Research on elastic recoil and restoration of vessel pulsatility of Zn-Cu biodegradable coronary stents.

Coronary stents made of zinc (Zn)-0.8 copper (Cu) (in wt%) alloy were developed as biodegradable metal stents (Zn-Cu stents) in this study. The mechanical properties of the Zn-Cu stents and the possible gain effects were characterized by in vitro and in vivo experiments compared with 316L stainless steel stents (316L stents). Young's modulus of the as-extruded Zn-0.8Cu alloy and properties of the stents, including their intrinsic elastic recoil, stent trackability were evaluated compared with 316L stents. In vivo study was also conducted to evaluate restoration of pulsatility of vessel segment implanted stents. Both Zn-Cu stents and 316L stents have good acute lumen gain. By comparison, the advantages of Zn-Cu stents are as follows: (I) Zn-Cu stents have less intrinsic elastic recoil than 316L stents; (II) stent trackability indicates that Zn-Cu stents have a smaller push force when passing through curved blood vessels, which may cause less mechanical stimulation to blood vessels; (III) in vivo study suggests that Zn-Cu stents implantation better facilitates the recovery of vascular pulsatility.

Ultrasound controlled paclitaxel releasing system-A novel method for improving the availability of coronary artery drug coated balloon.

OBJECTIVES: The aim of this study is to improve local-drug delivery efficiency and tissue absorption using the ultrasound (US)-responsible drug coating based on a newly developed US-controlled paclitaxel release balloon. BACKGROUND: Low availability of the drug coating remains a major concern of the current drug coated balloon (DCB). The goal of this study is to develop a method to use an US-responsible paclitaxel-loaded microcapsules (PM) as the main content of balloon drug coating to enhance bioavailability of DCB. METHODS: An US-controlled paclitaxel release balloon is designed and fabricated based on the US-responsible paclitaxel-loaded poly (lactic-co-glycolic acid) (PLGA) microcapsules. Rapid exchange percutaneous transluminal coronary angioplasty (PTCA) balloon catheters were coated with the PM. The deployment processes of the paclitaxel-loaded microcapsules coated balloons (PMCB) under US, PMCB without US and a homogenous matrix of paclitaxel and iopromide coated balloon (PICB) were then placed in healthy and stent implanted porcine coronary arteries. RESULTS: In vitro release assay demonstrated an ability of US (1 MHz, 1.22 W/cm2 , 1 minute) to affect the release kinetics of paclitaxel from PM by inducing a 76 ± 5.4% increase in the rate of release. The paclitaxel content in target vessels are 203 ± 37 µg/g for PMCB under US, 85 ± 23 µg/g for PMCB without US, and 107 ± 31 µg/g for PICB 1-hr post-surgery. The availability of the drug for the PMCB reaches 27% under US. CONCLUSIONS: The US-controlled paclitaxel release balloon significantly improved the drug content of the target vessels in the porcine model.

Meta-analysis of intracavitary electrocardiogram guidance for peripherally inserted central catheter placement.

BACKGROUND: Recently, intracavitary electrocardiogram technology has been applied to peripherally inserted central catheter placement and demonstrates many potential advantages. However, the tip positioning accuracy of intracavitary electrocardiogram technology compared to conventional X-ray method is unknown. OBJECTIVE: We did a meta-analysis to compare the tip positioning accuracy between intracavitary electrocardiogram technology and conventional X-ray method. DATA SOURCES: We searched several databases, including Cochrane Library, PubMed, Web of science, and Embase. Additional studies were identified through hand searches of bibliographies and Internet searches. All human studies published in full text, abstract, or poster form were eligible for inclusion. Search terms included peripherally inserted central catheter, PICC, intracavitary electrocardiogram, IC-ECG, EKG, ECG, and catheter tip location. STUDY ELIGIBILITY CRITERIA: Only randomized controlled trials of using intracavitary electrocardiogram technology versus X-ray method for peripherally inserted central catheter placement were included. All studies included adult patients aged at least 18 years. STUDY APPRAISAL AND SYNTHESIS METHODS: Independent extraction of articles by two authors using predefined data fields, including study quality indicators. Of the 178 citations identified, 5 studies that included 1672 patients met the eligibility criteria. It was found that statistical heterogeneity existed among the various studies (I2 = 16%, p < 0.00001); therefore, the fixed effect model was used in the meta-analysis (p < 0.05). The meta-analysis compared the tip positioning accuracy between intracavitary electrocardiogram technology and X-ray method and showed that intracavitary electrocardiogram technology had a better positioning accuracy (odds ratio: 2.88, 95% confidence interval: 2.15-3.87, p < 0.0001). LIMITATIONS: Only five randomized trial met inclusion criteria, and the lack of an incomplete search led to the publication bias seen in these results. CONCLUSION: The intracavitary electrocardiogram method had a more favorable positioning accuracy versus traditional X-ray method for peripherally inserted central catheter placement in adult patients. The intracavitary electrocardiogram can be a promising technique to guide tip positioning of peripherally inserted central catheter.

Radiofrequency Ablation Versus Antiarrhythmic Drug Therapy for Atrial Fibrillation: Meta-analysis of Safety and Efficacy.

BACKGROUND: Radiofrequency ablation (RFA) and antiarrhythmic drugs (AADs) are the main treatments used for atrial fibrillation (AF). In recent years, a number of articles comparing the 2 treatments have begun to emerge. Though, the influence of follow-up time in the meta-analysis was not considered in these articles. However, more recently, large-scale clinical trial articles have included follow-up with the patients up to 5 years after treatment. Therefore, the aim of this study was to assess the impact of variable follow-up times on the recurrence of AF by observing both the short-term and long-term efficacy and safety of catheter ablation and AADs for the treatment of AF. METHODS AND RESULTS: The primary investigators of eligible randomized controlled trials were invited to contribute standardized outcome data. Random effect summary estimates were calculated as standardized mean differences and odds ratios with 95% confidence intervals for continuous and binary outcomes. In this study, 9 randomized controlled trials (n = 1542 patients) were included. The rate of recurrence of AF with no limit on follow-up time, >12 months, >18 months, >24 months, >30 months, and approximately 36 months was compared. Furthermore, the gap between the RFA and AAD groups in the recurrence rate of AF was found to decrease inversely to follow-up time. When the follow-up time reached 24 months, the difference between RFA and AAD was relatively stable with an odds ratio of 0.45 (95% confidence interval: 0.32-0.62). Overall, RFA decreased adverse events in the remaining trials; however, AAD performed better in terms of safety and had fewer adverse events with RFA usually causing more serious complications. CONCLUSION: RFA is more advantageous in terms of recurrence rate of AF than drug therapy. In addition, the analysis suggests that this effect persists during long-term follow-up; however, these benefits appear to decrease with longer follow-up time. Finally, AAD performed better in terms of safety and had fewer adverse events.

Meta-analysis of the incidence of lead dislodgement with conventional and leadless pacemaker systems.

INTRODUCTION: Leadless cardiac pacemaker (LCP) implantation using a transcatheter was recently developed to avoid pocket- and lead-related complications. Although a LCP has an active fixation mechanism using tines or a helix, LCP and lead dislodgement issues remain a major safety concern for patients. This article reviews the literature to determine the incidence of lead and LCP dislodgement. METHODS AND RESULTS: A total of 18 studies which included 17,321 patients undergoing conventional single- or dual-chamber pacemaker implantation and three studies which included 2,116 patients undergoing LCP device implantation were reviewed. The incidence of lead dislodgement ranged from 1% to 2.69% in individual studies with a mean of 1.63%, weighted mean of 1.71%, and median of 1.60 %. There was a relatively higher lead dislodgement rate between atrial and ventricular electrodes (odds ratio [OR], 3.56; 95% confidence interval [CI], 1.9-6.70; P  =  0.6; I2   =  0%), and between magnetic resonance imaging conditional and conventional leads (OR, 2.79; 95% CI, 1.30-5.99; P  =  0.16; I2   =  46%). The use of active fixation leads (OR, 1.06; 95% CI, 0.66-1.70; P  =  0.29; I2   =  20%) showed no significant difference in dislodgement risk compared to passive fixation leads. The incidence of LCP device dislodgement was 0%, 0.13%, and 1% in three leadless pacemaker studies. CONCLUSIONS: The incidence rates of conventional pacemaker lead dislodgement vary in individual studies with an overall high incidence. Use of the currently available LCP systems appears to result in a lower rate of device dislodgement. This may reflect the effectiveness of this novel technology and the fixation design of LCP devices.