Medtronic said that its investigational EV ICD System was found to be safe and effective as per the longer-term follow-up results of the Extravascular Implantable Cardioverter Defibrillator (EV ICD) study.

The Medtronic EV ICD system is an implantable defibrillator intended for the treatment of dangerously fast heart rhythms that can cause sudden cardiac arrest.

The results from the EV ICD study included patients followed through an average of 17.1 months.

According to the results, 299 implanted patients, equal to around 6.8% (Kaplan-Meier estimate) of patients, experienced appropriate therapy by 18 months. The company said that 19 patients also experienced 80 spontaneous, appropriately treated arrhythmic episodes.

Additionally, 21/21 separate episodes that were given shock treatment were ended effectively. It was also shown that 35/52 episodes were successfully treated with anti-tachycardia pacing (ATP).

The ATP also avoided shocks in almost half of all spontaneous events.

Medtronic said that the chronic findings add to the 98.7% defibrillation efficacy results at implants previously reported for the system.

In the EV ICD study, the rate of freedom from major EV ICD system or procedure-related complications through 18 months was reported at 91.9%, according to the Kaplan-Meier estimate.

In terms of safety, lead dislodgment was the most common major complication, found between 0 to 120 days after the implant due to the lead-anchoring approach.

In complete follow-up, 35 patients experienced inappropriate shocks, with a rate of 10.2% (Kaplan-Meier estimate) at the end of one year. Medtronic previously reported crossing its safety endpoint at six months.

Extravascular ICD study principal investigator and cardiac electrophysiologist Paul Friedman said: “The findings from the EV ICD pivotal study confirm that this system provides the advantages of a device with the lead outside the heart, and continues to provide pause prevention pacing and anti-tachycardia pacing to avoid shocks with prolonged follow up.

“The EV ICD system is the first to include all of this functionality in a single extravascular device.”

The EV ICD study is a prospective, multicentre, single-arm, non-randomised, pre-market clinical trial that featured 356 patients at 46 sites in 17 countries. It evaluated the safety and effectiveness of the Medtronic EV ICD system in patients at risk of sudden cardiac death.