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Fulltext Numerical investigation of the effect of stenosis geometry on the coronary diagnostic parameters

Kamangar S, Kalimuthu G, Badruddin IA, Badarudin A, Ahmed NJ, Khan TM

ScientificWorldJournal, 2014;2014:354946.
PMID: 25258722 DOI: 10.1155/2014/354946

The present study deals with the functional severity of a coronary artery stenosis assessed by the fractional flow reserve (FFR). The effects of different geometrical shapes of lesion on the diagnostic parameters are unknown. In this study, 3D computational simulation of blood flow in three different geometrical shapes of stenosis (triangular, elliptical, and trapezium) is considered in steady and transient conditions for 70% (moderate), 80% (intermediate), and 90% (severe) area stenosis (AS). For a given percentage AS, the variation of diagnostic parameters which are derived from pressure drop across the stenosis was found in three different geometrical shapes of stenosis and it was observed that FFR is higher in triangular shape and lower in trapezium shape. The pressure drop coefficient (CDP) was higher in trapezium shape and lower in triangular model whereas the LFC shows opposite trend. From the clinical perspective, the relationship between percentage AS and FFR is linear and inversely related in all the three models. A cut-off value of 0.75 for FFR was observed at 76.5% AS in trapezium model, 79.5% in elliptical model, and 82.7% AS for the triangular shaped model. The misinterpretation of the functional severity of the stenosis is in the region of 76.5%-82.7 % AS from different shapes of stenosis models.

Matched MeSH terms: Coronary Stenosis/diagnosis
Fulltext 3D multimodal cardiac data reconstruction using angiography and computerized tomographic angiography registration

Moosavi Tayebi R, Wirza R, Sulaiman PS, Dimon MZ, Khalid F, Al-Surmi A, et al.

J Cardiothorac Surg, 2015;10:58.
PMID: 25896185 DOI: 10.1186/s13019-015-0249-2

Computerized tomographic angiography (3D data representing the coronary arteries) and X-ray angiography (2D X-ray image sequences providing information about coronary arteries and their stenosis) are standard and popular assessment tools utilized for medical diagnosis of coronary artery diseases. At present, the results of both modalities are individually analyzed by specialists and it is difficult for them to mentally connect the details of these two techniques. The aim of this work is to assist medical diagnosis by providing specialists with the relationship between computerized tomographic angiography and X-ray angiography.

Matched MeSH terms: Coronary Stenosis/diagnosis
Unravelment of Medtronic Onyx stent during bifurcation stenting using the jailed wire technique; An adverse effect of helical stent structure?

Leenders GE, Liew HB, Stella PR

Cardiovasc Revasc Med, 2018 12;19(8S):58-59.
PMID: 30115559 DOI: 10.1016/j.carrev.2018.03.016

A 62-year old male underwent treatment of a bifurcation lesion in the left anterior descending coronary artery using provisional stenting with a jailed wire technique. Severe longitudinal stent deformation and unravelment of the stent part proximal of the bifurcation occurred when we tried to pull the jailed wire from the side branch. The described case poses a caution on the use of this specific stent(-design) in bifurcation lesions.

Matched MeSH terms: Coronary Stenosis/diagnosis
Correlation and assessment of coronary artery luminal stenosis: Post-mortem computed tomography angiogram versus histopathology

Chainchel Singh MK, Abdul Rashid SN, Abdul Hamid S, Mahmood MS, Feng SS, Mohd Nawawi H, et al.

Forensic Sci Int, 2020 Mar;308:110171.
PMID: 32032870 DOI: 10.1016/j.forsciint.2020.110171

BACKGROUND: Post-mortem Computed Tomography (PMCT) allows non-invasive or minimally invasive detection of findings that may or may not be visible during conventional autopsy, however, it does not allow the investigator to draw any conclusions regarding patency of the vessel's lumen. To address this deficiency, Post-mortem Computed Tomography Angiography (PMCTA) utilizing different contrast media and techniques have been introduced with various studies looking at the correlation between PMCTA, autopsy (gross) findings and coronary artery histology in diagnosing coronary artery disease.
OBJECTIVES: The aim of this study is to investigate the sensitivity and specificity of PMCTA in diagnosing coronary artery stenosis using water-based contrast media introduced though the vessels of the neck, compared to the gold standard of diagnosis i.e. gross and histological evaluation of the coronary artery.
METHOD: This was a cross sectional study of 158 arterial sections involving 37 subjects recruited from the National Institute of Forensic Medicine (IPFN), Hospital Kuala Lumpur (HKL). An unenhanced PMCT was performed followed by PMCTA using water-based contrast media introduced though the vessels of the neck. Coronary artery stenosis was determined using multiplanar reconstructionD while the degree of stenosis was determined by calculating the percentage of luminal diameter divided by the diameter of the vessel internal elastic.
RESULTS: The analysis of PMCTA and histopathology examinations revealed a sensitivity of 61.5%, specificity of 91.7%; positive predictive value (PPV) of 40.0% and negative predictive value (NPV) of 96.4%.
CONCLUSION: PMCTA utilizing water-based contrast introduced though the vessels of the neck yielded similar results as other methods and techniques of PMCTA. We would therefore conclude that PMCTA utilizing this technique could be used to assess the degree of calcification and the presence of significant stenosis.

Matched MeSH terms: Coronary Stenosis/diagnosis*
Effect of porous media of the stenosed artery wall to the coronary physiological diagnostic parameter: a computational fluid dynamic analysis

Govindaraju K, Kamangar S, Badruddin IA, Viswanathan GN, Badarudin A, Salman Ahmed NJ

Atherosclerosis, 2014 Apr;233(2):630-635.
PMID: 24549189 DOI: 10.1016/j.atherosclerosis.2014.01.043

Functional assessment of a coronary artery stenosis severity is generally assessed by fractional flow reserve (FFR), which is calculated from pressure measurements across the stenosis. The purpose of this study is to investigate the effect of porous media of the stenosed arterial wall on this diagnostic parameter. To understand the role of porous media on the diagnostic parameter FFR, a 3D computational simulations of the blood flow in rigid and porous stenotic artery wall models are carried out under steady state and transient conditions for three different percentage area stenoses (AS) corresponding to 70% (moderate), 80% (intermediate), and 90% (severe). Blood was modeled as a non Newtonian fluid. The variations of pressure drop across the stenosis and diagnostic parameter were studied in both models. The FFR decreased in proportion to the increase in the severity of the stenosis. The relationship between the percentage AS and the FFR was non linear and inversely related in both the models. The cut-off value of 0.75 for FFR was observed at 81.89% AS for the rigid artery model whereas 83.61% AS for the porous artery wall model. This study demonstrates that the porous media consideration on the stenotic arterial wall plays a substantial role in defining the cut-off value of FFR. We conclude that the effect of porous media on FFR, could lead to misinterpretation of the functional severity of the stenosis in the region of 81.89 %-83.61% AS.

Matched MeSH terms: Coronary Stenosis/diagnosis
Fulltext Usefulness of FFR-CT to exclude haemodynamically significant lesions in high-risk NSTE-ACS

Meier D, Andreini D, Cosyns B, Skalidis I, Storozhenko T, Mahendiran T, et al.

EuroIntervention, 2025 Jan 06;21(1):73-81.
PMID: 39468963 DOI: 10.4244/EIJ-D-24-00779

BACKGROUND: Coronary computed tomography angiography (CCTA) and fractional flow reserve (FFR) derived from CCTA (FFR-CT) may provide a means of reducing unnecessary invasive coronary angiography (ICA) in patients with suspected non-ST-elevation acute coronary syndromes (NSTE-ACS).
AIMS: The aim of this study was to evaluate the capacity of FFR-CT and CCTA to rule out significant lesions in high-risk NSTE-ACS patients, using ICA with invasive FFR as the gold standard.
METHODS: High-risk NSTE-ACS patients admitted to 4 European centres were enrolled in this single-arm, prospective core lab-adjudicated study. Patients underwent CCTA with FFR-CT analysis, followed by ICA with invasive FFR.
RESULTS: Out of the 250 initially planned NSTE-ACS patients, 168 were included, of whom 151 (92%) had sufficient CCTA image quality to undergo CCTA and FFR-CT analysis. The median high-sensitivity troponin T level at 1 hour post-hospitalisation was 5.3 (interquartile range: 1.8-18.6) times the upper reference limit. At the patient level, the diagnostic performance of FFR-CT was numerically higher as compared to CCTA though not statistically significant (sensitivity: 94% vs 93%, specificity: 63% vs 54%, positive predictive value: 83% vs 79%, negative predictive value: 85% vs 80% and accuracy: 83% vs 79%; p=0.58), suggesting an enhanced capability to avoid unnecessary ICA. At the lesion level, the ability of FFR-CT to detect significant lesions was significantly better than that of CCTA (receiver operating characteristic curves: 0.84 vs 0.65 respectively; p<0.01).
CONCLUSIONS: In patients with high-risk NSTE-ACS, FFR-CT offers better diagnostic accuracy - though not statistically significant - and a higher ability to rule out haemodynamically significant stenoses as compared to CCTA. This indicates that FFR-CT can reduce unnecessary invasive procedures by more accurately identifying patients requiring further intervention.

Matched MeSH terms: Coronary Stenosis/diagnosis
Fulltext Severe left anterior descending artery stenosis with proximal arteriovenous malformation presenting as acute myocardial infarction

Oteh M, Azarisman SM, Hanim NM, Noorfaizan S

Singapore Med J, 2009 Feb;50(2):e76-8.
PMID: 19296018

Congenital coronary artery anomalies are rare, with an incidence of about 0.06-1.3 percent of all patients undergoing cardiac catheterisation. They are commonly asymptomatic, but potentially serious lesions may lead to myocardial ischaemia, infarction and/or sudden cardiac death. The occurrence of a concomitant stenotic lesion is exceedingly rare. We report an 80-year-old man who presented with acute anterior myocardial infarction. Coronary angiography revealed severe proximal left anterior descending (LAD) and arteriovenous malformation (AVM) from the first septal branch of the LAD. The LAD stenosis and the AVM were successfully treated with two Jomed covered stents.

Matched MeSH terms: Coronary Stenosis/diagnosis*