Primary safety results from the LEADLESS Observational Study


5 February Feb 2018 15 days ago
  • Tondo C

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, the Authors report the primary results of the LEADLESS Observational Study.

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 (serious adverse device effects), evaluated in 300 subjects enrolled post-pause, was 94.6% and demonstrated non-inferiority to a performance goal of 86% (P < 0.0001). The most frequently occurring events were cardiac perforation (1.3%), device dislodgement (0.3%), and vascular complications (1.3%).

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, – the Authors conclude, – was successfully met for the Nanostim LP. The occurrence of cardiac perforation and device dislodgement declined after changes following the study pause.


Sperzel J, Defaye P, Delnoy PP, Garcia Guerrero JJ, Knops RE, Tondo C, Deharo JC, Wong T, Neuzil P. Primary safety results from the LEADLESS Observational Study. Europace 2018 Jan 19. doi: 10.1093/europace/eux359. [Epub ahead of print] Go to PubMed