Sam Brusco, Associate Editor05.23.23
Medtronic released longer-term follow-up results for its investigational EV ICD system to treat dangerously fast heart rhythms that can lead to sudden cardiac arrest.
Findings from the Extravascular Implantable Cardioverter Defibrillator (EV ICD) pivotal study, including patients followed through an average 17.1 months were presented at Heart Rhythm 2023.
Medtronic’s EV ICD is a first-of-its-kind implantable defibrillator engineered to avoid the risks of transvenous ICDs because its lead is placed outside the heart and veins, under the sternum. It offers anti-tachycardia pacing (ATP) and pause prevention pacing, and the device is similar in size, shape, and battery longevity to transvenous ICDs.
The device is implanted below the left armpit in a minimally invasive approach.
"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," Paul Friedman, M.D., cardiac electrophysiologist and chair of the Department of Cardiology at Mayo Clinic in Rochester, Minn., and principal investigator of the Extravascular ICD pivotal study, told the press. "The EV ICD system is the first to include all of this functionality in a single extravascular device."
ATP successfully treated 67.3% of episodes and shocks were avoided in nearly half of all spontaneous episodes because of ATP’s availability. The chronic data builds on EV ICD’s previously reported defibrillation effectiveness results at implant (98.7%).
Rate of freedom from system- or procedure-related complications through 18 months was 91.9%, with the most common major complication being dislodgment (10 events in nine patients) predominantly related to the lead-anchoring technique. Inappropriate shocks occurred in 35 patients. The proprietary algorithm designed to reduce the number of inappropriate shocks successfully withheld inappropriate therapy caused by P-wave oversensing, the most common cause of inappropriate shocks, without compromising appropriate therapy. The algorithm reduced inappropriate detection due to P-wave oversensing by 57%.
At Heart Rhythm 2023, Anne B. Curtis, MD also presented findings from a new analysis of commercially available devices showing 45% of ICD patients receive appropriate therapy for ventricular tachyarrhythmias through seven years.
"Within the medical community, referral for ICD therapy is being delayed in light of newer classes of heart failure medications, but this study shows that patients do receive needed therapy from their ICDs," said Dr. Curtis, SUNY Distinguished Professor, Department of Medicine, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo. "This study gives physicians a contemporary view into the real-world impact of ICDs nationwide, underscoring the importance of indicated patients receiving these potentially life-saving devices."
Findings from the Extravascular Implantable Cardioverter Defibrillator (EV ICD) pivotal study, including patients followed through an average 17.1 months were presented at Heart Rhythm 2023.
Medtronic’s EV ICD is a first-of-its-kind implantable defibrillator engineered to avoid the risks of transvenous ICDs because its lead is placed outside the heart and veins, under the sternum. It offers anti-tachycardia pacing (ATP) and pause prevention pacing, and the device is similar in size, shape, and battery longevity to transvenous ICDs.
The device is implanted below the left armpit in a minimally invasive approach.
"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," Paul Friedman, M.D., cardiac electrophysiologist and chair of the Department of Cardiology at Mayo Clinic in Rochester, Minn., and principal investigator of the Extravascular ICD pivotal study, told the press. "The EV ICD system is the first to include all of this functionality in a single extravascular device."
Study Results
Of the 299 implanted patients, about 6.8% of patients experienced appropriate therapy by 18 months, with 19 patients experiencing 80 spontaneous, appropriately treated arrhythmic episodes. Of discrete episodes treated with shock, 100% were successfully terminated.ATP successfully treated 67.3% of episodes and shocks were avoided in nearly half of all spontaneous episodes because of ATP’s availability. The chronic data builds on EV ICD’s previously reported defibrillation effectiveness results at implant (98.7%).
Rate of freedom from system- or procedure-related complications through 18 months was 91.9%, with the most common major complication being dislodgment (10 events in nine patients) predominantly related to the lead-anchoring technique. Inappropriate shocks occurred in 35 patients. The proprietary algorithm designed to reduce the number of inappropriate shocks successfully withheld inappropriate therapy caused by P-wave oversensing, the most common cause of inappropriate shocks, without compromising appropriate therapy. The algorithm reduced inappropriate detection due to P-wave oversensing by 57%.
At Heart Rhythm 2023, Anne B. Curtis, MD also presented findings from a new analysis of commercially available devices showing 45% of ICD patients receive appropriate therapy for ventricular tachyarrhythmias through seven years.
"Within the medical community, referral for ICD therapy is being delayed in light of newer classes of heart failure medications, but this study shows that patients do receive needed therapy from their ICDs," said Dr. Curtis, SUNY Distinguished Professor, Department of Medicine, Jacobs School of Medicine & Biomedical Sciences, University at Buffalo. "This study gives physicians a contemporary view into the real-world impact of ICDs nationwide, underscoring the importance of indicated patients receiving these potentially life-saving devices."