Stent Underexpansion Research Articles

Complex, high-risk, and indicated percutaneous coronary angioplasty in essentially calcified stented coronary lesions using excimer laser coronary atherectomy with contrast mix injection.

Complex, coronary stenosis remains a technical challenge that may be responsible for in-stent restenosis and vessel thrombosis. Here we investigated the efficacy and safety of excimer laser coronary atherectomy (ELCA) with contrast mix injection for improving vessel wall stent apposition in undilatable, mostly calcified lesions. To assess ELCA with contrast mix injection in complex, stented, calcified coronary lesions. This prospective single-center observational study enrolled 52 consecutive patients (73 lesions), with suboptimal stents implanted in de novo lesions and lesions requiring in-stent restenosis (ISR) due to stent underexpansion using all available means to achieve an optimal result. Patients presenting with ST-segment elevation myocardial infarction were excluded. All patients underwent coronary angiography 6 months after ELCA with intravascular ultrasound or optical coherence tomography study. We used contrast media mixed with saline (25-75%) to supply maximum laser energy output when a standard approach was unsuccessful. Procedural success was defined as relative stent expansion of > 80% minimal stent area (MSA) divided by average reference lumen area. Procedural success was achieved in all cases. The cross-sectional area measured in treated segment improved significantly from 2.9 (0.72) mm2 to 7.3 (0.79) mm2 after ELCA. The in-hospital device-oriented major adverse cardiac event (DOCE) rate was 9.6%. No vessel perforation occurred during ELCA. After 6 months, the DOCE rate was 13.4%, while the rate of target lesion revascularization (TLR) was 8.2%. This registry confirms the efficacy and safety of ELCA with contrast mix injection as a possible approach for stent expansion/ISR in failed PCI.

778 IN-STENT USE OF INTRAVASCULAR LITHOTRIPSY IN THE TREATMENT OF STENT UNDEREXPANSION: A SYSTEMATIC REVIEW AND METAREGRESSION

Abstract Introduction Calcified coronary plaque (CCP) represents a challenging scenario for interventional cardiologist. Stent Underexpansion (SU), often associated with CCP, can predispose to stent thrombosis and in-stent restenosis. To date, SU with heavily CCP can be addressed by means of scoring/cutting balloons, very-high/high pressure non-compliant balloons, off-label rotational/orbital atherectomy and intravascular lithotripsy (IVL). Objective In this meta-analysis we investigate the success rate of IVL for the treatment of SU due to CCP. Methods Studies and case-based experiences reporting on the use of IVL strategy for treatment of SU were included. The primary outcome was IVL strategy success, defined as adequate expansion of the underexpanded stent. Metanalysis was performed for the main focuses to calculate proportions of procedural success rates with corresponding 95% confidence intervals (CI). Random effects models weighted by inverse variance were used because of clinical heterogeneity. Results Our study included 13 studies with 354 patients. Mean age was 71.3 years (95% CI: 64.9-73.1) and 77% (95% CI: 71.2-82.4%) were male. The mean follow-up time was 2.6 months (95% CI: 1–15.3). Strategy success was seen in 88.7% (95% CI: 82.3–95.1) of patients. The mean Minimal Stent Area (MSA) was reported in 6 studies, pre-IVL value was 3.4 mm2 (95% CI: 3–3.8) and post-IVL value was 6.9 mm2 (95% CI: 6.5–7.4). The mean diameter stenosis (%) was reported in 7 studies, pre-IVL value was 69.4% (95% CI: 60.7–78.2) and post-IVL value was 14.6% (95% CI: 11.1–18). The rate of intraprocedural complications was 1.6% (95% CI: 0.3-2.9). Conclusions The “stent-through” IVL plaque modification technique is a safe tool to treat SU due to CCP, with high success rate and very low incidence of complications.

1145 BAIL-OUT INTRAVASCULAR CORONARY LITHOTRIPSY FOR THE TREATMENT OF STENT IN-STENT UNDER EXPANSION

Abstract Background in-stent restenosis remains a significant clinical problem for which optimal treatment is under debate. Intravascular lithotripsy (IVL) is mostly used for safe and effective treatment of de novo coronary calcifications, while the use of this technology to support bailout procedures, including stent under-expansion, is still off-label. One of the advantages of lithotripsy is the possible use after stent deployment. Case presentation a 66-year-old male patient was admitted to our Institution due to a medically refractory angina and a coronary computed tomography (CCT) detecting three vessel disease with multiple critical stenosis. The patient had multiple comorbidities including history of hypertension, dyslipidemia, type 2 diabetes and multiple myocardial rivascularization. In 2003 he underwent coronary artery by-pass (CABG) with left internal mammal artery (LIMA) to left anterior descending (LAD) artery and free saphenous vein graft (VG) to the ramus intermedius (RI). In 2009 the patient underwent percutaneous coronary intervention (PCI) of the right coronary artery (RCA) with the implantation of a stent at the central segment, and a second stent at the crux cordis. For recurrent in-stent restenosis of the stent previously implanted at the central segment the patient was treated in 2013 with percutaneous balloon angioplasty (POBA) and in 2017 with the implantation of another drug eluting stent (Resolute Onyx, Medtronic, Santa Rosa, California) overlapping the proximal part of the scaffold. Coronary angiography revealed, a severe coronary artery disease with 80% stenosis of distal left main. The LAD was occluded at the middle segment and the ramus presented 99% stenosis at the proximal segment. The RCA had a diffuse severe in-stent restenosis involving the Resolute Onyx stent. Therefore, the operator decided to treat the restenosis with a direct stenting (Xience, Abbott Vascular Santa Clara, USA), but he was unaware of the fact that there was already an Onyx stent that was barely visible. After implantation, an inadequate expansion of the stents was observed (Figura 1A-B), which persisted despite post-dilation with non-compliant balloon (NCB) at high-pressure (Figure 1C). Given the persistence of stents under-expansion, it was decided to perform bail-out intravascular lithotripsy (IVL) therapy with a Shockwave balloon catheter (Figure 2A). The stent was then post-dilated with a NCB (Figure 2B). The final angiographic image and intravascular ultrasound (IVUS) showed an optimal stent expansion (Figure 3). Conclusion intravascular lithotripsy could be used to treat undilatable stent-in-stent restenosis. Of interest, the case presented demonstrated, for the first time, the possible use of IVL in 2-stent layers, with an optima final stent expansion.

76 INSIDE VEIN GRAFT FAILURE: A WORK FOR OCT

Abstract An 84-years-old woman with prior history of triple coronary artery bypass graft and subsequent percutaneous coronary intervention (PCI) of saphenous vein graft (SVG) for right coronary artery (RCA) was admitted for non-ST-elevation myocardial infarction and newly diagnosed atrial fibrillation. Coronary angiography showed chronic occlusion of native vessels and good flow in all grafts, in absence of critical stenoses. However, SVG for RCA presented a small filling defect of non-univocal interpretation (atherothrombosis, thromboembolus, venous valve). Optical coherence tomography (OCT) was performed for better assessment of the lesion, which was found to be a red thrombus, overlying a ruptured thin-cap fibroatheroma. To reduce the risk of distal embolization, a well-known complication of SVG PCI, direct stenting with conservative stent sizing was performed: everolimus-eluting stent diameter (3,5 mm) was chosen according to mean reference lumen diameter, while length (18 mm) was determined to obtain complete plaque coverage. Repeated OCT showed proximal stent malapposition and underexpansion at the mid portion. The stent was post-dilated with 4,0×12 mm non-compliant balloon and final OCT showed correction of both malapposition and underexpansion. The presented case offers an example of the advantages of intravascular imaging in diagnosis and treatment of SVG lesions. Venous grafts have high failure rate: up to 12% of graft are occluded before hospital discharge and up to 60% after 10 years. While in the first year graft occlusion is mainly caused by neointimal hyperplasia, after this period neoatherosclerosis is the leading cause of failure, as exemplified in the case. Intravascular imaging, and particularly OCT, may help to elucidate graft failure mechanism, with important implications for treatment strategy. Moreover, SVG interventions have higher incidence procedural complications, particularly no-reflow and periprocedural myocardial infarction, due to high plaque burden and friable atheromatous material. Proposed strategies to mitigate procedural risk include use of embolic protection devices, direct stenting and use of undersized stents. In this complex setting, intravascular imaging can guide stent sizing and optimization, thus reducing procedural complications and long-term lesion failure.

870 COMBINING PERCUTANEOUS CORONARY INTERVENTION AND TRASCATHETER AORTIC VALVE REPLACEMENT PROCEDURES: THE IMPORTANCE OF INTRAVASCULAR LITHOTRIPSY

Abstract Background Calcified coronary artery disease and severe valvular aortic stenosis (AS) often coexist. For instance, severely calcified lesions may strongly influence the revascularization strategy in patients undergoing transcutaneous aortic valve replacement (TAVR). Shock wave intravascular lithotripsy (S-IVL) (Shockwave Medical Inc. Santa Clara, CA) is the only technology available that cracks both medial and intimal calcium while minimizing trauma to the vessel wall, thus allowing a safe plaque debulking. We report a case of percutaneous coronary intervention (PCI) and TAVR in the same procedure, where S-IVL has been used to treat a heavily calcified lesion and optimize stent under-expansion. Case Report A 79 years-old male patient with a history of diabetes mellitus type 2, hypertension, and peripheral artery disease, was admitted to our institution with symptomatic severe AS and severe calcified left anterior descending (LAD) artery lesion at CT scan. Deemed eligible for TAVR, Heart Team planned a percutaneous coronary intervention (PCI) of LAD and TAVR in the same procedure. Through the left radial artery, coronary angiography confirmed 90% stenosis of the LAD at the central segment. Accordingly, pre-dilatation of the stenosis was performed with a 2.5×12 mm non-compliant balloon (NCB) and, because of the severe calcification, S-IVL with a 3.0×12 mm balloon inflated at 4-6 Atmospheres (ATM), delivering 40 pulses. Following, a 3.5×18-mm drug-eluting stent was implanted at 18 ATM. After implantation, an inadequate expansion of the stents was observed, which persisted despite post-dilation with 3.75×8 mm NCB at high-pressure. Bail-out S-IVL was then performed with the 3.0×12 mm balloon inflated at 4-6 ATM, delivering 40 pulses in-stent, followed by a further stent post-dilated with a 3.75×8 mm NCB up to 20 ATM. The final angiogram showed a satisfactory stent expansion. Since the low contrast volume was used, we decided to go ahead with transfemoral TAVR. Therefore, through the left femoral artery access, a 34-mm self-expandable Evolut R valve was implanted. Transthoracic echocardiography showed optimal valve implantation with a trivial periprosthetic leak. No complications were observed after the procedures and the patient was discharged after 6 days with 6 months of mandated dual antiplatelet therapy (Aspirin and Clopidogrel). Discussion In this case, the bail-out use of S-IVL was essential for an optima stent implantation, allowing TAVR procedure and avoiding prolonged theoretical antithrombotic therapy underlying suboptimal stent implantation. Despite encouraging initial results, future large studies with long-term observation are required to evaluate the safety and efficacy of S-IVL in this scenario.

Novel application of intravascular lithotripsy in stent under-expansion: A single-center experience.

Stent under-expansion due to calcification is associated with a less durable result. The development of intravascular lithotripsy (IVL) has provided clinicians with a readily available, simple-to-use treatment option for coronary calcification, but the use of IVL within a previously stented segment is currently off-license. There are, however, developing data suggesting that the use of IVL can be an effective treatment option for patients with calcific stent under-expansion. This was a single-center study of all patients treated with IVL for calcific stent under-expansion between January 2019 and June 2021. The impact of IVL on quantitative coronary angiography (QCA) stenosis and on the minimal stent area (MSA) derived from intracoronary imaging were recorded. The presence of periprocedural complications and adverse cardiovascular events was obtained from the clinical record during the study timeframe. Thirty-nine patients underwent IVL for calcific stent under-expansion during the study time frame with one patient treated with more than one lesion in the same session. In all lesions, there was an improvement in the QCA stenosis with 37 (92.5%) having a residual stenosis of ≤30%. The mean QCA stenosis pre-IVL was 68 ± 21% and following IVL the mean QCA was 18 ± 9% (p < 0.001). In all lesions, there was an improvement in the MSA, with 26 (92.9%) achieving an MSA of more than 4.5 mm2. The mean MSA pre-IVL was 3.88 ± 1.51 mm2 and following IVL the mean MSA was 7.41 ± 2.34 mm2 (p < 0.001). There were no major procedural complications. Over a mean follow-up of 506 ± 277 days, one patient died from ventricular arrhythmia but there were no other major adverse cardiovascular events. This single-center study demonstrates that IVL is a safe and effective treatment for calcific stent under-expansion with good medium-term results.

Excimer Laser coronary atherectomy as adjunctive treatment of severe stent underexpansion with bulky calcification

Excimer Laser coronary atherectomy has improved significantly in recent years, emitting high-energy ultraviolet and short wavelength with less penetration and heat emission, ultimately leading to less tissue damage and fewer complications. We described a case of a 66-year-old male patient, former smoker and suffering from hypertension, diabetes mellitus, and dyslipidemia. He underwent multiple percutaneous coronary interventions in the left anterior descending artery with bare metal and drug-eluting stents. In the last percutaneous coronary intervention, the stent was underexpanded and the patient presented acute stent thrombosis and recurrent stent restenosis. New percutaneous coronary interventions with adjunctive Excimer Laser coronary atherectomy were undertaken due to refractory angina, using progressive load and saline injection, followed by subsequent high-pressure balloon inflation and drug-eluting stent implantation with an excellent result. At 8-month follow-up, the patient was asymptomatic.

Unrecoverable stent deformation in the left main: Crush it or remove it?

Serial ostial and distal left main lesions continue to be one of the most difficult tasks for the interventional cardiologist, with many potential complications occurring. We present such a high-risk percutaneous coronary intervention where immediate stent explantation was deemed necessary because the metal deformation and high radial strength of the particular stent platform would prevent an acceptable procedural result if it had been crushed to the vessel wall. The aim of this paper was to discuss left main stent deformation, debate the risks and benefits of stent explantation and finally test in-vitro our theory on "insufficient" crush with stents with high radial strength and compare it with conventional stents. Bench-testing supports our ad-hoc explantation decision showing stent underexpansion, recoil, and malapposition, obtaining an inadequate minimal stent area.

Impact of ultrasound reverberation in calcified coronary arteries: Intravascular ultrasound study

Background and aimsIntravascular ultrasound (IVUS) often allows us to observe reverberations behind calcification in percutaneous coronary intervention (PCI) to heavily calcified lesions. However, clinical significance of reverberations remains unknown. The aim of this study was to assess the impact of reverberations on stent expansion and clinical outcomes after PCI with rotational atherectomy (RA) to heavily calcified lesions. MethodsWe considered 250 calcified lesions that underwent IVUS-guided PCI with RA. According to the number of reverberations (NR), those lesions were divided into the high NR (≥3) group (n = 36) and the low NR (≤2) group (n = 214). Stent expansion and the cumulative incidence of ischemia-driven target lesion revascularization (ID-TLR) were compared between the high and low NR groups. ResultsThe high NR group showed significantly smaller stent expansion rate than the low NR group (67.7% vs. 75.9%, respectively, p=0.02). The multivariate logistic regression analysis showed that high NR and calcified nodule were significantly associated with stent underexpansion. The incidence of ID-TLR was significantly higher in the high NR group than in the low NR group (p=0.03). In multivariate Cox hazard analysis, high NR and acute coronary syndrome were significantly associated with ID-TLR. ConclusionsHigh NR was significantly associated with stent underexpansion and ID-TLR. When high NR was detected by IVUS, the PCI strategy was be planned carefully to avoid stent underexpansion. The follow-up program of the patients with high NR might need to be scheduled prudently because of the high risk of TLR.

A novel optical coherence tomography‑based calcium scoring system can predict the stent expansion of moderate and severe calcified lesions.

Coronary calcified lesions can exert serious effects on stent expansion. A calcium scoring system, based on optical coherence tomography (OCT), has been previously developed to identify relatively mild calcified lesions that would benefit from plaque modification procedures. Therefore, the present study aimed to establish a novel OCT-based scoring system to predict the stent expansion of moderate and severe calcified lesions. A total of 33 patients who underwent percutaneous coronary intervention (PCI; 34 calcified lesions were observed using coronary angiography) were retrospectively included in the present study. Coronary angiography and OCT images were subsequently reviewed and analyzed. Furthermore, a calcium scoring system was developed based on the results of multivariate analysis before the optimal threshold for the prediction of stent underexpansion in patients with moderate and severe calcified lesions was determined. The mean age of the patients was 67±10 years. The present analysis demonstrated that the final post-PCI median stent expansion was 70.74%, where stent underexpansion (defined as stent expansion <80%) was observed in 23 lesions. The mean maximum calcium arc, length and thickness, which were assessed using OCT, were found to be 230˚, 25.10 mm and 1.18 mm, respectively. A multivariate logistic regression model demonstrated that age and the maximum calcium arc were independent predictors of stent underexpansion. A novel calcium scoring system was thereafter established using the following formula: (0.16 x age) + (0.03 x maximum calcium arc) according to the β-coefficients in the multivariate analysis, with the optimal cut-off value for the prediction of stent underexpansion being 16.87. Receiver operating characteristic curve analysis demonstrated that this novel scoring system yielded a larger area under the curve value compared with that from a previous study's scoring system. Therefore, in conclusion, since the calcium scoring system of the present study based on age and the maximum calcium arc obtained from OCT was specifically developed in the subjects with moderate and severe calcified lesions, it may be more accurate in predicting the risk of stent underexpansion in these patients.

Low burr-to-artery ratio predict stent underexpansion in patients with high OCT based calcium score underwent rotablator atherectomy

Abstract Background Stent under-expansion is the potent predictor for stent thrombosis. Purpose We aim to determine the incidence of stent under-expansion and its predictors in patient who undergoing rotational atherectomy (RA) assisted percutaneous coronary intervention (PCI) assessed by optical coherence tomography (OCT). Method The study included 83 consecutive patients who undergoing OCT guidance RA assisted PCI during January 2016 through September 2020. Baseline clinical characteristics and intracoronary imaging data were recorded. Stent under-expansion was defined as the minimal stent area divided by average of proximal and distal reference lumen area &amp;lt;80%. Results Majority of patients (83%) had OCT based calcium score 3–4. The incidence of stent under-expansion was 9.6%. Comparing between the patient with optimized stent expansion and stent under-expansion, patients with stent under-expansion has older age (79.1±6 vs 69.8±10.4, p=0.015), higher calcium thickness (1.01±0.83 vs 0.65±0.22, p&amp;lt;0.001), longer calcium length (18.68±1.88 vs 12.69±5.33, p&amp;lt;0.001). and lower burr to artery ratio (0.53±0.09 vs 0.65±0.09, p&amp;lt;0.001). The optimal cut-off values of burr to artery ratio &amp;lt;0.54 predict stent under-expansion. Conclusion In the patients with high OCT based calcium score underwent RA assisted PCI, burr to artery ratio&amp;lt;0.54 is a predictor for stent underexpansion. Funding Acknowledgement Type of funding sources: None.

Characterization of lipidic plaque materials at calcified atheroma: its association with calcification thickness evaluated by optical coherence tomography and near-infrared spectroscopy imaging

Abstract Introduction The degree of calcification and its thickness have been considered to affect stent expansion, leading to an increases risk of repeat revascularization in patients receiving PCI. Pathophysiologically, accumulation of lipidic materials within vessel wall could trigger the formation of plaque calcification. Elucidating characteristics of lipidic plaque components at calcified atheroma may enable to identify phenotypes with thick calcification which less likely responds to PCI. Purpose This study investigated the relationship of calcification thickness with lipidic plaque materials at calcified atheroma by using OCT and near-infrared spectroscopy (NIRS) imaging. Methods We analyzed 52 calcified lesions (culprit/non culprit lesions=44/8) in 47 CAD patients (stable CAD/ACS=36/11) from the REASSURE-NIRS registry (NCT04864171). OCT and NIRS imaging evaluated 4-mm segment exhibiting maximum superficial calcification arc. Calcification thickness on OCT imaging, its arc on IVUS imaging, and NIRS-derived lipid arc were analyzed at every 1-mm interval cross-sectional images. In addition, yellow-calcification ratio (YCR = lipid arc/calcification arc) was calculated (Figure 1). Results 53% of study subjects exhibited chronic kidney disease and 70% of them received a statin (averaged on-treatment LDL-C =89mg/dL). Throughout OCT and NIRS/IVUS imaging analysis of 260 cross-sectional images, the averaged calcification arc, its maximum thickness, lipid arc and YCR were 210° (167–285°), 0.78mm (0.62–0.95mm), 95° (31–169°) and 0.33 (0.09–0.59), respectively. As expected, thicker calcification more likely exhibited a greater calcification arc (r=0.30, p&amp;lt;0.001). Furthermore, a greater thickness of calcification was associated with smaller lipidic plaque burden, reflected by yellow arc (r=−0.36, p&amp;lt;0.001) and YCR (r=−0.36, p&amp;lt;0.001) (Figure 2). After adjusting age, gender and ACS, calcification arc (p&amp;lt;0.001) and YCR (p&amp;lt;0.001) continued to predict thicker calcification. Conclusion Thickening of calcification was associated with severer calcification arc, which was accompanied by the shrinkage of lipidic plaques. Our findings suggest the evaluation of lipidic plaque component as a potential tool to identify calcified atheroma harbouring thick calcification, which may cause a greater risk of stent underexpansion. Funding Acknowledgement Type of funding sources: None.

Experience with Optical Coherence Tomography Enhanced by a Novel Software (Ultreon™ 1.0 Software)-The First One Hundred Cases.

Introduction: Optical coherence tomography (OCT) intravascular imaging including the latest version Ultreon™ 1.0 Software (Abbott Vascular, Santa Clara, CA, USA), not only improve patients prognosis, but also facilitates improved percutaneous coronary intervention (PCI). Objectives: The aim of the study was to compare procedure related decision making, procedural indices, clinical outcomes according to the extent of stent expansion and assess risk factors of underexpansion in patients treated with PCI using OCT. Methods: The study comprised 100 patients, which were divided in groups according to the extent of stent expansion: <90 (29 patients) and ≥90% (71 patients). Comparison of OCT parameters, selected clinical and procedural characteristics was performed between groups. We assessed clinical outcomes during the follow-up: major adverse cardiovascular events and risk factors of stent underexpansion. Results: Patients from the stent underexpansion group were treated more often in the past with percutaneous peripheral interventions (p = 0.02), no other significant differences being noted in general characteristics, procedural characteristics or clinical outcomes comparing both groups. Significant predictors of stent underexpansion assessed by simple linear univariable analysis included: hypercholesterolemia, obstructive bronchial diseases and treatment with inhalators, family history of cardiovascular disease, PCI of other than the left main coronary artery, stent and drug-eluting stent implantation, PCI without drug-eluting balloon, paclitaxel antimitotic agent, greater maximal stent diameter and lower mean Euroscore II value. Univariable logistic regression analysis revealed a correlation between stent underexpansion and greater creatinine serum concentration before [OR: 0.97, 95%CI: 0.95–0.99, p = 0.01)] and after PCI [OR: 0.98, 95%CI: 0.96–0.99, p = 0.02)]. Conclusions: Based on the presented analysis, the degree of stent expansion is not related to the selected procedural, OCT imaging indices and clinical outcomes. Logistic regression analysis confirmed such a relationship for creatinine level.

Definition of Optimal Optical Coherence Tomography-Based Stent Expansion Criteria: In-Stent Minimum Lumen Area Versus Residual Stent Underexpansion.

The mismatch between in-stent minimum lumen area (sMLA) and reference vessel lumen area, defined as stent underexpansion (SU), could be an important determinant of stent failure. We tested the clinical predictive value of absolute sMLA in comparison to relative SU in the context of the CLI-OPCI (Centro Per La Lotta Contro L'Infarto-Optimisation of Percutaneous Coronary Intervention) project registry. We retrospectively analyzed end procedural optical coherence tomography findings in 1211 patients (1422 lesions) undergoing percutaneous coronary intervention, assessing the prevalence and magnitude of residual SU and exploring correlation with outcome in comparison with sMLA. In our series, both sMLA and SU were related to vessel size and anatomic lesion complexity. When compared with patients without adverse event at follow-up, those experiencing device-oriented cardiovascular events (composite of cardiac death, target vessel myocardial infarction, target lesion revascularization, and stent thrombosis) showed a lower sMLA (5.6±2.1 versus 6.1±2.1 mm2; P=0.011) but a comparable degree of SU (11.6±14.1% versus 11.2±13.3%; P=0.734). The prespecified cutoff value of sMLA <4.5 mm2, documented in 23.8% of cases, was confirmed as independent outcome predictor for device-oriented cardiovascular events (hazard ratio [HR], 2.05 [95% CI, 1.5-2.9]) including target lesion revascularization (HR, 2.43 [95% CI, 1.7-3.5]) and stent thrombosis (HR, 3.23 [95% CI, 1.7-6.3]). A residual SU of 10%, 20%, and 30% was observed in 38.0%, 18.2%, and 7.6% of cases, respectively. No grade of residual SU significantly increased the risk of stent failure, unless if an SU >20% was associated with an sMLA <4.5 mm2 (HR, 3.11 [95% CI, 1.7-5.6]). Finally, an association between stent overexpansion (ie, >110%) and device-oriented cardiovascular events was also observed (HR, 1.60 [95% CI, 1.1-2.3]). Final absolute sMLA and not relative SU was associated with an increased risk of stent failure. A variable grade of SU was common, but it resulted in being clinically relevant only when associated with an sMLA <4.5 mm2.

Coronary lithotripsy for the treatment of underexpanded stents: the international & multicentre CRUNCH registry.

Stent underexpansion increases the risk of cardiac adverse events. At present, there are limited options to treat refractory stent underexpansion. In this context, the intravascular lithotripsy (IVL) system might be a safe and effective strategy. We aimed to evaluate the safety and efficacy of IVL in addressing resistant stent underexpansion due to heavy underlying calcification. This was an international multicentre registry including patients receiving IVL therapy to treat stent underexpansion from December 2017 to August 2020. Angiographic and intracoronary imaging data were collected. The efficacy endpoint was device success (technical success with a final percentage diameter stenosis <50%). The safety endpoint was in-hospital major adverse cardiac events (MACE). Seventy patients were included, the mean age was 73±9.2 years and 76% were male. The median time from stent implantation to IVL therapy was 49 days (0-2,537). Adjuvant treatment with non-compliant balloon dilatations pre- and post-IVL was performed in 72.3% and 76.8% of patients, respectively, and additional stenting was performed in 22.4%. Device success was 92.3%. Minimum lumen diameter increased from 1.49±0.73 mm to 2.41±0.67 mm (p<0.001) and stent expansion increased by 124.93±138.19% (p=0.016). No IVL-related procedural complications or MACE were observed. The use of bailout IVL therapy directly after stenting and the presence of ostial underexpanded lesions negatively predicted lumen diameter gain. Coronary lithotripsy is safe and effective in increasing lumen and stent dimensions in underexpanded stents secondary to heavily calcified lesions.

TCT-285 Prevalence and Anatomical Factors to Be Associated With Stent Underexpansion in Non-Severely Calcified Lesions

TCT-285 Prevalence and Anatomical Factors to Be Associated With Stent Underexpansion in Non-Severely Calcified Lesions

Stent underexpansion in the CRUNCH registry: worth cracking?

Stent underexpansion in the CRUNCH registry: worth cracking?

TCT-188 Safety and Efficacy of Intravascular Lithotripsy in the Management of Stent Underexpansion Among Elderly Patients

TCT-188 Safety and Efficacy of Intravascular Lithotripsy in the Management of Stent Underexpansion Among Elderly Patients

Structural analysis of regional transcatheter aortic valve underexpansion and its implications for subclinical leaflet thrombosis.

Subclinical leaflet thrombosis has been increasingly recognized following transcatheter aortic valve replacement (TAVR). Determining the risk factors is vital in preventing clinical leaflet thrombosis and ensuring long-term value durability. Clinical data have indicated that regional stent under-expansion of transcatheter aortic valves (TAVs), particularly self-expanding devices, may be associated with an increased risk of subclinical leaflet thrombosis. This study aimed to determine the effects of regional TAV frame under-expansion on leaflet kinematics, leaflet structural characteristics, and explore its impact on the likelihood of leaflet thrombosis. In this study, mild and moderate regional frame under-expansion of a 26-mm CoreValve were examined using experimental testing and computational simulations. The results indicated that regional TAV frame under-expansion impairs leaflet kinematics and reduces the range of motion in leaflets with an angle less than 120°. The reduced range of motion can increase blood stasis on the surface of the TAV leaflets. The results also demonstrated that regional frame under-expansion induced localized high-stress regions in the leaflets close to the fixed boundary edge. The increased mechanical stress can lead to accelerated tissue degeneration. The study improves our understanding of the effects of regional stent under-expansion in TAVR. Post-procedural balloon dilatation of self-expanding TAVs can potentially be advantageous in reducing leaflet distortion and normalizing leaflet stress distribution. Large-scale, prospective, and well-controlled studies are needed to further investigate regional TAV frame under-expansion effects on subclinical leaflet thrombosis and long-term valve durability.

Treatment of In-Stent Restenosis Using a Dedicated Super High-Pressure Balloon

BackgroundTreatment of in-stent restenosis (ISR) is challenging and treatment failure rate remains high. Correction of stent under-expansion and neointimal compression using the twin-layer OPN™ highly non-compliant balloon (NCB) at high pressure (>30 atm) may lead to increased luminal gain and thus better clinical outcomes. We evaluated periprocedural safety and clinical long-term outcomes after ISR treatment using the OPN™ NCB in a real-world population. MethodsFrom an ongoing registry, consecutive ISR patients treated with the OPN™ NCB at a tertiary cardiology center in Switzerland were analyzed. We evaluated procedural efficacy, periprocedural complications, target lesion/vessel failure (TLF/TVF), and major adverse cardiovascular events (MACE). ResultsTotally, 208 ISR lesions were treated in 188 patients (mean age 68 ± 13 years, 78 % males). Most lesions were moderately to heavily calcified (89 %), the majority (70.2 %) had complex lesion characteristics (AHA Type B2/C lesions) and 50.5 % were non-focal ISR lesions. After ISR treatment using high pressure pre- and post-dilatation (mean pressure 33 ± 6 atm) with the OPN™ NCB device, the rate of major complications was low (0.96 % coronary perforation, 4 % major dissections, 1.9 % no-reflow and 0.5 % acute vessel closure). At 1-year follow-up, MACE occurred in 19.7 %; 15.4 % patients had TVF; MI and stent thrombosis was found in 5.9 % and 2.1 % of all patients, respectively; and 5 patients died. ConclusionsFor ISR treatment, using the super non-compliant OPN™ balloon at very high pressures is safe. Moreover, its use might lead to a low rate of TLF/TVF during long-term follow-up, but this requires further evaluation in dedicated comparative trials.