番茄社区

BOSTON -- A novel small-diameter lead wire had a high level of success for delivery of implantable cardioverter-defibrillator (ICD) shocks and low complications, the LEADR pivotal trial showed.

The OmniaSecure lead was placed in the desired right ventricular location in 99.5% of patients and achieved successful defibrillation testing at implantation in 97.5%.

Freedom from study lead-related major complications was estimated at 97.1% at 6 and 12 months. No lead fractures or unstable electrical performance occurred during a mean 12.7 months of follow-up.

Both measures exceeded primary endpoint objective thresholds, George H. Crossley, MD, of Vanderbilt University Medical Center in Nashville, Tennessee, reported at the .

OmniaSecure has a design based upon the commonly-used Medtronic 3830 pacing lead, which has been "very common in use" since it was introduced in 2003, Crossley noted. "Many people don't realize how long it's been, and it's performed incredibly well and had remarkably few fractures." The new lead design adds an extra layer of polyamide insulation for the high voltage conductor, making it a 4.7 French lead compared with the 4.1 French 3830.

"I think this is likely to become the go-to lead for Medtronic devices," Crossley told 番茄社区, predicting that, if approved by the FDA, it will be "a new tool that will increase safety and longevity of leads for patients and let us put it wherever it needs to go."

HRS session study discussant Robert Hauser, MD, emeritus at the Minneapolis Heart Institute, agreed: "It goes without saying that time will tell just how reliable this lead is. We learned that from the Fidelis experience and other lead experience. But there are solid reasons to believe that the OmniaSecure is going to be a reliable long-term defibrillation lead."

In vitro modeling of real-patient imaging showing lead bend points in a model, developed with reliability data from the and St. Jude Riata lead families and validated on the Fidelis and Medtronic Sprint Quattro 6947 leads, suggested that OmniaSecure would have a fracture-free rate of 99.97% at 12 months, which the researchers noted would be equivalent to one fracture in 3,333 patient-years.

Nevertheless, there were a few defibrillation threshold failures during the trial, Hauser pointed out.

Of the 643 successfully implanted patients in the international trial, 20 of the 119 with defibrillation testing required two consecutive 25 J shocks and three did not pass the protocol.

"While some implanting physicians believe fibrillation threshold testing is not necessary at implant, many of us believe it should be done routinely regardless of lead model," Hauser noted. "It certainly should be done during OmniaSecure implantation."

He also pointed out that OmniaSecure has integrated bipolar electrodes, where the shocking coil serves as the anode. Four P-wave oversensing events occurred in the trial, although none resulted in inappropriate shocks. "The implanting physician must be sure that the coil is positioned to avoid P-wave oversensing," Hauser suggested.

The trial included 675 patients at 45 sites who had an indication for de novo implant of an ICD or cardiac resynchronization therapy-defibrillator. New York Heart Association class IV heart failure patients were excluded as was conduction system pacing.

Through 12.7 months of follow-up, 25 of 643 leads (3.9%) were explanted, 15 in patients with lead-related major complications.

"The majority of the complications were related to lead dislodgement, mostly related to anchoring technique," Crossley noted.

No deaths were adjudicated to be causally related to the OmniaSecure lead. Three deaths were possibly related: one with insufficient information, another likely due to an infection related to something else, and a third in a patient who received unsuccessful shocks after implantation for Brugada syndrome. Autopsy showed that this patient also had multiple myeloma and systemic amyloidosis with endocardial scarring.

Which lead needs to go where is likely to change in the future, Crossley acknowledged, referring to the shift toward physiologic pacing. A separate, ongoing trial is looking at use for conduction system pacing, which was excluded in LEADR, he noted.

Emile Daoud, MD, chief of cardiac electrophysiology at The Ohio State University Wexner Medical Center in Columbus, noted that it isn't the first small lead or the first to be tested in defibrillation use. "We know that defibrillation part works. What we need to figure out is whether the stability of the lead in the left bundle pacing area is going to be of value, whether it's really going to work and sit there for 5 or 10 years and provide left bundle pacing, because then you eliminate the need for another lead. Right now you have to put a defibrillator lead in, then you have to put a separate pacing lead. So that would be pretty handy."

Comment