Optimizing Evaluation of Patients with Low-to-Intermediate-Risk Acute Chest Pain: A Randomized Study Comparing Stress Myocardial Perfusion Tomography Incorporating Stress-Only Imaging Versus Cardiac CT

Critical Appraisal of the Current Role of Myocardial Perfusion Imaging in the Management of Acute Chest Pain

This paper describes the evolution of nuclear cardiology techniques in the setting of acute coronary syndromes. Since the 1970s, the contribution of nuclear cardiology has been fundamental in delineating the physiopathology and diagnosis of acute myocardial infarction, when electrocardiogram (ECG) did not provide the diagnosis and when cardiac enzyme assessments were at a very early stage. In this clinical situation, at that time the role of pyrophosphate scintigraphy and antimyosin antibodies was important in ensuring diagnostic precision. However, these methods showed limitations and were abandoned in the late 80s and early 90s when therapeutic applications such as thrombolytic therapy, and primary-and rescue-percutaneous coronary intervention (PCI) were introduced. Beginning in the mid-80s, the introduction and widespread use of perfusion tracers such as 99mTc labelled compounds and technological advances such as SPECT, allowed to assess the efficacy of thrombolysis and early revascularization, as well as to assess in depth myocardial salvage. Currently, perfusion SPECT, especially using fast imaging techniques and dedicated cardiac SPECT with solid-state detectors, allows a quick confirmation or exclusion of acute coronary syndromes, particularly in low-to-intermediate likelihood of coronary artery disease (CAD), especially when there are absolute or relative contraindications to the use of coronary computed tomographic angiography (CCTA).

Comparative Effectiveness of Coronary CT Angiography and Standard of Care for Evaluating Acute Chest Pain: A Living Systematic Review and Meta-Analysis

Purpose

To perform a living systematic review and meta-analysis of randomized controlled trials comparing the effectiveness of coronary CT angiography (CCTA) and standard of care (SOC) in the evaluation of acute chest pain (ACP).

Materials and Methods

Multiple electronic databases were systematically searched, with the most recent search conducted on October 31, 2022. Studies were stratified into two groups according to the pretest probability for acute coronary syndrome (group 1 with predominantly low-to-intermediate risk vs group 2 with high risk). A meta-regression analysis was also conducted using participant risk, type of SOC used, and the use or nonuse of high-sensitivity troponins as independent variables.

Results

The final analysis included 22 randomized controlled trials (9379 total participants; 4956 assigned to CCTA arms and 4423 to SOC arms). There was a 14% reduction in the length of stay and a 17% reduction in immediate costs for the CCTA arm compared with the SOC arm. In group 1, the length of stay was 17% shorter and costs were 21% lower using CCTA. There was no evidence of differences in referrals to invasive coronary angiography, myocardial infarction, mortality, rate of hospitalization, further stress testing, or readmissions between CCTA and SOC arms. There were more revascularizations (relative risk, 1.45) and medication changes (relative risk, 1.33) in participants with low-to-intermediate acute coronary syndrome risk and increased radiation exposure in high-risk participants (mean difference, 7.24 mSv) in the CCTA arm compared with the SOC arm. The meta-regression analysis found significant differences between CCTA and SOC arms for rate of hospitalization, further stress testing, and medication changes depending on the type of SOC (P < .05).

Conclusion

The results support the use of CCTA as a safe, rapid, and less expensive in the short term strategy to exclude acute coronary syndrome in low- to intermediate-risk patients presenting with acute chest pain.Keywords: Acute Coronary Syndrome, Chest Pain, Emergency Department, Coronary Computed Tomography, Usual Care Supplemental material is available for this article. Published under a CC BY 4.0 license.

The chest pain guidelines revisited: cherry picking from the frequentist tree

The new chest pain guideline document was recently released. The biggest changes are in the recommendations for intermediate and high-risk patients with known and unknown CAD. Coronary CT angiography has been recommended as the preferred imaging test for patients < 65 years old with chest pain. This paper will review the major evidence and omissions in the document that prompted that recommendation and provide thoughts on potential actions going forward.

The Prognostic Value of CAC Zero Among Individuals Presenting With Chest Pain: A Meta-Analysis

BACKGROUND

There is little consensus on whether absence of coronary artery calcium (CAC) can identify patients with chest pain (CP) who can safely avoid additional downstream testing.

OBJECTIVES

The purpose of this study was to conduct a systematic review and meta-analysis investigating the utility of CAC assessment for ruling out obstructive coronary artery disease (CAD) among patients with stable and acute CP, at low-to-intermediate risk of obstructive CAD undergoing coronary computed tomography angiography (CTA).

METHODS

The authors searched online databases for studies published between 2005 and 2021 examining the relationship between CAC and obstructive CAD (≥50% coronary luminal narrowing) on coronary CTA among patients with stable and acute CP.

RESULTS

In this review, the authors included 19 papers comprising 79,903 patients with stable CP and 13 papers including 12,376 patients with acute CP undergoing simultaneous CAC and coronary CTA assessment. Overall, 45% (95% CI: 40%-50%) of patients with stable CP and 58% (95% CI: 50%-66%) of patients with acute CP had CAC = 0. The negative predictive values for CAC = 0 ruling out obstructive CAD were 97% (95% CI: 96%-98%) and 98% (95% CI: 96%-99%) among patients with stable and acute CP, respectively. Additionally, the prevalence of nonobstructive CAD among those with CAC = 0 was 13% (95% CI: 10%-16%) among those with stable CP and 9% (95% CI: 5%-13%) among those with acute CP. A CAC score of zero predicted a low incidence of major adverse cardiac events among patients with stable CP (0.5% annual event rate) and acute CP (0.8% overall event rate).

CONCLUSIONS

Among over 92,000 patients with stable or acute CP, the absence of CAC was associated with a very low prevalence of obstructive CAD, a low prevalence of nonobstructive CAD, and a low annualized risk of major adverse cardiac events. These findings support the role of CAC = 0 in a value-based health care delivery model as a "gatekeeper" for more advanced imaging among patients presenting with CP.

Clinical applications of cardiac computed tomography: a consensus paper of the European Association of Cardiovascular Imaging-part I

Cardiac computed tomography (CT) was introduced in the late 1990's. Since then, an increasing body of evidence on its clinical applications has rapidly emerged. From an initial emphasis on its technical efficiency and diagnostic accuracy, research around cardiac CT has now evolved towards outcomes-based studies that provide information on prognosis, safety, and cost. Thanks to the strong and compelling data generated by large, randomized control trials, the scientific societies have endorsed cardiac CT as pivotal diagnostic test for the management of appropriately selected patients with acute and chronic coronary syndrome. This consensus document endorsed by the European Association of Cardiovascular Imaging is divided into two parts and aims to provide a summary of the current evidence and to give updated indications on the appropriate use of cardiac CT in different clinical scenarios. This first part focuses on the most established applications of cardiac CT from primary prevention in asymptomatic patients, to the evaluation of patients with chronic coronary syndrome, acute chest pain, and previous coronary revascularization.

Noninvasive Imaging for Patients with COVID-19 and Acute Chest Pain

Acute chest pain is a common presentation in patients with COVID-19. Although noninvasive cardiac imaging modalities continue to be important cornerstones of management, the pandemic has brought forth difficult and unprecedented challenges in the provision of timely care while ensuring the safety of patients and providers. Clinical practice has adapted to these challenges, with several recommendations and societal guidelines emerging on the appropriate use of imaging modalities. In this review, we summarize the current evidence base on the use of noninvasive cardiac imaging modalities in COVID-19 patients with acute chest pain, with a focus on acute coronary syndromes.

ACR Appropriateness Criteria® Acute Nonspecific Chest Pain-Low Probability of Coronary Artery Disease

Patients with acute nonspecific chest pain and low probability for coronary disease remain an important clinical management dilemma. We focus on evidence for imaging, in an integrated decision-making setting. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Achieving Low Radiation Dose in "One-Stop" Myocardial Computed Tomography Perfusion Imaging in Coronary Artery Disease Using 16-cm Wide Detector CT

RATIONALE AND OBJECTIVES

To investigate the feasibility of "one-stop" myocardial computed tomography perfusion (CTP) imaging (combined anatomy, perfusion, and function) in coronary artery disease using 16-cm wide detector CT, compared to conventional coronary CT angiography (CCTA).

MATERIALS AND METHODS

442 patients with suspected coronary artery disease were randomly divided into two groups. Patients in group A underwent "one-stop" CTP, whereas group B underwent conventional CCTA. Image quality of CT images was assessed. Radiation and contrast medium doses and scan time of the two groups were recorded. Group A was further divided into four subgroups according to the degree of coronary artery stenosis, for which transmural perfusion ratio (TPR) and left ventricular ejection fraction (LVEF) were measured.

RESULTS

Scan time was 73.1 ± 7.3 (s) longer in group A than in group B with 11.7% reduction of radiation dose (p < 0.001) and no significant difference in image quality was noted. Significant differences regarding the minimum TPR (F = 24.657, p < 0.001) and LVEF (χ² =36.98, p < 0.001) were observed among four subgroups. A negative correlation was found between the degree of coronary artery stenosis and TPR of the corresponding myocardial segments (r = -0.55, p < 0.001). Patients with moderate to severe arterial stenosis exhibited a decreased LVEF compared to those with normal coronary arteries (48.0% vs 56.5%, p < 0.001).

CONCLUSION

Compared to conventional CCTA, our new developed "one-stop" CTP may provide more comprehensive information on myocardial perfusion, coronary artery stenosis, and LV cardiac function with reduced radiation and contrast medium doses.

Prognostic value of cardiac CT

In the past decades, coronary computed tomography angiography (CCTA) has become a powerful tool in the management of coronary artery disease. The diagnostic and prognostic value of CCTA has been extensively demonstrated in both large observational studies and clinical trials among stable chest pain patients. The quantification of coronary artery calcium score (CACS) is a well-established predictor of cardiovascular morbidity and mortality in asymptomatic subjects. Besides CACS, the main strength of CCTA is the accurate assessment of the individual total atherosclerotic plaque burden, which holds important prognostic information. In addition, CCTA, by providing detailed information on coronary plaque morphology and composition with identification of specific high-risk plaque features, may further improve the risk stratification beyond the assessment of coronary stenosis. The development of new CCTA applications, such as stress myocardial CT perfusion and computational fluids dynamic applied to standard CCTA to derive CT-based fractional flow reserve (FFR) values have shown promising results to guide revascularization, potentially improving clinical outcomes in stable chest pain patients. In this review, starting from the role of CACS and moving beyond coronary stenosis, we evaluate the existing evidence of the prognostic effectiveness of the CCTA strategy in real-world clinical practice.

Coronary computed tomography angiography vs. myocardial single photon emission computed tomography in patients with intermediate risk chest pain: a randomized clinical trial for cost-effectiveness comparison based on real-world cost

AIMS

To compare the cost-effectiveness of coronary computed tomography angiography (CCTA) vs. myocardial single photon emission computed tomography (SPECT) in patients with stable intermediate risk chest pain.

METHODS AND RESULTS

Non-acute patients with 10-90% pre-test probability of coronary artery disease from three high-volume centres in Korea (n = 965) were randomized 1:1 to CCTA or myocardial SPECT as the initial non-invasive imaging test. Medical costs after randomization, the downstream outcome, including all-cause death, acute coronary syndrome, cerebrovascular accident, repeat revascularization, stent thrombosis, and significant bleeding following the initial test and the quality-adjusted life-years (QALYs) gained by the EuroQoL-5D questionnaire was compared between the two groups. In all, 903 patients underwent the initially randomized study (n = 460 for CCTA, 443 for SPECT). In all, 65 patients underwent invasive coronary angiography (ICA) in the CCTA and 85 in the SPECT group, of which 4 in the CCTA and 30 in the SPECT group demonstrated no stenosis on ICA [6.2% (4/65) vs. 35.3% (30/85), P-value < 0.001]. There was no difference in the downstream clinical events. QALYs gained was higher in the SPECT group (0.938 vs. 0.955, P-value = 0.039) but below the threshold of minimal clinically important difference of 0.08. Overall cost per patient was lower in the CCTA group (USD 4514 vs. 5208, P-value = 0.043), the tendency of which was non-significantly opposite in patients with 60-90% pre-test probability (USD 5807 vs. 5659, P-value = 0.845).

CONCLUSION

CCTA is associated with fewer subsequent ICA with no difference in downstream outcome. CCTA may be more cost-effective than SPECT in Korean patients with stable, intermediate risk chest pain.

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.

Diagnostic accuracy of functional, imaging and biochemical tests for patients presenting with chest pain to the emergency department: A systematic review and meta-analysis

BACKGROUND

Non-invasive ischaemia tests and biomarkers are widely adopted to rule out acute coronary syndrome in the emergency department. Their diagnostic accuracy has yet to be precisely defined.

METHODS

Medline, Cochrane Library CENTRAL, EMBASE and Biomed Central were systematically screened (start date 1 September 2016, end date 1 December 2016). Prospective studies (observational or randomised controlled trial) comparing functional/imaging or biochemical tests for patients presenting with chest pain to the emergency department were included.

RESULTS

Overall, 77 studies were included, for a total of 49,541 patients (mean age 59.9 years). Fast and six-hour highly sensitive troponin T protocols did not show significant differences in their ability to detect acute coronary syndromes, as they reported a sensitivity and specificity of 0.89 (95% confidence interval 0.79-0.94) and 0.84 (0.74-0.9) vs 0.89 (0.78-0.94) and 0.83 (0.70-0.92), respectively. The addition of copeptin to troponin increased sensitivity and reduced specificity, without improving diagnostic accuracy. The diagnostic value of non-invasive tests for patients without troponin increase was tested. Coronary computed tomography showed the highest level of diagnostic accuracy (sensitivity 0.93 (0.81-0.98) and specificity 0.90 (0.93-0.94)), along with myocardial perfusion scintigraphy (sensitivity 0.85 (0.77-0.91) and specificity 0.92 (0.83-0.96)). Stress echography was inferior to coronary computed tomography but non-inferior to myocardial perfusion scintigraphy, while exercise testing showed the lower level of diagnostic accuracy.

CONCLUSIONS

Fast and six-hour highly sensitive troponin T protocols provide an overall similar level of diagnostic accuracy to detect acute coronary syndrome. Among the non-invasive ischaemia tests for patients without troponin increase, coronary computed tomography and myocardial perfusion scintigraphy showed the highest sensitivity and specificity.

Comparison of mid- to long-term clinical outcomes between anatomical testing and usual care in patients with suspected coronary artery disease: A meta-analysis of randomized trials

BACKGROUND

Controversies remain regarding clinical outcomes following initial strategies of coronary computed tomography angiography (CCTA) vs usual care with functional testing in patients with suspected coronary artery disease (CAD).

HYPOTHESIS

CCTA as initial diagnostic strategy results in better mid- to long-term outcomes than usual care in patients with suspected CAD.

METHODS

We searched PubMed, Embase, and Cochrane Library for randomized controlled trials comparing clinical outcomes during ≥6 months' follow-up between initial anatomical testing by CCTA vs usual care with functional testing in patients with suspected CAD. Occurrence of all-cause mortality, nonfatal myocardial infarction (MI), and major adverse cardiovascular events (MACE), and use of invasive coronary angiography and coronary revascularization, were compared between the 2 diagnostic strategies.

RESULTS

Twelve trials were included (20 014 patients; mean follow-up, 20.5 months). Patients undergoing CCTA as initial noninvasive testing had lower risk of nonfatal MI compared with those treated with usual care (risk ratio [RR]: 0.70, 95% confidence interval [CI]: 0.52-0.94, P = 0.02). There was a tendency for reduced MACE following initial CCTA strategy, but not for risk of all-cause mortality. Compared with functional testing, the CCTA strategy increased use of invasive coronary angiography (RR: 1.53, 95% CI: 1.12-2.09, P = 0.007) and coronary revascularization (RR: 1.49, 95% CI: 1.11-2.00, P = 0.007).

CONCLUSIONS

Anatomical testing with CCTA as the initial noninvasive diagnostic modality in patients with suspected CAD resulted in lower risk of nonfatal MI than usual care with functional testing, at the expense of more frequent use of invasive procedures.

Acute chest pain evaluation using coronary computed tomography angiography compared with standard of care: a meta-analysis of randomised clinical trials

Objective

Coronary CT angiography (CCTA) has certain advantages compared with stress testing including greater accuracy in identifying obstructive coronary disease. The aim of the study was to perform a systematical review and meta-analysis comparing CCTA with other standard-of-care (SOC) approaches in evaluation of patients with acute chest pain.

Methods

Electronic databases were systematically searched to identify randomised clinical trials of patients with acute chest pain comparing CCTA with SOC approaches. We examined the following end points: mortality, major adverse cardiac events (MACE), myocardial infarction (MI), invasive coronary angiography (ICA) and revascularisation. Pooled risk ratios (RR) and their 95% CIs were calculated using random-effects models.

Results

Ten trials with 6285 patients were included. The trials used different definitions and implementation for SOC but all used physiologic testing. The clinical follow-up ranged from 1 to 19 months. There were no significant differences in all-cause mortality (RR 0.48, 95% CI 0.17 to 1.36, p=0.17), MI (RR 0.82, 95% CI 0.49 to 1.39, p=0.47) or MACE (RR 0.98, 95% CI 0.67 to 1.43, p=0.92) between the groups. However, significantly higher rates of ICA (RR 1.32, 95% CI 1.07 to 1.63, p=0.01) and revascularisation (RR 1.77, 95% CI 1.35 to 2.31, p<0.0001) were observed in the CCTA arm.

Conclusions

Compared with other SOC approaches use of CCTA is associated with similar major adverse cardiac events but higher rates of revascularisation in patients with acute chest pain.