Coronary Angiography With Pressure Wire and Fractional Flow Reserve

Patient-specific in silico 3D coronary model in cardiac catheterisation laboratories

Coronary artery disease is caused by the buildup of atherosclerotic plaque in the coronary arteries, affecting the blood supply to the heart, one of the leading causes of death around the world. X-ray coronary angiography is the most common procedure for diagnosing coronary artery disease, which uses contrast material and x-rays to observe vascular lesions. With this type of procedure, blood flow in coronary arteries is viewed in real-time, making it possible to detect stenoses precisely and control percutaneous coronary interventions and stent insertions. Angiograms of coronary arteries are used to plan the necessary revascularisation procedures based on the calculation of occlusions and the affected segments. However, their interpretation in cardiac catheterisation laboratories presently relies on sequentially evaluating multiple 2D image projections, which limits measuring lesion severity, identifying the true shape of vessels, and analysing quantitative data. In silico modelling, which involves computational simulations of patient-specific data, can revolutionise interventional cardiology by providing valuable insights and optimising treatment methods. This paper explores the challenges and future directions associated with applying patient-specific in silico models in catheterisation laboratories. We discuss the implications of the lack of patient-specific in silico models and how their absence hinders the ability to accurately predict and assess the behaviour of individual patients during interventional procedures. Then, we introduce the different components of a typical patient-specific in silico model and explore the potential future directions to bridge this gap and promote the development and utilisation of patient-specific in silico models in the catheterisation laboratories.

Diagnostic Value of 99mTc-MIBI Myocardial Perfusion Imaging in Detecting Myocardial Ischemia of Children with Kawasaki Disease and Coronary Artery Lesions

Pediatric patients with coronary artery lesions (CALs) after Kawasaki disease (KD) may be complicated with myocardial ischemia. Although previous studies in adults have proven the diagnostic value of 99mTc-MIBI myocardial perfusion imaging (MPI) for ischemic heart disease, its feasibility and accuracy in this pediatric population remain uncertain. In this retrospective study, we collected data of 177 pediatric patients (Age range: 6 months to 14 years) who had undergone MPI and coronary artery angiography (CAG) between July 2019 and February 2023. Using the positive result of CAG as the reference standard of myocardial ischemia, we compared the results of 99mTc-MIBI MPI with other non-invasive examinations, including cardiac magnetic resonance imaging (CMRI), echocardiogram, and comprehensive electrocardiogram-related examinations. All patients finished adenosine triphosphate stress MPI without major side effects. The sensitivity of MPI was 79.17%, which was greater than CMRI and echocardiogram (P < 0.05). The negative predictive value and the accuracy of MPI were 89.9% and 71.75%, indicating the advantages over others. Composite monitoring strategy of MPI and CMRI effectively improved the diagnostic performance (P < 0.001). In 4 cases diagnosed with myocardial ischemia by "MPI + CMRI," despite the absence of significant stenosis, multiple giant coronary artery aneurysms (GCAA) were all observed in CAG. 99mTc-MIBI MPI is the preferred non-invasive examination for detecting myocardial ischemia in pediatric patients with CAL after KD. When combined with CMRI, it can enhance diagnostic accuracy. Multiple GCAAs without stenosis may be an isolated risk factor of myocardial ischemia.

German Radiological Society and the Professional Association of German Radiologists Position Paper on Coronary computed tomography: Clinical Evidence and Quality of Patient Care in Chronic Coronary Syndrome

This position paper is a joint statement of the German Radiological Society (DRG) and the Professional Association of German Radiologists (BDR), which reflects the current state of knowledge about coronary computed tomography. It is based on preclinical and clinical studies that have investigated the clinical relevance as well as the technical requirements and fundamentals of cardiac computed tomography. CITATION FORMAT: · Langenbach MC, Sandstede J, Sieren M et al. DRG and BDR Position Paper on Coronary CT: Clinical Evidence and Quality of Patient Care in Chronic Coronary Syndrome. Fortschr Röntgenstr 2023; 195: 115 - 133.

[German Radiological Society and the Professional Association of German Radiologists position paper on coronary computed tomography: clinical evidence and quality of patient care in chronic coronary syndrome]

This position paper is a joint statement of the German Radiological Society (DRG) and the Professional Association of German Radiologists (BDR), which reflects the current state of knowledge about coronary computed tomography (CT). It is based on preclinical and clinical studies that have investigated the clinical relevance as well as the technical requirements and fundamentals of cardiac computed tomography.

Diagnostic performance of coronary computed tomography angiography-derived fractional flow reverse in lesion-specific ischemia patients with different Gensini score levels

Background

Coronary pressure-derived fractional flow reverse (FFR) is the standard of the functional assessment of lesion severity. In spite of its strengths in determining ischemia-related coronary stenosis, the invasive operation involved still limits its clinical application. Coronary computed tomography angiography-derived FFR (CCTA-FFR) or computed tomography-derived FFR (CT-FFR) has been indicated as an effective and non-invasive index to evaluate lesion-specific ischemia. However, its diagnostic performance, especially in patients with different severity of coronary stenosis, remains unknown. The current research attempted to demonstrate this problem and provided the foundation for extensive clinical application of CCTA-FFR.

Methods

The design of this study was a diagnostic test. A total of 97 vessels from 91 patients who performed CCTA and coronary angiography (CAG) during a hospitalization collected from two research centers were included in this study. CCTA-FFR and FFR were obtained by CCTA and CAG separately. The Gensini score was calculated according to the CAG in each patient. FFR was indicated as the golden diagnosis of lesion-specific ischemia with a cut-off value of 0.80, which was consistent with most contemporary studies. A receiver-operating characteristic (ROC) curve, simple linear analysis, and Bland-Altman plot were performed to determine the diagnostic performance of CCTA-FFR.

Results

CCTA-FFR was well correlated with invasive FFR (R2=0.745, P<0.001) and the area under the curve (AUC) was 0.976. The sensitivity was 94.6% and the specificity was 95.1%. The mean difference between FFR and CT-FFR was 0.011, and the 95% confidence interval was -0.173 to 0.196. The AUCs were 0.989 and 0.928 in the low and high Gensini groups, respectively, and there was no significant difference in the diagnostic accuracies between these two groups (Z=0.003, P>0.500). CT-FFR still exhibited a good correlation with FFR (R2=0.713, P<0.001 in the low Gensini group and R2=0.743, P<0.001 in the high Gensini group). The systematic differences were calculated, and the mean difference between FFR and CT-FFR was -0.005 and 0.025, respectively, in these two groups.

Conclusions

CCTA-FFR exhibited good diagnostic performance in patients with different Gensini score levels. Our results indicate that CCTA-FFR could be an effective tool to screen lesion-specific ischemia in patients with coronary artery disease.

Identification of Flow-Limiting Coronary Stenosis With PCS: A New Cost-Effective Index Derived From the Product of Corrected TIMI Frame Count and Percent Diameter Stenosis

Background: Identifying functional coronary stenosis with simple and cost-effective methods during invasive coronary angiography is still challenging. Corrected TIMI frame count (CTFC) is considered to be the frame count velocity of coronary blood flow. We aimed to propose a simple and cost-effective index based on CTFC and percent diameter stenosis (DS) to identify flow-limiting coronary stenosis. For this, a new index was put forward as the product of CTFC and DS (PCS). PCS can be regarded as the loss of coronary blood flow due to diameter stenosis.

Methods: DS, CTFC, PCS, and Fractional flow reserve (FFR) of 111 vessels in 84 patients with suspected coronary heart disease were measured. FFR ≤0.80 was defined as flow-limiting. Models involving CTFC, DS, and PCS were developed. Logistic regression was performed to evaluate the values on diagnosing flow-limiting stenosis.

Results: Vessels with flow-limiting coronary stenosis exhibited higher CTFC values than those without (28.56 vs. 21.64). The performance including the AUC (0.887), sensitivity (87.8%), and Youden index (0.678) for detecting flow-limiting stenosis was improved by adding the CTFC to the DS, while PCS had the largest positive predictive value (PPV) and diagnostic accuracy (DA) being 72.0 and 82.9%, respectively. For vessels with ≥50% lesions, PCS still had the best DA (80.9%), specificity (85.9%), and PPV (72.9%). At the same stenosis severity level, the AUC, Youden index and, DA of PCS were higher than those of CTFC.

Conclusions: PCS is simple and accurate to identify flow-limiting coronary stenosis, especially at vessels with moderate to severe stenosis.

Maier L, Sechtem U, Silber S, Thiele H. Percutaneous Coronary Intervention in Stable Coronary Heart Disease -Is Less More?

BACKGROUND

This review concerns the putative benefit of percutaneous coronary intervention (PCI) over optimal medical therapy (OMT) for symptomatic patients with stable angina pectoris, or for asymptomatic persons in whom screening tests have revealed coronary heart disease (CHD; this entity has been newly designated chronic coronary syndrome, or CCS). Moreover, it addresses the question whether the indications for which PCI is now performed in Germany on patients with CCS are consistent with current scientific knowledge.

METHODS

The pathophysiological concept of CHD and ischemia induction is discussed in the light of the scientific literature. This concept implies that PCI might be beneficial in the treatment of CCS. The benefit of PCI over OMT has now been evaluated in seven randomized trials (the so-called milestone trials). The current situation in Germany is presented here as well, on the basis of the available data.

RESULTS

The pathophysiological concept of CHD implies that the particular coronary artery stenoses that are likely to give rise to a myocardial infarction (the so-called vulnerable plaques) cannot be identified prospectively with current methods. Moreover, a coronary artery stenosis will not necessarily cause myocardial ischemia. All of the randomized trials carried out to date that have compared OMT to PCI-plus-OMT in patients with CCS have led to the conclusion that PCI, because it focuses on individual coronary artery stenoses, cannot prolong survival or lower the incidence of myocardial infarction over the long term. This remains the case even if a single coronary artery stenosis is known to be causing moderate or severe myocardial ischemia (a conclusion of the ISCHEMIA trial). A PCI performed only because the coronary stenosis or stenoses meet certain morphological criteria, without any demonstration of a resulting functional disturbance, is generally detrimental to the health of the patient, with rare exceptions, and is inconsistent with the recommendations of current guidelines. The number of PCIs being performed in Germany at present is high compared to other countries; this arouses concern that the indications for it may be dubious in many cases.

CONCLUSION

Current data imply that PCI for CCS does not improve outcomes in a large percentage of cases. A symptomatic benefit exists only in patients with frequent angina pectoris. The selection of CCS patients for PCI needs to be more strictly bound to the recommendations of current guidelines, particularly in Germany.