Long-term outcome after CT angiography in patients with possible acute coronary syndrome

Evaluation of stable chest pain following emergency department presentation: Impact of first-line cardiac computed tomography diagnostic strategy in an Australian setting

OBJECTIVE

International guidelines provide increasing support for computed tomography coronary angiography (CTCA) in investigating chest pain. A pathway utilising CTCA first-line for outpatient stable chest pain evaluation was implemented in an Australian ED.

METHODS

In pre-post design, the impact of the pathway was prospectively assessed over 6 months (August 2021 to January 2022) and compared with a 6-month pre-implementation group (February 2021 to July 2021). CTCA was recommended first-line in suspected stable cardiac chest pain, followed by chest pain clinic review. Predefined criteria were provided recommending functional testing in select patients. The impact of CTCA versus functional testing was evaluated. Data were obtained from digital medical records.

RESULTS

Three hundred and fifteen patients were included, 143 pre-implementation and 172 post-implementation. Characteristics were similar except age (pre-implementation: 58.9 ± 12.0 vs post-implementation: 62.8 ± 12.3 years, P = 0.004). Pathway-guided management resulted in higher first-line CTCA (73.3% vs 46.2%, P < 0.001), lower functional testing (30.2% vs 56.6%, P < 0.001) and lower proportion undergoing two non-invasive tests (4.7% vs 10.5%, P = 0.047), without increasing investigation costs or invasive coronary angiography (ICA) (pre-implementation: 13.3% vs post-implementation: 9.3%, P = 0.263). In patients undergoing CTCA, 40.7% had normal coronaries and 36.2% minimal/mild disease, with no difference in disease burden post-implementation. More medication changes occurred following CTCA compared with functional testing (aspirin: P = 0.005, statin: P < 0.001). In patients undergoing ICA, revascularisation to ICA ratio was higher following CTCA compared with functional testing (91.7% vs 18.2%, P < 0.001). No 30-day myocardial infarction or death occurred.

CONCLUSIONS

The pathway increased CTCA utilisation and reduced downstream investigations. CTCA was associated with medication changes and improved ICA efficiency.

Contemporary Chest Pain Evaluation: The Australian Case for Cardiac CT

Computed tomography coronary angiography (CTCA) is a non-invasive diagnostic modality that provides a comprehensive anatomical assessment of the coronary arteries and coronary atherosclerosis, including plaque burden, composition and morphology. The past decade has witnessed an increase in the role of CTCA for evaluating patients with both stable and acute chest pain, and recent international guidelines have provided increasing support for a first line CTCA diagnostic strategy in select patients. CTCA offers some advantages over current functional tests in the detection of obstructive and non-obstructive coronary artery disease, as well as for ruling out obstructive coronary artery disease. Recent randomised trials have also shown that CTCA improves prognostication and guides the use of guideline-directed preventive therapies, leading to improved clinical outcomes. CTCA technology advances such as fractional flow reserve, plaque quantification and perivascular fat inflammation potentially allow for more personalised risk assessment and targeted therapies. Further studies evaluating demand, supply, and cost-effectiveness of CTCA for evaluating chest pain are required in Australia. This discussion paper revisits the evidence supporting the use of CTCA, provides an overview of its implications and limitations, and considers its potential role for chest pain evaluation pathways in Australia.

Major adverse cardiac events after emergency department evaluation of chest pain patients with advanced testing: Systematic review and meta-analysis

OBJECTIVES

Our primary objective was to describe the risk of major adverse cardiac events (MACE) at 1, 6, and 12 months after a negative coronary computed tomography angiogram (cCTA), electrocardiogram (ECG) stress test, stress echocardiography, and myocardial perfusion scintigraphy (MPS) in low- to intermediate-risk patients.

METHODS

Initially, 952 articles were identified for screening, 81 met criteria for full-text review, and once risk of bias was assessed, 33 articles were included in this meta-analysis. We utilized a random-effects model to assess pooled MACE event proportion for patients undergoing evaluation of acute coronary syndrome (ACS) when risk stratified to a low- to intermediate-risk category after undergoing standard testing. Heterogeneity analysis was performed using Cochrane's Q-test and I² statistic.

RESULTS

Twenty-one studies evaluated follow-up at 1 month with cCTA having a 0.09% (95% confidence interval [CI] = 0.03% to 0.26%) pooled MACE compared to 0.23% (95% CI = 0.01% to 5.8%) of the exercise stress testing (p = 1). MPS and cCTA had an overall event rate of 0.15% (95% CI = 0.06% to 0.41%) at 6 months (I²  = 0%). At 12 months, a subgroup analysis found a pooled cCTA MACE of 0.16% (95% CI = 0.04% to 0.65%) compared to 1.68% (95% CI = 0.01% to 2.6%) for stress echocardiography with low within-group heterogeneity (I²  = 0%). Subgroup analysis of cCTA with no disease versus nonobstructive disease (<50% stenosis) did not find statistical difference in the MACE at both 1 month (0.17% [95% CI = 0.04% to 0.67%] vs. 0.06% [95% CI = 0.01% to 0.34%]) and 12 months (0.44% [95% CI = 0.09% to 2.2% vs. 0.54% [95% CI = 0.19% to 1.5%]).

CONCLUSIONS

Patients presenting with chest pain who have a coronary CTA showing < 50% stenosis, negative ECG stress test, stress echocardiography, or stress myocardial perfusion scan in the past 12 months can be discharged without any further risk stratification if their ECG and troponin are reassuring given low MACE.

Use of Coronary CT Angiography to Predict Obstructive Lesions in Patients with Chest Pain without Enzyme and ST-Segment Elevation

It is challenging to rule out acute coronary syndrome among chest pain patients without both ST-segment elevation in electrocardiography and troponin elevation at emergency departments (ED). The purpose of this study was to develop a prediction model for rapidly determining the occurrence of significant stenosis in coronary computed tomography angiography (CCTA). Retrospective observational cohort study was conducted with 904 patients who had presented with chest pain without troponin elevation and ST-segment changes and underwent CCTA between January 2017 and December 2018. The primary endpoint was the presence of significant stenosis on CCTA, defined as narrowing above 70% diameter. The logistic regression model was used for development a new predictive model. One hundred and thirty-four patients (14.8%) were shown severe stenosis. The independent associated factors for significant stenosis were age ≥65 years, male, diabetes, history of acute coronary syndrome, and typical chest pain. Based these results, we developed a new prediction model. The area under the curve was 0.782 (95% confidence interval 0.742-0.822). Moreover, score of ≥5 was chosen as cut-off values with 86.6% sensitivity and 56.4% specificity. In conclusion, among chest pain patients without ST changes and troponin elevation, the new score will be helpful to identify potential candidate for CCTA such as patients with significant stenosis.

Prognostic Value of Coronary Artery Disease-Reporting and Data System Score for Major Adverse Cardiac Events in Patients Attending the Emergency Department With Acute Chest Pain

OBJECTIVE

This study aimed to compare the prognostic performance of Coronary Artery Disease (CAD)-Reporting and Data System (CAD-RADS) score with those of clinical risk factors and the extent of CAD classification for predicting major adverse cardiac events in emergency department patients.

METHODS

A total of 779 patients with acute chest pain at low to intermediate risk for CAD underwent cardiac computed tomography angiography. The primary end point was early and late major adverse cardiac events. We developed the following models: model 1, clinical risk factors; model 2, clinical risk factors and CAD-RADS scores; model 3, clinical risk factors and extent of CAD.

RESULTS

The C-statistics revealed that both CAD-RADS score and CAD extent improved risk stratification over the clinical risk factors (C-index for early events: C-index: 0.901 vs 0.814 and 0.911 vs 0.814; C-index for late events: 0.897 vs 0.808 and 0.905 vs 0.808; all P < 0.05).

CONCLUSIONS

The CAD-RADS score had additional risk prediction benefits over clinical risk factors for emergency department patients.

Accuracy and clinical outcomes of coronary CT angiography for patients with suspected coronary artery disease: a single-centre study in Singapore

INTRODUCTION

This study aimed to assess the accuracy and outcomes of coronary computed tomography angiography (CCTA) performed in a regional hospital in Singapore.

METHODS

The Changi General Hospital CCTA database was retrospectively analysed over a 24-month period. Electronic hospital records, catheter coronary angiography (CCA) and CCTA electronic databases were used to gather data on major adverse cardiovascular events (MACE) and CCA results. CCTA findings were deemed positive if coronary artery stenosis ≥ 50% was reported or if the stenosis was classified as moderate or severe. CCA findings were considered positive if coronary artery stenosis ≥ 50% was reported.

RESULTS

The database query returned 679 patients who had undergone CCTA for the evaluation of suspected coronary artery disease. Of the 101 patients in the per-patient accuracy analysis group, there were six true negatives, one false negative, 81 true positives and 13 false positives, resulting in a negative predictive value of 85.7% and positive predictive value of 86.2%. The mean age of the study sample was 53 ± 13 years and 255 (37.6%) patients were female. Mean duration of patient follow-up was 360 days. Of the 513 negative CCTA patients, none developed MACE during the follow-up period, and of the 164 positive CCTA patients, 19 (11.6%) developed MACE (p < 0.001).

CONCLUSION

Analysis of CCTA studies suggested accuracy and outcomes that were consistent with published clinical data. There was a one-year MACE-free warranty period following negative CCTA findings.

Coronary CT Angiography: Use in Patients With Chest Pain Presenting to Emergency Departments

OBJECTIVE

Previously published reports have shown that coronary CT angiography (CCTA) is a more efficient method of diagnosis than myocardial perfusion imaging (MPI) and stress echocardiography for patients presenting to emergency departments (EDs) with acute chest pain. In light of this evidence, the objective of this study was to examine recent trends in the use of these techniques in EDs.

MATERIALS AND METHODS

The nationwide Medicare Part B databases for 2006-2015 were the data source. The Current Procedural Terminology, version 4, codes for CCTA, MPI, and stress echocardiography were selected. Medicare place-of-service codes were used to determine procedure volumes in EDs. Medicare specialty codes were used to ascertain how many of these examinations were interpreted by radiologists, cardiologists, and other physicians as a group.

RESULTS

From 2006 to 2015, there was essentially no change in the number of MPI examinations performed in EDs for patients using Medicare (22,342 in 2006, 22,338 in 2015) or in the number of stress echocardiograms (3544 in 2006, 3520 in 2015). By contrast, the number of CCTA examinations increased rapidly, from 126 in 2006 to 1919 in 2015 (compound annual growth rate, 35%). Despite this rapid growth, patients in EDs underwent 11.6 times as many MPI as CCTA examinations in 2015. In that last year of the study, radiologists interpreted 78% of ED MPI and 83% of ED CCTA examinations.

CONCLUSION

Use of CCTA in EDs has increased rapidly, but far more MPI examinations are still being performed. This finding suggests that recently acquired evidence is not yet being fully acted upon.

Clinical implementation of an emergency department coronary computed tomographic angiography protocol for triage of patients with suspected acute coronary syndrome

OBJECTIVES

To evaluate the efficiency and safety of emergency department (ED) coronary computed tomography angiography (CTA) during a 3-year clinical experience.

METHODS

Single-center registry of coronary CTA in consecutive ED patients with suspicion of acute coronary syndrome (ACS). The primary outcome was efficiency of coronary CTA defined as the length of hospitalization. Secondary endpoints of safety were defined as the rate of downstream testing, normalcy rates of invasive coronary angiography (ICA), absence of missed ACS, and major adverse cardiac events (MACE) during follow-up, and index radiation exposure.

RESULTS

One thousand twenty two consecutive patients were referred for clinical coronary CTA with suspicion of ACS. Overall, median time to discharge home was 10.5 (5.7-24.1) hours. Patient disposition was 42.7 % direct discharge from the ED, 43.2 % discharge from emergency unit, and 14.1 % hospital admission. ACS rate during index hospitalization was 9.1 %. One hundred ninety two patients underwent additional diagnostic imaging and 77 underwent ICA. The positive predictive value of CTA compared to ICA was 78.9 % (95 %-CI 68.1-87.5 %). Median CT radiation exposure was 4.0 (2.5-5.8) mSv. No ACS was missed; MACE at follow-up after negative CTA was 0.2 %.

CONCLUSIONS

Coronary CTA in an experienced tertiary care setting allows for efficient and safe management of patients with suspicion for ACS.

KEY POINTS

• ED Coronary CTA using advanced systems is associated with low radiation exposure. • Negative coronary CTA is associated with low rates of MACE. • CTA in ED patients enables short median time to discharge home. • CTA strategy is characterized by few downstream tests including unnecessary ICA.

Long Term Prognostic Value of a Negative Work-Up for Acute Coronary Disease in Emergency Department Chest Pain Patients Without Known Coronary Artery Disease: A Cohort Study

BACKGROUND

To determine the rate of all cause and cardiac death, new myocardial infarction (MI) or coronary revascularisation at over three years from index visit in emergency department chest pain patients without known coronary artery disease (CAD) at index presentation who had a negative electrocardiogram (ECG) and biomarker workup for acute coronary syndrome (ACS).

METHODS

An unplanned sub-study of a prospective observational study of consecutive adult patients presenting to the ED with atraumatic chest pain (or equivalents). The primary outcome of interest was the predictive performance of a negative ECG and biomarker work-up for ACS for all cause and cardiac mortality over more than three years' follow-up in patients not known to have pre-existing CAD presenting to the ED with chest pain. Secondary outcomes were rate of new MI or revascularisation not related to the index visit.

RESULTS

237 patients were studied. Median age was 52 years (IQR 42 - 62) and 55.3% were male. Median follow-up was 48 months. There were seven deaths (3%, 95% CI 1.4 - 6%), one of which was potentially cardiac in origin with cause of death given as pulmonary hypertension and cardiac failure (0.4%, 95% CI 0.02 - 2.3%). There was one confirmed MI (0.6%, 95% CI 0.03 - 3.8%). The rate of revascularisation not related to the index visit was 3.1% (95% CI 1.1 - 7.4%).

CONCLUSION

Patients who present to ED with potentially cardiac chest pain but who do not have known CAD, and have non-ischaemic ECGs and troponin assays below the 99^th percentile are at low risk of cardiac death or MI in long-term follow-up. This challenges the recommendation for routine functional or anatomic testing.

Noninvasive cardiac imaging in suspected acute coronary syndrome

Noninvasive cardiac imaging has an important role in the assessment of patients with acute-onset chest pain. In patients with suspected acute coronary syndrome (ACS), cardiac imaging offers incremental value over routine clinical assessment, the electrocardiogram, and blood biomarkers of myocardial injury, to confirm or refute the diagnosis of coronary artery disease and to assess future cardiovascular risk. This Review covers the current guidelines and clinical use of the common noninvasive imaging techniques, including echocardiography and stress echocardiography, computed tomography coronary angiography, myocardial perfusion scintigraphy, positron emission tomography, and cardiovascular magnetic resonance imaging, in patients with suspected ACS, and provides an update on the developments in noninvasive imaging techniques in the past 5 years.

Chest pain: coronary CT in the ER

Cardiac CT has developed into a robust clinical tool during the past 15 years. Of the fields in which the potential of cardiac CT has raised more interest is chest pain in acute settings. In fact, the possibility to exclude with high reliability obstructive coronary artery disease (CAD) in patients at low-to-intermediate risk is of great interest both from the clinical standpoint and from the management standpoint. Several other modalities, with or without imaging, have been used during the past decades in the settings of new onset chest pain or in acute chest pain for both diagnostic and prognostic assessment of CAD. Each one has advantages and disadvantages. Most imaging modalities also focus on inducible ischaemia to guide referral to invasive coronary angiography. The advent of cardiac CT has introduced a new practice diagnostic paradigm, being the most accurate non-invasive method for identification and exclusion of CAD. Furthermore, the detection of subclinical CAD and plaque imaging offer the opportunity to improve risk stratification. Moreover, recent advances of the latest generation CT scanners allow combining both anatomical and functional imaging by stress myocardial perfusion. The role of cardiac CT in acute settings is already important and will become progressively more important in the coming years.

Cardiac computed tomography for the evaluation of the acute chest pain syndrome: state of the art

Coronary computed tomography angiography (CCTA) is recommended for the triage of acute chest pain in patients with a low-to-intermediate likelihood for acute coronary syndrome. Absence of coronary artery disease (CAD) confirmed by CCTA allows rapid emergency department discharge. This article shows that CCTA-based triage is as safe as traditional triage, reduces the hospital length of stay, and may provide cost-effective or even cost-saving care.

Cardiac CT: atherosclerosis to acute coronary syndrome

Coronary computed tomographic angiography (CCTA) is a robust non-invasive method to assess coronary artery disease (CAD). Qualitative and quantitative assessment of atherosclerotic coronary stenosis with CCTA has been favourably compared with invasive coronary angiography (ICA) and intravascular ultrasound (IVUS). Importantly, it allows the study of preclinical stages of atherosclerotic disease, may help improve risk stratification and monitor the progressive course of the disease. The diagnostic accuracy of CCTA in the assessment of coronary artery bypass grafts (CABG) is excellent and the constantly improving technology is making the evaluation of stents feasible. Novel techniques are being developed to assess the functional significance of coronary stenosis. The excellent negative predictive value of CCTA in ruling out disease enables early and safe discharge of patients with suspected acute coronary syndromes (ACS) in the Emergency Department (ED). In addition, CCTA is useful in predicting clinical outcomes based on the extent of coronary atherosclerosis and also based on individual plaque characteristics such as low attenuation plaque (LAP), positive remodelling and spotty calcification. In this article, we review the role of CCTA in the detection of coronary atherosclerosis in native vessels, stented vessels, calcified arteries and grafts; the assessment of plaque progression, evaluation of chest pain in the ED, assessment of functional significance of stenosis and the prognostic significance of CCTA.