August 2013
Cardiac rhythm
First-in-man study shows promise with leadless pacing
Vivek Reddy, Mount Sinai School of Medicine, New York, USA, told delegates at Heart Rhythm 2013 that leadless right ventricular cardiac pacing is feasible. According to the results of the LEADLESS study, he said: “This is a relatively small feasibility study, but raises the possibility of eliminating what has been the weak link in pacemakers: the lead”
T
he objective of the LEADLESS study was to investigate the percutaneous in vivo placement of a novel intracardiac leadless cardiac pacemaker (manufactured by Nanostim). Reddy told delegates that, although the current technology with leads is “highly mature and reliable”, they can cause mechanical failures, infections, and may need extractions and mobility restrictions, and further noted that they are incompat- ible with magnetic resonance imaging (MRI).
He highlighted that over 700,000 peo- ple globally were implanted with cardiac pacemakers and 50,000 of those people have experienced post-implant related problems.
The speaker addressed the need for leadless pacemakers and said that the benefits of using them were: catheter- based delivery, high-density energy source, low-power electronics, novel communication scheme, biocompatible materials, dependable fixation design and retrievable capability. He added that, because of device miniaturisation, the leadless pacemaker can be implanted per-
cutaneously with an 18F introducer and catheter through the femoral artery. The pacemaker remains self-contained in the right ventricle with the additional options of retrieval and conversion to traditional pacing leads.
Reddy then went on to speak about the results of the LEADLESS study, a prospective, non-randomised, single-arm, multicentre feasibility study to evaluate the performance of the new leadless car- diac pacemaker. He added that follow-up included a post-procedure X-ray and visits at two weeks, six weeks and three months. The indications for implantation, accord- ing to Reddy, were chronic atrial fibrilla- tion and a second- or third-degree block (60%), sinus rhythm with low activity or short lifespan (24%) and infrequent pauses and unexplained syncope (28%). According to Reddy, the study showed a success rate of 97% (out of 32 patients). In terms of adverse events, there was one minor groin haematoma, which required no treatment, and one cardiac perforation and tamponade which led to stroke and death.
Pacemaker retrieval was needed in Sleep apnoea increases risk of
sudden cardiac death A moderate case of obstructive sleep apnoea can significantly increase a person’s risk for sudden cardiac death, according to the largest study of its kind published online in the Journal of the American College of Cardiology
A
ccording to the National Heart, Lung and Blood
Institute, more than 12 mil- lion American adults suffer from obstructive sleep apnoea and many of them are undiagnosed. “The prevalence of obstructive sleep apnoea in Western populations is high and will likely only continue to grow given the obesity epidemic and direct relationship between obesity and sleep apnoea,” said Apoor Gami, lead author of the study and a cardiologist at Midwest Heart Specialists-Advocate Medical Group in Elmhust, USA.
It has been widely
reported that sleep apnoea can lead to a number of heart conditions, includ- ing hypertension and atrial fibrillation. Researchers in this study examined
the relationship between sleep apnoea and sudden cardiac death, building off of their prior study that found people with sleep apnoea more frequently died suddenly from cardiac causes during the hours of 10pm to 6am, which is the least likely time for sudden cardiac death in the general population.
The 10,701 patients were followed for an average of 5.3 years for incidents of resuscitated or fatal sudden cardiac death. In that time, 142 patients experienced sudden cardiac death, with the most common predic- tors being a patient aged 60 years, having 20 apnoea ep- isodes an hour and having a lowest oxygen saturation level of below 78%. The study showed that a drop in oxygen satura- tion level to below 78% increases that patients risk
of sudden cardiac death by 80%.
The study clarifies that sleep apnoea patients’ risk of sudden cardiac death does not simply shift from daytime hours to nighttime hours but that their overall risk of sudden cardiac death is higher than people without the condition. “Treating sleep apnoea in one person can improve the quality of life of both bed partners and may have the added benefit of helping to prevent cardiovascular disease,” said Virend K Somers, senior author on the study and a professor of Medicine at Mayo Clinic College of Medicine in Rochester, USA. “If the spouse sees the bed partner stop breathing repeat- edly during sleep, this is an important clue that he or she probably has sleep apnoea.”
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Vivek Reddy
two patients and was successful. He said that, in the first patient, the device was retrieved and another pacemaker was im- planted successfully. In the second patient, the device was retrieved successfully and an implantable cardioverter defibrillator (ICD) was then implanted. Reddy told the audience that com-
mercialisation of the device is expected to start later this year. He also added that a large multicentre US investigational device exemption (IDE) study is expected to start “hopefully” in 2014 and that an atrial leadless cardiac pacemaker for multichamber cardiac pacing is currently in development.
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