ROCHESTER, Minn. — A brand new sort of extravascular implantable cardioverter-defibrillator (ICD) utilizing a lead (skinny wire) positioned behind the sternum met security and effectiveness targets for individuals in a premarket international medical examine. The machine successfully terminated acute and persistent life-threatening ventricular arrhythmias. The findings have been introduced throughout a late-breaking session on the European Society of Cardiology Congress and have been concurrently printed in The New England Journal of Drugs.
Arrhythmias resembling ventricular fibrillation and ventricular tachycardia occur within the decrease coronary heart chambers, or ventricles. They’re harmful as a result of they intrude with the conventional coordinated filling and pumping of blood by the guts. These arrhythmias could cause collapse and dying if not quickly handled. The flexibility of ICDs to precisely detect and terminate ventricular arrhythmias in high-risk sufferers saves lives.
For examine individuals, the lead of the extravascular ICD was inserted underneath the sternum, in comparison with transvenous ICD leads which might be inserted by the veins into the guts, or subcutaneous ICDs which have a lead positioned beneath the pores and skin above the sternum. Sufferers with prior open-heart surgical procedure, or who required pacing for a sluggish coronary heart charge or had a pacemaker, weren’t candidates for this examine.
“This examine is encouraging. By putting the lead on this new place behind the sternum, the unusual however critical dangers related to transvenous ICDs, resembling lung collapse, injury to coronary heart valves and coronary heart perforation, could be prevented. Limitations of the subcutaneous ICD are additionally overcome. Because the lead is behind the sternum and near the guts, pacing could be delivered, and defibrillation requires much less power with an extended battery life than with the subcutaneous ICD,” says Paul Friedman, M.D., a cardiac electrophysiologist, and principal international investigator and first creator of the examine. Dr. Friedman chairs the Division of Cardiology at Mayo Clinic in Rochester.
“The brand new extravascular ICD delivered anti-tachycardia pacing — fast pacing — to painlessly terminate 70% of ventricular tachycardia episodes for which it was utilized, (which is) not less than pretty much as good as transvenous ICDs and never obtainable within the subcutaneous ICD,” says Dr. Friedman. “The extravascular ICD was additionally capable of present backup pacing to stop pauses and was capable of successfully defibrillate utilizing a tool half the dimensions of the subcutaneous ICD.”
Researchers from 17 nations participated within the examine. Of the 316 affected person individuals with an tried implant, 299 have been discharged with a working extravascular ICD system. The defibrillation success charge was 98.7%. At six months, 92.6% of individuals had no main system or procedure-related problems.
“You will need to be aware that electrophysiologists don’t routinely place machine leads behind the sternum. Nonetheless, we discovered that with a strong coaching program, we might safely achieve this within the electrophysiology lab. Preliminary implantations at every website included a heart specialist and a cardiac surgeon. The common process time was 74 minutes, just like that of the early subcutaneous ICD expertise,” says Yong-Mei Cha, M.D., director of the Implantable Gadget Lab at Mayo Clinic and website principal investigator of the examine.
“Whereas encouraging, these outcomes mirror an early expertise, and there may be extra to be discovered with longer follow-up and larger utilization,” says Dr. Friedman. “The charges of inappropriate shock are greater than with present units however related or decrease than the early expertise with different sorts of defibrillators, and steps have already been taken to decrease it. Moreover, this new machine shouldn’t be for everybody. Sufferers with earlier open-heart surgical procedure have been excluded from the examine and wouldn’t be candidates for this remedy at current.”
The examine was sponsored by Medtronic Inc., which additionally developed the machine. The extravascular ICD is premarket and has not been accepted by the Meals and Drug Administration. However it may be obtainable, pending evaluation, by a continued entry examine.
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