Experimental Evaluation of a New Single Wire Stainless Steel Fishscale Coronary Stent (Freedomª)

Recent randomized clinical trials revealed a significant reduction in angiographic restenosis rates when adjunctive stenting was performed after conventional coronary balloon angioplasty. Current approved coronary stents are however hampered by their rigidity, limiting their trackability in tortuous vessels and furthermore, needing high pressure deployment for optimal vessel apposition. New coronary stents are currently under development, using more biocompatible metal alloys and/or designs which better align to the vessel wall at moderate deployment pressures. We evaluated the safety, efficacy, angiographic and histological effect of a new stainless steel fishscale designed stent (Freedoma, Global Therapeutics, Co., USA) in a porcine coronary and peripheral artery model. Implantation in the right coronary artery was successful in all 20 pigs. Control angiograms at 6 weeks follow-up demonstrated patent vessels and morphologic evaluation showed only a mild fibromuscular neointimal response resulting in an area stenosis of 28.7 +/- 0.18% and a mean neointimal hyperplasia of 0.18 +/- 0.25 mm. Comparison with the Palmaz-Schatza coronary stent in a porcine peripheral artery model demonstrated similar quantitative angiographic and morphologic vessel analysis results. Also the morphometric data were comparable. Area stenosis: Palmaz-Schatz: 37 +/- 0.24%, Freedom: 21 +/- 0.14%, p = 0.07. Mean neointimal hyperplasia: Palmaz-Schatz: 0.33 +/- 0.24 mm, Freedom: 0.18 +/- 0.08 mm, p = 0.08. CONCLUSION: Freedom coronary stent implantation in a porcine model resulted in a high procedural success without subacute thrombotic occlusions, despite no further anticoagulation nor antiplatelet therapy. Six weeks histopathological and morphometric evaluation demonstrated only a mild fibromuscular neointimal hyperplasia.     

Experimental Evaluation of a New Tubular Coronary Stent (V-Flexª)

The safety, efficacy, angiographic and histological effects of a new 316 L, SS seamless stainless steel tubular stent (V-Flexa, Global Therapeutics, Broomfield, Colorado) was evaluated in a porcine coronary and peripheral artery model. Implantation in the right coronary artery was successful in all 16 pigs. Eight pigs were angiographically controlled after 6 weeks and then sacrificed for morphometric analysis. All stented coronary vessels were widely patent at this moment and morphometric analysis showed only a mild fibromuscular neointimal hyperplasia resulting in a neointimal hyperplasia of 1.15 +/- 0.38 mm2. The remaining 8 pigs were controlled and sacrificed at 12 weeks. At that time, all stented vessels were patent and neointimal hyperplasia was 1.22 +/- 0.34 mm2. Comparison with the Palmaz-Schatza coronary stent (Cordis, Miami, Florida) in a porcine peripheral artery model demonstrated significantly less neointimal hyperplasia at 6 weeks (1.11 +/- 0.73 vs. 2.40 +/- 0.36, p = 0.001) and at 12 weeks (1.53 +/- 0.42 vs. 2.47 +/- 0.63, p = 0.003) for the V-Flex stent. In conclusion, V-Flex coronary stent implantation in a porcine coronary and peripheral arteries results in a high procedural success rate without subacute thrombotic occlusions, despite no further anticoagulation nor antiplatelet therapy. Six and 12 week histopathological and morphometric evaluation demonstrated only a mild fibromuscular neointimal hyperplasia. Comparison with the Palmaz-Schatz coronary stent in a peripheral artery model showed significantly less neointimal hyperplasia in the V-Flex stent.     

Experimental Results with the Multi-Linkª Stent in a Porcine Model

OBJECTIVES: The purpose of this study was to assess the delivery characteristics and the vascular response to placement of the Multi-Linka stent in normal porcine coronary arteries. BACKGROUND: The Multi-Link stent is a balloon expandable stainless steel stent with an interconnected corrugated ring structure designed to provide a high degree of compressive resistance while preserving longitudinal flexibility. The placement characteristics and vascular response to this stent in normal porcine coronary arteries has not been characterized. METHODS: We tested the delivery characteristics and vascular response to the Multi-Link stent in 19 normolipemic miniature swine. Quantitative coronary angiography was used to define stent performance characteristics such as stent expansion and recoil. Histologic assessment of the stented arteries was used to evaluate the acute and chronic vascular response to stent placement. RESULTS: Thirty-five of thirty-five stents (100%) were successfully implanted in the left anterior descending (n = 14), left circumflex (n = 8) or right (n = 13) coronary arteries of nineteen swine. The baseline angiographic mean lumen diameter of the stented coronary segment was 3.41 +/- 0.32 mm and increased to 3.53 +/- 0.33 mm (p < 0.001) after stent placement. The balloon inflated stent diameter was 3.61 +/- 0.36 mm with minimal recoil to a final minimal lumen diameter of 3.53 +/- 0.33 mm after implant (p = 0.001). Linear regression analysis revealed that the percent stent recoil had a significant positive correlation with the stent to artery ratio or the degree of stent over-sizing (r = 0.67; p < 0.0001). Angiographic and histologic follow-up at 72 hours (n = 9), 14 days (n = 12) and 56 days (n = 12) demonstrated that all stents were patent without evidence of migration, intraluminal filling defect or side-branch occlusion. On histology, there was rare evidence of stent-induced deep arterial wall injury such as rupture of the internal elastic lamina and medial laceration. There was no significant difference in the mean injury score observed on day 3 (0.23 +/- 0.22), 14 (0.35 +/- 0.28) or 56 (0.36 +/- 0.27) after implant (p = 0.27). On day 3, the mean thrombus thickness overlying the stent wires was 70 +/- 98μ. The mean neointimal area was similar at 14 and 56 days after implant (1.63 +/- 1.25 mm2 versus 1.78 +/- 0.68 mm2, p = 0.54). CONCLUSIONS: The MULTI-LINK stent easily tracked the coronary arteries and deployed reliably in this experimental model. The multiple interconnected ring geometry of the stent provides adequate compressive resistance, longitudinal flexibility and uniform coverage of the arterial wall throughout the length of the endoprothesis. The stent has acceptable blood and tissue biocompatibility in normal porcine coronary arteries. Oversizing this stent (>10 percent) may have a theoretical disadvantage resulting in a proportionally higher degree of stent recoil. The results of clinical trials will determine if the design features of the Multi-Link stent favorably impact on procedural outcome or long-term patency.     

Study of Coronary Artery Disease in Single Aortic Valvular Disease

Objectives To analyze the results of coronary angiographies (CAG) in patients with single aortic valvular heart disease; To study the relationship between aortic valve diseases and coronary artery disease (CAD). Methods 105 patients with single aortic valvular heart disease before surgery underwent angiography. The data of clinical characteristics and angiographies were analyzed. Results 51 patients had symptoms of angina pectoris among 105 patients with single aortic valvular heart disease. Seven of them were confirmed coronary artery disease by angiographies. Although the incidence of angina in aortic valve stenosis group was significantly higher than that in aortic valve regurgitation, the probability of combination of CAD in aortic valve stenosis group was similar to the later. However, the probability of combination of CAD in degenerative aortic valve group was significantly higher than the groups of rheumatic, congenitally bicuspid aortic valves, and other causes (p < 0.01 ). Conclusions Angina pe     

The Evaluation of the Safety and Efficacy of Transradial Coronary Procedures

Objectives To evaluate the safety and efficacy of transradial coronary procedures (TRCP). Methods The data of 83 cases who accepted transradial coronary angiography (CAG) and transradial percutaneous coronary intervention (PCI) in our department were summarized. The success rates, proximal coronary complications, peripheral vascular complications, severe vagal reflex, mean operation time (MOT), mean recumbent time (MRT), mean hospital-staying time (MHT) were analyzed. The data were compared with that of 420 cases of transfemoral coronary procedures (TFCP) in the same period. Results Success rates and proximal coronary complications were similar in both groups. Severe vagal reflexes were less in TRCP group than in TFCP group. MOT was longer in TRCP group. MRT and MHT were shorter in TRCP group. 12( 14.5%) radial artery spasm, 3(3.6%) radial artery obstruction, 1 sudden respiratory arrest caused by jugular hematoma were observed in TRCP group. Conclusions The efficacy and safety of TRCP are definite. TRCP is more economical. For the purpose of properly evaluate the peripheral vascular complications of TRCP, it is necessary to pay special attention to radial artery occlusion, radial artery stenosis, and jugular hematoma.     

Is Postdilatation with a Noncompliant Balloon Necessary after Coronary Stent Deployment during Primary Angioplasty?

Background

Postdilatation (PD) with noncompliant balloon during elective percutaneous coronary intervention (PCI) is performed usually in clinical practice in order to optimize stent expansion. However, current knowledge about its use in patients undergoing primary PCI is controversial. This study aims to evaluate the angiographical and clinical results of PD in patients who underwent primary PCI with drug eluting stents (DESs).

Methods

A total of 405 consecutive patients (mean age 56.9 ± 12.3 years; 302 male) with ST elevation myocardial infarction were evaluated retrospectively. Patients received DES with or without predilatation according to physician's discretion. Eligible patients were divided into 2 groups based on PD procedure. The clinical end‐points were death, target vessel revascularization (TVR) and stent thrombosis at 6 months after PCI. The angiographic end‐points were postprocedural correct Thrombolysis in Myocardial Infarction (TIMI) frame count (cTFC), final TIMI flow, and myocardial blush grade (MBG).

Results

PD was performed in 214 patients (52.8%). Angiographical parameters such as TIMI flow, cTFC, and MBG did not differ after PD (P > 0.05). During 6‐month follow‐up, TVR and stent thrombosis rates were lower in the PD group (6 vs. 16, P = 0.03; and 3 vs. 10, P = 0.04, respectively). PD and diabetes were detected as independent predictors of MACE (β = 0.52, P = 0.01, and β = ?0.47, P = 0.02; respectively).

Conclusion

Our study revealed that PD does not yield adverse effects on final angiographic parameters when performed during primary PCI. Besides PD seems to decrease probability of stent thrombosis and TVR.

     

Evaluating Stent Optimisation Technique (StentBoost®) in a Dedicated Bifurcation Stent (the Tryton™)

Background/PurposeTo evaluate the use of StentBoost® in the Tryton™ dedicated SideBranch Stent.Methods & ResultsThe Tryton™ SideBranch Stent has been effectively used to manage complex bifurcations. However, the paucity of scaffolding in the proximal part of the stent makes it often difficult to visualise under standard radiographic imaging. We set out to evaluate whether by using an augmented radiographic imaging technique it was possible to aid visualisation of the stent. In particular the so call 'wedding ring' band which is crucial to the procedural success. We further evaluated whether it was possible to determine the apposition of the stent at the carina, its coverage and the ability to aid recrossing of the struts closest to the carina as well as the added radiation exposure.ConclusionsStentBoost® was found to be invaluable to the procedural success of the Tryton™ deployment without adding any extra cost to the procedure and with only a 3.7% increase in radiation to the patient. It allowed enhanced visualisation in all cases to aid apposition, recrossing and coverage.     

Clinical and Angiographic Results with the Multi-Linkª Coronary Stent System Ñ The West European Stent Trial (WEST)

BACKGROUND: The objectives for the West European Stent Trial (WEST) were to assess the safety and efficacy of the new ACS Multi-Linka coronary stent system with regards to bleedings and vascular complications and incidence of major adverse cardiac events during 12 months follow-up. METHODS AND RESULTS: The balloon-expandable Multi-Link stent is made from a single hypotube and is composed of 316 L stainless steel. In an open, non-randomized, multicenter registry, 102 patients with angina pectoris to be treated with this stent were recruited from 7 European centers. Following stent implantation, patients were given heparin infusion and oral coumadin treatment was maintained for 3 months. Procedural success was achieved in 100 of the 102 patients (98%). One patient had subacute stent thrombosis and 6 patients had major bleeds during the hospital stay. All patients were alive at 12 months and 85% were free of angina pectoris. Nineteen patients (19%) reached a primary clinical endpoint; four patients underwent bypass surgery (two in connection with the stent procedure), four patients suffered an acute myocardial infarction and 11 had a repeat angioplasty of the target vessel. Quantitative angiography showed that the minimum lumen diameter had decreased from 2.66 +/- 0.34 mm after stent deployment to 2.02 +/- 0.58 mm at 6 months and the percent diameter stenosis had increased from 18 +/- 7% to 33 +/- 16%. The in-stent restenosis rate was 12% and appearance of a stenosis in the target vessel outside the stent occurred in an additional 5%. CONCLUSION: The WEST study has demonstrated a high degree of safety and efficacy of the Multi-Link stent with a low incidence of complications and clinical events during follow-up. The results compare favorably with data from other stents.     

The Clinical and Angiograghic Outcome of 190 Cases after Stent Placement in Small Coronary Vessels

Objectives To invest the success procedure, immediate outcome after procedure, the rate of main adverse cardiac events after procedure and restenosis after stent placement in small coronary vessels. Methods 290 patients with selected or emergency stent implantation in small vessels from April, 1997 to March,2002. Total 299 vessels,304 lesions and 316 stents were statisted. The successs rate of procedure, immediate outcome after procedure, the rate of main adverse cardiac events after procedure and restenosis after stent placement in small coronary vessels were assessed. The patients were followed up 1 month to 4 years. Re-catheter angiography were done in 122/290 patients. Results The narrow rate of lesion dropped from 89% ± 12% before procedure to 5% ±5% after procedure (diameter). 202 patients were followed up 1 month (69.7%). 197/202 cases were survival. 5/202 cases died in 3hrs to 7days. 2/5 cases died of persistent hypotension after procedure. 1/5 case died of acute left heart failure. 2/5 cases     

Diagnostic Accuracy of Coronary CT Angiography for the Evaluation of Bioresorbable Vascular Scaffolds

Objectives

The purpose of this study was to assess the diagnostic accuracy of coronary computed tomography angiography (CTA) for bioresorbable vascular scaffold (BVS) evaluation.

One-year outcomes of a BioMime™ Sirolimus-Eluting Coronary Stent System with a biodegradable polymer in all-comers coronary artery disease patients: The meriT-3 study

ObjectivesThe aim of the merit-3 study was to determine the safety and performance of the BioMime Sirolimus-Eluting Coronary Stent System (SES) in all-comer patients with coronary artery disease (CAD) in one-year clinical follow-up period.MethodsThe meriT-3 was a multi-centre, observational, post-marketing study conducted in 1161 patients with CAD who were implanted with BioMime SES at 15 sites in India. The primary endpoint was major adverse cardiac event (MACE) at one year defined as the composite of cardiac death, myocardial infarction (MI) and target lesion revascularization (TLR). Clinical follow-up was performed at 1, 6, and 12 months. Major adverse cardiac event occurred at 30 days and subsequently at 6 months and at long-term follow-up of 1 year was analyzed.ResultsMACE observed at 1 and 6 months follow-up was 16 (1.38%) and 21 (1.83%) respectively. Cumulative 1 year MACE was 26 (2.35%) with 16 (1.39%) all cause death, 4 (0.35%) MI and 6 (0.52%) TLR. In addition, ST was observed in 1 (0.09%) patient.ConclusionsThe present study suggests that the BioMime SES is safe and effective in a “real-world”, all-comers CAD patients, indicating low rates of MACE.CTRI Acknowledgement NoREF/2016/07/011808.