Analysis: Intravascular Devices with a Higher Risk of Polymer Emboli: The Need for Particulate Generation Testing.

Hydrophilic polymer coatings on intravascular devices lower friction between the device and vasculature, thereby reducing trauma during interventional procedures. Polymer coating embolism-the detachment and downstream embolism of polymer particles-has been reported as an iatrogenic complication of coated interventional devices affecting the vasculature and various organs. The Food and Drug Administration (FDA) acknowledges this complication and continues to work with stakeholders to close gaps in performance testing and standards related to polymer coating integrity. Recent innovations within interventional technologies have led to development of new hydrophilic-coated devices with expanded indications for use. The 2018 FDA draft guidance for intravascular guidewires expands the application of particulate generation testing to most devices and recommends labeling changes to increase industry awareness. This article highlights current procedural trends where the phenomenon of polymer coating embolism may be more prevalent. It describes the mechanisms of polymer separation, reported clinical sequelae, and risk factors for relevant indications. These procedural trends and associated risk factors articulate the need for particulate testing and support the FDA's draft guidance recommendations for performance testing of applied coatings. If standardized, particulate assessments may allow characterization and comparisons of coating integrity among devices from various manufacturers, and are an important foundation for setting particulate limits. As hydrophilic coatings enable endovascular treatment for a range of patient populations, setting particulate limits or finding alternative solutions without compromise to device function may be essential. Particulate testing is relevant to physicians, regulators, and manufacturers for the purposes of product development and quality improvement of interventional devices.

Transcatheter aortic valve implantation for severe regurgitation in native and degenerated bioprosthetic aortic valves.

OBJECTIVES: We evaluated transcatheter aortic valve Implantation (TAVI) in high-risk patients with severe aortic regurgitation (AR) in native or degenerated bioprosthetic valves. BACKGROUND: TAVI has emerged as a viable treatment modality for severe aortic stenosis in inoperable or high-risk patients. The use of TAVI for treatment of severe AR has remained largely unexplored. METHODS: Eight patients (age 79.6 years ± 5.75 years) with severe AR underwent TAVI at six tertiary hospitals between April 2010 and May 2011. All patients were considered to be at prohibitive risk for surgical aortic valve replacement (SAVR).TAVI with the nitinol based Core Valve bioprosthesis (CRS) (Medtronic) was performed in all patients. RESULTS: Transfemoral access was used in all cases. Procedural success was obtained in all cases without any intraprocedural complications. There was no in hospital or 30-day mortality. There were no cases of atrioventricular blocks requiring permanent pacemaker implantation. At a mean follow up of 15.5 ± 15 months; all patients had improvement in New York Heart Association functional class. Follow up echocardiography revealed improved or stable left ventricular ejection fraction and optimal device function in all cases. CONCLUSIONS: TAVI with the CRS bioprosthesis is feasible and effective in appropriately selected cases of severe aortic regurgitation in native and bioprosthetic aortic valves.

Biolimus-eluting vs. other limus-eluting stents in NSTE-ACS: A pooled analysis of GLASSY and TWILIGHT.

BACKGROUND: Biodegradable polymer biolimus-eluting stents (BP-BES) may be associated with better outcomes in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI) compared to other current-generation limus-eluting stents (LES). AIMS: To compare BP-BES with other current-generation LES in ACS patients undergoing PCI. METHODS: We pooled individual data of Non-ST-segment elevation (NSTE)-ACS patients from two large randomized controlled trials (GLASSY and TWILIGHT). The BP-BES groups consisted mostly of GLASSY patients, while the control group (other current-generation LES) included exclusively TWILIGHT patients. The primary outcome was major adverse cardiovascular events (MACE), including cardiovascular death, myocardial infarction, or stent thrombosis; the key secondary outcome was target-vessel failure (TVF). To account for trial design differences, outcomes were assessed at 3 months (short-term) and between 3 and 12 months (long-term) after PCI and subsequently pooled to estimate the 12-month hazards. RESULTS: Of 7107 and 6053 NSTE-ACS patients included in the short- and long-term analysis, 32.7% and 36.5% received a BP-BES, respectively. Risk of MACE associated with BP-BES versus other LES was similar at short-term (1.1% vs 1.3%, adjusted HR 0.86, 95%CI 0.53-1.38), lower at long-term (1.7% vs 3.1%, adjusted HR 0.49, 95%CI 0.34-0.72), and lower in the entire 12-month period (pooled adjusted HR 0.61, 95%CI 0.45-0.82). The cumulative 12-month risk of TVF was reduced with BP-BES (adjusted HR 0.52, 95%CI 0.38-0.70). CONCLUSION: BP-BES was associated with lower 12-month risks of MACE and TVF compared to other current generation LES among NSTE-ACS patients treated with abbreviated or standard ticagrelor-based DAPT. These non-randomized findings are hypothesis-generating. CONDENSED ABSTRACT: Differences in clinical outcomes may exist between biodegradable polymer biolimus-eluting stents (BP-BES) and other current-generation limus-eluting stent (LES) in patients with acute coronary syndrome (ACS). We pooled individual data of about 7000 Non-ST-segment elevation ACS patients undergoing PCI and treated with ticagrelor with or without aspirin from two large randomized controlled trials (GLASSY and TWILIGHT). BP-BES patients derived very largely from GLASSY and other LES patients from TWILIGHT. In this population, BP-BES compared to other current generation LES, were associated with a lower 12-month risk of major adverse cardiovascular events and target-vessel failure.

Safety of temporary and permanent suspension of antiplatelet therapy after drug eluting stent implantation in contemporary "real-world" practice.

OBJECTIVES: To define the incidence of stent thrombosis (ST) and/or AMI (ST/AMI) associated with temporary or permanent suspension of dual antiplatelet therapy (DAPT) after coronary drug-eluting stent (DES) implantation in "real-world" patients, and additional factors influencing these events. BACKGROUND: Adherence to DAPT is critical for avoiding ST following DES implantation. However, the outcomes of patients undergoing antiplatelet therapy withdrawal following DES implantation remain to be clearly described. METHODS: Patients receiving DES from 05/01/2003 to 05/01/2008 were identified from a single-center registry. Complete follow-up data were available for 5,681 patients (67% male, age 66 ± 11 years, duration 1,108 ± 446 days) who were included in this analysis. RESULTS: Uninterrupted DAPT was maintained in 4,070/5,681 (71.6%) patients, with an annual ST/AMI rate of 0.43%. Antiplatelet therapy was commonly ceased for gastrointestinal-related issues, dental procedures or noncardiac/nongastrointestinal surgery. Temporary DAPT suspension occurred in 593/5,681 (10.4%) patients for 17.6 ± 74.1 days, with 6/593 (1.0%) experiencing ST/AMI during this period. Of patients permanently ceasing aspirin (n = 187, mean 338 ± 411 days poststenting), clopidogrel (n = 713, mean 614 ± 375 days) or both agents (n = 118, mean 459 ± 408 days), ST/AMI was uncommon with an annual rate of 0.1-0.2%. Overall, independent predictors of ST/AMI were unstable initial presentation, uninterrupted DAPT and lower left ventricular ejection fraction. Factors predicting uninterrupted DAPT included diabetes, unstable presentation, prior MI, left main coronary PCI, and multivessel coronary disease. CONCLUSIONS: In real-world practice, rates of ST/AMI following DES implantation are low, but not insignificant, following aspirin and/or clopidogrel cessation. Use of uninterrupted DAPT appears more common in high-risk patients.

Restenosis and drug-eluting stents.

The implantation of intracoronary stents for the treatment of coronary atherosclerotic disease is one of the most common percutaneous procedures. While the procedure brings long-term benefit for a large percentage of patients, a significant number of patients experience in-stent restenosis (ISR). ISR may be caused by a number of biological and procedural factors, including lesion characteristics as well as co-existing disease states like diabetes. Many strategies have been developed to try to reduce the incidence of ISR. The primary methods include systemic pharmacologic treatments, as well as attempts at modifying stents to reduce their role in the development of ISR. Drug-eluting stents are one such modality, and are expected to become a widely used tool in the field of interventional cardiology. This review will focus on the pathophysiology of ISR and possible ways to prevent it, including drug-eluting stents.

Simultaneous kissing stents (SKS) technique for treating bifurcation lesions in medium-to-large size coronary arteries.

The treatment of bifurcation lesions (BLs) is associated with high procedural complication and restenosis rates. Two techniques of BL interventions were compared: the simultaneous kissing stents (SKS) technique, involving 2 stents, 1 in the main vessel and 1 in the side branch (n = 100), and the conventional stent strategy (CSS) technique, involving a stent in the main vessel and provisional stenting for the side branch (n = 100). In-hospital and 30-day major adverse cardiac events were greater in the CSS group, with significantly less procedure time with the SKS technique. The incidence of target lesion revascularization was 5% in the SKS group and 18% in the CSS group (p = 0.007). Therefore, the SKS technique seems to be rapid, safe, and effective for the treatment of medium- to large-size BLs, with a trend toward fewer acute complications and promising mid-term results.

Simultaneous kissing drug-eluting stent technique for percutaneous treatment of bifurcation lesions in large-size vessels.

Treatment of bifurcation lesions is associated with high procedural complications and restenosis rate due to plaque shift, suboptimal angiographic results, difficulty in crossing the stent struts, and incomplete coverage of the side-branch ostium. The simultaneous kissing stent (SKS) technique involves two stents, one in main vessel (MV) and one in the side branch (SB) with overlapping stents in the MV proximally, extending proximally the carina of bifurcation. We analyzed our first 200 consecutive patients (202 lesions) who underwent SKS technique for true bifurcation lesions using sirolimus eluting stents, with a minimum follow-up of 6 months. Procedural success was 100% for MV and 99% for SB using SKS technique, with clinical success rate of 97%. In-hospital and 30-day major adverse cardiac events were 3% and 5%, respectively, with a procedure time of 36 +/- 14 min. At mean follow-up of 9 +/- 2 months, the incidence of target lesion revascularization was 4% in the entire group. Therefore, SKS technique using sirolimus-eluting stents may become an effective treatment strategy for large-size bifurcation lesions. However, in order to establish its superiority, SKS technique needs to be compared in a randomized manner with conventional stent techniques.