scholarly journals Application of speCtraL computed tomogrAphy to impRove specIficity of cardiac compuTed tomographY (CLARITY study): rationale and design

BMJ Open ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. e025793 ◽  
Author(s):  
Robbert Willem van Hamersvelt ◽  
Ivana Išgum ◽  
Pim A de Jong ◽  
Maarten Jan Maria Cramer ◽  
Geert E H Leenders ◽  
...  

IntroductionAnatomic stenosis evaluation on coronary CT angiography (CCTA) lacks specificity in indicating the functional significance of a stenosis. Recent developments in CT techniques (including dual-layer spectral detector CT [SDCT] and static stress CT perfusion [CTP]) and image analyses (including fractional flow reserve [FFR] derived from CCTA images [FFRCT] and deep learning analysis [DL]) are potential strategies to increase the specificity of CCTA by combining both anatomical and functional information in one investigation. The aim of the current study is to assess the diagnostic performance of (combinations of) SDCT, CTP, FFRCTand DL for the identification of functionally significant coronary artery stenosis.Methods and analysisSeventy-five patients aged 18 years and older with stable angina and known coronary artery disease and scheduled to undergo clinically indicated invasive FFR will be enrolled. All subjects will undergo the following SDCT scans: coronary calcium scoring, static stress CTP, rest CCTA and if indicated (history of myocardial infarction) a delayed enhancement acquisition. Invasive FFR of ≤0.80, measured within 30 days after the SDCT scans, will be used as reference to indicate a functionally significant stenosis. The primary study endpoint is the diagnostic performance of SDCT (including CTP) for the identification of functionally significant coronary artery stenosis. Secondary study endpoint is the diagnostic performance of SDCT, CTP, FFRCTand DL separately and combined for the identification of functionally significant coronary artery stenosis.Ethics and disseminationEthical approval was obtained. All subjects will provide written informed consent. Study findings will be disseminated through peer-reviewed conference presentations and journal publications.Trial registration numberNCT03139006; Pre-results.

Author(s):  
Sebastian Gassenmaier ◽  
Ilias Tsiflikas ◽  
Simon Greulich ◽  
Jens Kuebler ◽  
Florian Hagen ◽  
...  

Abstract Objectives To evaluate computed tomography fractional flow reserve (FFRCT) values in distal parts of the coronaries in an asymptomatic cohort of marathon runners without any coronary stenosis for potentially false-positive values. Methods Ninety-eight asymptomatic male marathon runners (age 53 ± 7 years) were enrolled in a prospective monocentric study and underwent coronary computed tomography angiography (CCTA). CCTA data were analyzed for visual coronary artery stenosis. FFRCT was evaluated in 59 participants without coronary artery stenosis in proximal, mid, and distal coronary sections using an on-site software prototype. Results In participants without coronary artery stenosis, abnormal FFRCT values ≤ 0.8 in distal segments were found in 22 participants (37%); in 19 participants in the LAD; in 5 participants in the LCX; and in 4 participants in the RCA. Vessel diameters in participants with FFRCT values > 0.80 compared to ≤ 0.80 were 1.6 ± 0.3 mm versus 1.5 ± 0.3 mm for distal LAD (p = 0.025), 1.8 ± 0.3 mm versus 1.6 ± 0.5 mm for distal LCX (p = 0.183), and 2.0 ± 0.4 mm versus 1.5 ± 0.2 mm for distal RCA (p < 0.001). Conclusions Abnormal FFRCT values of ≤ 0.8 frequently occurred in distal coronary segments in subjects without any anatomical coronary artery stenosis. This effect is only to some degree explainable by small distal vessel diameters. Therefore, the validity of hemodynamic relevance evaluation using FFRCT in distal coronary artery segment stenosis is reduced. Key Points • Abnormal FFRCT values (≤ 0.8) occurred in over a third of the subjects in the distal LAD despite the absence of coronary artery stenosis.. • Therefore, the validity of hemodynamic relevance evaluation in distal coronary artery segment stenosis is reduced. • Decision-making based on abnormal FFRCT values in distal vessel sections should be performed with caution and only in combination with visual assessment of the grade of stenosis..


2020 ◽  
Vol 14 (16) ◽  
pp. 1553-1561
Author(s):  
Mehmet Erdoğan ◽  
Mehmet A Erdöl ◽  
Selçuk Öztürk ◽  
Tahir Durmaz

Aim: The study aimed to investigate and compare the predictive capacity of a systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) to determine a hemodynamically significant coronary artery stenosis assessed by fractional flow reserve (FFR). Patients & methods: A total of 207 chronic coronary syndrome patients with FFR measurement were enrolled in the study. NLR, PLR and SII levels were calculated. Results: The cut-off value of the SII (620) was associated with 78.4% sensitivity and 64.0% specificity to predict a hemodynamically significant stenosis. SII level independently predicted FFR ≤0.80. Conclusion: SII is an independent predictor of functionally significant coronary stenosis detected by FFR in chronic coronary syndrome patients. SII levels can predict hemodynamically severe obstruction better than NLR and PLR.


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