Shortening the stent length reduces restenosis with bare metal stents: matched pair comparison of short stenting and conventional stenting

Same-day discharge after percutaneous coronary procedures-Consensus statement of the working group of interventional cardiology (AGIK) of the Austrian Society of Cardiology

INTRODUCTION

Percutaneous coronary intervention is a well-established revascularization strategy for patients with coronary artery disease. Recent technical advances such as radial access, third generation drug-eluting stents and highly effective antiplatelet therapy have substantially improved the safety profile of coronary procedures. Despite several practice guidelines and a clear patient preference of early hospital discharge, the percentage of coronary procedures performed in an outpatient setting in Austria remains low, mostly due to safety concerns.

METHODS

The aim of this consensus statement is to provide a practical framework for the safe and effective implementation of coronary outpatient clinics in Austria. Based on a structured literature review and an in-depth analysis of available practice guidelines a consensus statement was developed and peer-reviewed within the working group of interventional cardiology (AGIK) of the Austrian Society of Cardiology.

RESULTS

Based on the available literature same-day discharge coronary procedures show a favorable safety profile with no increase in the risk of major adverse events compared to an overnight stay. This document provides a detailed consensus in various clinical settings. The most important prerequisite for same-day discharge is, however, adequate selection of suitable patients and a structured peri-interventional and postinterventional management plan.

CONCLUSION

Based on the data analysis this consensus document provides detailed practice guidelines for the safe operation of daycare cathlab programs in Austria.

Venous stent versus conventional stent for the treatment of central vein obstruction in hemodialysis patients: a retrospective study

BACKGROUND

Endovascular treatment is a first-line treatment for upper thoracic central vein obstruction (CVO). Few studies using bare venous stents (BVS) in CVO have been conducted.

PURPOSE

To evaluate the treatment performance of upper thoracic central vein stenosis between BVS and conventional bare stent (CBS) in hemodialysis patients.

METHODS

Hemodialysis patients with upper thoracic central vein obstruction who underwent endovascular treatment at the interventional unit of our institution from 1 January 2008 to 31 December 2018 were enrolled in the present study. CBS was used to treat central vein obstruction in 43 patients and BVS in 34 patients. We compared the primary patency rates and complications between the two stent types. P values < 0.05 were considered statistically significant.

RESULTS

The patient demographic data between the CBS and BVS groups were similar. The characteristics of the lesions, procedures, and complications were not significantly different between the two groups (P > 0.05). There were no statistically significant differences of primary patency rates at three and six months between the BVS and CBS groups (94.1% vs. 86.0% and 73.5% vs. 58.1%, respectively; P > 0.05). The primary patency rate at 12 months in the BVS group was significantly higher than that in the CBS group (61.8% vs. 32.6%; P = 0.008).

CONCLUSION

Endovascular treatment of central vein obstruction with BVS provided a higher primary patency rate at 12 months than CBS.

Factors Affecting In-stent Restenosis in Patients Undergoing Percutaneous Coronary Angioplasty

Percutaneous coronary angioplasty (PCI) and stent implantation are the most common therapeutic strategies for coronary artery stenosis; however, in-stent restenosis (ISR) is one of its important challenges. Although in some studies, coronary artery disease (CAD) factors are deemed to be the causes of ISR, in some others, the relationship between CAD factors and ISR are not observed. Over the past ten years, there has been no review article on factors affecting the ISR. This article aimed to review the possible factors affecting ISR in patients undergoing PCI. This narrative review study was conducted on PubMed, Web of Science, Scopus, and Google Scholar databases between 1 January 1990 and 30 July 2017. After initial screening of 1728 retrieved articles, 1401 articles were excluded to due irrelevancy to the review; and finally, 39 papers were selected for data collection. Our study results showed that the site and length of implanted stent, hypertension and diabetes are the most probable factors affecting ISR. Further studies are required for evaluation of the effect of other possible risk factors such as genetic sequencing, obesity, chronic infections and hemoglobin A1C levels.

Evaluation and efficacy of long length Pronova XR Bioabsorbable Polymer stent in the treatment of long coronary lesions

Aim

The study aims an observational registry of the long and extra-long length (>33 mm) Pronova XR stents in patients with long coronary lesions (>30 mm) in a prospective real world study.

Methods and results

Current study was conducted at Ruby Hall Clinic Pune, between July 2012 and July 2013 including 30 patients who underwent PTCA using long and extra-long Pronova XR stents. Among the stents used, one stent - 33 mm, 2 stents - 38 mm, 5 stents - 43 mm and 25 stents were of 48 mm in length. In particular average stent length for the study was 46.03 mm and the average stent diameter was 3.09 ± 0.41 mm.

For this study coronary angioplasty was performed using femoral approach and standard practice. Lesions were predilated using undersized balloons and study stent was deployed at pressure 7–26 atm. (12.8 ± 3.2 atm.) The successful delivery of stent at the intended lesion with visual residual stenosis less than 50% was defined as Procedural success. Follow up studies were conducted for all the patients at 30 days, 3 months and 6 months intervals. The predefined QCA parameters were calculated using Sanders Data System QCA plus software (Palo Alto, CA, USA).

No procedural complication was observed during the whole study. 100% successful stent placement was achieved in all patients. Six months clinical follow-up was available for all patients. No adverse events (Acute closure, angina, REPCI, MI, death, sub acute stent thrombosis) or hospitalization was reported for any of the patients except one. The Quantative Coronary Core Lab analysis post 6 months showed well-flowing stent with average late lumen loss 0.10 mm ±0.26.

Conclusion

In patients with long coronary lesions and very long length stent implantation series, Pronova XR showed excellent in 6 months results. This is for the first time reported that use of long length Pronova XR stents has shown so low restenosis rate and absent of mortality in six month period. These results offer a new opportunity to single long length stenting.

Hemodynamics in stented vertebral artery ostial stenosis based on computational fluid dynamics simulations

Hemodynamic factors may affect the potential occurrence of in-stent restenosis (ISR) after intervention procedure of vertebral artery ostial stenosis (VAOS). The purpose of the present study is to investigate the influence of stent protrusion length in implantation strategy on the local hemodynamics of the VAOS. CTA images of a 58-year-old female patient with posterior circulation transient ischemic attack were used to perform a 3D reconstruction of the vertebral artery. Five models of the vertebral artery before and after the stent implantation were established. Model 1 was without stent implantation, Model 2-5 was with stent protruding into the subclavian artery for 0, 1, 2, 3 mm, respectively. Computational fluid dynamics simulations based on finite element analysis were employed to mimic the blood flow in arteries and to assess hemodynamic conditions, particularly the blood flow velocity and wall shear stress (WSS). The WSS and the blood flow velocity at the vertebral artery ostium were reduced by 85.33 and 35.36% respectively after stents implantation. The phenomenon of helical flow disappeared. Hemodynamics comparison showed that stent struts that protruded 1 mm into the subclavian artery induced the least decrease in blood speed and WSS. The results suggest that stent implantation can improve the hemodynamics of VAOS, while stent struts that had protruded 1 mm into the subclavian artery would result in less thrombogenesis and neointimal hyperplasia and most likely decrease the risk of ISR.

Comparison of full lesion coverage versus spot drug-eluting stent implantation for coronary artery stenoses

PURPOSE

The aim of this study was to evaluate and compare the long-term clinical outcomes of the spot drug-eluting stent (DES) implantation strategy, which is used to minimize implanted stent length and the number of stents, versus full lesion coverage for treatment of coronary artery stenoses.

MATERIALS AND METHODS

We evaluated 1-year clinical outcomes of 1619 patients with stent implantation for a single coronary lesion. They were divided into two groups: those treated by full lesion coverage (n=1200) and those treated with the spot stenting strategy (n=419). The combined occurrence of 1-year target vessel failure (TVF), including cardiac death, target-vessel related myocardial infarction, or ischemia-driven target-vessel revascularization was evaluated.

RESULTS

The spot DES implantation group had a shorter stent length (23.14±9.70 mm vs. 25.44±13.24 mm, respectively; p<0.001) and a fewer number of stents (1.09±0.30 vs. 1.16±0.41, respectively; p<0.001), even though the average lesion length was similar to the full lesion coverage group (21.36±10.30 mm vs. 20.58±10.97 mm, respectively; p=0.206). Spot DES implantation was superior to full DES coverage with respect to 1-year TVF (1.4% vs. 3.3%, p=0.044). Cox proportional hazard model analysis showed that the risk for 1-year TVF was almost 60% lower among patients who received spot DESs compared to those who received full DES coverage after adjustment for other risk factors (HR=0.40, 95% confidence interval=0.17-0.98; p=0.046).

CONCLUSION

Minimizing stent length and the number of stents with overlapping by spot DES implantation may result in reduced rates of 1-year TVF, compared with full DES coverage.

Restenosis after PCI. Part 1: pathophysiology and risk factors

Restenosis is a complex disease for which the pathophysiological mechanisms have not yet been fully elucidated, but are thought to include inflammation, proliferation, and matrix remodeling. Over the years, many predictive clinical, biological, (epi)genetic, lesion-related, and procedural risk factors for restenosis have been identified. These factors are not only useful in risk stratification of patients, they also contribute to our understanding of this condition. Furthermore, these factors provide evidence on which to base treatment tailored to the individual and aid in the development of novel therapeutic modalities. In this Review, we will evaluate the available evidence on the pathophysiological mechanisms of restenosis and provide an overview of the various risk factors, together with the possible clinical application of this knowledge.

Treatment of stenoses of vertebral artery origin using short drug-eluting coronary stents: improved follow-up results

BACKGROUND AND PURPOSE

Recent studies on stent placement of significant stenoses at the origin of the vertebral artery reported excellent immediate results. Long-term outcomes, however, were disappointing due to high restenosis rates and stent breakage. In the present study, we evaluated the application of a short drug-eluting balloon-expandable coronary stent for the endovascular treatment of these frequent lesions.

MATERIALS AND METHODS

In a period of 23 months, 48 patients (12 women, 36 men) with a mean age of 68 years (range, 46-82 years) harboring 52 significant ostial vertebral artery stenoses underwent treatment with short (8 mm) balloon-expandable paclitaxel-eluting coronary stents. Stents were deployed as closely as possible so that the proximal end was just at the origin of the vertebral artery, with high inflation pressure applied. Patients were under continuous medication with acetylsalicylic acid and clopidogrel before and after the treatment. Follow-up clinical assessment and angiography were performed in all patients.

RESULTS

Periprocedural complications were not encountered. Stenosis severity was reduced from 62 +/- 2% (mean +/- standard error of the mean) preprocedurally to 15 +/- 2% postprocedurally. Follow-up angiography at 7.7 +/- 0.6 months revealed a mean stenosis degree of 24 +/- 3%. None of the patients developed posterior circulation symptoms related to the treated segment during the follow-up period. Recurrent stenosis (>50%) at follow-up was found in 6 (12%) lesions.

CONCLUSIONS

Stent placement of significant ostial vertebral artery stenosis by using short drug-eluting stents is safe and yields good midterm patency rates and excellent protection from posterior circulation ischemia.

The accuracy of length measurements using different intravascular ultrasound motorized transducer pullback systems

Accurate length measurements by intravascular ultrasound (IVUS) are necessary for stent length selection and for IVUS volumetric analysis. The comparative accuracy of commercially available transducer pullback systems--a necessity for accurate IVUS length and volume measurements--has never been studied. We evaluated the accuracy of four IVUS pullback systems by studying 180 patients (45 in each group) who had been treated with a single stent of known length. Stented lesions were located in the left anterior descending artery (n = 77), left circumflex artery (n = 41), right coronary artery (n = 41), left main (n = 2), and saphenous vein grafts (n = 19). The known lengths of implanted stents ranged from 8 to 33 mm. The correlations between known stent length and IVUS-measured stent length in each group were 0.92 for CVIS, 0.83 for BSC Galaxy, 0.63 for Endosonics TrackBack, and 0.69 for Volcano Model R-l00 research pullback device, respectively. Furthermore, the absolute value of the difference between the two measurements was 9.1 +/- 13.1%, 8.8 +/- 10.2%, 18.6 +/- 21.5%, and 17.5 +/- 31.4%, respectively. With the Volcano Model R-l00 research pullback device, there were 3 extreme outliers; if these three outliers were excluded, then the correlation improved from 0.69 to 0.91; and the absolute deviation from known stent length improved from 17.5 +/- 31.4% to 9.7 +/- 8.3%. Thus, there is a significant variation in length measurement accuracy among IVUS pullback devices. This should be taken into account both clinically and when planning scientific studies.

Combining short stent implantation and drug-eluting stenting for routine use yields a low restenosis rate

BACKGROUND

The feasibility of using a single short bare metal stent (BMS) (less than 9 mm) in a high proportion of coronary artery lesions was shown in a previous study, which reported a low rate of restenosis. The present study aimed to investigate immediate and long-term results of a procedure that uses a single short BMS for all lesions that can be successfully treated with this method, and an implantation of a drug-eluting stent (DES) for all other lesions.

METHODS

In a series of 200 consecutive patients, 236 coronary artery lesions were treated with either a short BMS (168 of 236 [71.2%]) or with a DES (68 of 236 [28.8%]).

RESULTS

Angiographic success was achieved in 230 of 236 lesions (97.5%) and procedural success was achieved in 194 of 200 patients (97.0%). Restenosis occurred in 15 of 153 lesions (9.8%) after using a short BMS, in three of 62 lesions (4.8%) after using a DES and in 18 of 215 of all lesions (8.4%) at angiographic follow-up after six to eight months. Target vessel revascularization was performed in 16 of 218 lesions (7.4%).

CONCLUSIONS

Most of the coronary artery lesions in this small group of consecutive patients could be treated sufficiently with a single short BMS. The differential approach of treating lesions in medium- to large-sized vessels with a single short BMS if suitable, or with a DES in all other instances resulted in a low incidence of restenosis.

Combining short stent implantation and drug-eluting stenting for routine use yields a low restenosis rate

BACKGROUND

Stent length serves as a predictor of restenosis in use of bare metal stents (BMS). This has been demonstrated in a feasibility study that used a single short BMS implant (<9 mm) in a high proportion of lesions; the study observed a low rate of restenosis.

METHODS

We performed a pilot prospective study to investigate in a series of consecutive patients the immediate and long-term effects of implantation of either 1) a single short BMS for all lesions with low probability of restenosis or 2) a drug-eluting stent (DES) for all other lesions.

RESULTS

The 200 patients studied had 236 coronary artery lesions that were treated with short BMS in 168/236 patients (71.2%) and with DES in 68/236 patients (28.8%). Angiographic success was achieved in 230/236 lesions (97.5%) and procedural success in 194/200 patients (97.0%). Restenosis occurred in 15/153 lesions (9.8%) after short BMS, in 3/62 lesions (4.8%) after DES, and in 18/215 of all lesions (8.4%) angiographically controlled after six to eight months. Target vessel revascularization was performed in 16/218 lesion (7.4%).

CONCLUSION

Most of the coronary artery lesions in this small group of consecutive patients were treated sufficiently with a single BMS implant. This differential approach of treating suitable lesions in medium- to large-sized vessels with a single short BMS device and treating all other lesions with a DES implant resulted in a low incidence of restenosis.