This article is more than 5 years old. Information may no longer be current.
Transcatheter leadless pacemaker successful in real-world setting
Click Here to Manage Email Alerts
CHICAGO — A transcatheter leadless pacemaker had a high implant success rate and a low rate of major complications at 30 days, according to post-approval registry data presented at the Heart Rhythm Society Annual Scientific Sessions.
In the Micra IDE trial, which led to FDA approval of the Micra Transcatheter Pacing System (Medtronic), the implant success rate was greater than 99%, all efficacy and safety endpoints were met and the rate of major complications was low, researcher Mikhael F. El-Chami, MD, FHRS, director of electrophysiology at Emory Midtown and associate professor of medicine at Emory University School of Medicine in Atlanta, said during his presentation.
To determine whether these results bear out in a real-world setting, El-Chami and colleagues evaluated post-approval registry data of patients implanted with the leadless pacemaker.
In the ongoing, prospective, single-arm, observational study, the researchers compared data on the rate of system- or procedure-related major complications at 30 days after implantation in the 795 registry patients (mean age, 75 years; 62% men) with the rate found in the 726 patients from the investigational trial. Pacing capture thresholds at 0.24 ms at implant or prehospital discharge were also assessed.
Successful implantation occurred in all but three of the 795 patients (99.6%). At 30 days after implantation, 13 major complications occurred in 12 patients, translating to a rate of 1.51% (95% CI, 0.78-2.62). These complications included cardiac effusion or perforation (0.13%), device dislodgement (0.13%) and sepsis (0.13%), and the overall complication rate was numerically lower in the registry than in the investigational trial (1.51% vs. 2.89%; OR = 0.515; 95% CI, 0.251-1.053). However, this difference did not reach statistical significance, El-Chami said.
There were 22 deaths, six of which were cardiac, 12 of which were noncardiac and four of which had an unknown cause. One death from pulmonary edema related to aortic valve disease was adjudicated as related to the procedure, and no deaths were related to the device, El-Chami said. The 6-month Kaplan-Meier rate of all-cause mortality was 8.6% (95% CI, 5.3-13.6).
Additionally, the average pacing threshold at implant or prehospital discharge was 0.66 volts, which remained stable through the study duration, and the estimated battery longevity exceeded 12 years.
Importantly, the study population was diverse, El-Chami noted. The device was implanted by 149 operators — 86.6% of whom were new implanters — at 96 centers in 20 countries. Baseline characteristics were also typical for patients referred for a single-lead pacemaker, but, he said, it is important to note that 20.9% of patients in the registry had a condition that precluded the use of a transvenous pacemaker and 14.5% had a previously implanted cardiac electronic device, which were exclusion criteria for the investigational trial.
“These results are definitely encouraging. They show that the Micra leadless pacemaker, when implanted in a real-world setting and in the hands of new operators, can be implanted successfully with a very low complication rate,” El-Chami told Cardiology Today.
“Part of the endpoint of this post-approval registry is to look at intermediate and long-term outcomes. The first time this pacemaker was ever implanted in humans was in December 2013, so as with any new technology, it’s important to follow the performance. This registry was designed to follow all enrolled patients for 9 years, so I’m sure we will see interesting results in the future,” he said. – by Melissa Foster
Reference:
El-Chami MF. LBCT01-04. Presented at: Heart Rhythm Society Annual Scientific Sessions; May 10-13, 2017; Chicago.
Disclosure : The study was funded by Medtronic. El-Chami reports receiving compensation for services from Boston Scientific and Medtronic.
Perspective
Back to Top
Parikshit S. Sharma, MD, MPH, FACC
There has been a lot of excitement as well as skepticism about the Micra leadless pacemaker. It’s a device that is implanted via a large 27F sheath through femoral venous access. The original study demonstrated a positive feasibility outcome but a higher rate of complications, especially pericardial effusions and tamponade. The overall complication rate in the original trial was 2.9%, with about 11 pericardial effusions. The follow-up post-market approval real-world experience, however, revealed a more promising overall complication rate of only 1.5%. Success rates were also higher, and there were fewer deployments needed to successfully implant the leadless pacemaker. It was very encouraging to see that in a real-world setting of patients with more comorbidities, the success rate remains high and that the complications have decreased further.
As newer techniques and technologies emerge, it’s important to follow post-market approval data beyond the original trials. Clinical trials offer a very protected environment with participating physicians or operators with a lot of experience. Also, some of these trials are driven by industry, which could impact the data. Therefore, as we make these newer tools and techniques to other operators, it’s good to see that these devices continue to perform well.
Click Here to Manage Email Alerts