Ultrasound-guided deployment of ProGlide™ device in transfemoral transcatheter aortic valve implantation and risk reduction of vascular complications: A propensity-matched cohort study.

BACKGROUND: ProGlide is a percutaneous suture-mediated closure device used in arterial and venous closure following percutaneous intervention. Risk of vascular complications from use, particularly related to failure in hemostasis, or acute vessel closure, remains significant and often related to improper suture deployment. We describe a technique of ultrasound-guided ProGlide deployment in transfemoral transcatheter aortic valve implantation (TF-TAVI). AIMS: The aim of this study is to assess vascular outcomes for ultrasound-guided deployment of ProGlide vascular closure devices in patients undergoing TF-TAVI. METHODS: We collected relevant clinical data of patients undergoing TAVI in a large volume centre. PRIMARY OUTCOME: main access Valve Academic Research Consortium 3 (VARC-3) major vascular complication. SECONDARY OUTCOME: any major/minor VARC-3 vascular complication, its type (bleed or ischemia), and treatment required (medical, percutaneous, or surgical). We performed inverse weighting propensity score analysis to compare the population undergoing ultrasound-guided versus conventional ProGlide deployment for main TAVI access. Ultrasound technique for ProGlide insertion was performed as described below. RESULTS: Five hundred and seventeen patients undergoing TF-TAVI were included. PRIMARY OUTCOME: In 126 (ultrasound-guided) and 391 (conventional ProGlide insertion), 0% versus 1.8% (p < 0.001) had a major VARC-3 vascular complication, respectively. SECONDARY OUTCOME: 0.8% (one minor VARC-3 bleed) vs 4.1% (13 bleeds and three occlusions) had any VARC-3 vascular complication (major and minor) (p < 0.001). Surgical treatment of vascular complication was required in 0.8% versus 1.3% (p = NS). CONCLUSIONS: Ultrasound-guided deployment of ProGlide for vascular closure reduced the risk of major vascular complications in a large population undergoing TAVI.

Comprehensive biomechanical and anatomical atherosclerotic plaque metrics predict major adverse cardiovascular events: A new tool for clinical decision making.

BACKGROUND AND AIMS: Anatomical imaging alone of coronary atherosclerotic plaques is insufficient to identify risk of future adverse events and guide management of non-culprit lesions. Low endothelial shear stress (ESS) and high plaque structural stress (PSS) are associated with events, but individually their predictive value is insufficient for risk prediction. We determined whether combining multiple complementary, biomechanical and anatomical plaque characteristics improves outcome prediction sufficiently to inform clinical decision-making. METHODS: We examined baseline ESS, ESS gradient (ESSG), PSS, and PSS heterogeneity index (HI), and plaque burden in 22 lesions that developed subsequent events and 64 control lesions that remained quiescent from the PROSPECT study. RESULTS: 86 fibroatheromas were analysed from 67 patients. Lesions with events showed higher PSS HI (0.32 vs. 0.24, p<0.001), lower local ESS (0.56Pa vs. 0.91Pa, p = 0.007), and higher ESSG (3.82 Pa/mm vs. 1.96 Pa/mm, p = 0.007), while high PSS HI (hazard ratio [HR] 3.9, p = 0.006), high ESSG (HR 3.4, p = 0.007) and plaque burden>70 % (HR 2.6, p = 0.02) were independent outcome predictors in multivariate analysis. Combining low ESS, high ESSG, and high PSS HI gave both high positive predictive value (80 %), which increased further combined with plaque burden>70 %, and negative predictive value (81.6 %). Low ESS, high ESSG, and high PSS HI co-localised spatially within 1 mm in lesions with events, and importantly, this cluster was distant from the minimum lumen area site. CONCLUSIONS: Combining complementary biomechanical and anatomical metrics significantly improves risk-stratification of individual coronary lesions. If confirmed from larger prospective studies, our results may inform targeted revascularisation vs. conservative management strategies.

Heterogeneous plaque-lumen geometry is associated with major adverse cardiovascular events.

Aims: Prospective studies show that only a minority of plaques with higher risk features develop future major adverse cardiovascular events (MACE), indicating the need for more predictive markers. Biomechanical estimates such as plaque structural stress (PSS) improve risk prediction but require expert analysis. In contrast, complex and asymmetric coronary geometry is associated with both unstable presentation and high PSS, and can be estimated quickly from imaging. We examined whether plaque-lumen geometric heterogeneity evaluated from intravascular ultrasound affects MACE and incorporating geometric parameters enhances plaque risk stratification. Methods and results: We examined plaque-lumen curvature, irregularity, lumen aspect ratio (LAR), roughness, PSS, and their heterogeneity indices (HIs) in 44 non-culprit lesions (NCLs) associated with MACE and 84 propensity-matched no-MACE-NCLs from the PROSPECT study. Plaque geometry HI were increased in MACE-NCLs vs. no-MACE-NCLs across whole plaque and peri-minimal luminal area (MLA) segments (HI curvature: adjusted P = 0.024; HI irregularity: adjusted P = 0.002; HI LAR: adjusted P = 0.002; HI roughness: adjusted P = 0.004). Peri-MLA HI roughness was an independent predictor of MACE (hazard ratio: 3.21, P < 0.001). Inclusion of HI roughness significantly improved the identification of MACE-NCLs in thin-cap fibroatheromas (TCFA, P < 0.001), or with MLA ≤ 4 mm2 (P < 0.001), or plaque burden (PB) ≥ 70% (P < 0.001), and further improved the ability of PSS to identify MACE-NCLs in TCFA (P = 0.008), or with MLA ≤ 4 mm2 (P = 0.047), and PB ≥ 70% (P = 0.003) lesions. Conclusion: Plaque-lumen geometric heterogeneity is increased in MACE vs. no-MACE-NCLs, and inclusion of geometric heterogeneity improves the ability of imaging to predict MACE. Assessment of geometric parameters may provide a simple method of plaque risk stratification.

High-intensity statin treatment is associated with reduced plaque structural stress and remodelling of artery geometry and plaque architecture.

Aims: Plaque structural stress (PSS) is a major cause of atherosclerotic plaque rupture and major adverse cardiovascular events (MACE). We examined the predictors of changes in peak and mean PSS (ΔPSSpeak, ΔPSSmean) in three studies of patients receiving either standard medical or high-intensity statin (HIS) treatment. Methods and results: We examined changes in PSS, plaque size, and composition between 7348 co-registered baseline and follow-up virtual-histology intravascular ultrasound images in patients receiving standard medical treatment (controls, n = 18) or HIS (atorvastatin 80 mg, n = 20, or rosuvastatin 40 mg, n = 22). The relationship between changes in PSSpeak and plaque burden (PB) differed significantly between HIS and control groups (P < 0.001). Notably, PSSpeak increased significantly in control lesions with PB >60% (P = 0.04), but not with HIS treatment. However, ΔPSSpeak correlated poorly with changes in lumen and plaque area or PB, plaque composition, or lipid lowering. In contrast, ΔPSSpeak correlated significantly with changes in lumen curvature, irregularity, and roughness (P < 0.05), all of which were reduced in HIS patients. ΔPSSmean correlated with changes in lumen area, PA, PB, and circumferential calcification, and was unchanged with either treatment. Conclusion: Our observational study shows that PSSpeak changes over time were associated with baseline disease severity and treatment. The PSSpeak increase seen in advanced lesions with standard treatment was associated with remodelling artery geometry and plaque architecture, but this was not seen after HIS treatment. Smoothing plaques by reducing plaque/lumen roughness, irregularity, and curvature represents a novel mechanism whereby HIS may reduce PSS and, thus may protect against plaque rupture and MACE.

Heterogeneity of Plaque Structural Stress Is Increased in Plaques Leading to MACE: Insights From the PROSPECT Study.

OBJECTIVES: This study sought to determine if plaque structural stress (PSS) and other plaque stress parameters are increased in plaques that cause future major adverse cardiovascular event(s) (MACE) and if incorporating these parameters improves predictive capability of intravascular ultrasonography (IVUS). BACKGROUND: Less than 10% of coronary plaques identified as high-risk by intravascular imaging result in subsequent MACE. Thus, more specific measurements of plaque vulnerability are required for effective risk stratification. METHODS: Propensity score matching in the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study plaque cohort resulted in 35 nonculprit lesions (NCL) associated with future MACE and 66 matched NCL that remained clinically silent. PSS was calculated by finite element analysis as the mechanical loading within the plaque structure in the periluminal region. RESULTS: PSS was increased in the minimal luminal area (MLA) regions of NCL MACE versus no MACE plaques for all plaques (PSS: 112.1 ± 5.5 kPa vs. 90.4 ± 3.3 kPa, respectively; p = 0.001) and virtual histology thin-cap fibroatheromas (VH-TCFAs) (PSS: 119.2 ± 6.6 kPa vs. 95.8 ± 5.0 kPa, respectively; p = 0.005). However, PSS was heterogeneous over short segments, and PSS heterogeneity index (HI) was markedly greater in NCL MACE than in no-MACE VH-TCFAs (HI: 0.43 ± 0.05 vs. 0.29 ± 0.03, respectively; p = 0.01). Inclusion of PSS in plaque assessment improved the identification of NCLs that led to MACE, including in VH-TCFAs (p = 0.03) and plaques with MLA ≤4 mm2 (p = 0.03). Incorporation of an HI further improved the ability of PSS to identify MACE NCLs in a variety of plaque subtypes including VH-TCFA (p = 0.001) and plaques with MLA ≤4 mm2 (p = 0.002). CONCLUSIONS: PSS and variations in PSS are increased in the peri-MLA regions of plaques that lead to MACE. Moreover, longitudinal heterogeneity in PSS is markedly increased in MACE plaques, especially VH-TCFAs, potentially predisposing to plaque rupture. Incorporation of PSS and heterogeneity in PSS may improve the ability of IVUS to predict MACE.

Impact of combined plaque structural stress and wall shear stress on coronary plaque progression, regression, and changes in composition.

AIMS: The focal distribution of atherosclerotic plaques suggests that local biomechanical factors may influence plaque development. METHODS AND RESULTS: We studied 40 patients at baseline and over 12 months by virtual-histology intravascular ultrasound and bi-plane coronary angiography. We calculated plaque structural stress (PSS), defined as the mean of the maximum principal stress at the peri-luminal region, and wall shear stress (WSS), defined as the parallel frictional force exerted by blood flow on the endothelial surface, in areas undergoing progression or regression. Changes in plaque area, plaque burden (PB), necrotic core (NC), fibrous tissue (FT), fibrofatty tissue, and dense calcium were calculated for each co-registered frame. A total of 4029 co-registered frames were generated. In areas with progression, high PSS was associated with larger increases in NC and small increases in FT vs. low PSS (difference in ΔNC: 0.24 ± 0.06 mm2; P < 0.0001, difference in ΔFT: -0.15 ± 0.08 mm2; P = 0.049). In areas with regression, high PSS was associated with increased NC and decreased FT (difference in ΔNC: 0.15 ± 0.04; P = 0.0005, difference in ΔFT: -0.31 ± 0.06 mm2; P < 0.0001). Low WSS was associated with increased PB vs. high WSS in areas with progression (difference in ΔPB: 3.3 ± 0.4%; P < 0.001) with a similar pattern observed in areas with regression (difference in ΔPB: 1.2 ± 0.4%; P = 0.004). Plaque structural stress and WSS were largely independent of each other (R2 = 0.002; P = 0.001). CONCLUSION: Areas with high PSS are associated with compositional changes consistent with increased plaque vulnerability. Areas with low WSS are associated with more plaque growth in areas that progress and less plaque loss in areas that regress. The interplay of PSS and WSS may govern important changes in plaque size and composition.

Plaque Rupture in Coronary Atherosclerosis Is Associated With Increased Plaque Structural Stress.

OBJECTIVES: The aim of this study was to identify the determinants of plaque structural stress (PSS) and the relationship between PSS and plaques with rupture. BACKGROUND: Plaque rupture is the most common cause of myocardial infarction, occurring particularly in higher risk lesions such as fibroatheromas. However, prospective intravascular ultrasound-virtual histology studies indicate that <10% higher risk plaques cause clinical events over 3 years, indicating that other factors also determine plaque rupture. Plaque rupture occurs when PSS exceeds its mechanical strength; however, the determinants of PSS and its association with plaques with proven rupture are not known. METHODS: We analyzed plaque structure and composition in 4,053 virtual histology intravascular ultrasound frames from 32 fibroatheromas with rupture from the intravascular ultrasound-virtual histology in Vulnerable Atherosclerosis study and 32 fibroatheromas without rupture on optical coherence tomography from a stable angina cohort. Mechanical loading in the periluminal region was estimated by calculating maximum principal PSS by finite element analysis. RESULTS: PSS increased with increasing lumen area (r = 0.46; p = 0.001), lumen eccentricity (r = 0.32; p = 0.001), and necrotic core ≥10% (r = 0.12; p = 0.001), but reduced when dense calcium was ≥10% (r = -0.12; p = 0.001). Ruptured fibroatheromas showed higher PSS (133 kPa [quartiles 1 to 3: 90 to 191 kPa] vs. 104 kPa [quartiles 1 to 3: 75 to 142 kPa]; p = 0.002) and variation in PSS (55 kPa [quartiles 1 to 3: 37 to 75 kPa] vs. 43 kPa [quartiles 1 to 3: 34 to 59 kPa]; p = 0.002) than nonruptured fibroatheromas, with rupture primarily occurring either proximal or immediately adjacent to the minimal luminal area (87.5% vs. 12.5%; p = 0.001). PSS was higher in segments proximal to the rupture site (143 kPa [quartiles 1 to 3: 101 to 200 kPa] vs. 120 kPa [quartiles 1 to 3: 78 to 180 kPa]; p = 0.001) versus distal segments, associated with increased necrotic core (19.1% [quartiles 1 to 3: 11% to 29%] vs. 14.3% [quartiles 1 to 3: 8% to 23%]; p = 0.001) but reduced fibrous/fibrofatty tissue (63.6% [quartiles 1 to 3: 46% to 78%] vs. 72.7% [quartiles 1 to 3: 54% to 86%]; p = 0.001). PSS >135 kPa was a good predictor of rupture in higher risk regions. CONCLUSIONS: PSS is determined by plaque composition, plaque architecture, and lumen geometry. PSS and PSS variability are increased in plaques with rupture, particularly at proximal segments. Incorporating PSS into plaque assessment may improve identification of rupture-prone plaques.

High wall shear stress and high-risk plaque: an emerging concept.

In recent years, there has been a significant effort to identify high-risk plaques in vivo prior to acute events. While number of imaging modalities have been developed to identify morphologic characteristics of high-risk plaques, prospective natural-history observational studies suggest that vulnerability is not solely dependent on plaque morphology and likely involves additional contributing mechanisms. High wall shear stress (WSS) has recently been proposed as one possible causative factor, promoting the development of high-risk plaques. High WSS has been shown to induce specific changes in endothelial cell behavior, exacerbating inflammation and stimulating progression of the atherosclerotic lipid core. In line with experimental and autopsy studies, several human studies have shown associations between high WSS and known morphological features of high-risk plaques. However, despite increasing evidence, there is still no longitudinal data linking high WSS to clinical events. As the interplay between atherosclerotic plaque, artery, and WSS is highly dynamic, large natural history studies of atherosclerosis that include WSS measurements are now warranted. This review will summarize the available clinical evidence on high WSS as a possible etiological mechanism underlying high-risk plaque development.

A propensity score matched comparative study between paclitaxel-coated balloon and everolimus-eluting stents for the treatment of small coronary vessels.

OBJECTIVES: To compare the long-term clinical outcomes of paclitaxel drug-coated-balloons (DCB) and everolimus-eluting-stents (EES) following the treatment of de novo small vessel coronary artery disease. BACKGROUND: It is currently unclear whether treatment of de novo small vessel coronary disease with DCB is comparable to second generation drug-eluting stents, which are the current standard of care. METHODS: The present study enrolled 90 patients with small vessel coronary disease from the DCB treatment arm of the BELLO (Balloon Elution and Late Loss Optimization) trial and 2,000 patients treated with EES at the San Raffaele Scientific Institute. Propensity score matching was performed to adjust for differences in baseline clinical and angiographic characteristics, yielding a total of 181 patients: 90 patients with 94 lesions receiving DCB and 91 patients with 94 lesions receiving EES. Major adverse cardiac events (MACE) were defined as the composite of cardiac death, recurrent non-fatal myocardial infarction, and target vessel revascularization. RESULTS: After propensity score matching, baseline clinical and angiographic characteristics were similar between the two groups. The cumulative MACE rate at 1-year was 12.2% with DCB and 15.4% with EES (P = 0.538). Patients in the DCB group had similar TLR rates as compared to EES over the same interval (4.4% vs. 5.6%; P = 0.720). There were no cases of definite or probable stent or vessel thrombosis. CONCLUSIONS: The use of paclitaxel-DCB appears to be associated with similar clinical outcomes when compared to second-generation-EES in small coronary artery disease. The findings of this study should be confirmed with larger prospective randomized studies with longer follow-up. © 2017 Wiley Periodicals, Inc.

Comparison of paclitaxel drug-eluting balloon and paclitaxel-eluting stent in small coronary vessels in diabetic and nondiabetic patients - results from the BELLO (balloon elution and late loss optimization) trial.

OBJECTIVES: To evaluate the impact of diabetes on the efficacy of drug-eluting balloon (DEB) as compared to paclitaxel-eluting stent (PES) for the reduction of restenosis in small vessels according to the presence of diabetes in patients enrolled in the BELLO (Balloon Elution and Late Loss Optimization) trial. BACKGROUND: Small vessel disease is common in diabetic patients but currently there are no available data regarding DEB in these patients. METHODS: In the BELLO trial, 182 patients with lesions in small vessels were randomized 1:1 to receive DEB or PES. In the current sub analysis, patients were stratified according to the presence of diabetes. The diabetic group consisted of 74 patients (DEB=39, PES=35) and the nondiabetic group of 108 patients (DEB=51, PES=57). Angiographic endpoints examined were in-stent/in-balloon and in-segment late loss and binary restenosis at 6 months. Clinical endpoints were major adverse cardiac events (MACE; death, myocardial infarction, target vessel revascularization) at 1 year. RESULTS: In-stent/in-balloon late loss was significantly less with DEB as compared to PES in both diabetic (0.05±0.41 vs. 0.30±0.51mm, p=0.033) and nondiabetic patients (0.10±0.36 vs. 0.29±0.40mm, p=0.015). In patients with diabetes, angiographic restenosis and in-segment late loss were significantly lower with DEB as compared to PES (respectively, 6.3% vs. 25.0%; p=0.039 and -0.013±0.39 vs. 0.25±0.53; p=0.023), with no differences noted in nondiabetic patients. The cumulative MACE rate at 1 year was similar between DEB and PES in both the diabetic (13.2% vs. 25%, p=0.194) and nondiabetic groups (11.8% vs. 14.3%, p=0.699). CONCLUSIONS: Diabetes does not appear to have a negative impact on the efficacy of DEB in small vessels, which were associated with better angiographic outcomes at 6 months in this complex subgroup. Larger studies are needed to confirm these findings.

Distributed Simulation as a modelling tool for the development of a simulation-based training programme for cardiovascular specialties.

AIMS AND BACKGROUND: Distributed Simulation is the concept of portable, high-fidelity immersive simulation. Here, it is used for the development of a simulation-based training programme for cardiovascular specialities. We present an evidence base for how accessible, portable and self-contained simulated environments can be effectively utilised for the modelling, development and testing of a complex training framework and assessment methodology. Iterative user feedback through mixed-methods evaluation techniques resulted in the implementation of the training programme. APPROACH: Four phases were involved in the development of our immersive simulation-based training programme: (1) initial conceptual stage for mapping structural criteria and parameters of the simulation training framework and scenario development (n = 16), (2) training facility design using Distributed Simulation, (3) test cases with clinicians (n = 8) and collaborative design, where evaluation and user feedback involved a mixed-methods approach featuring (a) quantitative surveys to evaluate the realism and perceived educational relevance of the simulation format and framework for training and (b) qualitative semi-structured interviews to capture detailed feedback including changes and scope for development. Refinements were made iteratively to the simulation framework based on user feedback, resulting in (4) transition towards implementation of the simulation training framework, involving consistent quantitative evaluation techniques for clinicians (n = 62). For comparative purposes, clinicians' initial quantitative mean evaluation scores for realism of the simulation training framework, realism of the training facility and relevance for training (n = 8) are presented longitudinally, alongside feedback throughout the development stages from concept to delivery, including the implementation stage (n = 62). FINDINGS: Initially, mean evaluation scores fluctuated from low to average, rising incrementally. This corresponded with the qualitative component, which augmented the quantitative findings; trainees' user feedback was used to perform iterative refinements to the simulation design and components (collaborative design), resulting in higher mean evaluation scores leading up to the implementation phase. CONCLUSIONS: Through application of innovative Distributed Simulation techniques, collaborative design, and consistent evaluation techniques from conceptual, development, and implementation stages, fully immersive simulation techniques for cardiovascular specialities are achievable and have the potential to be implemented more broadly.

Plaque Structural Stress Estimations Improve Prediction of Future Major Adverse Cardiovascular Events After Intracoronary Imaging.

BACKGROUND: Although plaque rupture is responsible for most myocardial infarctions, few high-risk plaques identified by intracoronary imaging actually result in future major adverse cardiovascular events (MACE). Nonimaging markers of individual plaque behavior are therefore required. Rupture occurs when plaque structural stress (PSS) exceeds material strength. We therefore assessed whether PSS could predict future MACE in high-risk nonculprit lesions identified on virtual-histology intravascular ultrasound. METHODS AND RESULTS: Baseline nonculprit lesion features associated with MACE during long-term follow-up (median: 1115 days) were determined in 170 patients undergoing 3-vessel virtual-histology intravascular ultrasound. MACE was associated with plaque burden ≥70% (hazard ratio: 8.6; 95% confidence interval, 2.5-30.6; P<0.001) and minimal luminal area ≤4 mm(2) (hazard ratio: 6.6; 95% confidence interval, 2.1-20.1; P=0.036), although absolute event rates for high-risk lesions remained <10%. PSS derived from virtual-histology intravascular ultrasound was subsequently estimated in nonculprit lesions responsible for MACE (n=22) versus matched control lesions (n=22). PSS showed marked heterogeneity across and between similar lesions but was significantly increased in MACE lesions at high-risk regions, including plaque burden ≥70% (13.9±11.5 versus 10.2±4.7; P<0.001) and thin-cap fibroatheroma (14.0±8.9 versus 11.6±4.5; P=0.02). Furthermore, PSS improved the ability of virtual-histology intravascular ultrasound to predict MACE in plaques with plaque burden ≥70% (adjusted log-rank, P=0.003) and minimal luminal area ≤4 mm(2) (P=0.002). Plaques responsible for MACE had larger superficial calcium inclusions, which acted to increase PSS (P<0.05). CONCLUSIONS: Baseline PSS is increased in plaques responsible for MACE and improves the ability of intracoronary imaging to predict events. Biomechanical modeling may complement plaque imaging for risk stratification of coronary nonculprit lesions.

Treatment of calcified coronary artery lesions.

Heavily calcified coronary plaques represent a complex lesion subset and a challenge to the interventional cardiologist, as they are often resistant to simple plaque modification with conventional balloon angioplasty. Inadequate plaque modification can lead to stent underdeployment, which itself predisposes to in-stent restenosis and stent thrombosis. Over the years, a number of mechanical devices ranging from modified angioplasty balloons to atherectomy devices have become available in order to tackle such lesions. Here we review these devices concentrating on the evidence behind their use.

Drug-eluting balloon versus second-generation drug-eluting stent for the treatment of restenotic lesions involving coronary bifurcations.

AIMS: To report clinical outcomes in patients treated with drug-eluting balloon (DEB) versus second-generation drug-eluting stent (DES) for in-stent restenosis (ISR) involving a bifurcation lesion. METHODS AND RESULTS: Between February 2007 and November 2012, 167 bifurcation restenoses in 158 patients were treated with either DEB (n=73) or second-generation DES (n=85). The EuroSCORE was significantly higher in the DEB group (4.2±3.8 vs. 2.8±2.1, p=0.004). Regarding restenosed stent type, second-generation DES was more frequently seen in the DEB group (26.9% vs. 6.7%, p<0.001). In this group, there was also a trend towards more frequent stenting for a previous ISR (stent-in-stent) as compared with the DES group (25.6% vs. 15.6%, p=0.074). Over a median follow-up period of 701 days, there was no significant difference in major adverse cardiac events (MACE), defined as cardiac death, myocardial infarction including periprocedural myocardial infarction, target vessel revascularisation, between the two groups (p=0.585). Independent predictors of MACE on multivariate Cox regression analysis included stent-in-stent (HR: 2.16; 95% CI: 1.11 to 4.20; p=0.023) and true bifurcation lesions (HR: 2.98; 95% CI: 1.45 to 6.14; p=0.001). CONCLUSIONS: DEB for bifurcation restenosis may be an acceptable treatment option, especially in cases where repeat stenting has not already been performed for the treatment of a previous restenosis.

Intravascular ultrasound and optical coherence tomography imaging of coronary atherosclerosis.

Invasive imaging modalities, in particular intravascular ultrasound (IVUS) and optical coherence tomography (OCT), have become established tools for the in vivo study of coronary atherosclerosis. Their use in clinical studies has confirmed histopathological observations that certain important plaque features, such as thin fibrous caps and large lipid cores, are associated with plaque rupture, the precipitating event for the majority of myocardial infarctions. Serial imaging studies have also successfully been used for the evaluation of potential disease modifying pharmacological agents. Recent prospective IVUS studies have confirmed specific baseline imaging features associated with subsequent adverse clinical outcomes, although absolute event rates were too low for clinical utility. Development of hybrid IVUS-OCT imaging or integration of novel techniques, including near-infrared spectroscopy, plaque structural and endothelial shear stress, have great potential to improve our current ability to identify and stratify atheromatous plaques at risk of rupture.

Direct Comparison of Virtual-Histology Intravascular Ultrasound and Optical Coherence Tomography Imaging for Identification of Thin-Cap Fibroatheroma.

BACKGROUND: Although rupture of thin-cap fibroatheroma (TCFA) underlies most myocardial infarctions, reliable TCFA identification remains challenging. Virtual-histology intravascular ultrasound (VH-IVUS) and optical coherence tomography (OCT) can assess tissue composition and classify plaques. However, direct comparisons between VH-IVUS and OCT are lacking and it remains unknown whether combining these modalities improves TCFA identification. METHODS AND RESULTS: Two hundred fifty-eight regions-of-interest were obtained from autopsied human hearts, with plaque composition and classification assessed by histology and compared with coregistered ex vivo VH-IVUS and OCT. Sixty-seven regions-of-interest were classified as fibroatheroma on histology, with 22 meeting criteria for TCFA. On VH-IVUS, plaque (10.91±4.82 versus 8.42±4.57 mm(2); P=0.01) and necrotic core areas (1.59±0.99 versus 1.03±0.85 mm(2); P=0.02) were increased in TCFA versus other fibroatheroma. On OCT, although minimal fibrous cap thickness was similar (71.8±44.1 µm versus 72.6±32.4; P=0.30), the number of continuous frames with fibrous cap thickness ≤85 µm was higher in TCFA (6.5 [1.75-11.0] versus 2.0 [0.0-7.0]; P=0.03). Maximum lipid arc on OCT was an excellent discriminator of fibroatheroma (area under the curve, 0.92; 95% confidence interval, 0.87-0.97) and TCFA (area under the curve, 0.86; 95% confidence interval, 0.81-0.92), with lipid arc ≥80° the optimal cut-off value. Using existing criteria, the sensitivity, specificity, and diagnostic accuracy for TCFA identification was 63.6%, 78.1%, and 76.5% for VH-IVUS and 72.7%, 79.8%, and 79.0% for OCT. Combining VH-defined fibroatheroma and fibrous cap thickness ≤85 µm over 3 continuous frames improved TCFA identification, with diagnostic accuracy of 89.0%. CONCLUSIONS: Both VH-IVUS and OCT can reliably identify TCFA, although OCT accuracy may be improved using lipid arc ≥80° and fibrous cap thickness ≤85 µm over 3 continuous frames. Combined VH-IVUS/OCT imaging markedly improved TCFA identification.

Mid-term clinical outcomes of ABSORB bioresorbable vascular scaffold implantation in a real-world population: A single-center experience.

BACKGROUND: Available data on the use of the ABSORB bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, CA) in real-world patients is limited. The aim of this study was to assess the mid-term clinical outcomes in a real-world population treated with ABSORB BVS. METHODS AND MATERIALS: We retrospectively evaluated all patients treated with ABSORB at Papworth Hospital, Papworth Everard, UK between July 2012 and July 2014. A total of 108 patients (126 lesions) were identified. Clinical follow-up was performed on all subjects by clinic visit or telephone interview. RESULTS: Most patients were male (91.7%) with a relative high incidence of previous myocardial infarction (MI) (40.7%). Clinical presentation was equally divided between stable angina and acute coronary syndrome (ACS) (51.8% vs. 48.2%, p=0.59). Of the ACS patients, 26.9% presented with ST-elevation myocardial MI. Intravascular imaging was used in all cases. Predilatation (92.9%) and postdilatation (82.5%) were frequently performed. Major adverse cardiac event (MACE) rates defined as the composite of all-cause death, follow-up MI and target vessel revascularization were 2.5% at 6-month and 4.5% at 1-year. The 1-year target lesion failure rate, defined as the composite of cardiac death, target-vessel MI and target lesion revascularization was 1.9%. There was 1 case of subacute stent thrombosis. CONCLUSIONS: The use of ABSORB BVS in real-world patients appears to be associated with good mid-term clinical outcomes when guided by intravascular imaging. Larger studies are required to evaluate further the role of BVS in routine clinical practice and examine how this compares to metallic devices. SUMMARY: Available data on the use of the ABSORB BVS in real-world patients is limited. We retrospectively evaluated all patients treated with ABSORB BVS between July 2012 and July 2014. A total of 108 patients (126 lesions) were identified. Clinical presentation was equally divided between stable angina and acute coronary syndrome (51.8% vs. 48.2%, p=0.59). Predilatation (92.9%) and postdilatation (82.5%) were frequently performed. Estimated MACE rates at 6-month and 1-year were 2.5% and 4.5% respectively, with a 1-year TLF rate of 1.9%. These results suggest that the use of ABSORB BVS use in the real-world is associated with good mid-term clinical outcomes when guided by intravascular imaging.

Comparison between Plain Old Balloon Angioplasty and Drug-Eluting Stent Implantation for the Treatment of Stent Fracture.

OBJECTIVES: The aim of this study was to evaluate clinical outcomes after percutaneous coronary intervention (PCI) for stent fracture (SF). BACKGROUND: SF has been reported as a predictor of in-stent restenosis (ISR) and stent thrombosis (ST). METHODS: Between January 2009 and December 2012, consecutive SF cases treated with either drug-eluting stent (DES) or plain old balloon angioplasty (POBA) were retrospectively enrolled in this study. The study endpoints were all-cause death, cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), target lesion revascularization (TLR), ST, re-stent fracture (re-SF), and major adverse cardiac events (MACE) defined as the composite of cardiac death, MI, and TLR. RESULTS: Of 135 SF cases, 67 (49.6%) cases were treated with DES, whereas 68 (50.4%) cases with POBA. Median follow-up period was 1,401 (IQR: 967-1,771) days. The estimated MACE rate at 3 years was significantly lower in the DES group as compared with the POBA group largely driven by less TLR (25.7 vs. 55.8%, P < 0.001). Moreover, 1-year landmark analysis after PCI for SF revealed that MACE continued to occur even after 1 year irrespective of the treatment option (P = 0.47). On multivariable Cox regression analysis, POBA and large post-procedure angle (Δ) defined as the degree difference between the end systolic and diastolic angle were identified as independent predictors for TLR. CONCLUSIONS: DES implantation for SF is associated with better clinical outcomes as compared to POBA alone, due to a lower need for TLR. Large post-procedural angle (Δ) appears to be an independent predictor of TLR.

Transcatheter aortic valve implantation in patients with bicuspid aortic valve: A patient level multi-center analysis.

OBJECTIVE: We sought to evaluate the safety and efficacy of transcatheter aortic valve implantation (TAVI) in patients with bicuspid aortic valve (BiAV). BACKGROUND: BiAV remains a relative contraindication to TAVI resulting in exclusion from TAVI trials and thus limiting data on the clinical performance of transcatheter valves in these patients. METHODOLOGY: We conducted an international patient level multicenter analysis on outcomes in patients with BiAV undergoing TAVI. The primary outcome of the study was the combined early safety endpoint--a composite of 30 day mortality, stroke, life-threatening bleeding, acute kidney injury, coronary artery obstruction, major vascular complication and valve related dysfunction. Secondary endpoints included the individual components of the primary endpoint as well as post-TAVI paravalvular leak (PVL), rehospitalization, new pacemaker insertion and device success rates at 30 days and 1 year. RESULTS: A total of 108 patients with BiAV were identified in 21 centers in Canada, Spain, Italy, Poland and Singapore who underwent TAVI between January 2005 and March 2014. The composite primary outcome occurred in one quarter of patients (26.9%)--mainly driven by re-intervention for valve malposition (9.3%). The 30-day and 1 year mortality rates were 8.3% and 16.9% respectively with AR ≥ 3+ occurring in 9.6% of patients. Device success was achieved in 85.2% of cases with pacemaker insertion in 19.4%. While PVL was not associated with an increased risk of 30 day or 1 year mortality--Type I BiAV anatomy with left and right cusp fusion had significantly better outcomes than other valve variants. CONCLUSION: In selected patients with BiAV and severe aortic stenosis, TAVI appears both safe and feasible with acceptable clinical outcomes. Clinical studies of TAVI in this patient population are warranted.