Publications

No abstract is provided for this article.

Aim : The in vivo comparison of the accuracy of two 3‐dimensional quantitative coronary angiography (QCA) systems. Methods : Precision‐drilled plexiglass phantoms with five different luminal diameters (0.5–1.9 mm) were percutaneously inserted into the coronary arteries of four Yorkshire pigs. Twenty‐one angiographic images of these stenotic phantoms were acquired for in vivo validation testing. Quantitative assessments of the minimum, maximum, and mean luminal diameters together with the minimum luminal area were determined using two 3D QCA systems, the CardiOp‐B® and CAAS 5. Results : The CardiOp‐B system significantly underestimated the minimum luminal diameter MLD whilst both systems significantly overestimated the maximum luminal diameter at the minimal luminal area (MLA) over the phantom's true value. The CAAS 5 system had a greater degree of accuracy/mm (mean difference = 0.01 vs. 0.03) and precision/mm (SD = 0.09 vs. 0.23) than the CardiOp‐B in assessing the minimal LD. An increased precision/mm (SD = 0.01 vs. 0.29) and accuracy/mm (mean difference = 0.03 vs. 0.11) in the mean LD was observed with the CAAS 5. In comparing the MLA/mm 2 the CAAS 5 was more precise/mm 2 (SD = 0.14 vs. 0.55) and accurate/mm 2 (mean difference = 0.12 vs. 0.02) to the true phantom MLA compared to the CardiOp‐B system. Conclusions : In a 21 phantom study, the CAAS 5 3D QCA system had a greater degree of accuracy and precision in both the luminal and area measurements than the CardiOp‐B 3D QCA system. © 2008 Wiley‐Liss, Inc.

To assess the temporal effect of statin therapy on coronary atherosclerotic plaque volume measured by intravascular ultrasound (IVUS), we searched PubMed for eligible studies published between 1990 and January 2006. Inclusion criteria for retrieved studies were (1) IVUS volume analysis at baseline and follow-up and (2) statin therapy in ≥1 group of patients. All data of interest were abstracted in prespecified structured collection forms. Statistical analysis was performed with Review Manager 4.2. Random-effect weighted mean difference (WMD) was used as summary statistics for comparison of continuous variables. Nine studies of 985 patients (with 11 statin treatment arms) were selected. After a mean follow-up of 9.8 ± 4.9 months, we found a significant decrease in coronary plaque volume (WMD −5.77 mm3, 95% confidence interval −10.36 to −1.17, p = 0.01), with no significant heterogeneity across studies (p = 0.47). Prespecified subgroup analyses showed similar trends. Studies in which the achieved low-density lipoprotein (LDL) cholesterol level was <100 mg/dl showed a trend for plaque regression (WMD −7.88 mm3, 95% confidence interval −16.31 to 0.55, p = 0.07), whereas studies in which the achieved level of LDL cholesterol was ≥100 mg/dl, the trend was less evident (WMD −4.22 mm3, 95% confidence interval −10.27 to 1.82, p = 0.17). Plaque volume remained essentially unchanged in patients not treated with statins (WMD 0.13 mm3, 95% confidence interval −4.42 to 4.68, p = 0.96). In conclusion, statin therapy, particularly when achieving the target LDL level, appears to promote a significant regression of coronary plaque volume as measured by IVUS.

Transcatheter aortic valve replacement (TAVR) constitutes a relatively new treatment option for the patients with severe symptomatic aortic stenosis. Evidence from registries and randomized control trials has underscored the value of this treatment in inoperable and high risk populations, while new developments in valve technology and TAVR enabling devices have reduced the risk of complications, simplified the procedure, and broadened the applications of this therapy. The initial promising clinical results and the potential of an effective less invasive treatment of aortic stenosis has not only created high expectations but also the need to address the pitfalls of TAVR technology. The evolving knowledge concerning the groups of patients who would benefit from this treatment, the limited long term follow-up data, the concerns about devices' long term durability, and the severity of complications remain important caveats which restrict the widespread clinical adoption of TAVR. The aim of this review article is to present the recent advances, highlight the limitations of TAVR technology, and discuss the future perspectives in this rapidly evolving field.

Although intracoronary stenting has been advocated as an adjunct to balloon angioplasty to circumvent late restenosis, its effectiveness has not yet been verified. Therefore the aim of this study was to determine the differences in the immediate and long-term changes in stenosis geometry between Wallstent implantation and balloon angioplasty in native coronary artery lesions. To obtain two study populations with identical baseline stenosis characteristics, patients were matched for lesion site, vessel size, and minimal luminal diameter. Only patients undergoing elective and successful coronary intervention of a native coronary artery, in whom a control angiographic study had been performed, were included. A total of 186 patients (93 in each group) were selected. The coronary angiograms were analyzed with the computer-assisted cardiovascular angiographic analysis system. Matching was considered adequate, since there was an equal number of lesion sites in each study population and there were no differences in baseline reference diameter and minimal luminal diameter. Wallstent implantation resulted in a significantly greater increase in minimal luminal diameter (from 1.22 ± 0.34 mm to 2.49 ± 0.40 mm, p < 0.00001) compared with balloon angioplasty (from 1.21 ± 0.29 mm to 1.92 ± 0.35 mm, p < 0.00001). Despite a greater decrease in minimal luminal diameter after Wallstent implantation (0.48 ± 0.74 mm) than after balloon angioplasty (0.20 ± 0.46 mm), the minimal luminal diameter at follow-up was significantly greater after stent implantation (2.01 ± 0.75 mm vs 1.72 ± 0.54, p < 0.0001). It was concluded that Wallstent implantation results in a superior immediate and long-term increase in minimal luminal diameter compared with balloon angioplasty. The larger initial gain after stent implantation compensates for the late loss, and thus an improved initial result and not lessened neointimal hyperplasia is responsible for a reduced incidence of restenosis. Studies based on matching of angiographic variables are a surrogate for randomized studies, forecasting their results and offering insight into the effects of different interventional techniques. Moreover, these studies yield statistical information that may be helpful for the proper design of a randomized study (sample size, type II error).

No abstract is provided for this article.

No abstract is provided for this article.

Intracoronary ultrasound (ICUS) provides high-resolution tomographic images of selected segments of coronary arteries. Series of cross-sectional images are acquired with motorized pullback imaging catheters and used for quantitative analysis in intracoronary ultrasound studies (ICUS). Due to catheter displacement in the vascular lumen during the cardiac cycle the images that are typically acquired at 0.5 mm/s are anatomically shuffled. This results in a saw-tooth shaped appearance of the coronary segment in longitudinal reconstructed views (L-views) used frequently in quantitative coronary ultrasound (QCU) software. This paper describes a novel image-based gating method called "Intelligate", which overcomes this problem by automatic retrospective selection of end-diastolic frames from pre-recorded ICUS studies. Our evaluation shows that there are no quantitative differences between analysis results of hardware ECG-gated and intelligated ICUS studies.

Background Matrix fabricated from electrospinning of micro fibre of polyester is porous and permeable to blood, facilitates cell infiltration and late resorption of the biodegradable material. This biomaterial opens an avenue of research in recreating a novel and favourable endoluminal lining in diseased vessel. Previous preclinical work has shown that implants in aorta of rodents generate layers of endoluminal elastin. In humans, one of the most impervious arteries to atherosclerosis is the intra-thoracic artery; therefore, an attempt to induce similar structures with an implantable device was made. Methods For this study, novel tissue-engineered vascular grafts (T-TEVGs) were used in a preclinical rabbit iliac artery model. It was made of resorbable polyester biomaterial processed into fibrous tubular conduits. These T-TEVGs were implanted percutaneously. In total, twelve T-TEVGs in iliac arteries of nine rabbits were implanted. Follow-up were conducted on five rabbits with eight T-TEVGs at three months, two rabbits with two T-TEVGs at six months, and two rabbits with two T-TEVGs at twelve months. At follow-up, percutaneous optical coherence tomography (OCT) was performed, and OCT-derived luminal vessel wall dimensions and fractional flow reserve (OFR) derived from OCT were assessed. Results The overall pooled analysis at different timepoints on follow-up, documented an average MLA of 1.74±0.48mm2, average of proximal and distal reference area of 4.55±0.99 mm2, average area stenosis of 61±12%, and mean OFR value of 0.96±0.03 (OFR ranging from 0.89 to 0.99). There was a moderate positive correlation between minimum lumen area and OFR (r=0.590, p&amp;lt; 0.01). There was a strong negative correlation between percentage area stenosis and OFR (r= - 0.846, p&amp;lt; 0.01). At no timepoint in follow-up and in every vessel analysed, OFR value was lower than 0.89, suggesting that none of these vessels exhibited flow-limiting narrowing. Our study has a few limitations. 1) The preclinical model is a non-atherosclerotic rabbit; 2) There was no barotrauma prior to the implantation of the device; 3) Limited sample size, short and medium follow-up duration, and pooling of assessment at different timepoints. Conclusion The current study shows the durability and favourable hemodynamics of this bioresorbable fibrillated scaffold at short and medium term follow-up, supporting the potential utility of T-TEVEGs for peripheral human artery revascularisation. Long-term follow-ups are mandatory to confirm the durability of these results. Histopathology of this preclinical model should confirm the endoluminal elastin as previously documented in rodents (rats) and will be presented at the time of the congress.

Background and Aims Previous lipidomics analyses have demonstrated that several lipid molecules in plasma are associated with fatal outcome in patients with coronary artery disease (CAD). This study aims to investigate the associations of previously identified high risk lipid molecules in plasma with coronary plaque characteristics derived from intravascular ultrasound virtual histology (IVUS-VH) imaging, with coronary lipid core burden index (LCBI) on near-infrared spectroscopy (NIRS), and with one year cardiovascular outcome in patients with CAD. Methods Between 2008 and 2011, IVUS-VH imaging of a non-culprit coronary artery was performed in 581 patients who underwent coronary angiography for acute coronary syndrome (ACS) or stable CAD. NIRS imaging was additionally performed in 191 patients. Plasma concentrations of molecular lipids were measured with mass spectrometry. Results Several cholesteryl ester, ceramide and lactosylceramide species and ceramide ratios were associated with vulnerable plaque characteristics on IVUS-VH and NIRS imaging and with 1-year major adverse cardiac events (MACE, defined as all-cause mortality, ACS and unplanned coronary revascularization). In particular, ceramide d18:1/16:0 was consistently associated with higher necrotic core fraction on IVUS-VH (p = 0.001), higher LCBI (p = 0.024) on NIRS and higher MACE rate (adjusted HR 1.79 per standard deviation increase in log-transformed lipid concentration, 95%CI 1.24–2.59, p = 0.002). Conclusion Several molecular lipid species, and particularly ceramide(d18:1/16:0), are associated with the fraction of necrotic core tissue and lipid core burden in coronary atherosclerosis, and are predictive for 1-year clinical outcome after coronary angiography. These molecular lipids may improve risk stratification in CAD and may also be interesting therapeutic targets for the treatment of atherosclerotic disease.

The rupture of thin-cap fibroatheroma (TCFA) plaques is a major cause of acute coronary events. A TCFA has a trombogenic soft lipid core, shielded from the blood stream by a thin, possibly inflamed, stiff cap. The majority of atherosclerotic plaques resemble a TCFA in terms of overall structural composition, but have a more complex, heterogeneous morphology. An assessment of the material distribution is vital for quantifying the plaque's mechanical stability and for determining the effect of plaque-stabilizing pharmaceutical agents. We describe a new automated inverse elasticity method, intravascular ultrasound (IVUS) modulography, which is capable of reconstructing a heterogeneous Young's modulus distribution. The elastogram (i.e., spatial strain distribution) of the plaque is the input for the method, and is measured using the clinically available technique, IVUS elastography. Our method incorporates a novel divide-and-conquer strategy, allowing the reconstruction of TCFAs as well as heterogeneous plaques with localized regions of soft, weakened tissue. The method was applied to ex vivo elastograms, which were simulated from the cross sections of postmortem human coronary plaques. To demonstrate the clinical feasibility of the method, measured elastograms from human atherosclerotic coronary arteries were analyzed. One elastogram was measured in vitro; the other, in vivo . The method approximated the true Young's modulus distribution of all simulated plaques, while the in vitro reconstruction was in agreement with histology. In conclusion, the IVUS modulography in combination with the IVUS elastography has strong potential to become an all-encompassing modality for detecting plaques, for assessing the information related to their rupture-proneness, and for imaging their heterogeneous elastic material composition.