Clinical effectiveness of coronary computed tomographic angiography in the triage of patients to cardiac catheterization and revascularization after inconclusive stress testing: results of a 2-year prospective trial

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered.

STRUCTURE

Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. These guidelines present an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients.

METHODS

A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. These guidelines present an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated and shared decision-making with patients is recommended.

Coronary artery calcium score and risk of cardiovascular events without established coronary artery disease: a systemic review and meta-analysis

BACKGROUND

Coronary artery calcium (CAC) is an indicator of atherosclerosis, and the CAC score is a useful noninvasive assessment of coronary artery disease.

OBJECTIVE

To compare the risk of cardiovascular outcomes in patients with CAC > 0 versus CAC = 0 in asymptomatic and symptomatic population in patients without an established diagnosis of coronary artery disease.

METHODS

A systematic search of electronic databases was conducted until January 2018 for any cohort study reporting cardiovascular events in patients with CAC > 0 compared with absence of CAC.

RESULTS

Forty-five studies were included with 192 080 asymptomatic 32 477 symptomatic patients. At mean follow-up of 11 years, CAC > 0 was associated with an increased risk of major adverse cardiovascular and cerebrovascular events (MACE) compared to a CAC = 0 in asymptomatic arm [pooled risk ratio (RR) 4.05, 95% confidence interval (CI) 2.91-5.63, P < 0.00001, I2 = 80%] and symptomatic arm (pooled RR 6.06, 95% CI 4.23-8.68, P < 0.00001, I2 = 69%). CAC > 0 was also associated with increased risk of all-cause mortality in symptomatic population (pooled RR 7.94, 95% CI 2.61-24.17, P < 0.00001, I2 = 85%) and in asymptomatic population CAC > 0 was associated with higher all-cause mortality (pooled RR 3.23, 95% CI 2.12-4.93, P < 0.00001, I2 = 94%). In symptomatic population, revascularization in CAC > 0 was higher (pooled RR 15, 95% CI 6.66-33.80, P < 0.00001, I2 = 72) compared with CAC = 0. Additionally, CAC > 0 was associated with more revascularization in asymptomatic population (pooled RR 5.34, 95% CI 2.06-13.85, P = 0.0006, I2 = 93). In subgroup analysis of asymptomatic population by gender, CAC > 0 was associated with higher MACE (RR 6.39, 95% CI 3.39-12.84, P < 0.00001).

CONCLUSION

Absence of CAC is associated with low risk of cardiovascular events compared with any CAC > 0 in both asymptomatic and symptomatic population without coronary artery disease.

Personalized 3D printed coronary models in coronary stenting

Background

3D printing has shown great promise in cardiovascular disease, with reports mainly focusing on pre-surgical planning and medical education. Research on utilization of 3D printed models in simulating coronary stenting has not been reported. In this study, we presented our experience of placing coronary stents into personalized 3D printed coronary models with the aim of determining stent lumen visibility with images reconstructed with different postprocessing views and algorithms.

Methods

A total of six coronary stents with diameter ranging from 2.5 to 4.0 mm were placed into 3 patient-specific 3D printed coronary models for simulation of coronary stenting. The 3D printed models were placed in a plastic container and scanned on a 192-slice third generation dual-source CT scanner with images reconstructed with soft (Bv36) and sharp (Bv59) kernel algorithms. Thick and thin slab maximum-intensity projection (MIP) images were also generated from the original CT data for comparison of stent lumen visibility. Stent lumen diameter was measured on 2D axial and MIP images, while stent diameter was measured on 3D volume rendering images. 3D virtual intravascular endoscopy (VIE) images were generated to provide intraluminal views of the coronary wall and stent appearances.

Results

All of these stents were successfully placed into the right and left coronary arteries but 2 of them did not obtain wall apposition along the complete length. The stent lumen visibility ranged from 54 to 97%, depending on the stent location in the coronary arteries. The mean stent lumen diameters measured on 2D axial, thin and thick slab MIP images were found to be significantly smaller than the actual size (P<0.01). Thick slab MIP images resulted in measured stent lumen diameters smaller than those from thin slab MIP images, with significant differences noticed in most of the measurements (4 out of 6 stents) (P<0.05), and no significant differences in the remaining 2 stents (P=0.19-0.38). In contrast, 3D volume rendering images allowed for more accurate measurements with measured stent diameters close to the actual dimensions in most of these coronary stents, except for the stent placed at the right coronary artery in one of the models due to insufficient expansion of the stent. Images reconstructed with sharp kernel Bv59 significantly improved stent lumen visibility when compared to the smooth Bv36 kernel (P=0.01). 3D VIE was successfully generated in all of the datasets with clear visualization of intraluminal views of the stents in relation to the coronary wall.

Conclusions

This preliminary report shows the feasibility of using 3D printed coronary artery models in coronary stenting for investigation of optimal coronary CT angiography protocols. Future studies should focus on placement of more stents with a range of stent diameters in the quest to reduce the need for invasive angiography for surveillance.

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.

Prognostic Performance of Prospective versus Retrospective Electrocardiographic Gating in Coronary Computed Tomographic Angiography

Coronary computed tomographic angiography (CCTA) with prospective electrocardiographic gating reduces radiation exposure, but its prognostic power for predicting cardiovascular risk in patients with suspected CAD has not been fully validated. To determine whether prospective gating performs as well as retrospective gating in this population, we compared these scan modes in patients undergoing 64-slice CCTA. From January 2009 through September 2011, 1,407 patients underwent CCTA; of these, 915 (mean age, 57.8 ± 13.5 yr; 54% male) had suspected coronary artery disease at the time of CCTA and were included in the study. Prospective gating was used in 195 (21%) and retrospective gating in 720 (79%). The mean follow-up duration was 2.4 ± 0.9 years. Overall, 390 patients (42.6%) had normal results on CCTA, 382 (41.7%) had nonobstructive coronary artery disease, and 143 (15.6%) had obstructive disease. Major adverse cardiac events occurred in 32 patients (3.5%): 11 cardiac deaths, 15 late revascularizations, and 6 nonfatal myocardial infarctions. Total event occurrences were similar in both groups (retrospective, 3.8%; prospective, 2.6%; P=0.42), as were the occurrences of each type of event. On adjusted multivariate analysis, nonobstructive (P=0.015) and obstructive (P <0.001) coronary artery disease were independently associated with major adverse cardiac events. Scan mode was not a predictor of outcome. The mean effective radiation dose was 4 ± 2 mSv for prospective compared with 12 ± 4 mSv for retrospective gating (P <0.01). The prognostic value of CCTA with prospective electrocardiographic gating compares favorably with that of retrospective gating, and it involves significantly less radiation exposure.

An Audit on the Appropriateness of Coronary Computed Tomography Angiography Referrals in a Tertiary Cardiac Center

BACKGROUND

In response to growing concerns regarding the overuse of coronary computed tomography angiography (CCTA) in the clinical setting, multiple societies, including the American College of Cardiology Foundation, have jointly published revised criteria regarding the appropriate use of this imaging modality. However, previous research indicates significant discrepancies in the rate of adherence to these guidelines.

AIM

To assess the appropriateness of CCTA referrals in a tertiary cardiac center in Bahrain.

METHODS

This retrospective clinical audit examined the records of patients referred to CCTA between the April 1, 2015 and December 31, 2015 in Mohammed bin Khalifa Cardiac Center. Using information from medical records, each case was meticulously audited against guidelines to categorize it as appropriate, inappropriate, or uncertain.

RESULTS

Of the 234 records examined, 176 (75.2%) were appropriate, 47 (20.1%) were uncertain, and 11 (4.7%) were inappropriate. About 74.4% of all referrals were to investigate coronary artery disease (CAD). The most common indication that was deemed appropriate was the detection of CAD in the setting of suspected ischemic equivalent in patients with an intermediate pretest probability of CAD (65.9%). Most referrals deemed inappropriate were requested to detect CAD in asymptomatic patients at low or intermediate risk of CAD (63.6%).

CONCLUSION

This audit demonstrates a relatively low rate of inappropriate CCTA referrals, indicating the appropriate and efficient use of this resource in the Mohammed bin Khalifa Cardiac Center. Agreement on and reclassification of "uncertain" cases by guideline authorities would facilitate a deeper understanding of referral appropriateness.

Improving Image Quality of Coronary Computed Tomography Angiography Using Patient Weight and Height-Dependent Scan Trigger Threshold

RATIONALE AND OBJECTIVES

We aim to improve the image quality of coronary computed tomography angiography (CCTA) by using personalized weight and height-dependent scan trigger threshold.

MATERIALS AND METHODS

This study was divided into two parts. First, we performed and analyzed the 100 scheduled CCTA data, which were acquired by using body mass index-dependent Smart Prep sequence (trigger threshold ranged from 80 Hu to 250 Hu based on body mass index). By identifying the cases of high quality image, a linear regression equation was established to determine the correlation among the Smart Prep threshold, height, and body weight. Furthermore, a quick search table was generated for weight and height-dependent Smart Prep threshold in CCTA scan. Second, to evaluate the effectiveness of the new individual threshold method, an additional 100 consecutive patients were divided into two groups: individualized group (n = 50) with weight and height-dependent threshold and control group (n = 50) with the conventional constant threshold of 150 HU. Image quality was compared between the two groups by measuring the enhancement in coronary artery, aorta, left and right ventricle, and inferior vena cava. By visual inspection, image quality scores were performed to compare between the two groups.

RESULTS

Regression equation between Smart Prep threshold (K, Hu), height (H, cm), and body weight (BW, kg) was K = 0.811 × H + 1.917 × BW - 99.341. When compared to the control group, the individualized group presented an average overall increase of 12.30% in enhancement in left main coronary artery, 12.94% in proximal right coronary artery, and 10.6% in aorta. Correspondingly, the contrast-to-noise ratios increased by 26.03%, 27.08%, and 23.17%, respectively, and by 633.1% in contrast between aorta and left ventricle. Meanwhile, the individualized group showed an average overall decrease of 22.7% in enhancement of right ventricle and 32.7% in inferior vena cava. There was no significant difference of the image noise between the two groups (P > .05). By visual inspection, the image quality score of the individualized group was higher than that of the control group.

CONCLUSION

Using personalized weight and height-dependent Smart Prep threshold to adjust scan trigger time can significantly improve the image quality of CCTA.

Prevalence and Prognosis of Nonobstructive Coronary Artery Disease in Patients Undergoing Coronary Angiography or Coronary Computed Tomography Angiography: A Meta-Analysis

OBJECTIVE

To evaluate the prevalence, clinical characteristics, and risk of cardiac events in patients with nonobstructive coronary artery disease (CAD).

PATIENTS AND METHODS

We searched PubMed, EMBASE, and the Cochrane Library from January 1, 1990, to November 31, 2015. Studies were included if they reported prevalence or prognosis of patients with nonobstructive CAD (≤50% stenosis) among patients with known or suspected CAD. Patients with nonobstructive CAD were further grouped as those with no angiographic CAD (0% or ≤20%) and those with mild CAD (>0% or >20% to ≤50%). Data were pooled using random effects modeling, and annualized event rates were assessed.

RESULTS

Fifty-four studies with 1,395,190 participants were included. The prevalence of patients with nonobstructive CAD was 67% (95% CI, 63%-71%) among patients with stable angina and 13% (95% CI, 11%-16%) among patients with non-ST-segment elevation acute coronary syndrome. The prevalence varied depending on sex, clinical setting, and risk profile of the population investigated. The risk of hard cardiac events (cardiac death or myocardial infarction) in patients with mild CAD was lower than that in patients with obstructive CAD (risk ratio, 0.28; 95% CI, 0.20-0.38) but higher than that in those with no angiographic CAD (risk ratio, 1.85; 95% CI, 1.52-2.26). The annualized event rates of hard cardiac events in patients with no angiographic CAD, mild CAD, and obstructive CAD were 0.3% (95% CI, 0.1%-0.4%), 0.7% (95% CI, 0.5%-1.0%), and 2.7% (95% CI, 1.7%-3.7%), respectively, among patients with stable angina and 1.2% (95% CI, 0.02%-2.3%), 4.1% (95% CI, 3.3%-4.9%), and 17.0% (95% CI, 8.4%-25.7%) among patients with non-ST-segment elevation acute coronary syndrome. The correlation between CAD severity and prognosis is consistent regardless of clinical presentation of all-cause death, myocardial infarction, total cardiovascular events, and revascularization.

CONCLUSION

Nonobstructive CAD is associated with a favorable prognosis compared with obstructive CAD, but it is not benign. The high prevalence and impaired prognosis of this population warrants further efforts to improve the risk stratification and management of patients with nonobstructive CAD.

SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits

Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions.

Prognostic value of coronary CTA vs. exercise treadmill testing: results from the Partners registry

AIMS

We sought to compare the complementary prognostic value of exercise treadmill testing (ETT) and coronary computed tomographic angiography (CTA) among patients referred for both exams.

METHODS AND RESULTS

We studied 582 patients without known coronary artery disease (CAD) who were clinically referred for ETT and CTA within 6 months. Patients were followed for cardiovascular (CV) death, non-fatal myocardial infarction (MI), or late revascularization (>90 days), stratified by Duke Treadmill Score (DTS) and CAD severity (≥50% stenosis). Mean age was 54 ± 13 years (63% male). In median follow-up of 40 months, there were 3 CV deaths, 7 non-fatal MIs, and 26 late revascularizations. ETT was inconclusive in 23%, positive in 31%, and negative in 46%. CTA demonstrated no CAD in 37%, non-obstructive CAD in 28%, and obstructive CAD in 35%. Among low-risk ETT patients (n = 326), there were 3 MI, 10 late revascularizations, and the frequent presence of non-obstructive (32%, n = 105) and obstructive CAD (27%, n = 88). When present, ETT features (i.e., angina, DTS, ischaemic electrocardiogram changes, and exercise capacity) individually failed to predict CV death/MI after adjustment for Morise score. Conversely, both obstructive CAD [HR 4.9 (1.0-23.3), P = 0.048] and CAD extent by segment involvement score >4 [HR 3.9 (1.0-15.2), P = 0.049] predicted increased risk for CV death or MI.

CONCLUSION

Patients with a low-risk ETT have an excellent prognosis at 40 months, despite the frequent presence of non-obstructive (32%) and obstructive (27%) CAD. In patients with an intermediate- to high-risk ETT (DTS <5), CTA can provide incremental risk stratification for future CV events.

Korean guidelines for the appropriate use of cardiac CT

The development of cardiac CT has provided a non-invasive alternative to echocardiography, exercise electrocardiogram, and invasive angiography and cardiac CT continues to develop at an exponential speed even now. The appropriate use of cardiac CT may lead to improvements in the medical performances of physicians and can reduce medical costs which eventually contribute to better public health. However, until now, there has been no guideline regarding the appropriate use of cardiac CT in Korea. We intend to provide guidelines for the appropriate use of cardiac CT in heart diseases based on scientific data. The purpose of this guideline is to assist clinicians and other health professionals in the use of cardiac CT for diagnosis and treatment of heart diseases, especially in patients at high risk or suspected of heart disease.

Prognostic value of cardiac computed tomography angiography in patients with suspected coronary artery disease: a meta-analysis

OBJECTIVES

The diagnostic accuracy of cardiac computed tomography angiography (CCTA) is well reported. The prognostic value of CCTA has been described in several studies, but many of these were underpowered and an update of the meta-analysis is necessary to increase the power to predict rare events. The purpose of this study was to perform a meta-analysis of the ability of CCTA to predict future cardiovascular events.

METHODS

We searched multiple databases for longitudinal studies of CCTA with a follow-up of at least 12 months of symptomatic patients with suspected coronary artery disease (CAD) reporting major adverse cardiovascular events (MACE), death, myocardial infarction and revascularization. Summary test parameters and receiver-operating characteristic curves were calculated.

RESULTS

Eighteen studies evaluated 29,243 patients with a median follow-up of 25 months. For MACE in patients with negative findings on CCTA, there was a pooled negative likelihood ratio (LR) of 0.01 [95% confidence interval (CI) 0.00-0.08], a positive LR of 1.72 (95% CI 1.54-1.91), a sensitivity of 1.00 (95% CI 0.97-1.00), a specificity of 0.42 (95% CI 0.36-0.48) and a diagnostic odds ratio of 159.07 (95% CI 22.20-1,139.80). The weighted average annualized MACE rate for positive versus negative CCTA findings was 3.49 versus 0.21%. Stratifying by no CAD, nonobstructive CAD or obstructive CAD, there were incrementally increasing adverse events.

CONCLUSIONS

Adverse cardiovascular events among patients with normal findings on CCTA are rare. There are incrementally increasing future MACE with increasing CAD by CCTA.

Prognostic Value of Nonobstructive and Obstructive Coronary Artery Disease Detected by Coronary Computed Tomography Angiography to Identify Cardiovascular Events

Background—

The contribution of plaque extent to predict cardiovascular events among patients with nonobstructive and obstructive coronary artery disease (CAD) is not well defined. Our objective was to evaluate the prognostic value of plaque extent detected by coronary computed tomography angiography.

Methods and Results—

All consecutive patients without prior CAD referred for coronary computed tomography angiography to evaluate for CAD were included. Examination findings were classified as normal, nonobstructive (<50% stenosis), or obstructive (≥50%). Based on the number of segments with disease, extent of CAD was classified as nonextensive (≤4 segments) or extensive (>4 segments). The cohort included 3242 patients followed for the primary outcome of cardiovascular death or myocardial infarction for a median of 3.6 (2.1–5.0) years. In a multivariable analysis, the presence of extensive nonobstructive CAD (hazard ratio, 3.1; 95% confidence interval, 1.5–6.4), nonextensive obstructive (hazard ratio, 3.0; 95% confidence interval, 1.3–6.9), and extensive obstructive CAD (hazard ratio, 3.9; 95% confidence interval, 2.2–7.2) were associated with an increased rate of events, whereas nonextensive, nonobstructive CAD was not. The addition of plaque extent to a model that included clinical probability as well as the presence and severity of CAD improved risk prediction.

Conclusions—

Among patients with nonobstructive CAD, those with extensive plaque experienced a higher rate of cardiovascular death or myocardial infarction, comparable with those who have nonextensive disease. Even among patients with obstructive CAD, greater extent of nonobstructive plaque was associated with higher event rate. Our findings suggest that regardless of whether obstructive or nonobstructive disease is present, the extent of plaque detected by coronary computed tomography angiography enhances risk assessment.

Association of cardiac events with coronary artery disease detected by 64-slice or greater coronary CT angiography: a systematic review and meta-analysis

BACKGROUND

The value of ≥64-slice coronary CT angiography (CCTA) to determine odds of cardiac death or non-fatal myocardial infarction (MI) needs further clarification.

METHODS

We performed a systematic review and meta-analysis using publications reporting events/severity of coronary artery disease (CAD) in patients with suspected CAD undergoing CCTA. Patients were divided into: no CAD, non-obstructive CAD (maximal stenosis <50%), and obstructive CAD (≥50% stenosis). Odds ratios with 95% confidence intervals were calculated using a fixed or random effects model. Heterogeneity was assessed using the I(2) index.

RESULTS

We included thirty-two studies comprising 41,960 patients with 363 all-cause deaths (15.0%), 114 cardiac deaths (4.7%), 342 MI (14.2%), 69 unstable angina (2.8%), and 1527 late revascularizations (63.2%) over 1.96 (SD 0.77) years of follow-up. Cardiac death or MI occurred in 0.04% without, 1.29% with non-obstructive, and 6.53% with obstructive CAD. OR for cardiac death or MI was: 14.92 (95% CI, 6.78 to 32.85) for obstructive CAD, 6.41 (95% CI, 2.44 to 16.84) for non-obstructive CAD versus no CAD, and 3.19 (95% CI, 2.29 to 4.45) for non-obstructive versus obstructive CAD and 6.56 (95% CI, 3.07 to 14.02) for no versus any CAD. Similar trends were noted for all-cause mortality and composite major adverse cardiovascular events.

CONCLUSIONS

Increasing CAD severity detected by CCTA is associated with cardiac death or MI, all-cause mortality, and composite major adverse cardiovascular events. Absence of CAD is associated with very low odds of major adverse events, but non-obstructive disease significantly increases odds of cardiac adverse events in this follow-up period.

Prognostic utility of coronary computed tomographic angiography

Coronary computed tomographic angiography (CCTA) employing CT scanners of 64-detector rows or greater represents a noninvasive method that enables accurate detection and exclusion of anatomically obstructive coronary artery disease (CAD), providing excellent diagnostic information when compared to invasive angiography. There are numerous potential advantages of CCTA beyond simply luminal stenosis assessment including quantification of atherosclerotic plaque volume as well as assessment of plaque composition, extent, location and distribution. In recent years, an array of studies has evaluated the prognostic utility of CCTA findings of CAD for the prediction of major adverse cardiac events, all-cause death and plaque instability. This prognostic information enhances risk stratification and, if properly acted upon, may improve medical therapy and/or behavioral changes that may enhance event-free survival. The goal of the present article is to summarize the current status of the prognostic utility of CCTA findings of CAD.

Prognostic value of CT angiography in patients with inconclusive functional stress tests

OBJECTIVES

We attempted to determine the prognostic value of coronary computed tomographic angiography (CTA) in patients with inconclusive functional stress tests.

BACKGROUND

Patients with suspected coronary artery disease (CAD) and inconclusive noninvasive cardiac stress tests represent a frequent management challenge.

METHODS

We examined 529 consecutive patients with suspected CAD and prior inconclusive functional stress tests. All patients underwent a coronary CTA scan using a 64-slice multidetector row scanner. CAD severity by coronary CTA was categorized as: 1) no evidence of CAD; 2) nonobstructive coronary plaques (< 30%); 3) mild stenosis (30% to 49%); 4) moderate stenosis (50% to 69%); and 5) severe stenosis (≥ 70%). Patients were also categorized according to a modified Duke prognostic CAD index. Survival analyses were performed using Cox proportional hazards models adjusted for baseline risk factors and coronary artery calcium score. The primary outcome of the study was the combined endpoint of all-cause mortality and nonfatal myocardial infarction.

RESULTS

Among patients with inconclusive stress tests, the large majority (69%) did not demonstrate significant CAD by coronary CTA. During a mean follow-up of 30.1 ± 11.1 months, there were 20 (3.8%) deaths and 17 (3.2%) nonfatal myocardial infarctions. Multivariable Cox regression analysis revealed that the presence of increasing degrees of obstructive CAD by CTA was an independent predictor of adverse events (hazard ratio [HR]: 1.66 [95% confidence interval (CI): 1.23 to 2.23], p = 0.001). Indeed, the presence of ≥ 50% coronary stenosis was associated with an increased risk of events (HR: 3.15 [95% CI: 1.26 to 7.89], p = 0.01). Likewise, the Duke prognostic CAD index was also found to be an independent predictor of events (HR: 1.54 [95% CI: 1.20 to 1.97], p = 0.001).

CONCLUSIONS

Among patients with inconclusive functional stress tests, the noninvasive assessment of CAD severity by coronary CTA has been shown to provide incremental prognostic information beyond the evaluation of traditional risk factors and coronary artery calcium score.

Development and validation of a predictive screening tool for uninterpretable coronary CT angiography results

BACKGROUND

Coronary CT angiography (CCTA) is an excellent tool for noninvasive assessment of coronary arteries in low- to intermediate-risk individuals. However, the accuracy of CCTA heavily depends on image quality. Our objective was to develop and validate a tool to predict pre-CCTA risk of obtaining an uninterpretable result in symptomatic patients.

METHODS AND RESULTS

Among 8585 symptomatic patients, we identified variables independently associated with the presence of at least 1 uninterpretable major coronary segment to create the uninterpretable risk score (URS). This risk score was developed using both clinical variables and patient variables acquired at the time the CCTA was performed (heart rate and coronary calcium). The URS was then prospectively validated among an additional 915 symptomatic patients. The URS was predictive of uninterpretable results in both the development and the validation cohorts. For every 4-point increase in the URS (range, 0 to 12), the rate of at least 1 uninterpretable coronary segment per 100 CCTA studies increased ≈1.5 fold. Increased heart rate and coronary artery calcium score were predictive of uninterpretable CCTA study results. Uninterpretable results were associated with 3-month outcomes in the development cohort.

CONCLUSIONS

The URS can categorize patients who are likely to have at least 1 uninterpretable major coronary segment on CCTA. This may aid in appropriate patient selection for CCTA and avoiding radiation exposure in those likely to have an uninterpretable study. Clinical Trial Registration- URL: http:///www.clinicaltrials.gov. Unique identifier: NCT00640068.

Quantification of coronary arterial stenoses by multidetector CT angiography in comparison with conventional angiography methods, caveats, and implications

Multidetector computed tomography (MDCT) is a rapidly evolving technology for performing noninvasive coronary angiography. Despite good sensitivity and specificity for detecting significant coronary artery disease in patients, disagreement on individual coronary arterial stenosis severity is common between MDCT and the current gold standard, conventional angiography. The reasons for such disagreement are numerous, but are at least partly inherent to MDCT's modest spatial and temporal resolution at present. Less well acknowledged, however, is the fact that MDCT and conventional angiography are fundamentally different technologies, rendering good agreement on the degree of lumen narrowing rather unrealistic, given both of their respective limitations. Discrepant stenosis assessment by MDCT and conventional angiography receives remarkable attention, whereas its significance for patient outcome is less certain. On the other hand, the ability to noninvasively assess coronary arterial plaque characteristics and composition in addition to lumen obstruction shows strong promise for improved risk assessment and may at last enable us to move beyond mere coronary stenosis assessment for the management of patients with coronary artery disease.

Prognostic value of cardiac computed tomography angiography: a systematic review and meta-analysis

OBJECTIVES

The purpose of this study was to systematically review and perform a meta-analysis of the ability of cardiac computed tomography angiography (CCTA) to predict future cardiovascular events and death.

BACKGROUND

The diagnostic accuracy of CCTA is well reported. The prognostic value of CCTA has been described in several studies, but many were underpowered. Pooling outcomes increases the power to predict rare events.

METHODS

We searched multiple databases for longitudinal studies of CCTA with at least 3 months follow-up of symptomatic patients with suspected coronary artery disease (CAD) reporting major adverse cardiovascular events (MACE), consisting of death, myocardial infarction (MI), and revascularization. Annualized event rates were pooled using a bivariate mixed-effects binomial regression model to calculate summary likelihood ratios and receiver-operating characteristic curves.

RESULTS

Eighteen studies evaluated 9,592 patients with a median follow-up of 20 months. The pooled annualized event rate for obstructive (any vessel with >50% luminal stenosis) versus normal CCTA was 8.8% versus 0.17% per year for MACE (p < 0.05) and 3.2% versus 0.15% for death or MI (p < 0.05). The pooled negative likelihood ratio for MACE after normal CCTA findings was 0.008 (95% confidence interval [CI]: 0.0004 to 0.17, p < 0.001), the positive likelihood ratio was 1.70 (95% CI: 1.42 to 2.02, p < 0.001), sensitivity was 0.99 (95% CI: 0.93 to 1.00, p < 0.001), and specificity was 0.41 (95% CI: 0.31 to 0.52, p < 0.001). Stratifying by no CAD, nonobstructive CAD (worst stenosis <50%), or obstructive CAD, there were incrementally increasing adverse events.

CONCLUSIONS

Adverse cardiovascular events among patients with normal findings on CCTA are rare. There are incrementally increasing future MACE with increasing CAD by CCTA.

Prognostic value of absence or presence of coronary artery disease determined by 64-slice computed tomography coronary angiography a systematic review and meta-analysis

To determine via a meta-analysis the prognostic value of 64-slice computed tomography angiography (CTA) by quantifying risk of major adverse cardiac events (MACE) in different patient groups classified according to CT angiographic findings. A systematic literature search and meta-analyses was conducted on 10 studies examining stable, symptomatic and intermediate risk patients by 64-slice CTA. Patients were followed up for a mean of 21 month. Patient groups with CT-angiographic non-obstructive (stenosis <50% of luminal narrowing) or obstructive (stenosis ≥50% of luminal narrowing) CAD were compared to those having normal angiography without CAD. MACE (cardiac death, non-fatal myocardial infarction and revascularization) numbers were used to calculate odds ratios (OR) with 95% confidence interval (CI) in each group. Ten studies including 5,675 patients were eligible for meta-analysis. The cumulative MACE rate over 21 months were 0.5% in patients with normal CTA, 3.5% in non-obstructive CAD and 16% in obstructive CAD. Compared to normal CTA, non-obstructive CAD was associated with significant increased risk of MACE with OR=6.68 (3.01-14.82 CI 95%), P=0.0001. Obstructive CAD was associated with further significant increased risk of MACE with OR=41.19 (22.56-75.18, CI 95%), P=0.0001. The studies were homogenous, P-value >0.05 for heterogeneity. 64-slice CTA is able to differentiate low-risk from high-risk patients with suspected or known CAD. Absence of CAD predicts excellent prognosis, while obstructive CAD is associated with markedly increased risk of MACE.

Integration of coronary anatomy and myocardial perfusion imaging

Advances in cardiovascular imaging have resulted in the development of multiple noninvasive techniques to evaluate myocardial perfusion and coronary anatomy, each of which has unique strengths and limitations. For example, CT angiography can directly visualize the presence of atherosclerosis, but the hemodynamic effect of many lesions identified by this technique is unknown. Alternatively, myocardial perfusion imaging enables a physiological assessment, but it may underestimate the extent of atherosclerosis in patients with multivessel disease. Dual-modality simultaneous imaging or multimodal sequential imaging techniques facilitate integration of information on both myocardial perfusion and coronary anatomy, and thus have the potential to improve diagnostic and prognostic evaluation, which could translate into improved care of patients. This Review discusses the strengths and limitations of the currently available individual noninvasive techniques for imaging coronary anatomy and myocardial perfusion. Approaches to integration of these imaging modalities are described, followed by an exploration of the clinical utility and future directions of hybrid imaging.