Maximum Lumen Diameter Research Articles

Standardized angiographic projections allow evaluation of coronary artery side branches with quantitative flow ratio (QFR)

Quantitative flow ratio (QFR) is a novel, software-based noninvasive method for the quantitative evaluation of coronary physiology. QFR results correlate with invasive FFR measurements in the three main epicardial coronary arteries. However, QFR data for the evaluation of coronary side branches (SB) are scarce. The evaluation of QFR-performance of SB was retrospective and prospective. Eighty-seven patients with suspected chronic coronary syndrome, who received angiography using routine core lab projections, were retrospectively analyzed. On the second part 37 patients, who received angiography using recommended standardized coronary angiography projections, were prospectively analyzed. Quantitative analysis was performed for SB with a maximum lumen diameter proximal of ≥2 mm based on quantitative coronary angiography (QCA) by two certified experts with the software QAngio XA 3D 3.2. Using routine projections, QFR computation in 55 % of the SB were obtained (123 out of 224). Using standardized projections, 85 % of SB were computed by QFR (64 out of 75; p < 0.001 vs routine projections). The fluoroscopy time for recommended projections was not significantly different as opposed to routine projections (3.75 ± 2.2 vs. 4.58 ± 3.00 min, p = 2.6986). Using the standardized projections was associated with a higher amount of contrast medium (53.44 ± 24.23 vs. 87.95 ± 43.73 ml, p < 0.01), longer overall procedure time (23.23 ± 16.35 vs. 36.14 ± 17.21 min, p < 0.01) and a higher dose area product (1152.28 ± 576.70 vs. 2540.68 ± 1774.07 cGycm2, p < 0.01). Our study shows that the blood flow of the vast majority of coronary SB can be determined non-invasively by QFR in addition to the main epicardial coronary arteries when standardized projections are used.

TOGA Therapeutic Oxygen for Gastrointestinal Atony

Background and aimsIleus, mechanical bowel obstruction and acute colonic pseudo-obstruction [ACPO] are characterized by distension of the intestines with accumulated bowel gas. Current treatments are not completely satisfactory. MethodsBy manipulating the partial pressures of oxygen and nitrogen in the trapped air with a novel 6-hour treatment with 100% oxygen via non-rebreather mask [NRB], the bowel can be successfully decompressed, facilitating resolution of the underlying condition. ResultsA positive clinical response was seen in 7/8 [87.5%] patients after TOGA [therapeutic oxygen for gastrointestinal atony]. Maximal lumen diameter decreased by an average of 1.14 ± 0.87 cm [16%]. ConclusionsIn this first clinical report of TOGA, the provision of 100% oxygen via NRB is a useful therapy. It decreased the diameter of the intestinal lumen and enhanced resolution of ileus, ACPO, and bowel obstruction. This is a low-morbidity, low-cost treatment of gastrointestinal luminal distension. ClinicalTrials.gov Identifier NCT03386136.st

The role of imperforate tracheary elements and narrow vessels in wood capacitance of angiosperm trees

Summary There is a broad diversity of imperforate tracheary elements (ITEs) — libriform fibers, fiber-tracheids, true tracheids and vasicentric/vascular tracheids — described thoroughly by Sherwin Carlquist. However, in a quantitative sense, the functional meaning of different ITE types present in the wood of vessel-bearing angiosperms remains unclear because very few structure–function studies measure ITEs’ properties. ITEs with abundant pits and wide pit borders — vascular tracheids, vasicentric tracheids, and true tracheids sensu Carlquist — have been shown to conduct water and, thanks to this conductive ability and the multitude of pits, they could also contribute to wood capacitance. A dataset of 30 temperate angiosperm tree species was reanalysed to record the presence/absence of true, vasicentric, and vascular tracheids including data on conduits15 fraction and vessel-conduit15 contact fraction (conduits15 were defined as cells resembling vessels and with a maximum lumen diameter of 15 μm. They encompassed narrow vessels, vasicentric tracheids, and vessel tails). The presence of tracheids, conduits15 fraction, and contact fraction had no effect on wood capacitance, except, per given wood volumetric lumen water content, species with true tracheids tended to have lower capacitance. These results suggest that the presence of tracheids or conduits15 properties do not limit wood capacitance, but the results do not exclude the potential role these cells may play in internal water dynamics.

Evaluation of coronary artery side branches (SB) with Quantitative Flow Ratio (QFR) by comparing the use of recommended angiographic projections with routine angiographic projections as Reference

Abstract Background Contrast-flow quantitative flow ratio (QFR) is a novel, noninvasive method for the quantitative evaluation of coronary physiology using computational fluid dynamics based on 3D vessel reconstruction in angiograms. Computing this 3D-model with analyzing the dynamics of the contrast medium flow with a specialized algorithm, the software computes the virtual FFR. This new technique has shown a high accuracy in determining the functional significance of coronary stenosis of the three main epicardial coronary arteries using the gold standard FFR as reference. However, QFR data for the evaluation of coronary side branches (SB) are scarce. Therefore, the study aimed to determine the feasibility of this novel method to analyze SB and to characterize optimal viewing angles for evaluation using QFR. Methods A total of 87 patients, who underwent invasive coronary angiography with routine core lab projections, were enrolled in the study and were analyzed retrospectively by two certified experts with the software QAngio XA 3D 3.2. In addition, 37 patients were enrolled prospectively using coronary angiography projections recommended for the virtual QFR-Analysis. Quantitative Analysis was performed only for SB with a maximum lumen diameter (MLD) of ≥2mm. The following outcome parameters were analyzed: baseline characteristics, anatomical SB parameters such as MLD (mm) and vessel length (VL; mm) of the SB, result of the QFR-computation and procedure parameters, such as use of applicated contrast medium and fluoroscopy time. Results 187 side branches (obtuse marginal [OM], diagonal branch [DB], intermediate artery [IA], posterolateral branch [PLB] and posterior descending artery [PDA]) were analyzed using QFR. Out of 87 patients undergoing an invasive coronary angiography with routine core lab projections with 244 SB ≥2mm, 123 SB (55%) were computable with the use of QFR. In the prospective cohort of 37 patients with recommended angiographic projections for QFR analysis of main branches, 75 SB ≥2mm were found. 64 of the 75 SB (84%) were computable with the use of QFR. The use of recommended projections led to an overall higher evaluability of SB (85% vs. 55%). The data show that the fluoroscopy time for recommended QFR projections was not significantly different as the time for routine cath lab projections (3.7±2.2 vs. 4.6±3, p=2.69). The study shows a significant increase of the amount of contrast medium used for QFR projections (55.4±24.2 vs. 87.9±43.7, p&amp;lt;0.01). Conclusion To our knowledge this is the first study evaluating QFR for SB analysis. QFR is feasible for the routine assessment of side branches (SD) with MLD ≥2mm. The use of recommended projections significantly improved the quality of the QFR SB analysis apart from PDA, without increasing the fluoroscopy time during coronary angiography. Overall QFR could increase the use of physiologically guided coronary interventions, not only for the main epicardial vessels, but also for the SB. Funding Acknowledgement Type of funding sources: None.

Mechanism of transcatheter heart valve deployment for right ventricular outflow tract insufficiency after surgical reconstruction in childhood as assessed with intravascular ultrasound

Abstract Introduction Transcatheter heart valve (THV) deployment can be used to treat right ventricular outflow tract (RVOT) insufficiency. Purpose To study deployment mechanism of a balloon expandable THV (Melody or Edwards SAPIEN [ES] 3) implanted for pulmonary homograft insufficiency using intravascular ultrasound (IVUS) with Visions PV.035 Digital Catheter (Philips) offering an imaging field of 60mm. Methods Sequential (baseline and post-THV) IVUS was performed in 6 pts (median age 33 [20–44] yrs, 3 ♀, all with Tetralogy of Fallot) who had undergone prior corrective surgery (4 transannular patch, 1 bioprosthetic valve or 1 pulmonary homograft), but who presented with significant RVOT insufficiency. IVUS-visualized homograft cross-sections were perpendicular to its long axis and were obtained along the entire homograft length (Fig. 1). Volumetric measurements included the native pulmonary homograft (inner lumen and outer dimension) and the corresponding inner-stent/inner-THV cross-sections post-THV for a total of 16 evenly spaced cross-sections per analyzed region. Each THV (1 Melody [Ø 22mm, 28mm nominal length] and 5 ES3 [Ø 23mm, 18mm height; 4 Ø 29mm, 22.5mm height]) was implanted after pre-stenting using stents of 36, 39, or 48mm length, deployed on a 24mm (n=1) or 30mm (n=4) balloon-in-balloon catheter. Results Overall, there were 96 paired cross-sections. There was significant increase in average lumen dimension after THV deployment (Δ of 97.5mm2) accompanied by the similar increase in outer pulmonary homograft dimensions (Δ of 84.0mm2) (Table 1). Whereas the maximal lumen diameter was unchanged, the minimal lumen diameter increased significantly resulting in substantial decrease in the ratio of max/min lumen diameter of 1.41±0.20 vs 1.16±0.13 (p&amp;lt;0.001) representing a reduction in lumen eccentricity. Conclusions During balloon-expandable THV implantation to treat RVOT insufficiency, there is a significant increase in baseline lumen dimensions accompanied by a substantial outer RVOT dimension increase to normalize lumen eccentricity. Figure 1. IVUS intraprocedural visualisation Funding Acknowledgement Type of funding source: None

The relationship of pre-procedural Dmax based sizing to lesion level outcomes in Absorb BVS and Xience EES treated patients in the AIDA trial

Due to expansion limits of the Absorb bioresorbable scaffold a meticulous implantation with correct sizing is required. We sought to investigate the clinical outcomes based on the sizing of the device related to the maximal lumen diameter measured by quantitative coronary angiography in Absorb BVS and Xience EES treated lesions in the AIDA trial. Sizing of Absorb bioresorbable vascular scaffold (BVS) and Xience everolimus eluting stent (EES) was graded according to the definitions of device non-oversize and device oversize on pre-procedural angiography. Lesion-oriented outcomes (LOCE) (device thrombosis, TLR and TVMI) that occurred during 2 years follow-up were related to device non-oversized or oversized status. In the Absorb BVS group, LOCE occurred in 48 (7.4%) lesions in the oversized group and in 32 (8.2%) lesions in the non-oversized group (HR 0.91; 95% CI 0.58–1.42; p = 0.681), whereas TLR occurred in 34 (5.3%) lesions and in 23 lesions (5.9%), respectively (HR 0.89; 95% CI 0.52–1.51; p = 0.666). Definite scaffold thrombosis occurred in 11 (1.7%) device oversized treated lesions against 16 (4.1%) device non-oversized treated lesions (HR 0.41; 95% CI 0.19–0.89; p = 0.020). There were no differences in event rates between oversized and non-oversized groups in lesions treated with Xience EES. There was no significant difference in LOCE between oversized and non-oversized treated Absorb BVS and Xience EES treated lesions. Non-oversized Absorb BVS implantation was associated with a higher risk of scaffold thrombosis at complete 2 years follow-up. The majority of very late scaffold thrombosis occurred in properly sized devices.

Segmentation of the lumen and media‐adventitial borders in intravascular ultrasound images using a geometric deformable model

This study presents a geometric deformable model-based segmentation approach to segmentation of the intima and media-adventitial (MA) borders in sequential intravascular ultrasound (IVUS) images. The initial estimation of the vessel borders was done manually only for the first frame of each sequence. After the border initialisation, pre-processing including edge preservation, noise reduction, and dead zone preservation was successively performed on each IVUS frame. To improve segmentation performance, the image masks were determined preliminarily by local binary pattern-based mask initialisation. Then, the inner and outer borders were approximated using a modified distance regularised level set evolution model. The results showed superior performance of the suggested approach for estimating intima and MA layers from the IVUS images. The corresponding correlation coefficients of area, vessel perimeter, maximum vessel diameter, and maximum lumen diameter were r = 0.782, r = 0.716, r = 0.956, and r = 0.874 for the 20 MHz images, respectively, and r = 0.990, r = 0.995, r = 0.989, and r = 0.996 for the 45 MHz images, respectively. In addition, linear regression analysis indicated that the manual segmentation had significantly high similarity at r > 0.967 and r > 0.993 for 20 and 45 MHz images, respectively.

Scaffold thrombosis following implantation of the ABSORB BVS in routine clinical practice: Insight into possible mechanisms from optical coherence tomography.

To identify potential underlying mechanisms of early and (very) late scaffold thrombosis (ScT) by optical coherence tomography (OCT), in a frame-by-frame analysis. The absorb scaffold is associated with an increased risk of ScT compared with metallic stents. Several potential causes of bioresorbable ScT have been identified, however the precise etiology still remains unclear. Between February 2013 and February 2016, 13 patients presenting with definite ScT underwent OCT imaging. After guidewire passage or balloon inflations, OCT images were acquired. Pullbacks were assessed offline at each 1mm longitudinal interval within the treated segment and the 5mm segments adjacent to both edges. Primary cause of ScT was assessed by reviewing medical records, baseline angiographic films, and OCT pullback and angiographic films at time of ScT. 13 patients, with 14 thrombotic lesions presented either with early ScT (i.e., ≤30days) or very (late) (i.e., >30days). Analysis demonstrated a significantly smaller in-scaffold maximal lumen diameter in the early cases (2.75±0.85mm vs. 3.00±0.46mm; P=0.033) and a nonsignificant smaller minimal scaffold diameter (2.44±0.62mm vs. 2.58±0.37mm P=0.097). Per-strut analysis demonstrated significantly more malapposed scaffold struts in (very) late cases (6% versus 0.6%, P<0.001). Assessment of the predominate cause showed underexpansion as the dominant factor in the early cases, while malapposition was predominantly seen in the (very)late cases. OCT performed in patients presenting with Absorb ScT demonstrated that malapposition of scaffold struts was more prominent in patients presenting with (very) late ScT, while underexpansion was more frequent in the early cases.

Vasomotor Response to Nitroglycerine Over 5 Years Follow-Up After Everolimus-Eluting Bioresorbable Scaffold Implantation

ObjectivesThis study investigated the vasomotor response to nitroglycerine (NTG) up to 5 years after ABSORB implantation. BackgroundThere are no data regarding long-term vasomotor response after everolimus-eluting bioresorbable vascular scaffold ABSORB implantation. MethodsWe performed quantitative coronary angiography of the scaffolded and proximal and distal adjacent segments of patients from ABSORB Cohort B study before and after 200 μg of intracoronary NTG at 2, 3, and 5 years of follow-up. The mean changes of maximal and mean lumen diameters in the scaffolded and adjacent segments were calculated. ResultsThe mean in-scaffold lumen diameter change in response to NTG showed a trend to increase over time with absolute values of 0.03 ± 0.09 mm, 0.05 ± 0.12 mm, and 0.07 ± 0.08 mm at 2, 3, and 5 years, respectively (p = 0.40). The maximal in-scaffold lumen diameter change significantly increased with values of 0.03 ± 0.14 mm, 0.06 ± 0.16 mm, and 0.11 ± 0.1 mm at 2, 3, and 5 years, respectively (p = 0.03). The normalized mean lumen diameter change after NTG in the scaffold relative to the adjacent segments was 51.9 ± 54.8% at 5 years of follow-up (p = 0.60). ConclusionsAlthough there was a numerical increase of the vasomotor response to NTG after ABSORB implantation measured by quantitative coronary angiography with mean lumen diameter, the change was not statistically significant. However, the maximal lumen diameter changes increased over time from 2 to 5 years and attained statistical significance. The vasomotor response to NTG after ABSORB implantation moderately trended to increase, which is consistent with the progressive degradation and bioresorption of the scaffold, but the degree of vasomotor response remained lower in comparison with adjacent segments.

Automatic segmentation of coronary tree in CT angiography images

SummaryIn this study, we proposed an automatic approach to segment the three‐dimensional coronary tree from computed tomography angiography (CTA) image data. Compared to the previous studies, our approach can efficiently locate the coronary root through extracting aorta by using circular Hough transform. Then, we extracted the two‐dimensional coronary borders in multiple projection directions by dynamic programming and used the border information to reconstruct the coronary surface by the spline fitting. The performance of our approach has been validated on the CTA dataset from 50 subjects, with the comparison to the manual segmentation by an experienced medical physician on the corresponding CTA data and X‐ray angiography data. Our experiments have shown that the average bias between our approach and the manual segmentation are 2.44 mm2 with confidence interval [‐2.20 mm2, 6.68 mm2] for cross‐sectional lumen area, 0.84 mm with confidence interval [‐2.76 mm, 4.44 mm] for maximum lumen diameter, and 0.32 mm with confidence interval [‐1.14 mm, 1.78 mm] for minimum lumen diameter. The results can demonstrate the potential effectiveness of our approach in CTA image processing.

Wine Dilates the Brachial Artery but does not Increase Flow-mediated Dilatation over Two Hours

Epidemiological evidence suggests cardiovascular benefits from the consumption of alcoholic beverages, but corroboration by functional and outcome studies is still outstanding. Non-invasive functional tests on the brachial arteries of healthy volunteers were performed before and for two hours after consuming red wine. Brachial artery dimensions were determined by ultrasound at baseline, 30, 60 and 120 min. Flow-mediated dilatation (FMD) was similarly assessed. Putative minimum and maximum lumen diameters were determined after ice immersion and sublingual trinitroglycerine (TNG) at baseline and 60 min after wine consumption. Sixteen subjects had a mean resting brachial artery diameter of 3.84 mm, which significantly increased with wine to 4.44 mm at 30 min, 4.39 mm at 60 min and 4.49 mm at 120 min. The calculated blood flow rates during the study did not differ significantly over the measured intervals. The baseline mean diameter with TNG was not significantly different from the dilation with wine. The vasoconstrictor response varied, with a -2.6 ± 2.9% change with wine, compared with the baseline diameter. There was appreciable variation of the diameter relative to the range found with ice and TNG. The calculated FMDs (% changes) for the study were 10.8, 6.1, 5.6 and 7.5, indicating statistically significant effects of wine (p < 0.0001). The authors conclude that red wine consumption leads to beneficial arterial effects that may relate to different doses or other mechanisms than FMD. Further studies need to be done to discriminate between the effects of alcohol and phenolic compounds on vascular function.

Final shape of biovascular scaffolds and clinical outcome. Results from a multicenter all-comers study with intravascular imaging

AimsRadial strength of bioresorbable vascular scaffolds (BVS) implanted in coronary arteries is still under debate. Moreover, their final shape patterns, when implanted in an all-comer, unselected population, have not yet been completely correlated with clinical outcome and should be better investigated. Methods and resultsA multicenter collaborative analysis was performed on all consecutive patients with native coronary artery disease undergoing PCI with intravascular imaging-guided BVS implantation. The BVS was arbitrarily categorized as having a final “oval shape” through intravascular imaging, if maximal lumen diameter was longer than 150% of minimal lumen diameter at the target lesion. Primary study-endpoint was device-oriented major adverse events (DOCE) at mid-term follow-up. Sixty-seven consecutive patients were evaluated at 6 European centers. Mean patient age was 58±11years, and 12 patients (18%) had diabetes. Mean percent diameter stenosis was 79±12.5%. Average lesion length was 24.4±13.8mm and 66% of lesions were AHA/ACC type B2/C. Postdilation rate was 91% and all BVS resulted well apposed to the vessel wall. Procedural success was achieved in all patients and 10 (14.9%) had an “oval shape” at intravascular imaging. This occurrence was not associated with an increase in periprocedural myocardial infarction (p=0.37) or DOCE during hospitalization (p=0.65). Seven-month DOCE occurred in 3 patients (5.6%) of the oval shape group, they were target-vessel revascularization and did not differ significantly between patients with vs. without final “oval shape” (p=0.34). We did not register episodes of scaffold thromboses. ConclusionsIn an all-comer population with complex coronary lesions treated with BVS, a final oval shape after postdilation was not rare and not associated with immediate and medium term adverse events.

Relationships between tree-ring cell features of Pinus koraiensis and climate factors in the Changbai Mountains, Northeastern China

Anatomical characteristics have been proven useful for extracting climatic signals. To examine the climatic signals recorded by tree-ring cell features in the Changbai Mountains, we measured cell number and cell lumen diameter, in addition to ring widths, of Korean pine (Pinus koraiensis) tree rings at sites of varied elevation, and we developed chronologies of cell number (CN), mean lumen diameter (MLD), maximum lumen diameter (MAXLD) and tree-ring width (TRW). The chronologies were correlated with climatic factors monthly mean temperature and the sum of precipitation. As shown by our analysis, the cell parameter chronologies were suitable for dendroclimatology studies. CN and TRW shared relatively similar climatic signals which differed from MLD and MAXLD, and growth-climate relationships were elevation-dependent, as shown by the following findings: (1) at each elevation, MLD and MAXLD recorded different monthly climatic signals from those recorded by TRW for the same climatic factors; and (2) MLD and MAXLD recorded climatic factors that were absent from TRW at lower and middle elevations. Cell lumen diameter proved to be an effective archive for improving the climate reconstruction for this study area.

Abstract 367: Measurement of Lumen Dimensions in Non-stented and Stented Coronary Arteries: A Meta-analysis of Frequency Domain Optical Coherence Tomography versus Intravascular Ultrasound

Background: Intraluminal coronary morphology is traditionally evaluated by Intravascular Ultrasound (IVUS). Frequency Domain Optical Coherence Tomography (FD-OCT) is a novel method for evaluation of coronary lumen dimensions. Current literature has paucity of data with limited sample size comparing FD-OCT to IVUS. The objective of this meta-analysis is to compare the FD-OCT versus IVUS in assessment of lumen dimensions in non-stented and stented coronary arteries. Methods: PubMed and the Cochrane Center Register of Controlled Trials were searched through January 2015. Seven studies (n=169 vessels) comparing FD-OCT versus IVUS procedures in assessing lumen dimensions in non-stented and stented coronary arteries were included. Outcomes were minimum lumen area, minimum lumen diameter and maximum lumen diameter. The mean difference (MD) with 95% confidence interval (CI) was computed and p&lt;0.05 was considered as a level of significance. Results: FD-OCT measured significantly smaller minimum lumen area and maximum lumen diameter compared to IVUS in non-stented vessels (MD: -0.86 mm 2 , CI: -1.18 to -0.55, p&lt;0.00001 and MD: -0.21 mm, CI: -0.35 to -0.06, p=0.006, respectively). Minimum lumen diameter was not significantly different between two groups in non-stented coronary arteries (p=0.21). In stented vessels, no significant difference was found in measurement of minimum lumen area (p=0.34) and minimum lumen diameter (p=0.41) between FD-OCT and IVUS. Conclusion: The results of this study suggest that FD-OCT maybe a better modality to evaluate the severity of stenosis in non-stented coronary arteries. FD-OCT is comparable to IVUS in measuring lumen dimensions in stented vessels.

Broad Anatomical Variation within a Narrow Wood Density Range--A Study of Twig Wood across 69 Australian Angiosperms.

ObjectivesJust as people with the same weight can have different body builds, woods with the same wood density can have different anatomies. Here, our aim was to assess the magnitude of anatomical variation within a restricted range of wood density and explore its potential ecological implications.MethodsTwig wood of 69 angiosperm tree and shrub species was analyzed. Species were selected so that wood density varied within a relatively narrow range (0.38–0.62 g cm-3). Anatomical traits quantified included wood tissue fractions (fibres, axial parenchyma, ray parenchyma, vessels, and conduits with maximum lumen diameter below 15 μm), vessel properties, and pith area. To search for potential ecological correlates of anatomical variation the species were sampled across rainfall and temperature contrasts, and several other ecologically-relevant traits were measured (plant height, leaf area to sapwood area ratio, and modulus of elasticity).ResultsDespite the limited range in wood density, substantial anatomical variation was observed. Total parenchyma fraction varied from 0.12 to 0.66 and fibre fraction from 0.20 to 0.74, and these two traits were strongly inversely correlated (r = -0.86, P < 0.001). Parenchyma was weakly (0.24 ≤|r|≤ 0.35, P < 0.05) or not associated with vessel properties nor with height, leaf area to sapwood area ratio, and modulus of elasticity (0.24 ≤|r|≤ 0.41, P < 0.05). However, vessel traits were fairly well correlated with height and leaf area to sapwood area ratio (0.47 ≤|r|≤ 0.65, all P < 0.001). Modulus of elasticity was mainly driven by fibre wall plus vessel wall fraction rather than by the parenchyma component.ConclusionsOverall, there seem to be at least three axes of variation in xylem, substantially independent of each other: a wood density spectrum, a fibre-parenchyma spectrum, and a vessel area spectrum. The fibre-parenchyma spectrum does not yet have any clear or convincing ecological interpretation.

Lumen enlargement of the coronary segments located distal to chronic total occlusions successfully treated with drug-eluting stents at follow-up

Chronic total occlusions (CTO) are the final stage of atherosclerosis. Occluded coronary arteries have large plaque burden and negative remodelling. The aim of this study was to assess lumen and vessel changes of segments located distal to successfully recanalised CTO. Ninety-one CTO treated with drug-eluting stents underwent quantitative coronary angiography (QCA) at baseline and at 12-18 months; 31 underwent serial intravascular ultrasound (IVUS) imaging. Angiographic changes were assessed with QCA as differences in minimal, mean and maximal lumen diameter (MinLD, MeanLD and MaxLD, respectively). Vessel changes were assessed with IVUS as changes in plaque and vessel volume. At follow-up, angiographic MinLD increased 23.9% (from 0.88±0.32 to 1.09±0.35 mm; p<0.01), MeanLD 16.4% (from 1.59±0.44 to 1.85±0.45 mm; p<0.01) and MaxLD 11.7% (from 2.39±0.67 to 2.67±0.70 mm; p<0.01). Lumen enlargement was greater in non-restenotic lesions, small lumen area at the end of the index procedure and low LDL-cholesterol levels during the study. By IVUS, lumen volume increased 26.9% (from 108.1±89.2 to 137.3±115.3 mm3; p<0.01), vessel volume increased 12.1% (from 207.1±170.2 to 232.2±196.0 mm3; p<0.01) and plaque volume tended to decrease 3.9% (from 98.9±88.7 to 94.9±89.3 mm3; p=0.07). Small lumen at baseline was related to greater lumen enlargement. Segments distal to recanalised CTO showed a notable lumen and vessel enlargement with a trend toward mild plaque regression. Low LDL-cholesterol levels increase lumen enlargement.

Abstract 18608: Serial Quantitative Coronary Analyses for the Evaluation of One-Year Changes in Grafts and Native Vessels After a Coronary Artery Bypass Surgery: Insights From the Cardiac Catheterization for Bypass Graft Patency Rate Optimization (CABG-PRO) Study

Background: Left internal mammary arteries (LIMAs) and saphenous vein grafts (SVGs) are widely used for coronary artery bypass surgery (CABG), but there is limited information on the post-CABG remodeling of these vessels, as well as the bypassed native coronary arteries. We aimed to investigate the serial changes in lumen dimensions of SVGs, LIMAs and the bypassed native arteries in humans. Methods: Thirteen consecutive patients with recent CABG enrolled in our study and underwent angiography immediately after the surgery and one year later. Quantitative coronary analysis (using CAAS Workstation 5.11 software) was performed in 12 LIMAs, 26 SVGs and 59 native coronary arteries that were bypassed. Results: Mean age was 60.8±5.8 years and all the study patients were men while the initial clinical presentation was stable angina (76.9%). Compared to immediately post CABG, at 12 month follow-up angiography the minimal, maximal and mean SVG lumen diameters of the SVGs significantly decreased: (2.83±0.87mm vs 1.99±0.79mm, p&lt;0.0001; 5.10±1.52mm vs 3.82±1.20mm, p&lt;0.0001; 3.96±1.22mm vs 2.75±0.97mm, p&lt;0.0001; respectively). No significant differences were observed in the baseline and follow-up measurements of LIMA grafts (minimal lumen diameter 1.31± 0.78mm vs 0.86±0.72mm, p=0.17; maximal lumen diameter 2.74±1.25mm vs 2.28mm±1.52, p=0.31; mean lumen diameter 0.62±0.45mm vs 1.02±1.12mm, p=0.24) and the native coronary vessels (minimal lumen diameter 0.76±0.40mm vs 0.82±0.46mm, p=0.31; maximal lumen diameter 2.88±0.99mm vs 3.07±1.18mm, p=0.09; mean lumen diameter 1.84±0.65mm vs 1.86±0.76mm, p=0.74). Conclusions: During the first year post CABG SVGs undergo significant negative remodeling, inferred by lumen constriction, which is not observed in LIMA grafts and the grafted native coronary arteries. The impact of this negative remodeling on clinical outcomes remains to be determined.

Angiographic maximal luminal diameter and appropriate deployment of the everolimus-eluting bioresorbable vascular scaffold as assessed by optical coherence tomography: an ABSORB cohort B trial sub-study

Bioresorbable vascular scaffolds (BVS) present different mechanical properties as compared to metallic platform stents. Therefore, the standard procedural technique to achieve appropriate deployment may differ. Fifty-two lesions treated with a 3 x 18 mm BVS were imaged with optical coherence tomography (OCT) post-implantation and screened for parameters suggesting non-optimal deployment. These included minimal scaffold area (minSA)<5 mm², residual area stenosis (RAS)>20%, edge dissections, incomplete scaffold/strut apposition (ISA)>5% and scaffold pattern irregularities. The angiographic proximal and distal maximal lumen diameters (DMAX) were measured by quantitative coronary angiography. Based on the DMAX values, the population was divided into three groups: DMAX <2.5 mm (n=13), DMAX between 2.5-3.3 mm (n=30) and DMAX >3.3 mm (n=9). All three groups presented with similar pre-implantation angiographic characteristics except for the vessel size and were treated with similar balloon/artery ratios. The group with a DMAX <2.5 mm presented with a higher percentage of lesions with minSA <5 mm² (30.8% vs. 10.0% vs. 0%; p=0.08) and edge dissections (61.5% vs. 33.3% vs. 11.1%; p=0.05). Lesions with >5% of ISA were significantly higher in the group with DMAX >3.3 mm (7.7% vs. 36.7% vs. 66.7%; p=0.02). RAS >20% was similar between all groups (46.2 vs. 53.3 vs. 77.8%; p=0.47) and scaffold pattern irregularities were only documented in three cases. BVS implantation guided with quantitative angiography may improve the OCT findings of optimal deployment. The clinical significance of these angiographic and OCT findings warranted long term follow-up of larger cohort of patients.

In vitro validation of new Fourier-domain optical coherence tomography

To validate the accuracy and evaluate the intra- and inter-observer variability of vascular measurements using novel Fourier-domain optical coherence tomography (FD-OCT) versus intravascular ultrasound (IVUS) in a coronary phantom model. A dedicated cylindrical phantom comprised of four sections with differing dimensions was used to compare images generated by five FD-OCT and five IVUS catheters. Each FD-OCT catheter was tested using three different consoles, generating 15 imaging pullbacks. Two independent experts, blinded to the phantom data, performed measurements. There were 180 FD-OCT and 60 IVUS cross-sectional measurements of mean lumen diameter (MeanLD), minimal lumen diameter (MLD), maximum lumen diameter (MaxLD) and lumen area (LA) at three points in each section. FD-OCT measurements had excellent correlations with IVUS (concordance correlation coefficient [CCC]: ≥0.9769 for MeanLD, LA or longitudinal length [LL]) and phantom dimensions (CCCs for FD-OCT: ≥0.9958 for MeanLD, LA or LL). FD-OCT measurements were larger than IVUS (p<0.0001), but showed less measurement errors compared to IVUS (p<0.0001). Moreover, FD-OCT caused less discrepancy between MaxLD and MLD versus IVUS (p<0.0001). Intra- and inter-observer variability was low for both FD-OCT (CCCs for MeanLD, LA and LL ≥0.9996) and IVUS (≥0.9935). Image catheter position did not influence FD-OCT measurements. FD-OCT was more accurate than IVUS and had similar high reproducibility to determine vascular dimensions in vitro. These results support the use of FD-OCT in the clinical setting.

Usefulness of Computed Tomography in Differentiating Transmural Infarction from Nontransmural Ischemia of the Small Intestine in Patients With Acute Mesenteric Venous Thrombosis

To determine computed tomographic findings that are helpful in differentiating transmural infarction from nontransmural ischemia in patients with mesenteric ischemia secondary to acute mesenteric venous thrombosis (MVT). Twenty-seven patients with symptomatic acute MVT were categorized into 2 groups: a transmural infarction (n = 13) and a nontransmural ischemia group (n = 14) based on findings at surgery and clinical follow-up. Computed tomographic scans were retrospectively reviewed by the consensus of 2 radiologists. Computed tomographic findings were compared between the 2 groups using the Fisher exact and the independent sample t test. Multifactorial logistic regression analysis was performed to determine the best predictors for differentiating transmural infarction from nontransmural ischemia. Bowel segments with homogeneous enhancement (P = 0.001), decreased enhancement (P = 0.001), and indistinct outer margins (P = 0.006) were significantly more common in the transmural infarction group than in the nontransmural ischemia group. The differences in maximal lumen diameter (P = 0.027), extent of mesenteric haziness (P = 0.018), and amount of ascites (P = 0.035) were significant between the 2 groups. On multifactorial logistic regression analysis, decreased enhancement (P = 0.007) and maximal lumen diameter (P = 0.039) were independent significant variables in differentiating transmural infarction from nontransmural ischemia. In patients with acute MVT, computed tomography is valuable in differentiating transmural infarction from nontransmural ischemia.