A new Canadian study reports an alternative way to connect leads to cardiac defibrillators.
Leads are special connectors or wires that deliver energy from an implantable cardioverter defibrillator (ICD) to the heart. Placing an ICD involves placing a wire through a vein, into the chest and into the heart.
The ICD study, conducted by researchers at Population Health Research Institute (PHRI), has demonstrated that a new type of cardiac defibrillator called a subcutaneous (S-ICD) reduced patient complications by more than 90 %, compared to traditional defibrillator, called a transvenous ICD (TV-ICD).
The S-ICD, explained the researchers, is implanted under the skin just below the patient’s armpit. The S-ICD lead runs under the skin, alongside the breastbone. The procedure eliminates the need to place leads into the heart or blood vessels.
“The S-ICD greatly reduces perioperative, lead-related complications without significantly compromising ICD performance,” said Jeff Healey, a senior scientist at PHRI, a research institute of McMaster University and Hamilton Health Sciences (HHS).
The S-ICD is an “attractive alternative” to the TV-ICD, particularly in patients at increased risk for lead-related complications.
That’s partly because a drawback of the procedure is that leads are the least reliable component of a traditional defibrillator. They can cause complications such as perforations in the heart muscle or lungs and blood clotting in veins, according to Healey, a professor of cardiology at McMaster as well as an electrophysiologist at HHS.
Healey also noted they may contribute to premature revision of the system in up to 20% of patients during the typical lifespan of an ICD generator.
The study involved 544 electrocardiographically screened patients; 251 were randomized to receive the S-ICD (a Boston Scientific Emblem device), and 252 patients received a TV-ICD.
Patients were followed up for an average of 2.5 years to this point and follow-up is ongoing for the study.
Findings of the trial, Avoid Transvenous Leads in Appropriate Subjects (ATLAS) S-ICD, were presented at Heart Rhythm 2022 in San Francisco on April 30.
