Stent Diameter Research Articles

Use of intravascular ultrasound for optimal vessel sizing in chronic total occlusion percutaneous coronary intervention.

AimThe aim of this study is to provide evidence on how use of standardized intravascular ultrasound (IVUS) use impacts stent size choice in the setting of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) compared to visual estimation.Methods and resultsData of 82 consecutive patients who had successfully undergone IVUS-guided revascularization of CTO at the University Medical Center Mainz were analyzed. Angiography-based stent size prediction for the proximal and distal vessels was compared to the implanted stent diameter after IVUS assessment. Angiography-based stent size prediction for the proximal vessel was 3.09 ± 0.41, whereas IVUS use demonstrated larger vessel diameter, resulting in larger implanted stent diameter (3.24 ± 0.45, p < 0.001). Proximal vessel stent size prediction was underestimated in the majority of patients by angiographic estimation. Angiography-based stent size prediction for the distal vessel was 2.79 ± 0.38, whereas IVUS use demonstrated larger vessel diameter, resulting in larger implanted stent diameter (2.92 ± 0.39, p < 0.001).ConclusionPre-stent IVUS assessment in CTO PCI provides important information on vessel morphology and size. Angiography-based stent size prediction for the proximal and distal vessels was frequently underestimated, IVUS use demonstrated larger vessel diameter, resulting in significantly larger implanted stent diameter.

Predictors of No-Reflow in Patients undergoing Primary Percutaneous Coronary Intervention for Acute ST Elevation Myocardial Infarction at Tabba Heart Institute Karachi

Aim: To determine the predictors of no-reflow in patients undergoing Primary Percutaneous Coronary Intervention (PPCI) for acute ST elevation myocardial infarction (STEMI) at Tabba Heart Institute Karachi. Study duration: The study was carried out from September 2020 to September 2021. Methods: An observational study that was conducted at Tabba heart Institute Karachi. All patients with acute ST elevation myocardial infarction (STEMI) presenting within 12 hours of symptoms who undergoing primary PCI were included in the study. The patients were categorized Angiographically as no –reflow (with Thrombolysis in Myocardial Infarction (TIMI) &lt;3 and reflow (TIMI-3) flow groups. The data regarding age and gender, type of MI, time from symptoms onset, co-morbid conditions like diabetes mellitus, hypertension, smoking, baseline Thrombolysis In Myocardial Infarction Trials (TIMI flow), infarct related artery (IRA), diameter of stent used, and the TIMI flow in IRA after the completion of procedure but before the use of intracoronary adenosine if needed, was recorded on a pre-designed proforma. The data was analyzed using SPSS 20.0. Results: Total 296 patients who underwent primary PCI after acute MI were enrolled in the study. Mean age of the study population was 57±11 years. No reflow was present in 31.4% of patients. No reflow was more common in patients with age more than 60 years, females, symptom onset to primary PCI time of more than 6 hours, LAD infarct, and baseline TIMI flow &lt; 2. Conclusion: During primary PCI, no reflow occurs in a significant percentage of patients and is predictable by a number of factors which should be kept in mind to minimize the incidence of no reflow. Key words: No reflow, acute myocardial infarction, primary PCI

In-stent restenosis after vertebral artery origin stenosis stenting: a nomogram for risk assessment

ObjectiveTo propose a nomogram for individual risk assessment of in-stent restenosis (ISR) after vertebral artery origin stenosis (VAOS) stenting.MethodsWe included 793 patients with VAOS treated with stenting from October 2006...

Intravascular ultrasound evaluation during iliofemoral venous stenting is associated with improved midterm patency outcomes

ObjectiveIntravascular ultrasound (IVUS) examination is increasingly used in the treatment of iliofemoral venous disease and provides more sensitive and specific detection of stenotic lesions when compared with traditional multiplanar venography alone. Correlations with deep venous stent patency, however, have not yet been investigated. The objective of the study was to evaluate the impact of the use of IVUS examination in addition to multiplanar venography on iliofemoral venous patency. MethodsConsecutive patients who underwent stenting for symptomatic thrombotic or nonthrombotic iliofemoral venous lesions (NIVLs) between 2014 and 2020 at a single institution were identified and divided into two groups based on whether IVUS examination was used before stent deployment in addition to multiplanar venography compared with venography alone. A retrospective review of demographic, operative, and follow-up data was performed. Thirty-day and 2-year stent patency were measured as primary end points. χ2 analysis, logistic regression models, and Kaplan-Meier survival analysis were used to determine outcomes. Technical details and outcomes were additionally examined among patients treated for acute deep venous thrombosis, post-thrombotic syndrome, or NIVLs separately on subgroup analysis. ResultsWe identified 150 patients (173 limbs, 23 bilateral) who underwent iliofemoral stenting during the study period at our institution (mean age: 48.8 ± 16.8 years, 61% female). Adjunctive IVUS utilization before stent deployment was reported in 69 of 173 (39.9%) treated limbs. IVUS examination was more likely to be used in patients who underwent stenting for NIVLs compared with thrombotic disease (41.0% vs 11.2%, P < .01). There was no difference in the number of stents deployed between IVUS and non-IVUS cohorts. However, IVUS examination was associated with the increased total length of the stent deployed (126 ± 56 vs 112 ± 48 mm, P = .04) and a higher rate of infrainguinal stent extension (17.4% vs 6.7%, P = .03). In addition, mean stent diameter was significantly higher when IVUS examination was performed before stent placement (16.3 ± 3.7 vs 15.2 ± 1.9 mm, P < .01). Both 30-day (98.5% vs 89.4%, P = .02) and 2-year (90.3% vs 78.7%, P = .03) primary patency were significantly higher in the IVUS cohort. Adjunctive IVUS use was found to significantly protect against stent reintervention at 2 years on adjusted Cox regression analysis (hazard ratio: 0.22, 95% confidence interval: 0.07-0.71, P = .01). ConclusionsAdjunctive IVUS utilization is associated with differences in stent diameter and length selections as well as landing segments in the treatment of thrombotic and nonthrombotic iliofemoral venous disease. IVUS examination before stent deployment significantly protects against 30-day and 2-year stent reintervention when compared with the use of multiplanar venography alone. These data provide stronger evidence for routine IVUS use in addition to venography before iliofemoral venous stenting.

Predictors of restenosis following percutaneous coronary stent implantation: The role of trimetazidine therapy.

AimsIn-stent restenosis (ISR) is an unresolved problem following percutaneous coronary intervention (PCI), having a negative impact on clinical outcome. The main goal of this study was to find new independent predictors that may influence the development of ISR.Methods and resultsIn this retrospective analysis, 653 PCI patients were involved. All patients had coronary stent implantation and a follow-up coronary angiography. Based on the presence of ISR at follow-up, patients were divided into two groups: 221 in the ISR and 432 in the control group. When evaluating the medical therapy of patients, significantly more patients were on trimetazidine (TMZ) in the control compared to the ISR group (p = 0.039). TMZ was found to be an independent predictor of a lower degree of ISR development (p = 0.007). TMZ treatment was especially effective in bare metal stent (BMS)-implanted chronic coronary syndrome (CCS) patients with narrow coronary arteries. The inflammation marker neutrophil to lymphocyte ratio (NLR) was significantly elevated at baseline in the ISR group compared to controls. The reduction of post-PCI NLR was associated with improved efficacy of TMZ to prevent ISR development. Drug eluting stent implantation (p < 0.001) and increased stent diameter (p < 0.001) were the most important independent predictors of a lower degree of ISR development, while the use of longer stents (p = 0.005) was a major independent predictor of an increased ISR risk.ConclusionTMZ reduces the occurrence of ISR following PCI, with special effectiveness in BMS-implanted patients having CCS and narrow coronary arteries. TMZ treatment may help to lower ISR formation in countries with high BMS utilization rates.

Investigation of changing geometry parameters of nickel-titanium shape memory alloys wire stent in cardiovascular implants

The purpose of this investigation was to assess the effects of changing the Nitinol stent’s geometrical characteristics on the superelastic behavior of the stent using the finite element method. Four different geometrical parameters were considered and analyzed in sixteen stents. These geometrical parameters consisted of stent length, number of stent’s meanders, inside diameter of the stent and wire diameter. Results showed that decreasing either stent length or the number of stent meanders and increasing either the inside diameter of the stent or wire diameter generally result in more sensible superelastic behavior exposure. The effect of changing stent length is independent of the inside diameter and number of the stent’s meanders. Effects of changing inside diameter and number of stent's meanders were exactly dependent together. In addition, increasing wire diameter has a great effect on the maximum force. In conclusion, the results of this study may serve as guidelines for future stent design.

Comparison of the efficacies of 1.0 and 1.5 mm silicone tubes for the treatment of nasolacrimal duct obstruction

This retrospective observational study analyzed the postoperative outcomes of bicanalicular intubation using different diameters of tube stents for treating postsaccal nasolacrimal duct obstruction. A total of 130 patients diagnosed with postsaccal obstruction who underwent endoscopic-assisted silicone tube intubation were included in the study. Patients intubated with a 1.5-mm large-diameter tube were designated as the LD group, and those with a 1.0-mm normal-diameter tube were designated as the ND group. The patency rates of the two groups at 1 year after tube removal were compared using the Kaplan–Meier curve and restricted mean survival time (RMST) method with τ = 365 days. Results demonstrated that the recurrence rate after tube removal was significantly lower in the LD group as compared with the ND group (p = 0.001). The patency rates at 1 year after removal in the LD and ND group were 85.7% (95% confidence interval [CI]: 75.4, 91.9) and 73.9% (95% CI: 61.7, 82.8), respectively. When comparing the patency rates by the RMST method at τ = 365 days, the RMST difference, RMST ratio, and RMTL ratio were higher in the LD group at p = 0.045, 0.052, and 0.046, respectively.

Risk factors for post-endoscopic retrograde cholangiopancreatography cholangitis in patients with hepatic alveolar echinococcosis—an observational study

Background Hepatic alveolar echinococcosis (HAE) is considered to be one of the most deadly chronic parasitic diseases in the world. We have shown that the incidence of cholangitis in patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) was increased significantly. On this finding, we carried out, a preliminary study on the risk factors for cholangitis after ERCP. Aims To retrospectively detect the risk factors for post-ERCP cholangitis in patients with biliary tract affected by HAE. Methods The study included data from 51 cases of AE who had undergone therapeutic ERCP between January 2015 and December 2019. Demographic and treatment data were extracted from the medical records, and the association between potential risk factors and the development of post-ERCP cholangitis was evaluated using a collected database. Results There were five cases of mild cholangitis after ERCP (Tokyo criteria), and no moderate or severe cholangitis occurred. The incidence rate of cholangitis after ERCP was 9.8%. Univariate analysis showed hilar bile duct stenosis (p = .016), endoscopic retrograde biliary drainage (p = .007), a stent diameter ≥8.5 Fr (p = .000) and single stent implantation (p = .010) were risk factors for post -ERCP cholangitis. All cases of cholangitis improved under conservative treatment. Conclusion Patients with hilar bile duct compression or endoscopic retrograde biliary drainage appeared to be more likely to develop post-ERCP cholangitis. The number and diameter of biliary stents may influence post-ERCP cholangitis. Sample size and clinical heterogeneity are two insurmountable difficulties, and a larger sample size needs to be collected to verify the risk factors for screening. KEY MESSAGES Many studies reported the post-ERCP complications in patients with hepatic alveolar echinococcosis and found that the incidence of post-ERCP cholangitis was significantly high. Therefore, we conducted a preliminary study on the risk factors of postoperative cholangitis in patients who underwent ERCP. The incidence rate of cholangitis after ERCP was 9.8%. We found that hilar bile duct stenosis, and endoscopic retrograde biliary drainage, were risk factors for cholangitis, and stent diameter and the number of stent implantation may influence the incidence rate of cholangitis after ERCP. Sample size and clinical heterogeneity are two insurmountable difficulties, and a larger sample size needs to be collected to verify the risk factors of screening.

Procedure-Related Differences and Clinical Outcomes in Patients Treated with Percutaneous Coronary Intervention Assisted by Optical Coherence Tomography between New and Earlier Generation Software (Ultreon™ 1.0 Software vs. AptiVue™ Software).

(1) Introduction: Optical coherence tomography (OCT) intravascular imaging facilitates percutaneous coronary intervention (PCI). Software for OCT is being constantly improved, including the latest version Ultreon™ 1.0 Software (U) (Abbott Vascular, Santa Clara, CA, USA). In the current analysis, we aim to compare processing results, procedural indices as well as clinical outcomes in patients treated via PCI. This was conducted using earlier generation OCT imaging software versions (non-U) and the newest available one on the market (U). (2) Methods: The study comprised 95 subsequent and not selected patients (55 processed with U and 40 non-U). The non-U processings were transferred for evaluation by U software, while the comparison of OCT parameters, selected clinical and procedural indices was performed between groups. We further assessed clinical outcomes during the follow-up period, i.e., major adverse cardiovascular events (MACE) and predictors of stent expansion. (3) Results: We did not detect any differences in general features between either of the assessed groups at baseline. Non-U software was more often used for bare-metal stenting (p = 0.004), while PCIs in the U group demanded a greater number of stents (p = 0.03). The distal reference of external elastic lamina (EEL) diameter was greater in the non-U group (p = 0.02) with no concurrent differences in minimal (p = 0.27) and maximal (p = 0.31) stent diameter. It was also observed that MACE was more frequently observed in the non-U group (p = 0.01). Neither univariable (estimate: 0.407, 95%CI: (−3.182) − 3.998, p = 0.82) nor multivariable (estimate: 2.29, 95%CI: (−4.207) − 8.788, p = 0.5) analyses demonstrated a relationship between the type of software and stent expansion. (4) Conclusions: Improvement in the software for image acquisition and processing of OCT is not related to stent expansion. The EEL diameter is preferably used to select the distal stent diameter in newer software.

Procedural Performance of Ultrathin, Biodegradable-Polymer-Coated Stents Versus Durable-Polymer-Coated Stents Based on Intracoronary Imaging

Thinner stent struts might lead to a higher risk of recoil and subsequently a smaller minimal stent area (MSA), which is known to be the strongest predictor of stent failure. We compared procedural performance between an ultrathin-strut biodegradable-polymer sirolimus-eluting stent (BP-SES) and a durable-polymer zotarolimus-eluting stent (DP-ZES) using intracoronary imaging.A consecutive cohort of patients underwent percutaneous coronary intervention (PCI) with either BP-SES or DP-ZES in a pseudorandomized fashion between July 2018 and October 2019. In the present subanalysis, we included cases in which post-PCI imaging with intravascular ultrasound (IVUS) or optical coherence tomography (OCT) was performed. The primary endpoint of the study was MSA. Secondary endpoints included percentage stent expansion and presence of residual edge disease, malapposition, tissue protrusion, submedial edge dissections, or edge hematoma.A total of 141 treated lesions (78 BP-SES and 63 DP-ZES) in 127 patients were analyzed. Median age was 69.3 years (interquartile range [IQR], 57.3-75.6) and 74.0% of patients were male. All baseline and procedural characteristics were comparable between both groups. Median MSA was 5.80 mm² (IQR, 4.40-7.24) for BP-SES and 6.35 mm² (IQR, 4.76-8.31) for DP-ZES (P=.15). No significant differences in stent expansion, residual edge disease and presence of malapposition, tissue protrusion, submedial edge dissections, or edge hematomas were found. Stent diameter and stent length were found to be independent predictors of MSA.No significant differences in MSA were found between lesions treated with BP-SES vs DP-ZES. BP-SES and DP-ZES were comparable in terms of procedural performance.

Drainage of infected kidneys with ureteral stents: does size matter?

The purpose of our study was to evaluate the ability of ureteral stents with different diameters to drain pus that accumulates in an obstructed kidney using an in vitro model. We developed an in vitro model of an obstructed kidney filled with pus. The model included a silicon kidney unit based on computed tomography (CT) data, a 3D printed ureteral stone based on a real extracted ureteral stone, a latex ureter model, a bladder vessel, and a fluid with qualities resembling pus. Identical printed stones were inserted into four ureter models containing stents with varying diameters (4.8F, 6F, 7F, 8F), each of which was connected to the kidney unit and the bladder vessel. The kidney unit was filled with artificial pus to pressures of 30 cmH2O to simulate an infected and obstructed kidney. The obstruction was relieved with stents in place, while artificial urine was pumped into the kidney; pressure in the kidney and remaining pus were measured continuously. The rate of pressure drop and the final pressure measured in the kidney were unaffected by the diameter of the stent. For all stent diameters, the pressure reached non-obstructed levels within 30s, final pressure was reached within 90-120s, and minimal amounts of pus remained in the kidney after 120min. In vitro experiments demonstrate that all stent diameters drain pus-filled, obstructed kidneys with the same efficacy. The common perception that larger diameter tubes are more effective under such circumstances should be re-examined.

Risk factors for in-stent restenosis after vertebral artery stenting of V1 segment: A systematic review and meta-analysis.

In-stent restenosis (ISR) remains a challenge in the treatment of vertebral artery V1 segment stenosis. The aim of this meta-analysis is to identify the risk factors of ISR. Studies eligible for inclusion criteria were found in PubMed, Embase, and Cochrane Library databases. Data related to risk factors of ISR were extracted from the included studies, and pooled analysis was performed when data of the same factor were available in ≥2 studies. Dichotomous outcomes were analyzed with odds ratios (OR) and continuous outcomes were analyzed with a weighted mean difference (WMD). The Stata 14.0 program was used for the meta-analysis. A total of 11 studies involving 1356 patients were included in our analysis. Pooled analyses showed that younger age (p = 0.01; WMD= -1.958; 95% confidence interval [CI], -3.453 to -0.463) and V1 tortuosity (p = 0.004; OR = 4.145; 95%CI, 1.56-11.012) significantly associated with higher risk of ISR in V1 segment stenting. While bare-metal stents, stent diameter and length, diabetes mellitus, coronary artery disease, and smoking were not found to increase ISR rates. This meta-analysis showed that young age and V1 tortuosity increase the ISR rates after vertebral V1 segment stenting.

The role of transjugular intrahepatic portosystemic shunt in patients with cirrhosis and ascites: Recent evolution and open questions.

In selected patients with cirrhosis and ascites, transjugular intrahepatic portosystemic shunt (TIPS) placement improves control of ascites and may reduce mortality. In this review, we summarize the current knowledge concerning the use of TIPS for the treatment of ascites in patients with cirrhosis, from pathophysiology of ascites formation to hemodynamic consequences, patient selection, and technical issues of TIPS insertion. The combination of these factors is important to guide clinical decision-making and identify the best strategy for each individual patient. There is still a need to identify the best timing for TIPS placement in the natural history of ascites (recurrent vs. refractory) as well as which type and level of renal dysfunction is acceptable when TIPS is proposed for the treatment of ascites in cirrhosis. Future studies are needed to define the optimal stent diameter according to patient characteristics and individual risk of shunt-related side effects, particularly hepatic encephalopathy and insufficient cardiac response to hemodynamic consequences of TIPS insertion.

P.155 Giant aneurysm, tiny patient: flow diversion stenting of a giant MCA aneurysm in a young child

Background: A 3-year-old girl presented with a 6-day history of severe headaches. On examination, upper motor neuron signs were noted in the left upper and lower extremities with increased tone, reflexes, and a positive Babinski sign. MRI of the brain revealed a giant right middle cerebral artery (MCA) aneurysm with significant mass effect, associated with cerebral edema and ventricular effacement. CT and CT angiogram showed evidence of aneurysmal wall calcification and lamellar thrombosis within the aneurysmal sac. In addition, there was a smaller right MCA aneurysm in close proximity to the giant aneurysm. Methods: After a balloon occlusion test to assess collateral blood flow to the MCA territory, it was decided to treat both aneurysms with a flow diverting stent. Dual antiplatelet loading was done with aspirin and clopidogrel. The smallest available diameter of Pipeline Shield stent was deployed. Results: The patient remained neurologically unchanged. Early follow-up imaging demonstrated stent patency, reduced size and mass effect of the large aneurysm, reduced cerebral edema, and no flow into the smaller aneurysm. Conclusions: Flow diversion stenting may be employed successfully in pediatric patients, though has unique technical considerations including small size vessels and limited evidence for antiplatelet agent choice and dosing.

Feasibility of Cholangioscopy Using Multibending Ultra-Slim Endoscope Through a Lumen-Apposing Metal Stent for Choledochoduodenostomy.

Endoscopic ultrasound (EUS) guided choledochoduodenostomy using a lumen-apposing metal stent (LAMS) allows access to the biliary system with a sufficiently large diameter stent. However, an appropriate endoscope for this purpose is required. We evaluated the feasibility of per-oral cholangioscopy (POC) using a multibending ultra-slim endoscope through a LAMS for EUS-guided choledochoduodenostomy. Twelve patients who underwent EUS-guided choledochoduodenostomy, followed by POC via a LAMS, were enrolled. POC was performed with an multibending ultra-slim endoscope. The primary outcome was technical success, defined as examination of both hepatic ducts and either the distal common bile duct or stricture site within 10min. The types of intervention and adverse events were also assessed. Technical success was achieved in all cases with the multibending ultra-slim endoscope. Narrow-band imaging endoscopy was performed in five cases (41.7%) and POC-guided targeted biopsy was performed in three cases (25.0%). Stone extraction during POC was performed in two patients (16.7%) and foreign body removal from the intrahepatic duct was performed in one patient. One patient underwent additional metal stent insertion under direct visualization. After POC, no stent migration or severe adverse events were seen in any case. POC using a multibending ultra-slim endoscope for diagnostic or therapeutic purposes can be performed effectively and safely through a LAMS after EUS-guided choledochoduodenostomy.

Role of Intravascular Ultrasound for In Situ Sizing and Technical Assessment of Directional Branches During Branched Endovascular Aortic Repair

To compare intraoperative and early outcomes of branched endovascular aortic repair (BEVAR) of thoracoabdominal aortic aneurysms with or without the use of intravascular ultrasound (IVUS). We conducted a single-center retrospective study of consecutive patients treated for thoracoabdominal aortic aneurysms with branched devices (2019-2021). Two groups were compared. In standard BEVAR (s-BEVAR), sizing was based exclusively on the preoperative computed tomography angiogram, and the technical assessment consisted of intraoperative angiography. From 2020 (iv-BEVAR), IVUS (Philips platform with 0.035-in. Volcano IVUS catheter) was routinely used for in situ sizing of the bridging stent (diameter and length of the distal landing zone, total bridging stent length) and for technical assessment of the bridging stent after deployment (kink, compression, malapposition, or inadequate sealing). s-BEVAR and iv-BEVAR patients were compared in terms of procedural metrics (duration of surgery, radiation dose, radiation time, and contrast volume), technical success (successful introduction and deployment of the device and bridging stents, in the absence of surgical conversion or mortality, type I or III endoleak, branch occlusion, or graft limb obstruction), and 30-day outcomes. There were 59 target vessels (n = 15 patients) in the s-BEVAR group and 56 (n = 15 patients) in the iv-BEVAR group. Aneurysm anatomic classification was similar (extent I-III, 73% vs 67%; extent IV, 27% vs 33%; P = .999). Comparing s-BEVAR vs iv-BEVAR, the total operating time (280 ± 62 minutes vs 293 ± 84 minutes; P = .073) and contrast volume (168 ± 42 mL vs 153 ± 38 mL; P = .312) were similar, although iv-BEVAR had a lower radiation time (119 ± 35 minutes vs 92 ± 42 minutes; P = .042) and dose (745 ± 75 Gy vs 635 ± 85 Gy; P = .010). The use of IVUS identified a significant branch technical defect in 8 of 56 target vessels (14%) not identified by standard angiography; bridging stent compression in five cases and incomplete stent-to-wall apposition in three. These were all intraoperatively corrected with success. Technical success was 100% for both groups, and there were no postoperative deaths and no IVUS-related complications. At 30 days, there were no complications related to the main endograft or directional branches. The use of IVUS for in situ sizing and technical assessment of BEVAR was safe and allowed for reduced radiation time and exposure during BEVAR, maintaining a similar operating time. Compared with sole angiography, the intraoperative use of IVUS led to adjunctive intraoperative maneuvers in a non-negligible portion of target vessels. Further studies are needed to evaluate the clinical role of IVUS in BEVAR.

Assessment of Post-Dilatation Strategies for Optimal Stent Expansion in Calcified Coronary Lesions: Ex Vivo Analysis With Optical Coherence Tomography

IntroductionInterventional cardiologists make adjustments in the presence of coronary calcifications known to limit stent expansion, but proper balloon sizing, plaque-modification approaches, and high-pressure regimens are not well established. Intravascular optical coherence tomography (IVOCT) provides high-resolution images of coronary tissues, including detailed imaging of calcifications, and accurate measurements of stent deployment, providing a means for detailed study of stent deployment. ObjectiveEvaluate stent expansion in an ex vivo model of calcified coronary arteries as a function of balloon size and high-pressure, post-dilatation strategies. MethodsWe conducted experiments on cadaver hearts with calcified coronary lesions. We assessed stent expansion as a function of size and pressure of non-compliant (NC) balloons (i.e., nominal, 0.5, 1.0, and 1.5 mm balloons at 10, 20 and 30 atm). IVOCT images were acquired pre-stent, post-stent, and at all post-dilatations. Stent expansion was calculated using minimum expansion index (MEI). ResultsWe analyzed 134 IVOCT pullbacks from ten ex-vivo experiments. The mean distal and proximal reference lumen diameters were 2.2 ± 0.5 mm and 2.5 ± 0.7 mm, respectively, 80% of times using a 3.0 mm diameter stent. Overall, based on stent sizing, a good expansion (MEI ≥ 80%) was reached using the 1:1 NC balloon at 20 atm, and expansion > 100% was reached using the 1:1 NC balloon at 30 atm. In the subgroup analysis, comparing low-calcified and high-calcified lesions, good expansion (MEI ≥ 80%) was reached using the 1:1 NC balloon at nominal pressure (10 atm) versus using 1:1 NC balloon at 30 atm, respectively. Significant vessel rupture was identified in all the vessels mainly upon post-dilatation with larger balloons, and 60% of the experiments (6 vessels, 3 in each calcium subgroup) presented rupture with the +1.0 mm NC balloon at 20 atm. ConclusionWhen treating calcified lesions, good stent expansion was reached using smaller balloons at higher pressures without coronary injuries, whereas bigger balloons yielded unpredictable expansion even at lower pressures and demonstrated potential harmful damages to the vessels. As these findings could help physicians with appropriate planning of stent post-dilatation for calcified lesions, it will be important to clinically evaluate the recommended protocol.

Age influence on the results of the treatment of complex coronary bifurcated lesions using the mini-crush two-stent technique

Abstract Funding Acknowledgements Type of funding sources: None. Introduction There is limited evidence about the benefit of "double stenting" techniques over "provisional stenting" in percutaneous coronary intervention (PCI) of complex coronary bifurcation lesions. Elderly patients (&amp;gt;75 years) represent an unfavourable high-risk subgroup that have typically been under-represented in cardiovascular clinical trials. Purpose The aim of this study was to evaluate the influence of age on the rate of major adverse cardiovascular events (MACE): cardiovascular mortality, non-fatal myocardial infarction, target lesion revascularization (TLR) and stent thrombosis after prolonged follow-up (median 32 months). Methods Observational study in wich were included 152 consecutive patients (mean age 69.5 years, 73.7% male) with 152 complex bifurcated coronary severe lesions that underwent PCI with "mini-crush" two-stent technique and in which were compared the subgroup of elder patients (&amp;gt;75 years) from April 2014 to April 2020. Results The 53.3% of patients had stable coronary disease and 46.7% acute coronary syndrome (30.1% Non-STEMI and 16.6% STEMI). 35% of patients were &amp;gt;75 years old. We observed a significantly higher proportion of nonsmokers (51.2%), diabetics (38.8%) and hypertensive patients (75.3%). Clinical presentation, basal featured characteristics and antiplatelet pretreatment was similar in both groups. Mean Syntax score was higher in the older group (33.9 ± 13.7 vs. 28.1 ± 12.7, p=0.035). Left main bifurcation was the most frequently coronary artery affected in both groups and circumflex was the most common side vessel. There were no differences in pre-dilation rate either in final kissing balloon post-dilation rate. There were also no differences in the length and diameter of stents implanted and zotarolimus stent was the most commonly used in both groups as well as in the main vessel and in side branch. MACE incidence was higher in the older group (19.3% vs 8.4%, p=0.05), due to higher cardiovascular mortality (10.5% vs 2.1%, p=0.024). There were no differences in the remaining components separately. Conclusions Elderly patients with complex bifurcation coronary severe lesions treated with "mini-crush" technique had higher cardiovascular mortality at long-term follow-up compared with younger patients. There were no differences in other lesion-related outcomes.

A-7 | Drug Eluting Stent Length and Diameter Are Not Associated with Target Lesion Revascularization After Percutaneous Coronary Intervention

Stent length and diameter are thought to contribute to adverse outcomes following percutaneous coronary intervention (PCI) and diameter <3.0 mm is currently included in the ACC dual-antiplatelet therapy risk calculator. Stent characteristics associated with repeat revascularization are not well described for 3rd generation drug-eluting stents (DES).

‘Routine intravascular ultrasound evaluation and change in stenting strategy in primary percutaneous intervention (RIST PCI)’

Background Intravascular ultrasound (IVUS) provides better assessment of vessel size, lesion length and plaque characteristics. There is paucity of data regarding the impact of IVUS on stenting pattern during primary percutaneous intervention (PCI) for ST elevation myocardial infarction (STEMI). Methods We included patients with STEMI undergoing IVUS-guided primary PCI. Diagnostic angiograms were analysed by two different operators who were not part of procedure. They were asked to formulate a treatment plan which included choice of stent diameters, length and number of stents based on angiographic assessment alone. The data were then compared with actual metrics derived from IVUS evaluation. Results Sixty-two patients were included. Left anterior descending artery was involved in 38/62(61.3%) cases. Mean stent diameters assessed by angiogram were 2.94 ± 0.4 mm and 3.01 ± 0.32 mm by cardiologist 1 and 2, respectively. IVUS-derived mean stent diameter was 3.5 ± 0.65 mm (p < 0.001). Mean stent length was 42.29 ± 19.29 mm by IVUS evaluation; while angiographically assessed values were 33.53 ± 11.53 (cardiologist 1) and 35.24 ± 12.97 mm (cardiologist 2) with a mean difference of 8.76 mm and 7.05 mm respectively (p < 0.001). Mean number of stents by IVUS evaluation was 1.42 ± 0.56, while by angiographic evaluation were 1.11 ± 0.37 and 1.13 ± 0.34 respectively (p < 0.001). Conclusions There was significant difference between IVUS derived and angiographically assessed culprit vessel metrics in patients undergoing primary PCI. Clinical outcomes of this discrepancy need further studies.