Significance Of Coronary Artery Disease Research Articles

Diagnostic Performance of Diastolic Hyperemia-Free Ratio Compared With Invasive Fractional Flow Reserve for Evaluation of Coronary Artery Disease

Hyperemic and nonhyperemic pressure ratios are frequently used to assess the hemodynamic significance of coronary artery disease and to guide the need for myocardial revascularization. However, there are limited data on the diagnostic performance of the diastolic hyperemia-free ratio (DFR). We evaluated the diagnostic performance of the DFR compared with invasive fractional flow reserve (FFR). We performed a prospective, single-center study of 308 patients (343 lesions) who underwent DFR and FFR for evaluation of visually estimated 40% to 90% stenoses. Diagnostic performance of the DFR compared with FFR was evaluated using linear regression, Bland-Altman analysis, and receiver operating characteristic curves. The overall diagnostic accuracy of the DFR was 83%; the accuracy rates were 86%, 40%, and 95% when the DFR was <0.86, 0.88 to 0.90, and >0.93, respectively. The sensitivity, specificity, positive predicative value, and negative predictive value were 60%, 91%, 71%, and 87%, respectively. The Pearson correlation coefficient was 0.75 (p <0.05). The Bland-Altman analysis showed a mean difference of 0.09, and the area under the receiver operating characteristic curve was 0.88 (95% confidence interval 0.84 to 0.92, p <0.05). In conclusion, the DFR has a good diagnostic performance compared with FFR but 17% of the measurements were discordant. The diagnostic accuracy of the DFR was only 40% when the DFR was 0.88 to 0.90, suggesting that FFR may be useful in these arteries.

Temporal trends and outcomes of patients with chronic limb-threatening ischemia with and without history of coronary artery disease: insights from the us national inpatient sample database.

The burden and prognostic significance of coronary artery disease (CAD) in adults with peripheral artery disease and chronic limb-threatening ischemia (CLTI) is unknown. Temporal trends in prevalence of significant CAD (history of myocardial infarction or coronary revascularizations) in hospitalizations for CLTI were determined using the 2000 to 2018 National Inpatient Sample (NIS) database. A multivariable regression analysis of outcomes was performed based on presence or absence of CAD. Among 13 575 099 hospitalizations for CLTI (41% female, 69% white, mean age 69 years), 23% had concomitant CAD, of which 11% underwent lower extremity arterial revascularization (43.6% endovascular and 56.4% surgical). The prevalence of concomitant CAD with CLTI increased from 15.3% in 2000 to 23.1% in 2018. Furthermore, the frequency of endovascular revascularization in adults with CAD and CLTI increased from 15.1% to 48.3%, while there was a decreasing trend of surgical revascularization, from 84.9% to 51.7%. After multivariate adjustments, CLTI with CAD was associated with increased risk of in-hospital mortality (OR, 1.40; 95% CI, 1.32-1.47; P less than .0001) and bleeding requiring transfusion (OR, 1.10; 95% CI, 1.06-1.12; P less than .0001) compared with patients with CLTI without CAD. As compared with surgical revascularization, endovascular revascularization was associated with lower risk of in-hospital mortality in both patients with CLTI with CAD (OR, 0.69; 95% CI, 0.63-0.76; P less than .001) and CLTI without CAD (OR, 0.71; 95% CI, 0.67-0.76; P less than .001). Prevalence of CAD has increased in adults presenting with CLTI and is associated with poor outcomes, warranting the need for effective interventions and secondary prevention in this high-risk population.

Influenza Vaccination as Prevention Therapy for Stable Coronary Artery Disease and Acute Coronary Syndrome: A Meta-Analysis of Randomized Trials

BackgroundInfluenza can cause a significant burden on patients with coronary artery disease. This meta-analysis assessed the effectiveness of influenza vaccination in patients with acute coronary syndrome and stable coronary artery disease. MethodsWe searched the Cochrane Controlled Register of Trials (CENTRAL), Embase, MEDLINE, www.ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform from inception to September 2021. Estimates were summarized using the Mantel-Haenzel method and a random-effects model. To assess heterogeneity the I² statistic was used. ResultsFive randomized trials, comprising 4187 patients, were included, 2 of which included patients with acute coronary syndrome and 3 that included patients with stable coronary artery disease and acute coronary syndrome. Influenza vaccination significantly reduced the risk for all-cause mortality (relative risk [RR] = 0.56; 95% confidence interval [CI], 0.38-0.84), cardiovascular mortality (RR = 0.54; 95% CI, 0.37-0.80), major acute cardiovascular events (RR = 0.66; 95% CI, 0.49-0.88), and acute coronary syndrome (RR = 0.63; 95% CI, 0.44-0.89). On subgroup analysis, influenza vaccination remained effective for these outcomes in acute coronary syndrome but did not meet statistical significance in coronary artery disease. Furthermore, influenza vaccination did not reduce the risk for revascularization (RR = 0.89; 95% CI, 0.54-1.45), stroke or transient ischemic attack (RR = 0.85; 95% CI, 0.31-2.32), or heart failure hospitalization (RR = 0.91; 95% CI, 0.21-4.00). ConclusionsInfluenza vaccine is a cheap and effective intervention to reduce the risk for all-cause mortality, cardiovascular mortality, major acute cardiovascular events, and acute coronary syndrome among coronary artery disease patients, especially in those with acute coronary syndrome.

Left Ventricular Myocardial and Cavity Velocity Disturbances Are Powerful Predictors of Significant Coronary Artery Stenosis.

Background and Aim: Dobutamine stress echocardiography (DSE) is a well-established noninvasive investigation for significant coronary artery disease (CAD). The aim of this study was to evaluate the accuracy of cardiac Doppler parameters in predicting CAD. Methods: We prospectively studied 103 consecutive patients with suspected CAD based on typical symptoms; 59 proved to have CAD, and 44 patients proved to have no-CAD (n = 44). All patients underwent a complete stress Doppler echocardiographic examination. Total isovolumic time (T-IVT) as a marker of cavity dyssynchrony and wall motion score index (WMSI) were also calculated. Results: At peak dobutamine stress, the compromised LV longitudinal excursion (MAPSE), systolic septal and lateral velocities (s’), and diastolic indices were more pronounced in the CAD patients compared with those without CAD, but LV dimension did not differ between groups (p > 0.05). The WMSI was higher and t-IVT more prolonged in patients with CAD (p < 0.01 for both). Similarly, the changes were more pronounced in patients with significant CAD compared with insignificant CAD. On multivariate model, Δ mean s’, OR 2.016 (1.610 to 3.190; p < 0.001), Δ E velocity OR 2.502 (1.179 to 1.108; p < 0.001), Δ t-IVT 2.206 (1.180 to 2.780; p < 0.001) and Δ WMSI OR 1.911 (1.401 to 3.001; p = 0.001) were the most powerful independent predictors of the presence of CAD, particularly when significant (>75%). Δ mean s’ < 5.0 was 85% sensitive, 89% specific with AUC 0.92. Respective values for Δ E velocity <6.0 cm/s were 82%, 90% and 0.91; for Δ t-IVT > 4.5, 78%, 77% and 0.81 and for Δ FT ≥ 150 ms, 76%, 78% and 0.84 in predicating significant CAD. WMSI ≥ 0.7 was 75% sensitive, 77% specific with AUC of 0.81 in predicting significant CAD. The accuracy of DSE was higher in significant CAD compared to insignificant CAD (80% vs. 74%; p = 0.03). Conclusions: Compromised LV longitudinal systolic function, lower delta E wave, prolonged t-IVT, and increased WMSI were the most powerful independent predictors of the presence and significance of CAD. These finding strengthen the role of comprehensive DSE analysis in diagnosing ischemic disturbances secondary to significant CAD.

Left ventricular myocardial and cavity velocity disturbances are stronger predictors of stress induced ischaemia in patients with significant coronary artery disease

Abstract Background and aim Dobutamine stress echocardiography (DSE) is a well-established non-invasive investigation for significant coronary artery disease (CAD). The aim of this study was to evaluate the accuracy of cardiac Doppler parameters in predecting CAD. Methods We prospectively studied 103 consecutive patients with suspected CAD based on typical symptoms, 59 proved to have CAD and 44 patients proved to have no-CAD (n=44). All patients underwent a complete stress Doppler echocardiographic examination, including tissue Doppler, long axis velocities and total isovolumic time (T-IVT) as a marker of cavity dyssynchrony, determined as [60 − (total ejection time (ET) + total filling time (FT))]. The wall motion score index (WMSI) was also calculated. Results CAD patients were older, had less females, less prevalent cardiac risk factors and higher CT calcium score compared to patients with no-CAD (p&amp;lt;0.05, for all). At peak dobutamine stress the compromised LV longitudinal excursion (MAPSE), systolic septal and lateral velocities (s'), TAPSE and diastolic indices were more pronounced in the CAD patients compared to those without CAD, but LV dimension did not differ between groups (p&amp;gt;0.05). The WMSI was higher and t-IVT more prolonged in patients with CAD (p&amp;lt;0.01, for both). Similarly, the changes were more pronounced in patients with significant CAD compared to insignificant CAD. On multivariate model, delta mean s' OR 2.016 (1.610–3.490, p&amp;lt;0.001), delta E velocity OR 1.822 (1.179–2.360, p&amp;lt;0.001), delta t-IVT OR 1.406 (1.180–2.180, p&amp;lt;0.001), and delta FT OR 1.911 (1.401–2.710, p=0.001), were the most powerful independent predictors of the presence of CAD, particularly when significant (&amp;gt;50%). Delta mean s' &amp;lt;5.0 was 85% sensitive, 89% specific with AUC 0.92. Respective values for delta E velocity &amp;lt;6.0 cm/s were 82%, 90% and 0.91; for delta t-IVT &amp;gt;4.5, 78%, 77% and 0.81 and for delta FT ≥150ms, 76%, 78% and 0.84 in predicating significant CAD. WMSI≥0.7 was 75% sensitive, 77% specific with AUC of 0.81 in predicting significant CAD. The accuracy of DSE was higher in significant CAD compared to insignificant CAD (80% vs 74%; p=0.03). Conclusions Compromised LV longitudinal systolic function, lower delta E wave, prolonged t-IVT and increased WMSI were the most powerful independent predictors of the presence and significance of CAD. These finding strengthen the role of comprehensive DSE analysis in diagnosing ischaemic disturbances secondary to significant CAD. Funding Acknowledgement Type of funding sources: None.

Coronary Computed Tomography Angiography-derived Fractional Flow Reserve: An Expert Consensus Document of Chinese Society of Radiology.

Invasive fractional flow reserve (FFR) measured by a pressure wire is a reference standard for evaluating functional stenosis in coronary artery disease. Coronary computed tomography angiography-derived fractional flow reserve (CT-FFR) uses advanced computational analysis methods to noninvasively obtain FFR results from a single conventional coronary computed tomography angiography data to evaluate the hemodynamic significance of coronary artery disease. More and more evidence has found good correlation between the results of noninvasive CT-FFR and invasive FFR. CT-FFR has proven its potential in optimizing patient management, improving risk stratification and prognosis, and reducing total health care costs. However, there is still a lack of standardized interpretation of CT-FFR technology in real-world clinical settings. This expert consensus introduces the principle, workflow, and interpretation of CT-FFR; summarizes the state-of-the-art application of CT-FFR; and provides suggestions and recommendations for the application of CT-FFR with the aim of promoting the standardized application of CT-FFR in clinical practice.

Over-expression of IL1R2 in PBMCs of Patients with Coronary Artery Disease and Its Clinical Significance.

Background:IL-1 has been widely explored and played a role in regulating inflammatory and immune responses to various disorders. Nevertheless, the role of interleukin-1 receptor type II, a protein-coding gene of interleukin-1 in coronary artery disease patients with peripheral blood mononuclear cells, persists to be undetermined.Methods:Our study discovered the IL-1 receptor type II expression through gene expression omnibus (GEO) public repository based on bioinformatics tools and further validation was carried out between coronary artery disease patients and healthy participants using peripheral blood mononuclear cells samples in Second Hospital of Tianjin Medical University. A total of 180 participants, comprising 90 cases of coronary artery disease and 90 samples of healthy control were retrospectively evaluated and the correlation of IL-1 receptor type II was observed between serum levels of oxidized low-density lipoprotein and SYNTAX score. Furthermore, the clinical significance of IL-1 receptor type II was evaluated in peripheral blood mononuclear cells of coronary artery disease patients by the receiver operating curve using the area under the curve.Results:IL-1 receptor type II was markedly overexpressed in peripheral blood mononuclear cells and severe patients with coronary artery disease compared to the healthy control participants. Meanwhile, a positive correlation of IL-1 receptor type II expression was significantly observed between SYNTAX score and oxidized low-density lipoprotein of coronary artery disease patients. Further, the receiver operating curve achieved a significantly higher area under the curve of 0.813 in coronary artery disease patients with peripheral blood mononuclear cells. Thus, IL-1 receptor type II expressions were not only directly correlated with peripheral blood mononuclear cells but also showed potential significance in coronary artery disease patients.Conclusion:IL-1 receptor type II might be involved in the immune/inflammatory responses of coronary artery disease accompanied by other cytokine receptor genes.

Physiological Approach for CoronaryArtery Bifurcation Disease: Position Statement by Korean, Japanese, and EuropeanBifurcation Clubs.

Coronary artery bifurcation lesions are frequently encountered in cardiac catheterization laboratories and are associated with more complex procedures and worse clinical outcomes than nonbifurcation lesions. Therefore, anatomical and physiological assessment of bifurcation lesions before, during, and after percutaneous coronary intervention is of paramount clinical importance. Physiological assessment can help interventionalists appreciate the hemodynamic significance of coronary artery disease and guide ischemia-directed revascularization. However, it is important to understand that the physiological approach for bifurcation disease is more important than simply using physiological indexes for its assessment. This joint consensus document by the Korean, Japanese, and European bifurcation clubs presents the concept of a physiological approach for coronary bifurcation lesions, as well as current knowledge, practical tips, pitfalls, and future directions of applying physiological indexes in bifurcation percutaneous coronary intervention. This document aims to guide interventionalists in performing appropriate physiology-based assessments and treatment decisions for coronary bifurcation lesions.

The prevalence of risk factors and pattern of obstructive coronary artery disease in young indians (&amp;lt; 45 years) undergoing percutaneous coronary intervention: a gender-based multi-center study

Abstract Funding Acknowledgements Type of funding sources: None. Background In a retrospective study, we aimed to explore the prevalence of risk factors and trends of obstructive coronary artery disease (CAD) in Indian females under 45 years old compared to males of the same age group who underwent percutaneous coronary intervention (PCI). Purpose With changing lifestyles, the onset of traditional risk factors at the early stages of life is the major culprit for developing CAD at an early age. For several years, the significance of CAD in young women was underestimated. There are some sex-related variations in CAD, and symptoms of CAD in women, regardless of age, have low specificity even in the absence of risk factors. Materials and Methods This was a retrospective, observational, multi-centre study of young Indian females and males (&amp;lt; 45 years) who underwent PCI as per the guidelines at three high-volume centres of India. The study evaluated the prevalence of risk factors, clinical and angiographic patterns of obstructive CAD in young Indian women compared to men. Results In a cohort of 3656 patients who underwent PCIs, 113 young females comprised 3.1% of those with obstructive CAD, while 254 young males constituted 6.9%. Traditional risk factors such as hypertension, diabetes, and family history of premature CAD were the most common in both genders, whereas dyslipidaemia, obesity, smoking, and alcoholism were more common in young males. The acute coronary syndrome was the most common clinical presentation. The single-vessel disease was common with the involvement of the left anterior descending artery as a most common angiographic feature. The prevalence of cardiogenic shock was 4.4% in females and 4.1% in males while the in-hospital mortality rate was 1.77% in young females and 2% in young males. Conclusion CAD in young Indians is on the rise, and frequent screening for obstructive CAD should be done, especially in those with symptoms and risk factors.

Upregulation of the Long Non-coding RNA LINC01480 Is Associated With Immune Infiltration in Coronary Artery Disease Based on an Immune-Related lncRNA-mRNA Co-expression Network.

Coronary artery disease (CAD) is considered one of the leading causes of death worldwide. Although dysregulation of long non-coding RNAs (lncRNAs) has been reported to be associated with the initiation and progression of CAD, the knowledge regarding their specific functions as well their physiological/pathological significance in CAD is very limited. In this study, we aimed to systematically analyze immune-related lncRNAs in CAD and explore the relationship between key immune-related lncRNAs and the immune cell infiltration process. Based on differential expression analysis of mRNAs and lncRNAs, an immune-related lncRNA-mRNA weighted gene co-expression network containing 377 lncRNAs and 119 mRNAs was constructed. LINC01480 and AL359237.1 were identified as the hub immune-related lncRNAs in CAD using the random forest-recursive feature elimination and least absolute shrinkage and selection operator logistic regression. Furthermore, 93 CAD samples were divided into two subgroups according to the expression values of LINC01480 and AL359237.1 by consensus clustering analysis. By performing gene set enrichment analysis, we found that cluster 2 enriched more cardiovascular risk pathways than cluster 1. The immune cell infiltration analysis of ischemic cardiomyopathy (ICM; an advanced stage of CAD) samples revealed that the proportion of macrophage M2 was upregulated in the LINC01480 highly expressed samples, thus suggesting that LINC01480 plays a protective role in the progression of ICM. Based on the findings of this study, lncRNA LINC01480 may be used as a novel biomarker and therapeutic target for CAD.

Interleukin-35 Mitigates ox-LDL-Induced Proatherogenic Effects via Modulating miRNAs Associated with Coronary Artery Disease (CAD).

Recent emergence of miRNAs as important regulators of processes involving lesion formation and regression has highlighted miRNAs as potent therapeutic targets for the treatment of atherosclerosis. Few studies have reported the atheroprotective role of IL-35, a novel immunosuppressive and anti-inflammatory cytokine; however, miRNA-dependent regulation underlying the anti-atherosclerotic potential of IL-35 remains elusive. THP-1 macrophages were incubated with human recombinant IL-35 (rIL-35) either in the presence or absence of ox-LDL. qRT-PCR was conducted to validate the expression levels of previously identified miRNAs including miR-197-5p, miR-4442, miR-324-3p, miR-6879-5p, and miR-6069 that were differentially expressed in peripheral blood mononuclear cells of coronary artery disease (CAD) patients vs. controls. Additionally, bioinformatic analysis was performed to predict miRNA-associated targets and their corresponding functional significance in CAD. Exogenous IL-35 significantly decreased the average area of ox-LDL-stimulated macrophages, indicating the inhibitory effect of IL-35 on lipid-laden foam cell formation. Furthermore, rIL-35 treatment alleviated the ox-LDL-mediated atherogenic effects by modulating the expression levels of aforementioned CAD-associated miRNAs in the cultured macrophages. Moreover, functional enrichment analysis of these miRNA-related targets revealed their role in the molecular processes affecting different stages of atheroslerotic plaque development, such as macrophage polarization, T cell suppression, lipoprotein metabolism, foam cell formation, and iNOS-mediated inflammation. Our observations uncover the novel role of IL-35 as an epigenetic modifier as it influences the expression level of miRNAs implicated in the pathogenesis of atherosclerosis. Thus, IL-35 cytokine therapy-mediated miRNA targeting could be an effective therapeutic strategy against the development of early atheromas in asymptomatic high-risk CAD patients.

Left ventricular regional longitudinal strain assessed during speckle-tracking stress echocardiography with physical exercise may identify severe coronary artery disease

Abstract Funding Acknowledgements Type of funding sources: None. Background. Assessment of global longitudinal strain of the left ventricular (LV) myocardium during stress echocardiography showed promising results in diagnosing transient myocardial ischemia. Regional longitudinal strain (RLS) allows to evaluate LV systolic function more precisely. However, due to the heterogeneity of LV segments contraction, an isolated assessment of LV RLS values can be challenging. We suggest that evaluation of the mean LV RLS values for the basal, middle and apical regions of the LV during stress echocardiography may be more useful in clinical setting. Aim of the study. The aim of the study was to determine the diagnostic capabilities of the LV RLS assessed during stress echocardiography with exercise on the treadmill in defining the presence and significance of coronary artery disease (CAD). Methods. The study included 132 patients (65.0 ± 9.3 years, 85 men) with known or suspected CAD. All patients underwent speckle-tracking stress echocardiography with exercise on the treadmill. At rest and after treadmill test all patients were measured for the values of LV RLS using the AFI (Automated functional imaging) algorithm. The LV RLS values for basal, middle and apical regions were calculated as the ratio of the sum of LV RLS values of the segments of each region to the number of segments. Segments of the LV were represented with the standard 17-segment model of the LV, 1-6 segments were assigned as basal segments; 7-12 segments as middle segments and 13-17 as apical segments (Picture 1). All patients underwent coronary angiography; the severity of CAD was assessed using the Gensini score. According to the results of coronary angiography, patients were divided into 3 groups: group 1 – 42 patients without CAD, group 2 – 63 patients with moderate CAD (&amp;lt;34 points on the Gensini score) and group 3 – 27 patients with severe CAD (≥ 35 points on the Gensini score). Results. At rest LV RLS values in basal, middle and apical regions did not significantly differ between the groups. Picture 2 shows that after the load, LV RLS values in basal, middle and apical regions in patients with severe CAD were significantly lower than in groups of patients without CAD and with moderate CAD. The values of LV RLS in patients with severe CAD decreased in all regions after the load, while in patients without CAD and with moderate CAD, LV RLS values increased in middle and apical regions and decreased in basal region. Conclusion. In patients with severe CAD (≥ 35 points on the Gensini score) after the load on the treadmill LV RLS values in all regions were significantly lower than in patients without CAD and with moderate CAD. Thus, LV RLS assessed during speckle-tracking stress echocardiography on the treadmill may be useful in identifying patients with severe CAD. Abstract Figure. Picture 1. 17-segment model of the LV Abstract Figure. Picture 2. Results of stress test

Agreement Between iFR and Other Non-Hyperaemic Pressure Ratios in Severe Aortic Stenosis

BackgroundInstantaneous wave-free ratio (iFR) can reliably assess the physiological significance of coronary artery disease (CAD). Previous studies have demonstrated its interchangeability with other non-hyperaemic pressure ratios (NHPR), but there is no data exploring whether this association is maintained in patients with severe aortic stenosis (AS). MethodsForty-two patients (67 lesions) with severe AS were recruited and underwent invasive pressure-wire assessment. Data were extracted to calculate iFR, resting Pd/Pa, diastolic pressure ratios (DPR and dPR), and Diastolic Hyperaemia-Free Ratio (DFR). iFR was then compared with other NHPR to determine agreement and accuracy. ResultsMean aortic gradient and dimensionless index were 44.3 ± 11.6 mmHg and 0.23 ± 0.04, respectively. Of the 67 vessels, 57% were LAD, 15% LCx, 13% RCA and 12% other. There was strong positive correlation between iFR and all other NHPR, including Pd/Pa (r = 0.91, p < 0.001), DPR (r = 0.99, p < 0.001), dPR (r = 0.97, p < 0.001) and DFR (r = 0.98, p < 0.001). While Bald-Altman analysis demonstrated that Pd/Pa and DFR were numerically different from iFR, ROC analyses demonstrated iFR ≤0.89 was accurately identified by all NHPRs; Pd/Pa (AUC = 0.965, 95% CI [0.928–0.994]), DPR (AUC = 1.000, 95% CI [1.000–1.000]), dPR (AUC = 0.974, 95% CI [0.937–1.000]), DFR (AUC = 0.989, 95% CI [0.968–1.000]). ConclusionIn patients with severe AS, all the included NHPR in this analysis accurately predicted iFR < 0.89. These data should reassure clinicians that use of alternative NHPR to iFR is reasonable when assessing the physiological significance of CAD in patients with severe AS.

Static CT myocardial perfusion imaging: image quality, artifacts including distribution and diagnostic performance compared to 82Rb PET

BackgroundRubidium-82 positron emission tomography (82Rb PET) MPI is considered a noninvasive reference standard for the assessment of myocardial perfusion in coronary artery disease (CAD) patients. Our main goal was to compare the diagnostic performance of static rest/ vasodilator stress CT myocardial perfusion imaging (CT-MPI) to stress/ rest 82Rb PET-MPI for the identification of myocardial ischemia.MethodsForty-four patients with suspected or diagnosed CAD underwent both static CT-MPI and 82Rb PET-MPI at rest and during pharmacological stress. The extent and severity of perfusion defects on PET-MPI were assessed to obtain summed stress score, summed rest score, and summed difference score. The extent and severity of perfusion defects on CT-MPI was visually assessed using the same grading scale. CT-MPI was compared with PET-MPI as the gold standard on a per-territory and a per-patient basis.ResultsOn a per-patient basis, there was moderate agreement between CT-MPI and PET-MPI with a weighted 0.49 for detection of stress induced perfusion abnormalities. Using PET-MPI as a reference, static CT-MPI had 89% sensitivity (SS), 58% specificity (SP), 71% accuracy (AC), 88% negative predictive value (NPV), and 59% positive predictive value (PPV) to diagnose stress-rest perfusion deficits on a per-patient basis. On a per-territory analysis, CT-MPI had 73% SS, 65% SP, 67% AC, 90.8% NPV, and 34% PPV to diagnose perfusion deficits.ConclusionsCT-MPI has high sensitivity and good overall accuracy for the diagnosis of functionally significant CAD using 82Rb PET-MPI as the reference standard. CT-MPI may play an important role in assessing the functional significance of CAD especially in combination with CCTA.

Beyond Coronary CT Angiography: CT Fractional Flow Reserve and Perfusion

심장 전산화단층촬영은 비약적인 기술발전과 다양한 연구 결과를 바탕으로 심혈관위험 계층화와 치료 결정을 위한 관상동맥 질환의 진단과 예후 평가성능이 입증되었다. 전산화단층촬영 관상동맥조영술은 폐쇄성 관상동맥 질환에 대한 음성 예측도가 높아서 침습적 혈관조영술의 빈도를 줄일 수 있는 관상동맥 질환 관련 검사의 관문으로 부상했지만, 진단특이도가 상대적으로 낮다. 하지만 심장 전산화단층촬영을 이용한 분획혈류예비력과 심근관류를 분석하여 관상동맥 질환의 혈역학적 유의성을 확인하는 기능적 평가를 통해 그 한계를 극복할 수 있다. 최근에는 이를 보다 객관적이고 재현 가능하도록 인공지능을 접목하는 연구들이 활발히 진행되고 있다. 본 종설에서는 심장 전산화단층촬영의 기능적 영상화 기법들에 대해 알아보고자 한다.

Fractional flow reserve for coronary stenosis assessment derived from fusion of intravascular ultrasound and X-ray angiography.

Intravascular ultrasound (IVUS) provides good insight into lumen boundary and plaques; however, it is still difficult to detect functionally significant stenosis from IVUS images for the guidance of coronary percutaneous intervention (PCI). This study aimed to develop a novel method to estimate fractional flow reserve (FFR) value for determining the functional significance of coronary artery disease through the fusion of IVUS and X-ray angiographic images. We developed a novel approach to 3D vessel reconstruction by integrating IVUS with X-ray angiographic images. Based on the reconstructed geometry and the inlet flow derived from the thrombolysis in myocardial infarction (TIMI) frame count, a simplified fluid dynamics equation was established to compute the pressure drop and IVUS-derived FFR (AccuFFRivus) was subsequently obtained. To validate the feasibility and performance of this IVUS-based FFR method, we performed AccuFFRivus calculations on 32 coronary vessels with invasive FFR as the reference standard. Great correlation (r=0.86, P<0.001) was observed between AccuFFRivus and FFR. The area under the receiver-operating characteristic curve (AUC) was higher for AccuFFRivus than minimal lumen area (MLA, <4 mm2) and diameter stenosis rate (DS% ≥50%) [0.98 (95% CI: 0.86 to 1.0) vs. 0.78 (95% CI: 0.60 to 0.91) and 0.66 (95% CI: 0.47 to 0.82)]. Bland-Altman plot showed a mean difference value of -0.011 (limits of agreement: -0.156 to 0.134). AccuFFRivus is a novel method for hybridizing IVUS and X-ray angiographic images to identify functionally significant stenosis with FFR ≤0.80. The good diagnostic performance from the initial validation study demonstrates the potential for clinical utilization of physiologically guided decision-making. Further validation is required in future studies with a large number of cases.

Abnormal fractional flow reserve and non-hyperaemic pressure ratios in patients with severe aortic stenosis and non-obstructive coronary artery disease

Abstract Background Fractional flow reserve (FFR) and non-hyperaemic pressure ratios (NHPRs) are well-validated tools that assess the physiological significance of coronary artery disease (CAD). Low coronary lumen to myocardial mass (V/M) ratio on CT is associated with lower FFR/NHPRs and predisposes towards ischaemia in CAD. Whilst CAD and aortic stenosis (AS) frequently co-exist, patients report angina despite obstructive disease. Purpose We therefore sought to study the interrelationship between V/M and invasive pressure indices in patients with severe AS. Methods 35 patients with severe AS were prospectively recruited as part of CAST-FFR study. Patients underwent CT coronary angiography and invasive pressure-wire assessment. All pressure-indices were assessed in the left anterior descending artery (LAD). Data was extracted to calculate FFR, iFR, diastolic pressure ratios (DPR and dPR) and Diastolic Hyperaemia-free Ratio (DFR). Patient-specific V/M were extracted off-site by independent core lab. Results Mean age was 75±7.5 years, median V/M ratio was 20.7 and mean aortic gradient and DI were 44.3±11.6mmHg and 0.23±0.4 respectively. 79% of patients had CADRADs score of &amp;lt;2. There were moderate positive correlations between FFR/NHPRs and V/M, including FFR (r=0.60), PdPa (r=0.48), iFR (r=0.59), DPR (r=0.59), dPR (r=0.63), DFR (r=0.67), (all p&amp;lt;0.005). In patients with positive pressure assessments, 69% (FFR), 71% (iFR), 70% (DPR) and 65% (DFR) had CADRADs score &amp;lt;2. In severe AS, lower V/M was associated with lower pressure-indices (FFR 0.75 vs 0.86, iFR 0.79 vs 0.92, DFR 0.80 vs 0.91, all p&amp;lt;0.005), leading to high rates of positive physiologic assessment (FFR 88%, PdPa 72%, iFR 67%, DPR 78%, DFR 74%). Conclusion Patients with severe AS exhibit high rates of abnormal FFR and NHPR values, despite having no obstructive CAD. Their propensity for having abnormal physiological results is, in part, influenced by coronary volume to mass ratio. These results are important for clinicians considering using invasive physiological tools to guide revascularisation decisions in patients with severe AS. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Monash University, Cardiac Society of Australia and New Zealand Correlation between NHPR/FFR and VMInvasive pressure indices and VM

Diagnostic performance of CT-derived resting distal to aortic pressure ratio (resting Pd/Pa) vs. CT-derived fractional flow reserve (CT-FFR) in coronary lesion severity assessment.

BackgroundComputed tomography-derived fractional flow reserve (CT-FFR) has emerged as a promising non-invasive substitute for fractional flow reserve (FFR) measurement. Normally, CT-FFR providing functional significance of coronary artery disease (CAD) by using a simplified total coronary resistance index (TCRI) model. Yet the error or discrepancy caused by this simplified model remains unclear.MethodsA total of 20 consecutive patients with suspected CAD who underwent CTA and invasive FFR measurement were retrospectively analyzed. CT-FFR and CT-(Pd/Pa)rest values derived from the coronary CTA images. The diagnostic performance of CT-FFR and CT-(Pd/Pa)rest were evaluated on a per-vessel level using C statistics with invasive FFR<0.80 as the reference standard.ResultsOf the 25 vessels eventually analyzed, the prevalence of functionally significant CAD were 64%. The Youden index of the ROC curve indicated that the best cutoff value of invasive resting Pd/Pa was 0.945 for identifying functionally significant lesions. Sensitivity, specificity, negative predictive value, positive predictive value and accuracy were 85%, 91%, 92%, 83% and 88% for CT-(Pd/Pa)rest and 85%, 58% 69%, 78% and 72% for CT-FFR. Area under the receiver-operating characteristic curve (AUC) to detect functionally significant stenoses of CT-(Pd/Pa)rest and CT-FFR were 0.87 and 0.90.ConclusionsIn this study, the results suggest CT-derived resting Pd/Pa has a potential advantage over CT-FFR in triaging patients for revascularization.

A novel algorithm for the computation of the diastolic pressure ratio in the invasive assessment of the functional significance of coronary artery disease.

Invasive functional assessment is a mainstay in the management of patients with coronary artery disease (CAD), but there is uncertainty on the comparative accuracy of diagnostic indices of functional significance. We aimed to validate the diagnostic performance of a novel non-hyperemic diastolic pressure ratio (dPR). We performed a retrospective analysis including two separate registries (VERIFY 2, Latina, Italy) of patients in whom functional indices were measured for lesions with angiographically moderate severity. On top of fractional flow reserve, distal coronary pressure (Pd)/aortic pressure (Pa) ratio, instantaneous wave-free ratio (iFR) and diastolic pressure ratio (dPR) were computed using a novel dedicated algorithm over 4 consecutive beats. Agreement/discrepancy between indexes was appraised Bland-Altman analysis, area under the receiver operating characteristic curve (AUC), and unsupervised machine learning. A total of 525 lesions from 479 patients were included. The novel dPR was highly correlated with iFR (R2=0.99, P<0.001), with a mean difference of -0.004±0.014. The diagnostic performance of dPR (best cutoff value: ≤0.89) against iFR was as follows: accuracy =96%; sensitivity =94%; specificity =97%; positive-predictive value =94%; and negative-predictive value =96%. Additionally, AUC to predict iFR≤0.89 was 0.99, which was significantly higher than that of Pd/Pa (0.97, P<0.001). In the iFR range of 0.85-0.93 ("grey zone"), the diagnostic performance was well maintained (accuracy =91%; sensitivity =87%; specificity =93%; and AUC=0.96). Results were supported also by unsupervised learning analysis. This multicenter registry suggests this novel dPR algorithm provides results that are numerically equivalent to iFR. Pending further studies, physicians may consider using this novel dPR algorithm to gauge the functional significance of a coronary lesion.

Evaluation of strain parameters during stress-echocardiography with physical exercise may be significant in detecting severe coronary artery disease

Abstract Funding Acknowledgements Type of funding sources: None. Background. Assessment of the left ventricular strain during speckle-tracking stress echocardiography may be significant in diagnosing transient myocardial ischemia. So it is challenging to evaluate left ventricular global longitudinal strain (GLS) and post-systolic shortening indicators during stress-echocardiography and compare their diagnostic value with the data obtained with invasive methods of diagnosing coronary artery disease (CAD). Aim of the study. The aim of this study was to determine the diagnostic capabilities of the left ventricular GLS, delta GLS, left ventricular post-systolic index (PSI) and post-systolic time (PST) obtained during stress echocardiography with exercise on the treadmill in defining the presence and significance of CAD. Methods. The study included 113 patients (mean age 64.8 ± 9.4 years; 43 females) with known or suspected CAD. All patients underwent stress echocardiography with exercise on the treadmill. At rest and after treadmill-test, all patients were measured for the values of left ventricular GLS, left ventricular PSI and PST using the AFI (Automated functional imaging) algorithm. The delta of the left ventricular GLS values was also counted. The delta of the left ventricular GLS values was counted as the difference of the left ventricular GLS values after the load and at rest. All patients underwent coronary angiography, assessment of the severity of CAD was counted according to the Gensini score. According to the results of coronary angiography, the patients were divided into 3 groups: 41 patients without CAD, 53 patients with moderate CAD (≤34 points on the Gensini score) and 19 patients with severe CAD (&amp;gt;35 points on the Gensini score). Results. In the group of patients with severe CAD, values of left ventricular GLS after the load significantly differed from the group of patients without CAD (16,1 compared with 20,3; p = 0,003) and from the group of patients with moderate CAD (16,1 compared with 19,4; p = 0,003). At rest GLS values didn’t differ significantly between all groups. Left ventricular GLS delta in the group of patients with severe CAD differed significantly with the group of patients without CAD (-1,8 compared with 1,3; p = 0,003) and with the group of patients with moderate CAD (-1,8 compared with 0,6; p = 0,03). Left ventricular PSI differed significantly between the group of patients with severe CAD and the group of patients without CAD after the load (8,4 compared with 5,1; p = 0,03) and at rest didn’t differ significantly. Left ventricular PST values didn’t differ significantly at rest and after the load in all groups. Conclusions. Strain parameters such as left ventricular GLS, left ventricular GLS delta and left ventricular PSI assessed during stress-echocardiography on the treadmill may be useful in identifying patients with severe CAD. Left ventricular PST didn’t show significance in identifying CAD.