Kerckhoff-Klinik GmbH, Benekestrasse 2-8, Bad Nauheim, Hesse, Germany.
CHU Grenoble, BP 217, Grenoble, France.
Europace. 2018 Sep 1;20(9):1491-1497. doi: 10.1093/europace/eux359.
A prospective, single-arm, multicentre, post-market study was conducted to confirm the short-term safety of the Nanostim™ leadless pacemaker (LP). In this study, we report the primary results of the LEADLESS Observational Study.
Subjects meeting VVIR pacemaker indications were enrolled and followed up after successful LP implantation, prior to discharge and post-implantation at 90 days, 180 days, and every 6 months thereafter for the assessment of adverse events. The primary safety endpoint was evaluated in terms of freedom from serious adverse device effects (SADEs) at 6 months in 300 subjects. Data for all enrolled subjects were also presented. A total of 470 subjects were enrolled (75.8 ± 13.1 years, 62.8% male). The study paused in April 2014 following the occurrence of perforation events that led to changes in the protocol and investigator training. Freedom from SADEs, evaluated in 300 subjects enrolled post-pause, was 94.6% (95% confidence interval 91.0-97.2%) and demonstrated non-inferiority to a performance goal of 86% (P < 0.0001). Eighteen SADEs were observed in 16 (5.3%) subjects. The most frequently occurring events were cardiac perforation (1.3%), device dislodgement (0.3%), and vascular complications (1.3%). In the 470 subjects, 34 similar SADEs were observed in 31 (6.6%) subjects. After stratifying the results in relation to the study pause, there was a statistically significant difference in the final LP location (septum vs. apex) (P < 0.0001) and the number of repositioning attempts (<2 vs. ≥2) (P = 0.05) and a decreasing trend in the rates of cardiac perforation and device dislodgement.
The primary safety endpoint at 6 months was successfully met for the Nanostim LP. The occurrence of cardiac perforation and device dislodgement declined after changes following the study pause.
一项前瞻性、单臂、多中心、上市后研究旨在确认 Nanostim™无导线起搏器（LP）的短期安全性。在这项研究中，我们报告了 LEADLESS 观察性研究的主要结果。
符合 VVIR 起搏器适应证的受试者入选，并在成功植入 LP 后进行随访，在出院前、植入后 90 天、180 天以及此后每 6 个月进行不良事件评估。主要安全性终点是在 300 例受试者中评估 6 个月时无严重不良器械效应（SADE）的发生率。还报告了所有入组受试者的数据。共纳入 470 例受试者（75.8±13.1 岁，62.8%为男性）。2014 年 4 月，由于穿孔事件的发生导致方案和研究者培训的改变，研究暂停。在暂停后入组的 300 例受试者中，无 SADE 发生率为 94.6%（95%置信区间 91.0-97.2%），且不劣于 86%的性能目标（P<0.0001）。16 例（5.3%）受试者出现 18 例 SADE。最常见的事件是心脏穿孔（1.3%）、器械移位（0.3%）和血管并发症（1.3%）。在 470 例受试者中，31 例（6.6%）受试者出现 34 例类似的 SADE。根据研究暂停对结果进行分层后，最终 LP 位置（间隔 vs. 心尖）（P<0.0001）和重新定位尝试次数（<2 次 vs. ≥2 次）（P=0.05）存在统计学差异，且心脏穿孔和器械移位的发生率呈下降趋势。
Nanostim LP 在 6 个月时成功达到主要安全性终点。研究暂停后，心脏穿孔和器械移位的发生率下降。
