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.

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.

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 2-year outcomes between zotarolimus-eluting and everolimus-eluting new-generation cobalt-chromium alloy stents in real-world diabetic patients.

BACKGROUND: To date, it remains unknown whether different types of new-generation drug-eluting stents have a differential impact on long-term outcomes in diabetic patients. METHODS AND RESULTS: In this historical cohort study (two Italian centers), we analyzed 400 diabetic patients with 553 coronary lesions treated with new-generation CoCr zotarolimus-eluting stents (R-ZES: 136 patients, 196 lesions) or everolimus-eluting stents (EES: 264 patients, 357 lesions) between October 2006 and August 2012. Primary endpoint was the occurrence of major adverse cardiac events (MACE) over a 2-year follow-up period. MACE was defined as all-cause mortality, any myocardial infarction (MI) and/or target lesion revascularization (TLR). Multivessel revascularization, intervention for restenotic lesion and use of intravascular ultrasound were significantly higher in the R-ZES group, whereas small stent (≤2.5 mm) deployment was significantly higher in the EES group. At 2-year follow-up, there was no significant difference in occurrence of MACE (R-ZES vs EES: 22.8% vs 18.9%, P = 0.39). Similarly, no significant differences were observed in the composite endpoint of all-cause mortality/MI (10.0% vs 10.3%, P = 0.86) or TLR (12.4% vs 7.4%, P = 0.11). Adjustment for confounders and baseline propensity-score matching did not alter the aforementioned associations. CONCLUSION: After 2 years of follow up similar outcomes (MACE, all-cause mortality/MI, TLR) were observed in real-world diabetic patients, including those with complex lesions and patient characteristics, treated with R-ZES and EES.

Comparison of early clinical outcomes between ABSORB bioresorbable vascular scaffold and everolimus-eluting stent implantation in a real-world population.

OBJECTIVES: To compare the early clinical outcomes between ABSORB bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, CA) and cobalt chromium everolimus-eluting stents in real-world patients with mostly complex disease. BACKGROUND: BVS represents the most interesting development in the drug-eluting stent field over recent years with promising results emerging from clinical trials. Available data however on the use of the ABSORB in real-world patients is limited. METHODS: All patients (n = 92) treated with BVS and 1296 patients treated with EES were included in this study. Propensity score matching was performed to adjust for differences in baseline clinical characteristics, yielding 92 patient pairs (BVS = 92 patients with 137 lesions and EES = 92 patients with 124 lesions). Clinical outcomes were examined between the 2 groups at 6-months. RESULTS: In both groups, most lesions were classified as either B2 or C (83.9% vs. 77.4%, P = 0.19). Predilatation (97.8% vs. 75.8%, P < 0.01) as well as postdilation (99.3% vs. 77.4%, P < 0.01) was more common in the BVS group. Clinical outcomes at 6-months were similar between the two groups with respect to both target lesion revascularization (3.3% vs. 5.4%, P = 0.41) and major adverse cardiac events (defined as the composite of target vessel revascularization, follow-up myocardial infraction and all-cause death) (3.3% vs. 7.6%, P = 0.19). CONCLUSIONS: ABSORB BVS for the treatment of complex lesions appears to be associated with good procedural and early clinical outcomes similar to those observed with conventional drug-eluting stents. Larger studies with long-term follow-up are required in order to fully assess the role of BVS in the treatment of such lesions and how this compares with that of conventional stents. © 2014 Wiley Periodicals, Inc.

First generation versus new generation drug-eluting stents for the treatment of ostial/midshaft lesions in unprotected left main coronary artery: the Milan and New-Tokyo (MITO) registry.

OBJECTIVES: To compare the clinical outcomes following unprotected left main coronary artery (ULMCA) percutaneous coronary intervention (PCI) of ostial/midshaft lesions between first and new generation drug-eluting stents (DES). BACKGROUND: Clinical outcomes after treatment of ostial/midshaft lesions in ULMCA with first generation DES were favorable. However, to date, data regarding treatment for those lesion subsets with new generation DES have not been reported. METHODS: A total of 219 patients with ostial/midshaft lesions in ULMCA treated with first (n = 139) or new generation DES (n = 80) were analyzed. RESULTS: There was a higher prevalence of IVUS use (35.2% vs. 50.0%, P = 0.032) and postdilation (70.5% vs. 93.8%, P < 0.001) with larger maximum balloon diameter (3.81 ± 0.45 vs. 4.08 ± 0.44, P < 0.001) in the new generation DES group. At a median follow-up period of 730 days, there were no significant differences in the propensity-score adjusted analyses, for major adverse cardiac events (MACE) defined as composite endpoint of all-cause death, myocardial infarction, and target vessel revascularization (hazard ratio (HR) [new vs. first generation DES]: 1.22; 95% confidence interval (CI): 0.64-2.31; P = 0.549). Of note, target lesion revascularization rates at 2-years were only 0.9% and 2.7%, for first and new generation DES groups, respectively (P = 0.339). On multivariable analysis, SYNTAX score (HR: 1.06; 95% CI: 1.02-1.11, P = 0.006) and European System for Cardiac Operative Risk Evaluation (HR: 1.14; 95% CI: 1.00-1.31, P = 0.051) were independent predictors for MACE. CONCLUSIONS: This study suggests that new generation DES for ostial/midshaft lesions in ULMCA are associated with favorable clinical outcomes, similar to those observed with first generation DES.

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.

Comparison of abluminal biodegradable polymer biolimus-eluting stents and durable polymer everolimus-eluting stents in the treatment of coronary bifurcations.

OBJECTIVES: To compare biodegradable polymer biolimus-eluting (BES) with abluminal drug elution and durable polymer everolimus-eluting (EES) stents in the treatment of bifurcation lesions. BACKGROUND: The persistence of a polymer in drug-eluting stents (DES) following drug elution has been viewed as a possible culprit for restenosis. DES with biodegradable polymer may thus be associated with improved clinical outcomes, especially in high-risk lesions such as those at bifurcation sites. METHODS: We performed a retrospective study of consecutive de novo bifurcation lesions treated with EES between October 2006 and October 2011 and BES between February 2008 and March 2012. Study endpoints included major adverse cardiac events (MACE) defined as all-cause death, myocardial infarction (MI), including peri-procedural MI, and target vessel revascularization (TVR) as well as target lesion revascularization (TLR) separately. RESULTS: We analyzed 236 bifurcation lesions treated with either BES (79 lesions in 69 patients) or EES (157 lesions in 154 patients). Patient and procedural characteristics were broadly similar between the two groups. Estimated MACE and TVR rates at 2-year follow-up were similar between the BES and EES groups (MACE = 13.6 ± 4.6% vs. 14.6 ± 3.2% (P = 0.871); TVR = 6.9 ± 3.5% vs. 8.0 ± 2.7% (P = 0.889). No significant differences were noted between the two groups following propensity-score matched analysis. There was no probable or definite stent thrombosis. CONCLUSION: BES use in the treatment of bifurcation lesions appears to be associated with good clinical outcomes, comparable to those seen with EES, at long-term follow-up. These results are hypothesis-generating and need to be validated with larger studies.

Drug-eluting balloon in the treatment of in-stent restenosis and diffuse coronary artery disease: real-world experience from our registry.

OBJECTIVES: To report a single-center experience of drug-eluting balloons (DEB) in the treatment of in-stent restenosis (ISR) and de novo coronary artery disease. BACKGROUND: DEB are emerging as an alternative treatment for coronary stenosis especially when metal scaffolding is undesirable (in-stent restenosis and small-vessel de novo disease). Although there are various randomized trials and registry studies, the data from real-world cohorts are lacking. METHODS: Consecutive patients treated with the In.Pact Falcon™ (Medtronic Inc., Minneapolis, MN, USA) paclitaxel-eluting balloon between January 2009 and December 2011 were retrospectively studied. The measured end-points were cardiac death, myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), and major adverse cardiac events (MACE) defined as combination of cardiac death, MI, and TVR. RESULTS: A total of 275 lesions were successfully treated in 184 patients. The mean age was 66.2 ± 9.6 years, and 87% were males. The predominant indication for DEB use was ISR (62%), with de novo lesions accounting for the remainder (38%). A mean of 1.48 ± 0.9 DEB were used per patient. Bailout stenting was required in 24% of lesions. The median clinical follow-up was 14.6 months (IQR 12-23). The overall rates of cardiac death, MI, TLR, TVR, and MACE were 3.8%, 1.6%, 16.8%, 17.9%, and 21.7%, respectively. The overall rate of stent thrombosis was 0.5% (n = 1). CONCLUSION: Our results suggests that DEB can be considered in lesions where the use of stents is not desirable, especially restenotic lesions. Further long-term follow-up of these patients will provide us more insights on the long-term outcomes.

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.

Correcting common OCT artifacts enhances plaque classification and identification of higher-risk plaque features.

BACKGROUND: Optical coherence tomography (OCT) is used widely to guide stent placement, identify higher-risk plaques, and assess mechanisms of drug efficacy. However, a range of common artifacts can prevent accurate plaque classification and measurements, and limit usable frames in research studies. We determined whether pre-processing OCT images corrects artifacts and improves plaque classification. METHODS: We examined both ex-vivo and clinical trial OCT pullbacks for artifacts that prevented accurate tissue identification and/or plaque measurements. We developed Fourier transform-based software that reconstructed images free of common OCT artifacts, and compared corrected and uncorrected images. RESULTS: 48 % of OCT frames contained image artifacts, with 62 % of artifacts over or within lesions, preventing accurate measurement in 12 % frames. Pre-processing corrected >70 % of all artifacts, including thrombus, macrophage shadows, inadequate flushing, and gas bubbles. True tissue reconstruction was achieved in 63 % frames that would otherwise prevent accurate clinical measurements. Artifact correction was non-destructive and retained anatomical lumen and plaque parameters. Correction improved accuracy of plaque classification compared against histology and retained accurate assessment of higher-risk features. Correction also changed plaque classification and prevented artifact-related measurement errors in a clinical study, and reduced unmeasurable frames to <5 % ex-vivo and ~1 % in-vivo. CONCLUSIONS: Fourier transform-based pre-processing corrects a wide range of common OCT artifacts, improving identification of higher-risk features and plaque classification, and allowing more of the whole dataset to be used for clinical decision-making and in research. Pre-processing can augment OCT image analysis systems both for stent optimization and in natural history or drug studies.

Single-stent crossover technique from distal unprotected left main coronary artery to the left circumflex artery.

OBJECTIVES: To report the clinical outcomes of single-stenting from distal unprotected left main coronary artery (LMCA) to the left circumflex artery (LCx). BACKGROUND: Percutaneous coronary intervention of distal LMCA is usually performed by stenting into the left anterior descending artery (LAD). In some cases, stenting from LMCA to LCx alone is performed. METHODS: Between April 2002 and April 2011, single-stenting with drug-eluting stents for distal unprotected LMCA disease was performed in 584 patients. Thirty-one patients underwent LMCA-LCx stenting, who were compared with the remaining 553 LMCA-LAD stented patients. RESULTS: At 3-year follow-up, there were no significant differences between LMCA-LCx and LMCA-LAD stenting groups in major adverse cardiac events (24.1% vs. 19.6%; P = 0.540), cardiac death, and myocardial infarction. A trend toward higher target lesion revascularization (TLR) in the LMCA-LCx stenting group was noted. This was significant when the stented branch was only considered (18.2% vs. 3.0%; P < 0.001). In both TLR subgroups, LCx ostium was frequently involved (83.3% in LMCA-LCx vs. 66.2% in LMCA-LAD TLR subgroups; P = 0.39). The LAD ostium was more frequently involved in LMCA-LCx TLR subgroup (83.3% vs. 21.0%; P < 0.001). On the multivariable Cox regression analysis, LMCA-LCx stenting was an independent predictor of TLR for restenosis at the ostium of the stented branch (HR 6.49; 95% CI 2.27-18.53; P < 0.001). CONCLUSIONS: TLR rate at the LCx ostium is high irrespective of LMCA-LCx or LMCA-LAD stenting. The former also seems to be associated with high TLR at the LAD ostium. It may therefore be important to evaluate alternative strategies for treating distal LMCA disease that extends into the LCx but not LAD.

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.

Leukocyte telomere length is associated with high-risk plaques on virtual histology intravascular ultrasound and increased proinflammatory activity.

OBJECTIVE: Leukocyte telomere length (LTL), a marker of cellular senescence, is inversely associated with cardiovascular events. However, whether LTL reflects plaque extent or unstable plaques, and the mechanisms underlying any association are unknown. METHODS AND RESULTS: One hundred seventy patients with stable angina or acute coronary syndrome referred for percutaneous coronary intervention underwent 3-vessel virtual histology intravascular ultrasound; 30 372 mm of intravascular ultrasound pullback and 1096 plaques were analyzed. LTL was not associated with plaque volume but was associated with calcified thin-capped fibroatheroma (OR, 1.24; CI, 1.01-1.53; P=0.039) and total fibroatheroma numbers (OR, 1.19; CI, 1.02-1.39; P=0.027). Monocytes from coronary artery disease patients showed increased secretion of proinflammatory cytokines. To mimic leukocyte senescence, we disrupted telomeres and binding and expression of the telomeric protein protection of telomeres protein-1, inducing DNA damage. Telomere disruption increased monocyte secretion of monocyte chemoattractant protein-1, IL-6, and IL-1ß and oxidative burst, similar to that seen in coronary artery disease patients, and lymphocyte secretion of IL-2 and reduced lymphocyte IL-10. CONCLUSIONS: Shorter LTL is associated with high-risk plaque morphology on virtual histology intravascular ultrasound but not total 3-vessel plaque burden. Monocytes with disrupted telomeres show increased proinflammatory activity, which is also seen in coronary artery disease patients, suggesting that telomere shortening promotes high-risk plaque subtypes by increasing proinflammatory activity.

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.

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.

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.

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.