Comparison of Coronary Intravascular Lithotripsy and Rotational Atherectomy in the Modification of Severely Calcified Stenoses.

Debulking techniques are often necessary for successful lesion preparation in percutaneous coronary intervention. The aim of this study was to compare plaque modification of severely calcified lesions by coronary intravascular lithotripsy (IVL) with that of rotational atherectomy (RA) using optical coherence tomography (OCT). ROTA.shock was a 1:1 randomized, prospective, double-arm, multicenter noninferiority trial designed to compare final minimal stent area after IVL with RA for lesion preparation in percutaneous coronary interventional treatment of severely calcified lesions. On the basis of OCT acquired before and immediately after IVL or RA in 21 of the 70 patients included, we performed a detailed analysis of the modification of the calcified plaque. After RA and IVL, calcified plaque fractures were present in 14 of the patients (67%), with a significantly greater number of fractures after IVL (3.23 ± 0.49) than after RA (1.67 ± 0.52; p < 0.001). Plaque fractures after IVL were longer than after RA (IVL: 1.67 ± 0.43 mm vs RA: 0.57 ± 0.55 mm; p = 0.01), resulting in a greater total volume of the fractures (IVL: 1.47 ± 0.40 mm3 vs RA: 0.48 ± 0.27 mm3; p = 0.003). Use of RA was associated with a greater acute lumen gain than was use of IVL (RA: 0.46 ± 0.16 mm2 vs IVL: 0.17 ± 0.14 mm2; p = 0.03). In conclusion, we were able to show differences in plaque modification of calcified coronary lesions by OCT: although RA leads to a greater acute lumen gain, IVL induces more and longer fractures of the calcified plaque.

Coronary Stent Strut Fractures: Classification, Prevalence and Clinical Associations.

INTRODUCTION: The frequency, characteristics and clinical implications of Strut fractures (SFs) remain incompletely understood. METHODS AND RESULTS: A total of 185 (160 patients) newer-generation drug-eluting stents (DES) were imaged. SFs were found in 21 DES (11.4%) and were classified in four patterns: one single stacked strut (41%); two or more stacked struts (23%); deformation without gap (27%); transection (9%). In multivariable analysis, calcific and bifurcation lesions were associated with SF in DES (OR: 3.5 [1.1-11] and 4.0 [2.2-7.2], p < 0.05). Device eccentricity and asymmetry as well as optical coherence tomography (OCT) features of impaired strut healing were also associated with SF. The prevalence of fractures was similar in a set of 289 bioresorbable scaffolds (BRS). In a separate series of 20 device thromboses and 36 device restenoses, the prevalence of SF was higher (61.2% of DES and 66.7% of BRS, p < 0.001 for both), with a higher frequency of complex SF patterns (p < 0.0001). In logistic regression analysis, fractures were a correlate of device complications (p < 0.0001, OR = 24.9 [5.6-111] for DES and OR = 6.0 [1.8-20] for BRS). DISCUSSION: The prevalence of OCT-diagnosed SF was unexpectedly high in the setting of elective controls and it increased by about three-fold in the setting of device failure. Fractures were associated with increased lesion complexity and device asymmetry/eccentricity and were more frequent in the setting of device failure such as restenosis and thrombosis.

Optical Coherence Tomography Assessment in Patients Treated With Rotational Atherectomy Versus Modified Balloons: PREPARE-CALC OCT.

[Figure: see text].

Incidental Finding of Strut Malapposition Is a Predictor of Late and Very Late Thrombosis in Coronary Bioresorbable Scaffolds.

Malapposition is a common finding in stent and scaffold thrombosis (ScT). Evidence from studies with prospective follow-up, however, is scarce. We hypothesized that incidental observations of strut malapposition might be predictive of late ScT during subsequent follow-up. One hundred ninety-seven patients were enrolled in a multicentre registry with prospective follow-up. Optical coherence tomography (OCT), performed in an elective setting, was available in all at 353 (0-376) days after bioresorbable scaffold (BRS) implantation. Forty-four patients showed evidence of malapposition that was deemed not worthy of intervention. Malapposition was not associated with any clinical or procedural parameter except for a higher implantation pressure (p = 0.0008). OCT revealed that malapposition was associated with larger vessel size, less eccentricity (all p < 0.01), and a tendency for more uncovered struts (p = 0.06). Late or very late ScT was recorded in seven of these patients 293 (38-579) days after OCT. OCT-diagnosed malapposition was a predictor of late and very late scaffold thrombosis (p < 0.001) that was independent of the timing of diagnosis. We provide evidence that an incidental finding of malapposition-regardless of the timing of diagnosis of the malapposition-during an elective exam is a predictor of late and very late ScT. Our data provide a rationale to consider prolonged dual antiplatelet therapy if strut malapposition is observed.

OCT-assessment of scaffold resorption: Analysis of strut intensity by a new resorption index for poly-l-lactic acid bioresorbable vascular scaffolds.

BACKGROUND: The aim of this study was to analyze individual differences in resorption of bioresorbable vascular scaffolds (BRS) through optical coherence tomography (OCT) analysis and to identify factors potentially influencing the resorption process. METHODS: Between April 2016 and July 2017 clinically driven invasive coronary angiography and OCT examinations were performed in 36 patients who had previously been treated with a total of 48 BRS (ABSORB BVS, Abbott Vascular, Santa Clara, CA). For each scaffold, a new BRS-RESORB-INDEX (BRI) was calculated. RESULTS: The mean time interval since implantation was 789 ± 321 days. In OCT, BRS struts remained detectable in all 48 BRS. Normalized light intensity as a marker for the resorption of BRS struts increased with time in a linear fashion (Spearman Rho: p < .001, correlation coefficient = .90; R2 [linear] = .91). Multivariable analysis identified diabetes (BRI of patients with diabetes vs. patients without diabetes: 0.34 ± 0.13 vs. 0.58 ± 0.22; p = .002) and presence of Peri-strut low intensity areas (PSLIA, BRI of 10 patients with PSLIA vs. 26 patients without PSLIA: 0.44 ± 0.21 vs. 0.61 ± 18; p = .027) as independent predictors for a prolonged BRS resorption, whereas the resorption rate in ACS patients (STEMI, NSTEMI, and unstable angina; n = 13) was significantly higher as compared to patients without ACS (0.62 ± 0.17 vs. 0.43 ± 0.24; p = .012). CONCLUSION: In humans, BRS resorption rate is significantly influenced by numerous factors. Our data suggest that diabetes and PSLIA are associated with a prolonged resorption process, whereas in ACS patients, BRS resorption appears to be significantly faster.

Procedural Predictors for Bioresorbable Vascular Scaffold Thrombosis: Analysis of the Individual Components of the "PSP" Technique.

The technique used at the time of implantation has a central role in determining the risk of thrombosis in bioresorbable vascular scaffolds (BRS). Different definitions of the "optimal" implantation technique exist, however. The impact of individual procedural characteristics on the risk of scaffold thrombosis (ScT) was evaluated in a single-center observational study that enrolled 657 patients (79% males, mean age 63 ± 12 years) with 763 lesions who received a total of 925 BRS for de novo lesions. During a median 1076 (762⁻1206) days' follow-up there were 28 cases of thrombosis. Independent predictors of ScT included the use of predilatation balloons bigger than the nominal BRS diameter (hazard ratio (HR) = 0.4 (0.16⁻0.98), p = 0.04), sizing (implantation in vessels with reference vessel diameter >3.5 mm or <2.5 mm: HR = 5.71 (2.32⁻14.05), p = 0.0002) and the degree of vessel expansion (ratio of minimum lumen to reference vessel diameter, HR: 0.005 (0.0001⁻0.23), p = 0.007). In addition, a mild BRS oversizing (final BRS diameter to vessel diameter 1.14⁻1.28) was associated with a lower thrombosis risk, whereas undersizing and more severe oversizing (final BRS diameter to vessel diameter <1.04 and >1.35, respectively) were associated with an increased risk of ScT (HR = 0.13 (0.02⁻0.59), p = 0.0007). In conclusion, different components of the "optimal" technique have different impacts on the risk of BRS thrombosis. Besides predilatation with a balloon larger than the BRS diameter, correct vessel size selection and a mild to moderate oversizing appear to be protective.

Major coronary evaginations following implantation of bioresorbable vascular scaffolds - Clinical and OCT characteristics.

BACKGROUND: Coronary evaginations can occur after implantation of bioresorbable vascular scaffolds (BRS) and may be associated with scaffold thrombosis. Aim of this study was to clarify the clinical manifestation, extent and time course of coronary artery remodeling in vessel segments that develop angiographically detectable evaginations following BRS implantation through optical coherence tomography (OCT) analysis. METHODS: In 8 patients, 10 BRS (Absorb, Abbott Vascular, Santa Clara, CA, USA) which displayed coronary evaginations in clinically driven late invasive coronary angiograms were identified and findings were compared to 10 BRS in 8 patients without coronary evaginations. Vessel and device geometry was analyzed in serial OCT cross-sections at a spacing of 200 µm. Measured BRS dimensions were normalized to the reference vessel size at implantation. RESULTS: In OCT, major evaginations on average affected 24 ±â€¯19% of the scaffold length. Scaffolds with major evaginations had a significantly larger lumen area than scaffolds without evaginations (mean normalized lumen area 1.19 ±â€¯0.58 vs. 0.77 ±â€¯0.38; p < 0.001), and also displayed a significantly larger scaffold area (mean normalized scaffold area: 1.36 ±â€¯0.6 vs. 1.13 ±â€¯0.43; p < 0.001), and scaffold diameter (mean normalized scaffold diameter: 1.17 ±â€¯0.33 vs.1.04 ±â€¯0.19; p < 0.001). Lumen area (r = 0.47; p < 0.001), scaffold area (r = 0.52; p < 0.001), and scaffold diameter (r = 0.74; p < 0.001) in the evagination group were positively correlated to the time since scaffold implantation. CONCLUSION: Coronary evaginations following BRS implantation are associated with an increased scaffold area, indicating that the scaffold follows the outward remodeling of the artery. The process affects the entire scaffold length and seems to be continuously progressing following implantation.

Effect of non-compliant balloon postdilatation on magnesium-based bioresorbable vascular scaffolds.

BACKGROUND: Optimal implantation results of bioresorbable scaffolds (BRS) are typically assumed to require postdilatation with non-compliant (NC) balloons to achieve full scaffold apposition and minimize event rates. We systematically evaluated the mechanical effect of NC balloon postdilatation on magnesium-based BRS (Magmaris®, Biotronik AG, Bülach, Switzerland) in vivo. METHODS: In 35 patients, 40 Magmaris® BRS were implanted to treat 37 de novo coronary artery stenoses. A systematic implantation protocol was followed. After appropriately sized NC balloon predilatation (1:1:1 vessel:balloon:scaffold ratio), Magmaris® BRS were implanted with a pressure of 10 atm, followed by NC balloon postdilatation at nominal BRS size (standardized at 16 atm). OCT was performed before and after postdilatation and OCT images were analyzed at a spacing of 0.2 mm to measure BRS dimensions and determine apposition as well as to detect strut fractures. RESULTS: PCI with Magmaris® BRS (mean diameter: 3.21 ± 0.32 mm; mean length: 20 ± 4 mm) was successful in all cases, in one case a non-flow-limiting distal edge dissection occurred after implantation and before postdilatation. NC balloon postdilatation led to significantly larger mean scaffold diameter (3.21 ± 0.32 mm vs. 2.80 ± 0.39 mm, P < 0.001), abluminal scaffold area (7.92 ± 1.43 mm2 vs. 6.72 ± 1.28 mm2 , P < 0.001) and lumen area (7.58 ± 1.1 mm2 vs. 6.83 ± 1.12 mm2 , P < 0.001). Incomplete scaffold apposition area was significantly lower if postdilatation was performed (0.01 ± 0.04 mm2 vs. 0.17 ± 0.11 mm2 , P < 0.001). Strut fractures could neither be observed before nor after postdilatation. CONCLUSION: NC balloon postdilatation of Magmaris® BRS is required to achieve optimal expansion. It significantly reduces malapposition and can safely be performed without relevant rates of strut fracture.

Three-years outcomes of diabetic patients treated with coronary bioresorbable scaffolds.

BACKGROUND: Diabetes is among the strongest predictors of outcome after coronary artery stenting and the incidence of negative outcomes is still high in this specific group. Data of long-term outcomes comparing diabetic patients with non-diabetic patients treated with bioresorbable scaffolds are still incomplete. This work evaluates the long-term outcomes after implantation of a coronary bioresorbable scaffold (BRS) in diabetic patients compared to non-diabetics. METHODS: Patients who received at least one Absorb BRS in the time of May 2012 to December 2014 were enrolled into this single-center registry. Quantitative coronary angiography (QCA) was performed. RESULTS: Six hundred fifty seven patients including 138 patients (21%, mean age 65 ± 11, 78% male) with diabetes were enrolled. Patients in the diabetic group were significantly older, were more likely to suffer from hypertension and hyperlipidemia and had more often a prior stroke or TIA as well as a reduced renal function (all P < 0.05). The initial stenosis was less severe in the diabetic group (74.8% vs. 79.6%, P = 0.036), but the residual stenosis after BRS implantation exceeded that of the control group (16.7% vs. 13.8%, P = 0.006). History of diabetes had no impact on the incidence of events within one year after BRS implantation. Beyond 1 year, diabetic patients had a higher incidence of cardiovascular death (6.9 vs. 1.4%, HR:5.37 [1.33-21.71], P = 0.001), scaffold restenosis (17.6 vs. 7.8%, HR:3.56 [1.40-9.05], P < 0.0001) and target lesion revascularization (P = 0.016). These results were confirmed in the propensity score analysis. In both diabetics and non-diabetics, there was a strong association (HR:18.6 [4.7-73.3]) between the risk of restenosis and the technique used at implantation; in contrast, the impact of vessel size was more manifest in non-diabetics than in diabetic patients, and an increased risk of restenosis was demonstrated for both large and small vessels. CONCLUSION: As for metal stents, beyond one year after implantation, diabetes was associated with an increased incidence of scaffold restenosis and related outcomes. This negative impact of diabetes was reset when an optimal implantation technique was used.

Bioresorbable everolimus-eluting vascular scaffold for patients presenting with non STelevation-acute coronary syndrome: A three-years follow-up1.

AIM: To investigate three-year outcomes of patients presenting with nonSTelevation acute coronary syndrome (NSTE-ACS) treated with bioresorbable everolimus-eluting vascular scaffolds (BRS). METHODS AND RESULTS: The study included a total of 488 consecutive patients, enrolled between May 2012 and December 2013 (median age 65 [56-74], 392 men. 269 patients presented with either NSTEMI or unstable angina at the time of enrolling, 219 patients with stable or silent angina. The primary device-oriented endpoint (Target Lesion Failure, TLF) was defined as a combination of cardiovascular death, target vessel myocardial infarction or clinically driven target lesion revascularization.Among the cardiac risk factors, NSTE-ACS patients were more frequently smokers (P = 0.028), had less frequently dyslipidemia (P = 0.003) and a history of prior PCI (P < 0.01).The median follow-up was 1070[763-1197] days. The three-years incidence of TLF was slightly higher but did not differ significantly between groups (NSTE-ACS: 16.3% vs. 15.9%, p = 0.163). Accordingly, there was no difference in any of the other endpoints. CONCLUSION: Treatment of NSTE-ACS with BRS appears to be safe and effective. In this group, risk factors for events during follow up did not differ as compared to the general population.

Characteristics and outcome of patients with complex coronary lesions treated with bioresorbable scaffolds: three-year follow-up in a cohort of consecutive patients.

AIMS: The safety of bioresorbable scaffolds (BRS) has recently been challenged. However, it is unclear whether outcomes depend on the complexity of the lesion or on the technique used to implant the device. The aim of this study was to report on the outcomes after BRS implantation in complex lesions. METHODS AND RESULTS: This investigator-initiated, single-centre, single-arm observational study recruited 657 consecutive patients (79% male, 66.7% acute coronary syndrome, age 63±12 years). Three hundred and twenty-two lesions (42.3%) in 297 (45.2%) patients with type B2 or C lesions were classified as the "complex lesions group". Post-procedural residual stenosis was slightly but significantly greater in the complex lesions group (15.7±11.3% vs. 13.5±10.2%, p=0.0109). The median follow-up was 1,076 (762-1,206) days without difference between groups. The Kaplan-Meier rates of early scaffold thrombosis (3.5% vs. 1.1%, p=0.0478, HR 3.03 [1.06-8.70]) and scaffold restenosis (9.9% vs. 9.1%, p=0.0262, HR 2.34 [1.11-4.94]) were higher in patients with complex lesions than in those with simple lesions. Late/very late thrombosis, death, repeat myocardial infarction, or repeat coronary interventions were not different. In patients in whom strict guidelines for implantation were applied, the incidence of thrombosis was reduced by 76% in complex lesions and by 92% in simple ones, such that there were no differences between groups (2.3% vs. 0.5%, p=0.3899). In contrast, the incidence of scaffold restenosis was reduced by 59% and 89%, and a difference between groups persisted (7.0% vs. 1.6%, p=0.0235). CONCLUSIONS: BRS implantation in complex lesions is, as expected, associated with higher incidence of events as compared to simple ones. The technique used at the time of the implantation, however, reduces the incidence of adverse outcomes.

Characteristics, Predictors, and Mechanisms of Thrombosis in Coronary Bioresorbable Scaffolds: Differences Between Early and Late Events.

OBJECTIVES: The study sought to investigate the incidence, characteristics, predictors, and possible mechanisms of early and 3-year coronary scaffold thrombosis (ScT). BACKGROUND: An increased incidence of both early and late ScT has been shown in randomized trials. METHODS: Consecutive patients were enrolled in a single-center registry. Quantitative coronary angiography was performed. Incidence and predictors of ScT were assessed with Kaplan-Meier and Cox regression analyses. RESULTS: A total of 657 patients (63 ± 12 years of age, 79% men, 21% diabetic, 64% acute coronary syndrome) who received 925 coronary bioresorbable scaffolds (BRS) (Abbott Vascular, Santa Clara, California) between May 2012 and January 2015 were enrolled. Clinical and procedural characteristics and outcome data at 1,076 (interquartile range: 762 to 1,206) days (3-year follow-up rate 93%) were collected. Twenty-eight ScTs were recorded: 14 early (Kaplan-Meier estimate: 2.2%), 5 late (Kaplan-Meier estimate: 0.9%), and 9 very late (Kaplan-Meier estimate: 1.7%). The incidence of ScT followed a U-shaped curve with highest incidence at the extremes of the distributions of reference vessel diameter (RVD) and the ratio of BRS nominal diameter to RVD. At quantitative coronary angiography, RVD (hazard ratio [HR]: 0.14; 95% confidence interval [CI]: 0.04 to 0.49) and BRS oversizing (ratio of BRS nominal diameter to RVD >1.15; HR: 107.40; 95% CI: 9.20 to 1,261.30) emerged as potent predictors of early ScT. RVD (HR: 9.55; 95% CI: 3.90 to 23.42) and BRS undersizing (ratio of BRS nominal diameter to RVD <0.85; HR: 0.0004; 95% CI: 0.0000 to 0.0400) predicted late or very late ScT (all p < 0.0001). The incidence of both early and late or very late ScT were lower (∼80% reduction) when an optimal implantation technique was used. The most important factor appeared to be vessel and BRS sizing. CONCLUSIONS: Different mechanisms underlie early and late ScT: although incomplete BRS deployment was a predictor of the former, the latter was associated with large vessel size and BRS undersizing. However, both phenomena are significantly less frequent with an optimized implantation technique. (Mainz Intracoronary Database. The Coronary Slow-flow and Microvascular Diseases Registry [MICAT]; NCT02180178).

Incidence, Clinical Presentation, and Predictors of Clinical Restenosis in Coronary Bioresorbable Scaffolds.

OBJECTIVES: The aim of this study was to describe the incidence and clinical characteristics, including intracoronary imaging features, of clinical restenosis in bioresorbable coronary scaffolds (BRS). Further, the authors searched for clinical and procedural predictors of scaffold restenosis (ScR) and report on the clinical outcomes after treatment of ScR in a cohort of consecutive all-comer patients. BACKGROUND: Data from randomized controlled trials demonstrate a higher rate of target lesion failure in patients treated with BRS as compared with those treated with metal drug-eluting stents. Although in-scaffold thrombosis has been thoroughly investigated, there are little data available on the incidence and characteristics of ScR. METHODS: A total of 657 consecutive patients (age 63 ± 12 years, 79% men, 21% diabetics, 67% acute coronary syndrome) who received a total of 883 BRS for the treatment of coronary artery stenoses between May 2012 and January 2015 were enrolled in a retrospective registry. RESULTS: During the median follow-up of 1,076 days (interquartile range: 762 to 1,206 days), a total of 49 cases of ScR were found in 41 patients (Kaplan-Meier incidence: 2.4%, 6.0%, and 9.0% at 12-, 24-, and 36-month follow-up, respectively). ScR presented as stable angina or as incidental finding in 73% of the cases. The angiographic pattern was complex (type II to IV) in 55% of the ScR lesions. The neointima was homogeneous with high signal intensity in all but 3 cases at optical coherence tomography. Prior revascularization (hazard ratio [HR]: 2.7; 95% confidence interval [CI]: 1.5 to 5.1; p = 0.002), diabetes (HR: 2.9; 95%CI: 1.5 to 5.4; p = 0.001), lesion types B2 or C (HR: 2.8; 95% CI: 1.5 to 5.4; p = 0.002), and implantation technique (HR: 0.3; 95% CI: 0.1 to 0.6; p = 0.001) emerged as independent predictors of ScR. Oversizing (HR: 6.29; 95% CI: 2.4 to 16.4), undersizing (HR: 5.15; 95% CI: 1.99 to 13.30), and a residual stenosis >27% (HR: 8.9; 95% CI: 3.6 to 21.8) were associated with an increased ScR risk. CONCLUSIONS: The 3-year incidence of ScR was similar to that observed in similar settings with newer-generation drug-eluting stents. It is often associated with a benign presentation and a complex angiographic pattern. Predictors of ScR match those of metallic stent restenosis, and the implantation technique used at index appears to play an important role.

Bioresorbable Coronary Scaffold Thrombosis: Multicenter Comprehensive Analysis of Clinical Presentation, Mechanisms, and Predictors.

BACKGROUND: Recent reports suggest an elevated incidence of bioresorbable vascular scaffold (BVS) thrombosis (scaffold thrombosis [ScT]). OBJECTIVES: This study investigated occurrence rates, clinical and angiographic characteristics, and possible mechanisms of ScT in all-comer patients undergoing BVS implantation at 2 German and 2 Swiss hospitals. METHODS: A total of 1,305 consecutive patients (mean age 64 years, 78% male) who received 1,870 BVS (mean 1.4 ± 0.8 BVS/patient) were enrolled. Clinical/procedural characteristics, mortality, and ScT data at 485 days (range 312 to 652 days) were examined. RESULTS: ScT occurred in 42 patients. The incidence of probable and definite ScT was 1.8% at 30 days and 3.0% at 12 months, without differences among centers (p = 0.60). A total of 22 (52%) ScTs presented as ST-segment elevation myocardial infarction and 6 (17%) as sudden cardiac death. In multivariable analysis, ostial lesions (p = 0.049) and impaired left ventricular ejection fraction (p = 0.019) were independently associated with ScT. Nine (21%) of the ScTs occurred in patients who had suspended dual antiplatelet therapy, in 6 cases prematurely. Lower post-procedural minimum lumen and reference vessel diameters were hallmarks of ScT (all p < 0.0001). The risk of ScT appeared to rapidly increase for post-procedural minimum lumen diameters below 2.4 mm (for the 2.5- to 3.0-mm BVS) and 2.8 mm (for the 3.5-mm BVS). When a BVS-specific implantation strategy was implemented, 12-month ScT rates fell from 3.3% to 1.0%, an effect that remained significant when adjusted for multivariable propensity score (p = 0.012; hazard ratio: 0.19; 95% confidence interval: 0.05 to 0.70). CONCLUSIONS: The 12-month incidence of ScT reached 3% and could be significantly reduced when an optimized implantation strategy was employed. (retrospective multicentric registry and Mainz Intracoronary Database. The Coronary Slow-flow and Microvascular Diseases Registry [MICAT]; NCT02180178).

Coronary evaginations and peri-scaffold aneurysms following implantation of bioresorbable scaffolds: incidence, outcome, and optical coherence tomography analysis of possible mechanisms.

BACKGROUND: Peri-stent coronary evaginations may disturb flow and have been proposed as possible risk factor for late stent thrombosis. We describe incidence, predictors, and possible mechanisms of coronary evaginations 12 months after implantation of bioresorbable vascular scaffolds (BVS). METHODS AND RESULTS: One hundred and two BVS implanted in 90 patients (age 63 ± 13 years, 71 males, 14 diabetics) were analysed with angiography and optical coherence tomography (OCT) 12 months after implantation. Evaginations were identified as any hollow in the luminal vessel contour between well-apposed struts and were classified as major when extending ≥3 mm with a depth ≥10% of the BVS diameter. Fifty-five (54%) of the BVS (50(56%) of the patients) had at least one evagination (6.1 ± 6.2 evaginations per BVS), with a mean volume of 1.9 ± 1.9 mm(3). Major evaginations were only found in one patient, and in-BVS aneurysms in three patients (4BVS). The presence of evaginations was strongly associated with that of malapposition (P = 0.003) and strut fractures (P = 0.01). No association could be shown between the presence and volume of the evaginations and any clinical variable or the presence of uncovered struts (P > 0.5). Peri-strut low-intensity areas (PSLIA) were present in 29 (53%) of the BVS with evaginations and 12 (26%) of those without (P = 0.0049); their presence was independently associated with the presence, the number (P < 0.003) and volume of the evaginations (P = 0.004) and with that of strut fracture. CONCLUSIONS: Optical coherence tomography-detected evaginations are relatively common after BVS implantation, but, as for modern drug-eluting metallic stents, major evaginations are very rare. Optical coherence tomography evidence of immature neointima and strut fractures were associated with more severe development of evaginations.

Optical Coherence Tomography Findings in Bioresorbable Vascular Scaffolds Thrombosis.

BACKGROUND: Everolimus-eluting bioresorbable vascular scaffolds have been developed to improve late outcomes after coronary interventions. However, recent registries raised concerns regarding an increased incidence of scaffold thrombosis (ScT). The mechanism of ScT remains unknown. METHODS AND RESULTS: The present study investigated angiographic and optical coherence tomography findings in patients experiencing ScT. Fifteen ScT (14 patients, 79% male, age 59±10 years) occurred at a median of 16 days (25%-75% interquartile range: 1-263 days) after implantation. Early ScT (<30 days) occurred in 8 cases (53%). Possible causal factors in these patients included insufficient platelet inhibition in 2 cases and procedural factors (scaffold underexpansion, undersizing, or geographical miss) in 4 cases. No obvious cause could be found in 2 early ScT. In late (>1 month) and very late (>1 year) ScT (respectively, 5 and 2 cases), 5 scaffolds showed intimal neovessels or marked peristrut low-intensity areas. Scaffold fractures were additionally found in 2 patients, and scaffold collapse was found in 1 patient with very late ScT. Extensive strut malapposition was the presumed cause for ScT in 1 case. One scaffold did not show any morphological abnormality. Thrombectomy specimens were analyzed in 3 patients and did not demonstrate increased numbers of inflammatory cells. CONCLUSIONS: The mechanisms of early ScT seem to be similar to metallic stents (mechanical and inadequate antiplatelet therapy). The predominant finding in late and very late ScT is peristrut low-intensity area.

Clinical, Angiographic, Functional, and Imaging Outcomes 12 Months After Implantation of Drug-Eluting Bioresorbable Vascular Scaffolds in Acute Coronary Syndromes.

OBJECTIVES: The purpose of this study was to describe the multimodal outcome 12 months after implantation of coronary bioresorbable scaffolds (BVS) for the treatment of patients with acute coronary syndromes (ACS). BACKGROUND: Functional and imaging data on the use of BVS are limited to simple, stable lesions; in the setting of ACS, only short-term clinical follow-up data are available, and no information from intracoronary imaging and vasomotion tests has been reported. METHODS: A total of 133 patients (age 62 ± 12 years, 74% males, 15% diabetic) underwent BVS (n = 166) implantation for the treatment of thrombotic lesions in the setting of ACS (43% non-ST-segment elevation myocardial infarction, 38% ST-segment elevation myocardial infarction, 20% unstable angina). Clinical, angiographic, intracoronary imaging, and vasomotor endpoints were evaluated at 12 months. RESULTS: During the 374 days (interquartile range: 359 to 411 days) of follow-up, there were 4 deaths; 3 definite and 1 probable in-BVS thromboses (all in the first 6 months). At 12-month angiography (75 patients, 83 BVS), in-segment late lumen loss was 0.19 ± 0.45 mm, and 3 (4%) patients showed binary restenosis. Optical coherence tomography (80 BVS, n = 70) showed a mean lumen area of 6.3 ± 2.3 mm(2). Malapposition was evidenced in 21 (26%) BVS. Endothelium-dependent and -independent vasodilation were observed in 48% and 49% of the BVS. CONCLUSIONS: Twelve months after BVS implantation, clinical, intracoronary imaging, and vasomotion data appear to provide a rationale for the use of BVS in the setting of ACS and the basis for a randomized study.