Integration of non-invasive functional assessments with anatomical risk stratification in complex coronary artery disease: the non-invasive functional SYNTAX score

Comparison of myocardial perfusion scintigraphy and strain echocardiography in patients undergoing coronary angiography

OBJECTIVE

Myocardial perfusion scintigraphy is a common non-invasive method for assessing ischemic burden, though artifacts can affect accuracy. Speckle-tracking strain echocardiography improves left ventricular function assessment, and global longitudinal strain correlates well with coronary artery disease. The aim of this study was to compare myocardial perfusion scintigraphy with global longitudinal strain in stable angina pectoris patients.

METHODS

A total of 133 suspected coronary artery disease patients who underwent myocardial perfusion scintigraphy and coronary angiography were prospectively enrolled and classified as myocardial perfusion scintigraphy true positives or false positives based on coronary angiography results. Global longitudinal strain values for the epicardium, endocardium, and myocardium (avg) were calculated.

RESULTS

Ischemic percentages of myocardial perfusion scintigraphy>12% and mid-wall global longitudinal strain<-18.4% correlated with true positive coronary angiography results. Left ventricular ejection fraction/global longitudinal strain mid ratio positively correlated with coronary artery disease presence and severity. Higher ischemic percentages of myocardial perfusion scintigraphy showed a negative correlation (r: -0.2606, p: 0.002) with global longitudinal strain, indicating a greater likelihood of coronary artery disease (OR 0.25, 95%CI 0.08-0.73, p: 0.012). Female sex was linked to fewer true positive myocardial perfusion scintigraphy results.

CONCLUSION

The GLS value of the Left Ventricle obtained by two-dimentional strain echocardiography offers sensitivity and specificity similar to myocardial perfusion scintigraphy in the detection of coronary artery disease.. An elevated left ventricular ejection fraction/global longitudinal strain ratio is a significant predictor of the presence and severity of coronary artery disease.

Predictors of percutaneous coronary intervention derived from CCTA in patients with chronic coronary syndrome

BACKGROUND

To identify anatomical and morphological plaque features predictors of PCI and create a multiparametric score to increase the predictive yield. Moreover, we assessed the incremental predictive value of FFRCT (Fractional Flow Reserve derived from CCTA) trans-lesion gradient (ΔFFRCT) when integrated into the score.

METHODS

Observational cohort study including patients undergoing CCTA for suspected coronary artery disease, with FFRCT available, referred to invasive coronary angiogram and assessment of fractional flow reserve. Plaque analysis was performed using validated semi-automated software. Logistic regression was performed to identify anatomical and morphological plaque features predictive of PCI. Optimal thresholds were defined by area under the receiver-operating characteristics curve (AUC) analysis. A scoring system was developed in a derivation cohort (70 ​% of the study population) and tested in a validation cohort (30 ​% of patients).

RESULTS

The overall study population included 340 patients (455 vessels), among which 238 patients (320 vessels) were included in the derivation cohort. At multivariate logistic regression analysis, absence of left main disease, diameter stenosis (DS), non-calcified plaque (NCP) volume, and percent atheroma volume (PAV) were independent predictors of PCI. Optimal thresholds were: DS ​≥ ​50 ​%, volume of NCP>113 ​mm3 and PAV>17 ​%. A weighted score (CT-PCI Score) ranging from 0 to 11 was obtained. The AUC of the score was 0.80 (95%CI 0.74-0.86). The integration of ΔFFRCT in the CT-PCI score led to a mild albeit not significant increase in the AUC (0.82, 95%CI 0.77-0.87, p ​= ​0.328).

CONCLUSIONS

Plaque anatomy and morphology derived from CCTA could aid in identifying patients amenable to PCI.

Computed Tomography-Derived Physiology Assessment: State-of-the-Art Review

Coronary computed tomography angiography (CCTA) and CCTA-derived fractional flow reserve (FFRCT) are the best non-invasive techniques to assess coronary artery disease (CAD) and myocardial ischemia. Advances in these technologies allow a paradigm shift to the use of CCTA and FFRCT for advanced plaque characterization and planning myocardial revascularization.

Treatment recommendation based on SYNTAX score 2020 derived from coronary computed tomography angiography and invasive coronary angiography

The diagnostic performance of the SYNTAX score 2020 (SS-2020) when calculated using CCTA remains unknown. This study aimed to compare treatment recommendations based on the SS-2020 derived from coronary computed tomography angiography (CCTA) versus invasive coronary angiography (ICA). This interim analysis included 57 of the planned 114 patients with de-novo three-vessel disease, with or without left main coronary artery disease, enrolled in the ongoing FASTTRACK CABG trial. The anatomical SYNTAX scores derived from ICA or CCTA were evaluated by two separate teams of blinded core-lab analysts. Treatment recommendations were based on a maximal individual absolute risk difference in all-cause mortality between percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) of 4.5% ([predicted PCI mortality] - [predicted CABG mortality]). The level of agreement was evaluated with Bland-Altman plots and Cohen's Kappa. The mean age was 66.2 ± 9.2 years and 89.5% of patients were male. Mean anatomical SYNTAX scores derived from ICA and CCTA were 35.1 ± 11.5 and 35.6 ± 11.4 (p = 0.751), respectively. The Bland-Altman analysis showed mean differences of - 0.26 and - 0.93, with standard deviation of 3.69 and 5.23, for 5- and 10-year all-cause mortality, respectively. The concordance in recommended treatment for 5- and 10-year mortalities were 84.2% (48/57 patients) and 80.7% (46/57 patients), with Cohen's κ coefficients of 0.672 and 0.551. There was moderate to substantial agreement between treatment recommendations based on the SS-2020 derived using CCTA and ICA, suggesting that CCTA could be used as an alternative to ICA when making decisions regarding the modality of revascularization.

Computed Tomography-Derived Physiology Assessment: State-of-the-Art Review

Coronary computed tomography angiography (CCTA) and CCTA-derived fractional flow reserve (FFRCT) are the best non-invasive techniques to assess coronary artery disease (CAD) and myocardial ischemia. Advances in these technologies allow a paradigm shift to the use of CCTA and FFRCT for advanced plaque characterization and planning myocardial revascularization.

The Potential Role of Cardiac CT in the Evaluation of Patients With Known or Suspected Cardiomyopathy: From Traditional Indications to Novel Clinical Applications

After 15 years from its advent in the clinical field, coronary computed tomography (CCTA) is now widely considered as the best first-step test in patients with low-to-moderate pre-test probability of coronary artery disease. Technological innovation was of pivotal importance for the extensive clinical and scientific interest in CCTA. Recently, the advent of last generation wide-coverage CT scans paved the way for new clinical applications of this technique beyond coronary arteries anatomy evaluation. More precisely, both biventricular volume and systolic function quantification and myocardial fibrosis identification appeared to be feasible with last generation CT. In the present review we would focus on potential applications of cardiac computed tomography (CCT), beyond CCTA, for a comprehensive assessment patients with newly diagnosed cardiomyopathy, from technical requirements to novel clinical applications.

Correlation between coronary CTASYNTAX score and invasive coronary angiographySYNTAX score

It is important to evaluate the complex coronary artery disease in the diagnosis and treatment of coronary heart disease.The SYNTAX score based on invasive coronary angiography (ICA) (also referred to as ICA-SYNTAX score) plays a positive role in the selection of revascularization of complex coronary artery disease and the prediction of adverse events.The development of coronary computed tomography angiography (CCTA) technology promotes the clinical application of SYNTAX score (CCTA-SYNTAX score) based on coronary CTA, and also enriches the examination methods of patients with coronary heart disease. The CCTA-SYNTAX score has the advantages of non-invasiveness, simple operation, good reproducibility, and relatively low cost, which can make it play an increasingly important role in the diagnosis of coronary heart disease. A number of foreign studies have confirmed that CCTA-SYNTAX score is highly correlated with ICA-SYNTAX score, which further promotes the study of CCTA-SYNTAX score in revascularization of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) and adverse event prediction.Therefore, the CCTA-SYNTAX score can be an auxiliary method for the ICA-SYNTAX score, as the first choice for preoperative evaluation and postoperative review of patients with coronary heart disease.

The Impact of War-Related Stress on Coronary Artery Disease Severity in War Survivors: A SYNTAX Study

Background: Due to the strong relationship between stress and heart disease, particularly acute myocardial infarction (MI), this study investigated the complexity of coronary artery disease (CAD) among Syrian refugee patients referred to Jordan University Hospital and its relation to war-related stressors. Methods: This is a retrospective study that utilized the SYNTAX I score in order to evaluate all Syrian refugees that underwent coronary artery catheterization at Jordan University Hospital during the period between May of 2014 and December of 2017. Results: There was a significant association between war-related stressors and high SYNTAX score (SX score), thus indicating a higher complexity of CAD in Syrian war survivors with higher stress scores. The strongest war-related correlation was observed with crossing green-lines, in which Syrian refugee patients who had crossed such lines had significantly higher SYNTAX scores. Regression analysis demonstrated that war stressors were positive predictors of increased SYNTAX scores even when adjusted for conventional CAD risk factors. Surprisingly, none of the CAD risk factors were significantly associated with SYNTAX score. Conclusion: Our findings suggest that exposure to multiple war-related stressors may increase the complexity and severity of CAD in Syrian war survivors. Thus, special attention, efforts, and resources should be allocated to screen for such vulnerable patients in order to provide them with the appropriate healthcare.

Prognostic implication of CT-FFR based functional SYNTAX score in patients with de novo three-vessel disease

AIMS

This study was aimed at investigating whether a machine learning (ML)-based coronary computed tomographic angiography (CCTA) derived fractional flow reserve (CT-FFR) SYNTAX score (SS), 'Functional SYNTAX score' (FSSCTA), would predict clinical outcome in patients with three-vessel coronary artery disease (CAD).

METHODS AND RESULTS

The SS based on CCTA (SSCTA) and ICA (SSICA) were retrospectively collected in 227 consecutive patients with three-vessel CAD. FSSCTA was calculated by combining the anatomical data with functional data derived from a ML-based CT-FFR assessment. The ability of each score system to predict major adverse cardiac events (MACE) was compared. The difference between revascularization strategies directed by the anatomical SS and FSSCTA was also assessed. Two hundred and twenty-seven patients were divided into two groups according to the SSCTA cut-off value of 22. After determining FSSCTA for each patient, 22.9% of patients (52/227) were reclassified to a low-risk group (FSSCTA ≤ 22). In the low- vs. intermediate-to-high (>22) FSSCTA group, MACE occurred in 3.2% (4/125) vs. 34.3% (35/102), respectively (P < 0.001). The independent predictors of MACE were FSSCTA (OR = 1.21, P = 0.001) and diabetes (OR = 2.35, P = 0.048). FSSCTA demonstrated a better predictive accuracy for MACE compared with SSCTA (AUC: 0.81 vs. 0.75, P = 0.01) and SSICA (0.81 vs. 0.75, P < 0.001). After FSSCTA was revealed, 52 patients initially referred for CABG based on SSCTA would have been changed to PCI.

CONCLUSION

Recalculating SS by incorporating lesion-specific ischaemia as determined by ML-based CT-FFR is a better predictor of MACE in patients with three-vessel CAD. Additionally, the use of FSSCTA may alter selected revascularization strategies in these patients.

Feasibility of coronary CT angiography for guidance of CABG

OBJECTIVE

To assess the clinical safety and effectiveness of coronary revascularization in patients who underwent coronary artery bypass grafting (CABG) based exclusively on coronary computed tomography angiography (CCTA) results.

METHODS

53 patients (62.3 ± 7.1 years) underwent CCTA before a CABG surgery without prior invasive coronary angiography (ICA). Primary endpoints were all-cause mortality and major adverse cardiovascular events (MACE). The secondary endpoint was quality of life (QoL) assessed with the Minnesota Living with Heart Failure Questionnaire (MLHFQ). All were collected one year after the surgery.

RESULTS

CCTA revealed multivessel coronary artery disease (CAD) in 52 patients. Indication for bypass surgery was made exclusively based on CCTA results. 136 distal anastomoses were performed. Assessment at 1 year (13.3 ± 1.4 months) was completed in 98.1% of the patients. MACE and mortality rates were 0%. The MLHFQ total score was 21.8 ± 8.7, and active lifestyle was maintained in all patients.

CONCLUSIONS

In this proof of concept prospective pilot study, we observed that non-invasive coronary angiography may provide adequate anatomic detail to guide CABG surgery. Further study of this concept is warranted.

Usefulness of Immature Granulocytes to Predict High Coronary SYNTAX Score in Acute Coronary Syndrome; a Cross-sectional Study

INTRODUCTION

Immature granulocytes (IG) in peripheral blood indicate increased bone marrow activation and inflammation, and SYNTAX score (SS) is an anatomical scoring system based on coronary angiogram. This study, aimed to evaluate the relationship between IG and SS, as a new inflammatory marker in patients with acute coronary syndrome (ACS).

METHODS

Patients aged >18 years who were diagnosed with ACS in the emergency department were included in this study, which was planned as a cross-sectional study. Patients were divided into two groups of patients with high and low SSs according to coronary angiography results. Demographic and laboratory parameters were compared between the groups.

RESULTS

Our study consisted of 78 patients diagnosed with ACS, who met the inclusion criteria. The average age of the study group was 59 years, and 67.9% of the patients were male. 21 patients (26.9%) had high SSs and 57 patients (73.1%) had low SSs. Mean IG% was significantly higher in high SS group compared to low SS group (0.71±0.25 vs 0.44±0.21 mg/dl, p<0.001). IG% can present a high SS with 76.2% sensitivity and 75.4% specificity at a cut-off value of 0.7.

CONCLUSION

IG was significantly higher in ACS patients with high SSs. It seems that IG can be used as a parameter, which is quickly accessible and cheap, in order to predict high SS in ACS patients in daily clinical practice.

Hybrid anatomo-functional imaging of coronary artery disease: Beneficial irrespective of its core components

Coronary artery disease (CAD) is the most common and important cause of ischemic heart disease, with major implications on global morbidity and mortality. Non-invasive testing is crucial in the diagnostic and prognostic work-up of patients with or at risk of CAD, and also to guide decision making in terms of pharmacologic and revascularization therapy. The traditional paradigm is to view anatomic (i.e., coronary computed tomography) and functional imaging (e.g., myocardial perfusion scintigraphy) tests as opposing alternatives. Such approach is too reductionist and does not capitalize on the strengths of each type of test while risking to overlook the inherent limitations. The combination of anatomic and functional tests in a logic of hybrid imaging holds the promise of overcoming the limitations inherent to anatomic and functional testing, enabling more accurate diagnosis, prognosis, and guidance for revascularization in patients with CAD.

Risk Stratification in Patients with Coronary Artery Disease: A Practical Walkthrough in the Landscape of Prognostic Risk Models

Although a combination of multiple strategies to prevent and treat coronary artery disease (CAD) has led to a relative reduction in cardiovascular mortality over recent decades, CAD remains the greatest cause of morbidity and mortality worldwide. A variety of individual factors and circumstances other than clinical presentation and treatment type contribute to determining the outcome of CAD. It is increasingly understood that personalised medicine, by taking these factors into account, achieves better results than "one-size-fitsall" approaches. In recent years, the multiplication of risk scoring systems for CAD has generated some degree of uncertainty regarding whether, when and how predictive models should be adopted when making clinical decisions. Against this background, this article reviews the most accepted risk models for patients with evidence of CAD to provide practical guidance within the current landscape of tools developed for prognostic risk stratification.

Fractional Flow Reserve Derived From Computed Tomographic Angiography in Patients With Multivessel CAD

BACKGROUND

The functional SYNTAX score (FSS) has been shown to improve the discrimination for major adverse cardiac events compared with the anatomic SYNTAX score (SS) while reducing interobserver variability. However, evidence supporting the noninvasive FSS in patients with multivessel coronary artery disease (CAD) is scarce.

OBJECTIVES

The purpose of this study was to assess the feasibility of and validate the noninvasive FSS derived from coronary computed tomography angiography (CTA) with fractional flow reserve (FFR_CT) in patients with 3-vessel CAD.

METHODS

The CTA-SS was calculated in patients with 3-vessel CAD included in the SYNTAX II (SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery II) study. The noninvasive FSS was determined by including only ischemia-producing lesions (FFR_CT ≤0.80). SS derived from different imaging modalities were compared using the Bland-Altman and Passing-Bablok method, and the agreement on the SS tertiles was investigated with Cohen's Kappa. The risk reclassification was compared between the noninvasive and invasive physiological assessment, and the diagnostic accuracy of FFR_CT was assessed by the area under the receiver-operating characteristic curve using instantaneous wave-free ratio as a reference.

RESULTS

The CTA-SS was feasible in 86% of patients (66 of 77), whereas the noninvasive FSS was feasible in 80% (53 of 66). The anatomic SS was overestimated by CTA compared with conventional angiography (27.6 ± 6.4 vs. 25.3 ± 6.9; p < 0.0001) whereas the calculation of the FSS yielded similar results between the noninvasive and invasive imaging modalities (21.6 ± 7.8 vs. 21.2 ± 8.8; p = 0.589). The noninvasive FSS reclassified 30% of patients from the high- and intermediate-SS tertiles to the low-risk tertile, whereas invasive FSS reclassified 23% of patients from the high- and intermediate-SS tertiles to the low-risk tertile. The agreement on the classic SS tertiles based on Kappa statistics was slight for the anatomic SS (Kappa = 0.19) and fair for the FSS (Kappa = 0.32). The diagnostic accuracy of FFR_CT to detect functional significant stenosis based on an instantaneous wave-free ratio ≤0.89 revealed an area under the receiver-operating characteristics curve of 0.85 (95% CI: 0.79 to 0.90) with a sensitivity of 95% (95% CI: 89% to 98%), specificity of 61% (95% CI: 48% to 73%), positive predictive value of 81% (95% CI: 76% to 86%), and negative predictive value of 87% (95% CI: 74% to 94%).

CONCLUSIONS

Calculation of the noninvasive FSS is feasible and yielded similar results to those obtained with invasive pressure-wire assessment. The agreement on the SYNTAX score tertile classification improved with the inclusion of the functional component from slight to fair agreement. FFR_CT has good accuracy in detecting functionally significant lesions in patients with 3-vessel CAD. (A Trial to Evaluate a New Strategy in the Functional Assessment of 3-Vessel Disease Using SYNTAX II Score in Patients Treated With PCI; NCT02015832).

A Comparative Preliminary Study on CT Contrast Attenuation Gradient Versus Invasive FFR in Patients with Unstable Angina

The aim of this preliminary study was to assess the effectiveness of transluminal contrast attenuation gradient (TAG) determined by computed tomographic angiography (CTA), for the evaluation of the functional significance of coronary artery stenoses in patients with acute coronary syndromes produced by vulnerable coronary plaques, and to demonstrate the correlation between this new parameter and the vulnerability markers of the culprit lesions.

Material and methods: This is a preliminary pilot study on 10 patients with acute coronary syndromes – unstable angina type, who underwent CTA for the assessment of coronary lesions, followed by invasive angiography and the determination of fractional flow reserve (FFR) prior to a revascularization procedure. Patients were divided into 2 groups, according to their FFR values: Group 1 consisted of 6 patients with an FFR value <0.8 (functionally significant lesion), and Group 2 consisted of 4 patients who presented an FFR value >0.8 (functionally non-significant lesion).

Results: FFR values were 0.64 ± 0.07, 95% CI: 0.5–0.7 in Group 1, and 0.86 ± 0.05, 95% CI: 0.7–0.9 in Group 2. Plaques associated with an FFR<0.8 presented a higher amount of plaque volume (192.7 ± 199.7 mm3 vs. 42.1 ± 27.3 mm3, p = 0.1), necrotic core (66.7 ± 72.9 mm3 vs. 10.0 ± 9.3 mm3, p = 0.1), and fibro-fatty tissue (29.7 ± 37.4 mm3 vs. 6.2 ± 3.8 mm3, p = 0.2). At the same time, TAG significantly correlated with the presence of a functionally significant lesion. Coronary lesions associated with low FFR presented significantly higher values of TAG along the plaque as compared with lesions with FFR values >0.8 (TAG values 22.1 ± 5.8 HU vs. 11.7 ± 2.5 HU, p = 0.01). Linear regression identified a significant correlation between TAG and FFR values as a measure of functional significance of the lesion (r = 0.7, p = 0.01).

Conclusions: Contrast attenuation gradient along the culprit lesion, determined by CTA, correlates with the FFR values and with CT markers of plaque vulnerability, indicating that the presence of vulnerability features inside a coronary plaque could increase the functional significance of a coronary lesion.