Performance of an implantable cardioverter-defibrillator lead family.

BACKGROUND: Lead failure is the major limitation in implantable cardioverter-defibrillator (ICD) therapy. Long-term follow-up data for Biotronik Linox ICD leads are limited. Therefore, we analyzed the performance of all these leads implanted at our institution. MATERIALS AND METHODS: All Linox and Linox Smart ICD leads implanted between 2006 and 2015 were identified. Lead failure was defined as electrical dysfunction (oversensing, abnormal impedance, exit block). Lead survival was described, according to Kaplan-Meier. Associations between lead failure and specific variables were examined. p < .05 was considered significant. RESULTS: We included 417 ICD leads. The median follow-up time for Linox (n = 205) was 81 months and for Linox Smart (n = 212) 75 months. During that follow-up time, 30 Linox (14.6%) and 16 Linox Smart leads (7.6%) showed a malfunction. The 5-year lead survival probability was 97.4% for Linox and 95.2% for Linox Smart (log-rank test, p = .19). The 6- and 8-year lead survival probability for Linox was 93.6% and 84.6%, and for Linox Smart 93% and 91.9%. The only factor significantly associated with lead failure was younger patient age at implantation (hazard ratio/year: 0.97, 95% CI: 0.94-0.99, p = .002). CONCLUSION: This relatively large study with a long follow-up period highlights a relevant failure rate of Biotronik Linox leads. The performance of Linox versus Linox Smart ICD leads was comparable. Although we show an acceptable 5-year lead survival probability, we observed a marked drop after just 1 more year of follow-up. In an era of improving heart failure survival probability, a prolonged follow-up of ICD leads is increasingly clinically relevant.

Investigation of potential adverse central nervous system effects after long term oral administration of gadolinium in mice.

OBJECTIVES: To examine potential gadolinium (Gd) accumulation in the brain of healthy mice after long-term oral administration of Gd-containing food pellets and to investigate whether Gd leads to adverse central nervous system (CNS) effects, specifically focussing on locomotor impairment in Gd exposed compared to control animals. MATERIALS AND METHODS: The local Animal Experimental Ethics Committee approved all procedures and applications. Fifteen female C57Bl/6 mice were orally exposed to a daily intake of 0.57 mmol Gd chloride/ kg body weight over a period of 90 weeks from the age of 4 weeks on. Gd-free, but otherwise equivalent experimental diets were given to the control group (N = 13). The animals were monitored daily by animal caretakers regarding any visible signs of distress and evaluated clinically every four weeks for the first 60 weeks and afterwards every two weeks for a better temporal resolution of potential long-term effects regarding impairment of motor performance and loss of body weight. The individual Gd content was measured using mass spectrometry in a sub-cohort of N = 6 mice. RESULTS: The absolute brain Gd levels of the Gd-exposed mice were significantly increased compared to control mice (0.033± 0.009 vs. 0.006± 0.002 nmol Gd/ g brain tissue). Long-term oral Gd exposure over almost the entire life-span did not lead to adverse CNS effects including locomotor changes (rotarod performance, p = 0.1467) in healthy mice throughout the study period. Gd-exposed mice showed less increased body weight compared to control mice during the study period (p = 0.0423). Histopathological alterations, such as hepatocellular vacuolization due to fatty change in the liver and a loss of nucleated cells in the red pulp of the spleen, were found in peripheral organs of both groups. CONCLUSIONS: Low levels of intracerebral Gd caused by chronic oral exposure over almost the entire life span of mice did not lead to alterations in locomotor abilities in healthy mice throughout the normal aging process.

Balloon angioplasty versus stenting for pulmonary vein stenosis after pulmonary vein isolation for atrial fibrillation: A meta-analysis.

BACKGROUND: The incidence of pulmonary vein stenosis (PVS) as complication after pulmonary vein isolation (PVI) for atrial fibrillation (AF) has decreased in the last decade. However, as PVI for AF is becoming more prevalent, the incidence remains considerable in absolute terms. The purpose of this meta-analysis is to investigate the optimal approach for management of PVS after PVI for AF. METHODS AND RESULTS: We searched electronic scientific databases for studies comparing plain balloon angioplasty (BA) versus stenting for PVS after PVI for AF. Aggregate data were pooled to perform a meta-analysis. The primary and secondary outcomes were restenosis requiring repeated intervention and procedure-related complications, respectively. A total of 4 studies, treating 315 PVS in 188 patients (BA, n=171 versus stent, n=144 PVS) were considered. After a median follow-up of 32months, the overall incidence of restenosis was 46%. A percutaneous therapy with BA was associated with a higher risk for restenosis requiring repeat intervention compared to stent (risk ratio - RR, 95% confidence interval [95% CI]=2.18 [1.64-2.89], p<0.001). Procedure-related complications were comparable between BA and stent (RR [95% CI]=0.96 [0.19-4.96], p=0.96). The time to diagnosis of PVS after PVI for AF did not modify the treatment effect for the primary outcome with BA versus stent (p for interaction=0.16). CONCLUSIONS: In patients presenting PVS after PVI for AF, a percutaneous therapy with BA is associated with higher risk for restenosis requiring repeat intervention as compared to stent. These percutaneous therapies display comparable safety.