Quantitative Angiographic Analysis Research Articles

Effect of singular value decomposition on removing injection variability in 2D quantitative angiography: An in silico and in vitro phantoms study.

Intraoperative 2D quantitative angiography (QA) for intracranial aneurysms (IAs) has accuracy challenges due to the variability of hand injections. Despite the success of singular value decomposition (SVD) algorithms in reducing biases in computed tomography perfusion (CTP), their application in 2D QA has not been extensively explored. This study seeks to bridge this gap by investigating the potential of SVD-based deconvolution methods in 2D QA, particularly in addressing the variability of injection durations. Building on the identified limitations in QA, the study aims to adapt SVD-based deconvolution techniques from CTP to QA for IAs. This adaptation seeks to capitalize on the high temporal resolution of QA, despite its two-dimensional nature, to enhance the consistency and accuracy of hemodynamic parameter assessment. The goal is to develop a method that can reliably assess hemodynamic conditions in IAs, independent of injection variables, for improved neurovascular diagnostics. The study included three internal carotid aneurysm (ICA) cases. Virtual angiograms were generated using computational fluid dynamics (CFD) for three physiologically relevant inlet velocities to simulate contrast media injection durations. Time-density curves (TDCs) were produced for both the inlet and aneurysm dome. Various SVD variants, including standard SVD (sSVD) with and without classical Tikhonov regularization, block-circulant SVD (bSVD), and oscillation index SVD (oSVD), were applied to virtual angiograms. The method was applied on virtual angiograms to recover the aneurysmal dome impulse response function (IRF) and extract flow related parameters such as Peak Height PHIRF, Area Under the Curve AUCIRF, and Mean transit time MTT. Next, correlations between QA parameters, injection duration, and inlet velocity were assessed for unconvolved and deconvolved data for all SVD methods. Additionally, we performed an in vitro study, to complement our in silico investigation. We generated a 2D DSA using a flow circuit design for a patient-specific internal carotid artery phantom. The DSA showcases factors like x-ray artifacts, noise, and patient motion. We evaluated QA parameters for the in vitro phantoms using different SVD variants and established correlations between QA parameters, injection duration, and velocity for unconvolved and deconvolved data. The different SVD algorithm variants showed strong correlations between flow and deconvolution-adjusted QA parameters. Furthermore, we found that SVD can effectively reduce QA parameter variability across various injection durations, enhancing the potential of QA analysis parameters in neurovascular disease diagnosis and treatment. Implementing SVD-based deconvolution techniques in QA analysis can enhance the precision and reliability of neurovascular diagnostics by effectively reducing the impact of injection duration on hemodynamic parameters.

Deep learning-based quantitative image analysis for detecting coronary artery stenosis, calcification, and vulnerable plaque in coronary computed tomography angiography

Abstract Purpose To develop a quantitative image analysis for detecting coronary artery stenosis, calcification, and vulnerable plaque in reconstructed coronary computed tomography angiography. Materials and Methods 2,978 reconstructed coronary artery CT angiography (CCTA) of our hospital in South Korea from 2014 to 2022 were enrolled. For each CCTA scan, a total of 13 images were reconstructed for each coronary artery (CA) by CT Cardiac Package, TeraRecon Inc. A total of 769 CT images were independently selected as the test data set in the last period, while the remaining were utilized in a 4:1 ratio as train and validation datasets. The locations of stenosis and vulnerable plaques were strongly labeled by an expert radiologist with more than 10 years of experience to train a 2D segmentation model (SM). First of all, the correlation between a quantitative stenosis index (QSI) and conventionally measured quantitative angiographic analysis (QCA) was evaluated. We developed an SM for CA and stenosis using 2D nnU-Net. Using SM, the position and length of stenosis per image were evaluated, and a CA diameter profile was analyzed through Full Width at Half Maximum analysis. The QSI is acquired through the calculation of the CA diameter profile. Secondly, images with marked calcifications and calcification scores (CS) were evaluated by an expert cardiologist with more than 15 years of experience. The CS was calculated by measuring the number of voxels over 1100 Hounsfield units in the CA using the previously developed vascular SM. The result of CS was evaluated by visual scoring of the expert cardiologist with a 10-scale. Lastly, the presence or absence of vulnerable plaques per CA was evaluated. In addition, another SM for normal CA and vulnerable plaques were trained. For the evaluation method, sensitivity and specificity were calculated for each CA. Results The correlation between QSI and QCA was 0.715. Visual scoring on the result of CS was 7.150 ±2.354 to 10. The sensitivity and specificity of the vulnerable plaque for evaluating vascular unit classification were 0.929 and 0.910, respectively. Conclusions We developed an automated quantitative image analysis for evaluating QSI, detecting calcification, and vulnerable plaque in CCTA, which could be used in the actual screening setting.

Larger Posterior Revascularization Associated with Reduction of Choroidal Anastomosis in Moyamoya Disease: A Quantitative Angiographic Analysis.

Choroidal anastomosis, a hemorrhage-prone periventricular collateral manifestation in Moyamoya disease, outflows to the cortex posterior to the central sulcus. The objective of the present study was to test whether the angiographic extent of revascularization posterior to the central sulcus contributes to the postoperative reduction of choroidal anastomosis. This retrospective cohort study included choroidal anastomosis-positive hemispheres before direct bypass surgery. The postoperative reduction of choroidal anastomosis was determined by a consensus of 2 raters according to the previous research. An imaging software automatically traced the angiographic revascularization area, which was subsequently divided into anterior and posterior parts by an anatomic line corresponding to the central sulcus. Each area was quantitatively measured as a percentage relative to the whole supratentorial area. Postoperative reduction of choroidal anastomosis was achieved in 68 (85.0%) of the 80 included hemispheres. The revascularization area posterior to the central sulcus was significantly larger in the hemispheres with reduction than in those with no reduction (mean, 15.2% [SD, 7.1%] versus 4.2% [SD, 3.4%], P < .001), whereas no significant difference was observed in the revascularization area anterior to the central sulcus. Multivariate analysis revealed that the revascularization area posterior to the central sulcus was the only significant factor associated with reduction (OR, 1.57; 95% CI, 1.21-2.03, for every 1% increase). The results suggest that a larger revascularization posterior to the central sulcus is associated with postoperative reduction of choroidal anastomosis regardless of the extent of anterior revascularization. It might facilitate optimal selection of the revascularization site for preventing hemorrhage.

Early experience with coronary debulking devices in a newcomer facility after introducing revised facility criteria in Japan.

Coronary debulking devices are essential in obtaining optimal results in percutaneous coronary intervention (PCI) for severely calcified lesions. However, since the introduction of these devices in Japan, the presence of full-time cardiovascular surgeons in their own facilities has been an essential condition (on-site surgical back-up) as the facility criteria for their use. The criteria were revised in April 2020, making their implementation possible at our hospital. Between May 2020 and January 2022, we administered PCIs using rotational atherectomy (RA) for 33 lesions in 28 patients and orbital atherectomy system (OAS) for 36 lesions in 27 patients. The most preferred strategy in our hospital is OAS via the distal radial approach using a 6Fr Glide sheath or RA via the femoral approach using a 7Fr sheath. The percentages of usable imaging modality as an initial device without lesion modification were 57.1 and 66.7% in the RA and OAS groups, respectively. In the RA procedure, 1.5- and 2.0-mm Rota burrs were more frequently adopted for the initial and second sessions, respectively. In the OAS procedure, the debulking was always initiated at a low speed. Nineteen of the 27 patients underwent additional high-speed debulking. Pre-procedural quantitative coronary angiographic analysis revealed that the minimal lumen diameter was significantly smaller in the RA than in the OAS group. Debulking procedures were successful in all patients excluding two instances of procedure-related complications in the RA group, one of which was coronary perforation safely treated via covered stent deployment without any resulting hemodynamic instability. Our early experience with coronary debulking devices with off-site surgical back-up clearly reveals the safety and feasibility of this procedure in a newcomer facility.

Prediction of type 4a myocardial infarction with the angiography-derived hemodynamic (ADDED) index.

Percutaneous coronary intervention (PCI) is frequently complicated by type 4a myocardial infarction (MI), which is associated with an increased risk of mortality. We assessed the usefulness of the angiography-derived hemodynamic index (ADDED), which is based on the extent of myocardium at risk and on the anatomical lesion severity, in predicting type 4a MI in patients with chronic coronary syndrome (CCS) undergoing PCI. We enrolled 442 patients treated with single-vessel PCI. The ADDED index was calculated as the ratio of the Duke Jeopardy Score to the minimum lumen diameter assessed with quantitative angiography analysis. Type 4a MI was defined according to the 4th Universal Definition of MI. The overall population was divided into tertiles of ADDED index. Type 4a MI occurred in 5 patients (3.3%) in the ADDED-low tertile, 8 (5.5%) in the ADDED-mid tertile, and 26 (17.7%) in the ADDED-high tertile (p < 0.0001). At ROC curve analysis, the ADDED index could significantly discriminate between patients with and without type 4a MI (area under the curve 0.745). At multivariate analysis, an ADDED index value > 5.25 was the strongest independent predictor type 4a MI. Our results support the role of the ADDED index as a predictor of type 4a MI in patients with CCS treated with elective PCI of a single vessel. Whether a selective use of additional preventive measures in patients considered at high risk based on ADDED index values may improve peri-procedural and long-term outcomes remains to be tested in dedicated investigations.

730 Prediction of type 4a myocardial infarction with the angiography-derived haemodynamic (added) index

Abstract Aims Percutaneous coronary intervention (PCI) is frequently complicated by type 4a myocardial infarction (MI). We assessed the usefulness of the angiography-derived haemodynamic index (ADDED) index in predicting type 4a MI in patients with chronic coronary syndrome (CCS) undergoing PCI. Methods and results We enrolled 442 patients treated with single-vessel PCI. The ADDED index was calculated as the ratio of the Duke Jeopardy Score (DJS) to the minimum lumen diameter (MLD) assessed with quantitative angiography analysis (QCA). Patients in the higher ADDED tertile presented higher occurrence of type 4a MI (17.7%, P &amp;lt; 0.0001). At ROC curve analysis, the ADDED index could significantly discriminate between patients with and without type 4a MI (area under the curve 0.745). At multivariate analysis, an ADDED index value &amp;gt;5.25 was the strongest independent predictor type 4a MI. Conclusions Our results support the role of the ADDED index as a predictor of type 4a MI in patients with CCS treated with elective PCI.

Effect of Hinge Motion on Stent Edge-Related Restenosis After Right Coronary Artery Treatment in the Current Drug-Eluting Stent Era.

Stent edge-related restenosis (SER) remains a potential limitation of drug-eluting stent (DES). Hinge motion at the stent edge could lead to mechanical stress and contribute to incidents of SER. We investigated the effect of hinge motion on SER after implantation of current-generation DES in the right coronary artery (RCA), where excessive vessel movement is commonly observed.Methods and Results:Of 647 consecutive lesions in the RCA treated with second-generation or later DESs, 426 with follow-up angiography were included in this study. Intravascular imaging analysis was performed for 584 stent edges and reference segments. Binary restenosis occurred in 42 lesions (9.9%), and 55% were SERs. The hinge angle was significantly larger in the SER group than in the other restenosis or the no-restenosis group (17.9° vs. 11.6° and 10.6°, respectively; P<0.001). Lesions with an excessive hinge angle (>11.5°) had an increased rate of target lesion revascularization (19.1% vs. 7.2%; P<0.001) during the median follow-up period of 1,578 days. In per-edge analysis, hinge angle and residual plaque burden were independent predictors of SER. The coexistence of excessive hinge motion and residual plaque burden had a synergistic effect on stenotic progression in quantitative angiographic analysis (Pinteraction<0.001) at follow-up angiography. Substantial stress determined by angulation at a stent edge and its interaction with residual plaque can be considered as one plausible mechanism for SER.

Impact of hinge motion on stent edge restenosis after new generation drug-eluting-stent implantation in RCA

Abstract Background Edge restenosis still occurs after stent implantation, even by using new generation drug-eluting stents (DES) considered to have favorable biomechanical properties. Mechanical stress imposed on the stent edge are thought to be aggravated by hinge motion at a point between the stented and unstented segments, inducing chronic local inflammation and neointimal overgrowth. Purpose The aim of this study was to investigate the association between the development of edge restenosis and hinge motion in right coronary artery (RCA) where the excessive vessel movement is commonly observed. Methods Among consecutive 650 lesions in RCA where new generation DESs were implanted between 2009 and 2019, 427 serial lesions with sets of angiographies at baseline and follow-up (6–18 month) were included. In addition to conventional quantitative angiography analysis, hinge angle at stent edges was measured (Fig. 1). All the appropriate data for intravascular imaging were analyzed for both stent edges and reference segments. Results Binary restenosis occurred in 43 lesions, and 39 of them were referred to re-intervention. Fifty five percent of them were related to stent edges (15 at proximal and 9 at distal edges). Classical risk factors including diabetes and hemodialysis were more prevalent in the restenosis group (p&amp;lt;0.05). Hinge angle was statistically larger in edge restenosis group than body restenosis or no restenosis group (17.3° vs 11.6° vs 10.6°, p&amp;lt;0.001, Fig. 2). In per-edge analysis, hinge angle, dissection and residual plaque ratio were the independent predictors for binary restenosis (Table 1) with the optimal cut-off value of hinge angle 11.5°. The coexistence of excessive hinge angle and residual plaque burden had an amplified effect on the angiographic stenotic progression at stent edge (p for interaction &amp;lt;0.001) and the incidents of binary restenosis (16.7% vs 1.7% p&amp;lt;0.01, Figs. 3,4). Conclusion Substantial stress determined by angulation at the stent edge and its interaction with residual plaque can be considered as one of the plausible mechanisms for edge restenosis. For tortuous RCA lesions, it would be important to decide the stent-landing zone for minimizing hinge motion and optimize the future stent design. Funding Acknowledgement Type of funding source: None

Arterial Steal to the Penumbra Area in Patients with Acute MCA Occlusion: A Quantitative Angiographic Analysis.

PurposeIn acute middle cerebral artery (MCA) occlusion, collateral vessels provide retrograde supply to the occluded territory. We hypothesized that such collateral flow reduces perfusion of the non-occluded donor region (steal effect).Materials and MethodsPatients with an MCA occlusion with opacification of both ipsi- and contralateral anterior cerebral arteries (ACA) on angiography prior to endovascular treatment were selected. Arteriovenous transit time (AVTT) for both ACA territories was compared for different grades of collateral supply to the MCA territory. In addition, the influence of diabetes and hypertension was analyzed. After successful revascularization, AVTT was re-assessed to determine reversibility.ResultsForty-one patients were analyzed. An AVTT of 8.6 seconds (standard deviation [SD] 2.4 seconds) was seen in the ACA territory of the affected hemisphere in comparison to 6.6 seconds (SD 2.1 seconds) for the contralateral side (P<0.001). A more prolonged (but not significant) AVTT was seen in cases with a higher collateral grade. No difference in AVTT was seen in patients with diabetes or hypertension. After successful MCA revascularization, AVTT delay was 7.4 seconds (SD 2.1 seconds).ConclusionA cerebral steal effect occurs in patients with an acute MCA occlusion, probably related to augmented flow to the penumbra area.

Clinical indicators and coronary angiographic features of expansive arterial remodelling in patients with abdominal aortic aneurysms.

The co-existence of expansive arterial remodelling in both coronary arteries (CAs) and the abdominal aorta has already been reported, although the clinical indicators and quantitative analysis have not been well studied. We therefore aimed to clarify the clinical and anatomical characteristics of patients with abdominal aortic aneurysms (AAAs). 123 AAA patients who underwent coronary angiography were compared to 123 control patients selected by propensity score matching. CA diameters of all 3 vessels were measured by quantitative coronary angiographic analysis. Coronary artery ectasia (CAE) was defined as local or generalized aneurysmal change of the CAs. Excessive expansive CA remodelling was defined as the maximal diameter of the right or left circumflex artery in the upper 75th percentile (>4.8 mm). Multivariable logistic regression analyses were used to determine predictors of CAE and excessive expansive CA remodelling. The prevalences of CAE and excessive expansive CA remodelling were significantly higher in the AAA group than in the non-AAA group (28% vs. 8% and 31% vs. 19%; both p<0.05). On multivariable analysis, the presence of AAA (odds ratio (OR), 4.56; 95% confidence intervals (95%CI) 2.18–10.4) and body mass index (BMI) (OR, 1.11; 95%CI 1.03–1.21) were independently associated with CAE, and higher high-sensitivity C-reactive protein (OR, 2.19; 95%CI 1.08–4.52) and BMI (OR, 1.11; 95%CI 1.02–1.21) were independently associated with excessive expansive CA remodelling. In conclusions, this study showed a higher prevalence of ectatic CA disease in AAA patients and suggests that higher inflammation and obesity are associated with expansive arterial remodelling in coronary arteries.

An Animal Model of Human Peripheral Arterial Bending and Deformation

BackgroundDesigning peripheral arterial stents has proved challenging, as implanted devices will repetitively and unpredictably deform and fatigue during movement. Preclinical testing is often inadequate, given the lack of relevant animal models. The purpose of this study was to test the hypothesis that deformation of the human peripheral vasculature could be qualitatively and quantitatively modeled using an experimental animal. MethodsAnteroposterior contrast angiography was performed in domestic Landrace-Yorkshire farm pigs. Images were obtained with the hind limbs naturally extended then repeated, (1) flexed approximately 90° at the hip and knee, (2) overflexed in a nonphysiological fashion. Quantitative vascular angiographic analysis was utilized to measure arterial diameter, length, and deformation. Percent axial arterial compression and bending were assessed. ResultsEight iliofemoral arteries in four animals were imaged. Mean luminal diameters of the iliac and femoral segments in the neutral position were 5.4 ± 0.5 mm and 4.6 ± 0.5 mm. Hind limb physiologic flexion induced profound arterial compression, 17 ± 8% and 29 ± 6% and bending, 36°±10° and 76° ± 13° within the iliac and femoral segments, respectively. With extreme flexion, the femoral artery could be reliably bent >90°. The observed findings exceeded the deformation observed historically within the human superficial femoral (∼5% compression and 10° bending) and popliteal artery (∼10% compression and 70° bending). ConclusionsSignificant nonradial deformation of the porcine iliofemoral arteries was observed during manual hind limb flexion and exceeded that typically observed in humans. This model constitutes a “worst case” scenario for testing deformation and fatigue of intravascular devices indicated for the human peripheral vasculature.

Prevalence of longitudinal and radial shortening of drug eluting stents during routine PCI without imaging assistance: A quantitative coronary angiographic analysis.

Prevalence of longitudinal and radial shortening of drug eluting stents during routine PCI without imaging assistance: A quantitative coronary angiographic analysis.

Association of stent-induced changes in coronary geometry with late stent failure: Insights from three-dimensional quantitative coronary angiographic analysis.

The relationship between vessel angulation and large changes in vessel geometry after stent implantation and the occurrence of stent failure still remains unclear. We sought to investigate the association of the change in the coronary bending angle after stenting and the risk for late stent failure by three-dimensional quantitative coronary angiography (3D QCA). The bending angle in coronary lesions that presented with late stent failure and those without stent failure was computed during the cardiac cycle, before and after stenting using a recently developed 3D QCA software. A total of 40 lesions with stent failure (cases) were successfully matched to 47 lesions without stent failure (controls).The mean duration to follow-up coronary angiography was 1,011 days in cases and 1,109 days in the control group (P = 0.14). In stent failure, the systolic bending angle after stenting was smaller (14.45° [12.18, 17.68] versus 18.20° [14.00, 20.30], P = 0.01), while the stent-induced change in systolic bending angle was significantly larger (4.15° [1.13, 7.20] versus 1.80° [-1.90, 4.40], P = 0.004). Multivariable logistic regression analysis suggested that systolic bending angle after stenting (odds ratio: 0.88; 95% CI: 0.79-0.99; P = 0.03), and decrease in systolic bending angle after stenting (odds ratio: 1.13; 95% CI: 1.02-1.26; P = 0.03) were predictors of stent failure. Our study suggests that a change in the natural tortuous course of the coronaries by stent implantation with the decrease in coronary bending angle is a potentially major contributor in stent failure.

Percutaneous transcatheter aortic valve replacement induces femoral artery shrinkage: angiographic evidence and predictors for a new side effect.

We sought to investigate the possible impact of transaortic valve replacement (TAVR) on common femoral artery (CFA) integrity as assessed by angiography. CFA represents the most adopted access for TAVR but various degrees of vascular damage may be induced by the procedure. Patients underwent percutaneous transfemoral TAVR who had both pre- and post-TAVR access-site angiography were retrospectively selected. Clinical and procedural data (including technique and complications) were prospectively recorded into a structured TAVR database. Pre-TAVR and post-TAVR angiograms were analyzed using a quantitative angiographic analysis software to assess reference diameters, minimum luminal diameter (MLD), and percentage of diameter stenosis (DS). A total of 124 patients entered the study (mean age: 85 years, mean Euroscore II: 10%). ProStar (13.5%) and double ProGlide (82.2%) preclosure were the main hemostatic techniques. CFA exhibited a significant shrinkage with TAVR as assessed by significant MLD reduction (5.6 mm after TAVR vs. 6.8 mm before, P < .001) and DS increase (30.3% after vs. 17.0%, P < .001). Such differences remained statistically significant after exclusion of 18 patients (14.2%) who had (minor or major) vascular complications. At multivariable analysis, pre-TAVR DS (P = .03) and history of peripheral arterial disease (P = .01), were significantly associated with vascular complications. Percutaneous TAVR induces an angiographically detectable CFA lumen reduction. Such findings call for further studies assessing clinical impact of this phenomenon and open the door for further refinements of the TAVR access management aimed at preserving vessel integrity.

1973Does the stent induced change in coronary geometry affect prognosis? Insights from 3-dimensional quantitative coronary angiographic analysis on the impact of vessel bending on coronary in-stent resten

1973Does the stent induced change in coronary geometry affect prognosis? Insights from 3-dimensional quantitative coronary angiographic analysis on the impact of vessel bending on coronary in-stent resten

Pivotal Study of a Next-Generation Balloon-Expandable Stent-Graft for Treatment of Iliac Occlusive Disease

Purpose: To evaluate the safety and efficacy of a next-generation balloon-expandable stent-graft for the treatment of arterial occlusive disease in patients with de novo or restenotic lesions in the common and/or external iliac arteries. Methods: A prospective, multicenter, single-arm safety and efficacy study ( ClinicalTrials.gov identifier: NCT02080871) of the VBX Stent Graft for treatment of de novo or restenotic lesions in the iliac arteries was conducted under an Investigational Device Exemption at 26 US sites and 1 New Zealand center. The study eligibility criteria were established with the aim of enrolling more “real-world” patients compared with previous iliac stent studies supporting Food and Drug Administration approval. The study enrolled 134 patients (mean age 66±9.5 years; 79 men) with 213 iliac lesions. Three-quarters of the population (101, 75.4%) had Rutherford category 3 ischemia, and 43 (32.1%) patients presented with TASC II C/D lesions. The primary endpoint was a composite of device- or procedure-related death within 30 days, myocardial infarction within 30 days, target lesion revascularization (TLR) within 9 months, and amputation above the metatarsals in the treated leg within 9 months. Results: In all, 234 devices were implanted in 213 lesions with 100% technical success; 57 (42.5%) patients received kissing stents at the aortic bifurcation. No devices exhibited a discernable change in length after final deployment as determined by independent core laboratory quantitative angiographic analysis. At 9 months, 3 (2.3%) of 132 patients (1 lost to follow-up, 1 unrelated death) experienced a major adverse event (3 TLRs) related to the primary endpoint. At 9 months, there were no device-related serious adverse events or unanticipated adverse device effects. Conclusion: The next-generation balloon-expandable stent-graft demonstrated notable 9-month safety and efficacy in treating iliac occlusive disease in patients reflecting common clinical practice.

A Quantitative Angiographic Comparison of Restenotic Tissue Following Placement of Drug-Eluting Stents and Bare Metal Stents in Symptomatic Patients With Femoropopliteal Disease

Purpose: To evaluate the patterns of in-stent restenosis (ISR) within femoropopliteal bare metal stents (BMS) and drug-eluting stents (DES) as determined by quantitative angiographic analysis. Methods: Utilizing results from independent core laboratory angiographic imaging analysis, quantitative assessment of the restenotic tissue burden was evaluated in 33 patients with symptomatic femoropopliteal ISR, including 20 lesions in 19 patients (mean age 71.5±8.1 years; 11 men) treated with DES and 14 lesions in 14 patients (mean age 70.6±9.2 years; 9 men) treated with BMS. Results: The average time to target lesion revascularization was similar (8.7 months) for the DES and BMS groups. The DES group had significantly less recurrent disease burden (17.1%) compared with the BMS group (27.8%, p=0.03), representing a 39% relative reduction. Conclusion: Reduced restenotic tissue after endovascular intervention is associated with improved hemodynamics and fewer clinical symptoms and may explain the reduced need for reintervention in restenotic lesions initially treated with DES as compared with BMS. Further study of treatment failure modes may lead to improved device selection criteria to treat patients with peripheral artery disease.

Prospective randomized comparison of clinical and angiographic outcomes between everolimus-eluting vs. zotarolimus-eluting stents for treatment of coronary restenosis in drug-eluting stents: intravascular ultrasound volumetric analysis (RESTENT-ISR trial).

At present no proven standard treatment for drug-eluting stent (DES) restenosis is available, and the efficacy and safety of everolimus-eluting stent (EES) and zotarolimus-eluting stent (ZES) for DES restenosis are limited. The purpose of this prospective, randomized 9-month intracoronary ultrasound (IVUS) and 3-year clinical follow-up study was to compare the effects of EESs and ZESs on neointima volume and major adverse cardiovascular events (MACEs) such as death, myocardial infarction (MI), target lesion revascularization (TLR) and stent thrombosis in DES restenosis patients. Patients were eligible for this study if they were between 40 and 75 years old with in-stent restenosis >50% by quantitative coronary angiographic analysis in DES or within 5 mm of the stent edges with signs of ischaemia. Eligible patients (n = 304, 146 women and 158 men) were randomly assigned to receive either EES (158 patients) or ZES (146 patients). The primary endpoint of the study was to compare neointima volume between the EES and ZES groups at the 9-month follow-up IVUS. MACEs, including death, non-fatal MI, stent thrombosis and the need for repeated TLR within 3 years, were noted. The 9-month angiographic and IVUS follow-up showed no significant differences in late lumen loss (0.40 ± 0.56 vs. 0.45 ± 0.61 mm, P = 0.57, respectively) and neointima volume (0.51 ± 0.48 vs. 0.56 ± 0.54 mm3/1 mm, P = 0.47, respectively) in the EES and the ZES groups. Composite MACEs such as death, MI, stent thrombosis and TLR during 3-year follow-up were comparable between the two groups [15.8% (n = 25) in the EES group and 22.6% (n = 33) in the ZES group, P = 0.276], independent of de novo DES type, sex, age, body mass index, presence of diabetes, hypertension and dyslipidaemia. Patients with first- and second-generation DES restenosis, both EES and ZES implantation were effective and safe in reducing neointima volume and late loss with a comparable rate of MACEs independent of cardiovascular risk factors.

12-month intravascular ultrasound observations from BiOSS® first-in-man studies.

The aim of this study was to analyze the difference in neointima pattern assessed by intravascular ultrasound (IVUS) between two dedicated bifurcation stents, BiOSS® Expert and BiOSS® LIM at 12-month follow-up. This manuscript reports IVUS findings obtained from the analysis of patients enrolled into first-in-man registries initially assessing the BiOSS Expert® (paclitaxel) and BiOSS LIM® (sirolimus) stents. Quantitative angiographic analysis was performed pre, post-stenting, and at follow-up. IVUS examination was performed at 12 months. There were analyzed 34 cases (BiOSS Expert® 11 patients, BiOSS LIM® 23 patients). Procedural characteristics in the two groups were similar, except for rates of main vessel predilatation and FKB/POT, which were higher in BiOSS® LIM group, 54.5 % vs 73.9 % (P < 0.05) and 0 % vs 39.1 % (P < 0.05), respectively. When comparing late lumen loss (LLL) for both stents there were significantly bigger values for main vessel and main branch in the BiOSS® Expert group, but not in side branch. Intravascular ultrasound examination showed that in the BiOSS LIM® group comparing with the BiOSS Expert® group there was lower neointima burden in the whole stent (24.7 ± 7.5 % vs 19.4 ± 8.6 %, P < 0.05) as well as in main vessel (22.8 ± 5.6 % vs 16.9 ± 6.1 %, P < 0.05) and main branch (36.1 ± 6.5 % vs 27.6 ± 8.7 %, P < 0.05), but not at the level of bifurcation (15.1 ± 3.8 % vs 13.6 ± 5.4 %, P = NS). In addition, we found that final kissing balloon/proximal optimization technique (FKB/POT) was associated with significantly smaller value of LLL in main vessel (0.24 ± 0.09 mm vs 0.32 ± 0.14 mm, P < 0.05), which in IVUS analysis resulted in smaller neointima burden in main vessel (13.7 ± 3.9 % vs 18.9 ± 4.45 %, P < 0.05) as well as at the bifurcation site (12.6 ± 4.1 % vs 14.1 ± 2.4 %, P < 0.05). The obtained results suggest that neointima proliferation was the largest in main branches of both stents assessed in quantitative angiography (LLL) as well as in IVUS (neointima burden) and the neointima increase was smaller in BiOSS LIM® stents than in BiOSS Expert® stents. Moreover, the middle part of the stent seems to not to be associated with excessive neointima proliferation and more aggressive protocol of implantation with the use FKB/POT seems to decrease this process.Electronic supplementary materialThe online version of this article (doi:10.1007/s10554-016-0926-9) contains supplementary material, which is available to authorized users.

Long-term follow-up of renal arteries after radio-frequency catheter-based denervation using optical coherence tomography and angiography

Optical coherence tomography (OCT) imaging at the time of renal denervation (RDN) showed that procedure might cause spasm, intimal injury or thrombus formation. In the present study, we assessed the healing of renal arteries after RDN using OCT and renal angiography in long-term follow-up. OCT and renal angiography were performed in 12 patients (22 arteries) 18.41±5.83months after RNS. There were no adverse events or complications during the long-term follow-up. In ten patients (83%), significant reductions of blood pressure was achieved without a change of the antihypertensive medications. We demonstrated the presence of 26 areas of focal intimal thickening identified by OCT in 10 (83%) patients and in 14 (63%) arteries. The mean area of focal intimal thickening was 0.054±0.033mm(2). No vessel dissection, thrombus, intimal tear or acute vasospasm were observed during the OCT analysis. Also, the quantitative angiography analysis revealed a significant reduction of the minimal and proximal lumen diameters at follow-up as compared to measurements obtained before RDN. Renal arteries have a favorable "long-term" vessel healing response after RDN. Focal intimal thickening and a modest reduction of the minimal lumen diameter may be observed after RF denervation. Further studies are needed to determine whether intravascular imaging may be helpful in evaluating the vessel healing of RF RDN.