTA testing had an abnormal test. Of these 9 patients, 7 patients underwent invasive coronary angiography and 6 patients were found to have obstructive coronary artery disease. Normal CTP/CTA test was found in 34 patients (79%), who were discharged home and all patients were free of major adverse cardiac events at 30 days. The mean length of stay was significantly shorter by 28% (mean difference: 14.7 ​h; 95% CI: 0.7, 21) among stress CTP/CTA (20 ​h [IQR: 16, 37]) compared to SPECT-MPI (30 ​h [IQR: 19, 44.5]). Mean direct costs were significantly lower by 44% (mean difference: $1535; 95% CI: 987, 2082) among stress CTA/CTP ($1750 [IQR: 1474, 2114] compared to SPECT-MPI ($2837 [IQR: 2491, 3554]).

CONCLUSION

Combined stress CTP/CTA is a feasible strategy for evaluation of chest pain patients presenting to ED at intermediate-risk for ACS and has the potential to lead to shorter length of stay and lower direct costs.

CT coronary imaging-a fast evolving world

Computed tomography (CT) has become an important modality in the evaluation of coronary artery disease (CAD). The tremendous technological advances in CT in the last two decades has made it possible to obtain high quality images of coronary arteries with high spatial and temporal resolutions. Multiple trials have confirmed the accuracy of CT compared to invasive catheter angiography. CT is also able to evaluate beyond the lumen in characterizing and quantifying atherosclerotic plaques, including evaluation of high risk features. Although CTA has low specificity in identification of lesion-specific ischemia, functional techniques are now possible such as CT myocardial perfusion and CT-fractional flow reserve (FFR) which evaluate the hemodynamic significance of stenosis and help with revascularization strategies. Multi-energy CT provides additional information beyond what is possible with a conventional CT and is useful in variety of clinical applications, including myocardial perfusion imaging, lesion characterization and low contrast studies. Large trials have confirmed the ability of CT to predict major adverse cardiovascular events and recent trials have even demonstrated improved clinical outcomes by using CT for the evaluation of CAD. CT is also useful in structural heart disease and 3 D printing is now increasingly used for surgical/interventional planning. Machine learning is evolving rapidly and is likely to impact diagnosis and management.

Cardiac CT in the Emergency Department: Contrasting Evidence from Registries and Randomized Controlled Trials

PURPOSE OF REVIEW

To compare outcomes between registries and randomized controlled trials of coronary computed tomographic angiography (CCTA)-based versus standard of care approaches to the initial evaluation of patients with acute chest pain.

RECENT FINDINGS

Randomized trials have demonstrated CCTA to be a safe and efficient tool for triage of low- to intermediate-risk patients presenting to the emergency department with chest pain. Recent studies demonstrate heterogeneous result using different standard of care approaches for evaluation of hard endpoints in comparison with standard evaluation. Also, there has been continued concern for increase in subsequent testing after coronary CTA. Although CCTA improves detection of coronary artery disease, it is uncertain if it will bring improvement of long-term health outcomes at this point of time. Careful analysis of the previous results and further investigation will be required to validate evaluation of hard endpoints.

Myocardial ischemia testing with computed tomography: emerging strategies

Although cardiac computed tomography (CT) has high negative predictive value to exclude obstructive coronary artery disease (CAD), particularly in the low to intermediate risk population, it has low specificity in the diagnosis of ischemia-inducing lesions. This inability to predict hemodynamically significant stenosis hampers the ability of CT to be an effective gatekeeper for invasive angiography and to guide appropriate revascularization. Recent advances in CT technology have resulted in the development of multiple techniques to provide hemodynamic information and detect lesion-specific ischemia, namely CT perfusion (CTP), CT-derived fractional flow reserve (CT-FFR) and coronary transluminal attenuation gradient (TAG). In this article, we provide a perspective on these emerging CT techniques in the evaluation of myocardial ischemia.

Clinical risk factors alone are inadequate for predicting significant coronary artery disease

OBJECTIVE

We sought to derive and validate a model for identifying suspected ACS patients harboring undiagnosed significant coronary artery disease (CAD).

METHODS

This was a secondary analysis of data from a randomized control trial (RCT). Patients randomized to the CTA arm of an RCT examining a CTA-based strategy for ruling-out acute coronary syndrome (ACS) constitute the derivation cohort, which was randomly divided into a training dataset (2/3, used for model derivation) and a test dataset (1/3, used for internal validation (IV)). ED patients from a different center receiving CTA to evaluate for suspected ACS constitute the external validation (EV) cohort. Primary outcome was CTA-assessed significant CAD (stenosis of ≥50% in a major coronary artery).

RESULTS

In the derivation cohort, 11.2% (76/679) of subjects had CTA-assessed significant CAD, and in the EV cohort, 8.2% of subjects (87/1056) had CTA-assessed significant CAD. Age was the strongest predictor of significant CAD among the clinical risk factors examined. Predictor variables included in the derived logistic regression model were: age, sex, tobacco use, diabetes, and race. This model exhibited an area under the receiver operating characteristic curve (ROC AUC) of 0.72 (95% CI: 0.61-0.83) based on IV, and 0.76 (95% CI: 0.70, 0.82) based on EV. The derived random forest model based on clinical risk factors yielded improved but not sufficient discrimination of significant CAD (ROC AUC = 0.76 [95% CI: 0.67-0.85] based on IV). Coronary artery calcium score was a more accurate predictor of significant CAD than any combination of clinical risk factors (ROC AUC = 0.85 [95% CI: 0.76-0.94] based on IV; ROC AUC = 0.92 [95% CI: 0.88-0.95] based on EV).

CONCLUSIONS

Clinical risk factors, either individually or in combination, are insufficient for accurately identifying suspected ACS patients harboring undiagnosed significant coronary artery disease.

Coronary CT angiography in the emergency department utilizing second and third generation dual source CT

BACKGROUND

Coronary computed tomography angiography (coronary CTA) allows efficient triage of low to intermediate risk patients with suspected acute coronary syndrome (ACS) in the emergency department (ED). Techniques for coronary CTA acquisition in the ED continue to evolve with the establishment of standardized scan protocols and the introduction of newer generations of CT hardware.

OBJECTIVES

To evaluate qualitative and quantitative image quality and radiation dose exposure of coronary CTA acquired on 2nd versus 3rd generation dual source CT (DSCT) scanners using a standardized institutional scan protocol designed for the ED.

METHODS

A retrospective observational case-control study was performed of 246 ED patients referred to coronary CTA with suspicion of ACS (56.5% male; mean age 53.3 ± 11.6 years) between October 2013 and August 2015.123 consecutive patients were scanned on 3rd generation DSCT, and a cohort of 123 patients matched by age, BMI and heart rate were identified who had undergone 2nd generation DSCT imaging utilizing the same standard clinical protocol. Qualitative and quantitative image quality parameters and radiation exposures were evaluated.

RESULTS

Qualitative image quality was significantly higher using 3rd generation DSCT as compared to 2nd generation (p < 0.001). Mean attenuation in the proximal coronary arteries was also significantly higher on 3rd generation DSCT than for 2nd generation (586 HU vs. 426 HU in the left main coronary artery (LM), p < 0.001). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) values, however, were lower in 3rd generation DSCT than 2nd generation (SNR 11.2 [9.9-13.4] vs 13.5 [11.0-15.5] and CNR 12.4 [10.9-14.8] vs 15.2 [12.8-17.9] in the LM, p < 0.001). Median effective dose was also lower for 3rd generation DSCT than for 2nd generation (2.9 [2.3-5.0] mSv and 3.7 mSv [2.5-5.7], respectively) although this trend did not reach statistical significance (p = 0.065).

CONCLUSION

Qualitative image quality and mean CT attenuation values of the assessed coronary segments were significantly higher using 3rd generation DSCT. SNR and CNR were lower on 3rd generation DSCT, however this was accompanied by a trend toward lower radiation dose exposure when using the same standard institutional protocol.

Coronary computed tomographic angiography for patients with low-to-intermediate risk chest pain: A systematic review and meta-analysis

Coronary computed tomographic angiography (CCTA) can image the coronary vasculature rapidly and detect the presence and severity of luminal stenosis accurately. However, whether CCTA based care strategy could gain more benefits than conventional strategy with functional tests for patients with low-to-intermediate risk chest pain remains unknown. In this study we performed a meta-analysis to compare the clinical efficacy of CCTA versus conventional strategy. Eight randomized controlled trials with 14749 patients were finally included in this review after database searching. Compared with conventional strategy, CCTA significantly increased the rates of invasive coronary angiography (RR 1.44; 95% CI 1.28 to 1.63) and revascularization (RR 1.94; 95% CI 1.65 to 2.29), but did not change the rates of major adverse cardiovascular events (RR 1.10; 95% CI 0.92 to 1.30), death (RR 0.95; 95% CI 0.64 to 1.40) and hospital readmission (RR 0.96; 95% CI 0.66 to 1.40). Consequently, compared with conventional strategy, CCTA seemed not to improve clinical outcomes for patients with low-to-intermediate risk chest pain.

Comparative Trends and Downstream Outcomes of Coronary Computed Tomography Angiography and Cardiac Stress Testing in Emergency Department Patients With Chest Pain: An Administrative Claims Analysis

OBJECTIVES

Coronary computerized tomography angiography (CCTA) is a rapidly emerging technology for the evaluation of chest pain in the emergency department (ED). We assessed trends in CCTA use and compared downstream healthcare utilization between CCTA and cardiac stress testing modalities.

METHODS

Using administrative claims data (Optum Labs Data Warehouse) from over 100 million geographically diverse privately insured and Medicare Advantage enrollees across the United States, we identified 2,047,799 ED patients from January 2006 to December 2013 who presented with chest pain and had a CCTA or cardiac stress test within 72 hours. Cohorts were established based on CCTA or functional stress testing (myocardial perfusion scintigraphy [MPS], stress echocardiogram [SE], or treadmill exercise electrocardiogram [TMET]) performed within 72 hours of the ED visit. We tracked subsequent invasive cardiac procedures (invasive coronary angiography [ICA], percutaneous coronary intervention [PCI], and coronary artery bypass grafting [CABG]), repeat noninvasive testing, return ED visits, hospitalization, and the rate of acute myocardial infarction (AMI) within 30 days. We used propensity-score matching to adjust for coronary artery disease (CAD) risk factors, Charlson-Deyo comorbidity index, and baseline differences between patients selected for CCTA or cardiac stress testing. Logistic regression was used to measure adjusted associations between testing modality and outcomes.

RESULTS

During the study period, CCTA use increased from 0.8% to 4.5% of all cardiac testing within 72 hours, a change of 434% (p-value for trend < 0.001), while rates of other cardiac stress testing modalities decreased (-22% for TMET [p < 0.001]; -11% for SE [p = 0.11]; -6% for MPS [p = 0.04]. After matching, there was no difference in the 30-day rate of AMI between testing modalities. Compared to MPS, CCTA was associated with higher rates of PCI (odds ratio [OR] = 1.25, 95% confidence interval [CI] = 1.04 to 1.51), and CABG (OR = 1.47; 95% CI = 1.03 to 2.13). Compared to SE and treadmill stress testing, CCTA was associated with more invasive procedures, hospitalizations, return ED visits, and repeat noninvasive testing.

CONCLUSIONS

CCTA use increased fourfold during the study period and was associated with higher rates of PCI, CABG, repeat noninvasive testing, hospitalization, and return ED visits. The authors have no relevant financial information or potential conflicts to disclose.

Remote reading of coronary CTA exams using a tablet computer: utility for stenosis assessment and identification of coronary anomalies

The feasibility of remote reading of coronary CT examinations on tablet computers has not been evaluated. The purpose of this study is to evaluate the accuracy of coronary CT angiography reading using an iPad compared to standard 3D workstations. Fifty coronary CT angiography exams, including a spectrum of coronary artery disease and anatomic variants, were reviewed. Coronary CT angiography exams were interpreted by two readers independently on an iPad application (Siemens Webviewer) and a clinical 3D workstation at sessions 2 weeks apart. Studies were scored per vessel for severity of stenosis on a 0-3 scale (0 none, 1 <50 %, 2 ≥50-69 %, 3 ≥70 %). Coronary anomalies were recorded. A consensus read by two experienced cardiac imagers was used as the reference standard. Level of agreement with the reference for iPad and 3D workstations was compared. Multivariate logistic regression was used to analyze the relationship between agreement and display type and to adjust for inter-reader differences. For both readers, there was no significant difference in agreement with the reference standard for per-vessel stenosis scores using either the 3D workstation or the iPad. In a multivariable logistic regression analysis including reader, workstation, and vessel as co-variates, there was no significant association between workstation type or reader and agreement with the reference standard (p > 0.05). Both readers identified 100 % of coronary anomalies using each technique. Reading of coronary CT angiography examinations on the iPad had no influence on stenosis assessment compared to the standard clinical workstation.

[Multimodal imaging of ischemic heart diseases: A 2015 update]

Current realities and future possibilities of imaging in the ischemic heart diseases are very broad and constantly evolving, with the improvement of existing technologies and the introduction of new features such as dual-energy CT, strain ultrasound, multimodality fusion or perfusion MRI. Regular collaboration between prescribing clinicians, cardiologists, radiologists and nuclear radiologists is therefore essential to tailor the examination to the specific clinical question. The indications for each modality will therefore depend on its diagnostic performance, cost, acquisition and post-processing times and eventual radiation exposure. This review will detail principles and applications of current cardiac imaging examinations: echocardiography, nuclear medicine, MRI, CT and coronary angiography, emphasizing their current strengths and weaknesses in the ischemic heart diseases management.

Recent Trends in Imaging for Suspected Coronary Artery Disease: What Is the Best Approach?

PURPOSE

The aim of this study was to ascertain recent trends in noninvasive imaging utilization for suspected coronary artery disease.

METHODS

The Medicare Part B databases for 2001 to 2013 were reviewed. Current Procedural Terminology primary codes for radionuclide myocardial perfusion imaging (MPI), stress echocardiography (SE), and coronary CT angiography (CCTA) were selected. Physician specialty codes were used to designate providers as radiologists, cardiologists, and all others as a group. Procedure volumes were tabulated, and utilization rates per 1,000 Medicare beneficiaries were calculated over the period of study.

RESULTS

Total MPI utilization rates per 1,000 rose rapidly from 63.4 in 2001 to a peak of 88.0 in 2006 but declined every year thereafter, dropping to 61.9 in 2013. SE rates generally held steady around 12 to 13 from 2001 to 2010 but then began to decline, reaching 10.8 in 2013. Cardiologists predominate in both MPI and SE. CCTA rates were far lower. They peaked at 2.1 in 2007, but then dropped before leveling off at 1.07 in both 2012 and 2013. Radiologists and cardiologists have approximately equal roles in this procedure.

CONCLUSIONS

Both MPI and SE seem to be declining in use in recent years. This is likely due to unfavorable reimbursement trends caused by code bundling and resulting in the closure of many private cardiology offices. CCTA use is far lower than the two other types of imaging and has also declined in recent years. This is puzzling, as it is a new and promising procedure that has some advantages over MPI and SE. In 2013, 58 times as many MPI studies as CCTA studies were performed.

Cardiac CT angiography for evaluation of acute chest pain

Chest pain is the second most common emergency department (ED) presentation in the United States. Cardiac computed tomography angiography (CCTA) now plays an important role in the evaluation of patients with suspected acute coronary syndrome in the ED setting. In this article, we review the available techniques focused on the use of CCTA to evaluate patients fosr coronary atherosclerosis for timely triage of acute chest pain.