Long-term health outcomes and cost-effectiveness of coronary CT angiography in patients with suspicion for acute coronary syndrome

Cardiac CT: Competition, complimentary or confounder

Coronary CT angiography (CCTA) has been gradually adopted into clinical practice over the last two decades. CCTA has high diagnostic accuracy, prognostic value, and unique features such as assessment of plaque composition. CCTA-derived functional assessment techniques such as fractional flow reserve and CT perfusion are also available and can increase the diagnostic specificity of the modality. These properties propound CCTA as a competitor of functional testing in diagnosis of obstructive CAD, however, utilizing CCTA in a concomitant fashion to potentiate the performance of the latter can lead to better patient care and may provide more accurate prognostic information. Although multiple diagnostic challenges such as evaluation of calcified segments, stents, and small distal vessels still exist, the technologic developments in hardware as well as growing incorporation of artificial intelligence to daily practice are all set to augment the diagnostic and prognostic role of CCTA in cardiovascular disorders.

Agreement among high-sensitivity cardiac troponin assays and non-invasive testing, clinical outcomes, and quality-of-care outcomes based on the 2020 European Society of Cardiology Guidelines

AIMS

Quality-of-care and safety of patients with suspected acute coronary syndrome (ACS) would benefit if management was independent of which high-sensitivity cardiac troponin (hs-cTn) assay was used for risk stratification. We aimed to determine the concordance of hs-cTn assays to risk-stratify patients with suspected ACS according to the European Society of Cardiology (ESC) 2020 Guidelines.

METHODS AND RESULTS

Blood samples were obtained at arrival and at 2 h from patients with suspected ACS using four hs-cTn assays. The patients were classified into rule-out/observe/rule-in strata based on the ESC 2020 Guidelines. Concordance was determined among the assays for rule-out/observe/rule-in strata. The prevalences of significant underlying disease (≥50% stenosis on coronary computed tomography or inducible myocardial ischaemia on stress testing) and adjudicated ACS, plus quality-of-care outcomes, were compared. Among 238 patients (52.7 ± 8.0 years; 40.3% female), the overall concordance across assays to classify patients into rule-out/observe/rule-in strata was 74.0% (176/238). Platforms significantly differed for rule-out (89.9 vs. 76.5 vs. 78.6 vs. 86.6%, P < 0.001) and observe strata (6.7 vs. 20.6 vs. 17.7 vs. 9.2%, P < 0.001), but not for rule-in strata (3.4 vs. 2.9 vs. 3.8 vs. 4.2%, P = 0.62). Among patients in ruled-out strata, 19.1-21.6% had significant underlying disease and 3.3-4.2% had ACS. The predicted disposition of patients and cost-of-care differed across the assays (all P < 0.001). When compared with observed strata, conventional troponin-based management and predicted quality-of-care outcomes significantly improved with hs-cTn-based strategies (direct discharge: 21.0 vs. 80.3-90.8%; cost-of-care: $3889 ± 4833 vs. $2578 ± 2896-2894 ± 4371, all P < 0.001).

CONCLUSION

Among individuals with suspected ACS, patient management may differ depending on which hs-cTn assay is utilized. More data are needed regarding the implications of inter-assay differences.

TRAIL REGISTRATION

NCT01084239.

The Cost Effectiveness of Coronary CT Angiography and the Effective Utilization of CT-Fractional Flow Reserve in the Diagnosis of Coronary Artery Disease

Given the high global disease burden of coronary artery disease (CAD), a major problem facing healthcare economic policy is identifying the most cost-effective diagnostic strategy for patients with suspected CAD. The aim of this review is to assess the long-term cost-effectiveness of coronary computed tomography angiography (CCTA) when compared with other diagnostic modalities and to define the cost and effective diagnostic utilization of computed tomography-fractional flow reserve (CT-FFR). A search was conducted through the MEDLINE database using PubMed with 16 of 119 manuscripts fitting the inclusion and exclusion criteria for review. An analysis of the data included in this review suggests that CCTA is a cost-effective strategy for both low risk acute chest pain patients presenting to the emergency department (ED) and low-to-intermediate risk stable chest pain outpatients. For patients with intermediate-to-high risk, CT-FFR is superior to CCTA in identifying clinically significant stenosis. In low-to-intermediate risk patients, CCTA provides a cost-effective diagnostic strategy with the potential to reduce economic burden and improve long-term health outcomes. CT-FFR should be utilized in intermediate-to-high risk patients with stenosis of uncertain clinical significance. Long-term analysis of cost-effectiveness and diagnostic utility is needed to determine the optimal balance between the cost-effectiveness and diagnostic utility of CT-FFR.

Role of Coronary CT Angiography in the Evaluation of Acute Chest Pain and Suspected or Confirmed Acute Coronary Syndrome

Advances in CT technology have resulted in improved imaging of the coronary anatomy in patients with stable coronary artery disease, using coronary CT angiography (CCTA). Recent data suggest that CCTA may play a role in higher risk patients, such as those evaluated in the emergency room with acute chest pain. Data thus far support the use of CCTA in low-risk patients with acute chest pain. Recent literature suggests that CCTA may play a role in the risk stratification of selected intermediate-risk patients. In this review, the authors discuss the emerging role of CCTA in higher risk patients, such as those with suspected or confirmed acute coronary syndrome (ACS). The excellent accuracy of CCTA in detecting obstructive coronary artery disease in patients with ACS is detailed, along with a highlighting of the safety of using CCTA in this setting. The authors also discuss the role for CCTA atheromatous plaque characterization, which is being increasingly recognized as an important predictor of clinical outcomes.

Non-invasive coronary imaging in patients with COVID-19: a narrative review

SARS-CoV-2 infection, responsible for COVID-19 outbreak, can cause cardiac complications, worsening outcome and prognosis. In particular, it can exacerbate any underlying cardiovascular condition, leading to atherosclerosis and increased plaque vulnerability, which may cause acute coronary syndrome. We review current knowledge on the mechanisms by which SARS-CoV-2 can trigger endothelial/myocardial damage and cause plaque formation, instability and deterioration. The aim of this review is to evaluate current non-invasive diagnostic techniques for coronary arteries evaluation in COVID-19 patients, such as coronary CT angiography and atherosclerotic plaque imaging, and their clinical implications. We also discuss the role of artificial intelligence, deep learning and radiomics in the context of coronary imaging in COVID-19 patients.

Coronary Computed Tomography Angiography Assessment of High-Risk Plaques in Predicting Acute Coronary Syndrome

Coronary computed tomography angiography (CCTA) is a comprehensive, non-invasive and cost-effective imaging assessment approach, which can provide the ability to identify the characteristics and morphology of high-risk atherosclerotic plaques associated with acute coronary syndrome (ACS). The development of CCTA and latest advances in emerging technologies, such as computational fluid dynamics (CFD), have made it possible not only to identify the morphological characteristics of high-risk plaques non-invasively, but also to assess the hemodynamic parameters, the environment surrounding coronaries and so on, which may help to predict the risk of ACS. In this review, we present how CCTA was used to characterize the composition and morphology of high-risk plaques prone to ACS and the current role of CCTA, including emerging CCTA technologies, advanced analysis, and characterization techniques in prognosticating the occurrence of ACS.

The Radiologist as a Gatekeeper in Chest Pain

Chest pain is a symptom that can be found in life-threatening conditions such as acute coronary syndrome (ACS). Those patients requiring invasive coronary angiography treatment or surgery should be identified. Often the clinical setting and laboratory tests are not sufficient to rule out a coronary or aortic syndrome. Cardiac radiological imaging has evolved in recent years both in magnetic resonance (MR) and in computed tomography (CT). CT, in particular, due to its temporal and spatial resolution, the quickness of the examination, and the availability of scanners, is suitable for the evaluation of these patients. In particular, the latest-generation CT scanners allow the exclusion of diagnoses such as coronary artery disease and aortic pathology, thereby reducing the patient's stay in hospital and safely selecting patients by distinguishing those who do not need further treatment from those who will need more- or less-invasive therapies. CT additionally reduces costs by improving long-term patient outcome. The limitations related to patient characteristics and those related to radiation exposure are weakening with the improvement of CT technology.

Prospective Validation and Comparative Analysis of Coronary Risk Stratification Strategies Among Emergency Department Patients With Chest Pain

Background

Coronary risk stratification is recommended for emergency department patients with chest pain. Many protocols are designed as “rule‐out” binary classification strategies, while others use graded‐risk stratification. The comparative performance of competing approaches at varying levels of risk tolerance has not been widely reported.

Methods and Results

This is a prospective cohort study of adult patients with chest pain presenting between January 2018 and December 2019 to 13 medical center emergency departments within an integrated healthcare delivery system. Using an electronic clinical decision support interface, we externally validated and assessed the net benefit (at varying risk thresholds) of several coronary risk scores (History, ECG, Age, Risk Factors, and Troponin [HEART] score, HEART pathway, Emergency Department Assessment of Chest Pain Score Accelerated Diagnostic Protocol), troponin‐only strategies (fourth‐generation assay), unstructured physician gestalt, and a novel risk algorithm (RISTRA‐ACS). The primary outcome was 60‐day major adverse cardiac event defined as myocardial infarction, cardiac arrest, cardiogenic shock, coronary revascularization, or all‐cause mortality. There were 13 192 patient encounters included with a 60‐day major adverse cardiac event incidence of 3.7%. RISTRA‐ACS and HEART pathway had the lowest negative likelihood ratios (0.06, 95% CI, 0.03–0.10 and 0.07, 95% CI, 0.04–0.11, respectively) and the greatest net benefit across a range of low‐risk thresholds. RISTRA‐ACS demonstrated the highest discrimination for 60‐day major adverse cardiac event (area under the receiver operating characteristic curve 0.92, 95% CI, 0.91–0.94, P<0.0001).

Conclusions

RISTRA‐ACS and HEART pathway were the optimal rule‐out approaches, while RISTRA‐ACS was the best‐performing graded‐risk approach. RISTRA‐ACS offers promise as a versatile single approach to emergency department coronary risk stratification.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03286179.

The Journal of Cardiovascular Computed Tomography: 2020 Year in review

The purpose of this review is to highlight the most impactful, educational, and frequently downloaded articles published in the Journal of Cardiovascular Computed Tomography (JCCT) for the year 2020. The JCCT reached new records in 2020 for the number of research submissions, published manuscripts, article downloads and social media impressions. The articles in this review were selected by the Editorial Board of the JCCT and are comprised predominately of original research publications in the following categories: Coronavirus disease 2019 (COVID-19), coronary artery disease, coronary physiology, structural heart disease, and technical advances. The Editorial Board would like to thank each of the authors, peer-reviewers and the readers of JCCT for making 2020 one of the most successful years in its history, despite the challenging circumstances of the global COVID-19 pandemic.

Cost-effectiveness Analysis of Anatomic vs Functional Index Testing in Patients With Low-Risk Stable Chest Pain

IMPORTANCE

Both noninvasive anatomic and functional testing strategies are now routinely used as initial workup in patients with low-risk stable chest pain (SCP).

OBJECTIVE

To determine whether anatomic approaches (ie, coronary computed tomography angiography [CTA] and coronary CTA supplemented with noninvasive fractional flow reserve [FFRCT], performed in patients with 30% to 69% stenosis) are cost-effective compared with functional testing for the assessment of low-risk SCP.

DESIGN, SETTING, AND PARTICIPANTS

This cost-effectiveness analysis used an individual-based Markov microsimulation model for low-risk SCP. The model was developed using patient data from the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial. The model was validated by comparing model outcomes with outcomes observed in the PROMISE trial for anatomic (coronary CTA) and functional (stress testing) strategies, including diagnostic test results, referral to invasive coronary angiography (ICA), coronary revascularization, incident major adverse cardiovascular event (MACE), and costs during 60 days and 2 years. The validated model was used to determine whether anatomic approaches are cost-effective over a lifetime compared with functional testing.

EXPOSURE

Choice of index test for evaluation of low-risk SCP.

MAIN OUTCOMES AND MEASURES

Downstream ICA and coronary revascularization, MACE (death, nonfatal myocardial infarction), cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) of competing strategies.

RESULTS

The model cohort included 10 003 individual patients (median [interquartile range] age, 60.0 [54.4-65.9] years; 5270 [52.7%] women; 7693 [77.4%] White individuals), who entered the model 100 times. The Markov model accurately estimated the test assignment, results of anatomic and functional index testing, referral to ICA, revascularization, MACE, and costs at 60 days and 2 years compared with observed data in PROMISE (eg, coronary CTA: ICA, 12.2% [95% CI, 10.9%-13.5%] vs 12.3% [95% CI, 12.2%-12.4%]; revascularization, 6.2% [95% CI, 5.5%-6.9%] vs 6.4% [95% CI, 6.3%-6.5%]; functional strategy: ICA, 8.1% [95% CI, 7.4%-8.9%] vs 8.2% [95% CI, 8.1%-8.3%]; revascularization, 3.2% [95% CI, 2.7%-3.7%] vs 3.3% [95% CI, 3.2%-3.4%]; 2-year MACE rates: coronary CTA, 2.1% [95% CI, 1.7%-2.5%] vs 2.3% [95% CI, 2.2%-2.4%]; functional strategy, 2.2% [95% CI, 1.8%-2.6%] vs 2.4% [95% CI, 2.3%-2.4%]). Anatomic approaches led to higher ICA and revascularization rates at 60 days, 2 years, and 5 years compared with functional testing but were more effective in patient selection for ICA (eg, 60-day revascularization-to-ICA ratio, CTA: 53.7% [95% CI, 53.3%-54.0%]; CTA with FFRCT: 59.5% [95% CI, 59.2%-59.8%]; functional testing: 40.7% [95% CI, 40.4%-50.0%]). Over a lifetime, anatomic approaches gained an additional 6 months in perfect health compared with functional testing (CTA, 25.16 [95% CI, 25.14-25.19] QALYs; CTA with FFRCT, 25.14 [95% CI, 25.12-25.17] QALYs; functional testing, 24.68 [95% CI, 24.66-24.70] QALYs). Anatomic strategies were less costly and more effective; thus, CTA with FFRCT dominated and CTA alone was cost-effective (ICERs ranged from $1912/QALY for women and $3,559/QALY for men) compared with functional testing. In probabilistic sensitivity analyses, anatomic approaches were cost-effective in more than 65% of scenarios, assuming a willingness-to-pay threshold of $100 000/QALY.

CONCLUSIONS AND RELEVANCE

The results of this study suggest that anatomic strategies may present a more favorable initial diagnostic option in the evaluation of low-risk SCP compared with functional testing.