Utilizing a New Implantable Cardiac Monitor: Initial Experience From First-in-Human Study

In November 2015, BIOTRONIK announced that patients in European countries would now be able to benefit from the BioMonitor 2, a subcutaneous, insertable cardiac monitor. In August 2015, BIOTRONIK had announced CE approval and the results of a recent Australian pilot study into the performance of the BioMonitor 2. In this interview, we speak with Dr. Sze Yuan Ooi, who took part in the pilot study. 

Tell us about the size of your EP program and the number of cases you see.

I am a coronary interventionalist and cardiac device implanter based at the Eastern Heart Clinic and Prince of Wales Hospital in Randwick, Australia. The Eastern Heart Clinic was established in 1992 and along with its sister clinic, The Sutherland Heart Clinic, it provides tertiary and quaternary level care to over 6000 cardiac patients each year. This includes complex electrophysiology, device implantation, and lead extraction, and is staffed by four electrophysiologists and three implanting physicians.

How long have you been using the BioMonitor 2? What patient populations do you utilize this technology for?

I had the opportunity to use the BioMonitor 2 device during the first-in-human (FIH) study, which commenced in December 2014. The indication for implantation in the majority of patients was for atrial fibrillation (AF) detection and the investigation of syncope, although a small number of patients were implanted for the investigation of palpitations and following cryptogenic stroke.

What attracted you to this technology? Are you seeing an increasing influx of patients with AF into your practice?

The diagnostic capabilities of implantable cardiac monitors are an important piece of equipment in the cardiologist’s toolkit. This is particularly so in the detection of infrequent arrhythmia and asymptomatic atrial fibrillation, as Holter monitoring and event monitoring have their diagnostic limitations and are cumbersome for the patient.

Implantable cardiac monitors are minimally intrusive, the insertion procedure is simple and quick, and the devices are easy for the patient to use. Certainly, the BioMonitor 2 device is flat and sits comfortably inside the patient. The flexible antenna seems to contour well to the patient’s body. The BioMonitor 2 activation tool and remote monitoring system are intuitive and were demonstrated to be extremely reliable in the FIH study.

Tell us about the capabilities of the BioMonitor 2. What features make it unique?

The BioMonitor 2 was designed specifically to improve the sensing amplitude, thereby reducing the impact of noise on diagnostic performance. This was achieved by the flexible antenna, which effectively lengthened the sensing vector. In the FIH study, an average R-wave amplitude of 0.85 mV was recorded, which is significantly greater than for the predecessor BioMonitor device.

In addition, the BioMonitor 2 device takes advantage of BIOTRONIK’s remote monitoring capabilities and provides daily updates with outstanding reliability, as demonstrated in the FIH study. The device also boasts a minimum battery life of four years, which is longer than the industry standard.

Tell us about the insertion process and what a typical procedure is like. How much time does the process take, on average, in your experience?

The insertion process is simple and quick, and performed under local anesthesia. A 15 mm incision is made with a scalpel. The pocket is formed using the purpose-made FIT-1 tool and the device is inserted with the aid of the FIT-2 support tool. The wound is then closed with a combination of absorbable sutures and adhesive dressings. The median time from skin incision to completion of the procedure was nine minutes in the FIH study.

Are there any special implant considerations that you would offer? 

In the FIH trial, all but one of the devices were implanted in a parasternal position, either parallel to the sternum or in line with the vertical cardiac axis with the flexible antenna pointing inferiorly. This seemed to be a very comfortable position for patients and yielded excellent sensing amplitudes.

What do you like about using the BioMonitor 2? What benefits does it offer physicians? 

The BioMonitor 2 is easy to implant, and the accompanying BIOTRONIK Home Monitoring system is easy for patients to use. The principal benefit to physicians is its diagnostic capabilities and the reliability of the automated remote transmissions. It is an indispensable tool in the investigation of patients with arrhythmia.

Have you received feedback from your patients about their experience with this ICM? 

My patients were delighted with the simplicity of the implant procedure and the final cosmetic result. 

What cardiac remote monitoring technologies were you utilizing before the BioMonitor 2? 

I have and still use remote monitoring systems for the monitoring of pacemakers, implantable defibrillators, and implantable cardiac monitors from multiple vendors.

What were some of the challenges you faced when using more traditional methods such as event monitors and Holters, or other insertable or wearable technologies?

The principal problem with all wearable technology is the lack of constant long-term monitoring. Also, Holters and event monitors are uncomfortable and, in my experience, patient compliance with the use of event monitors is poor. Implantable cardiac monitors solve all of these issues.

Is there anything else you’d like to add? 

The BioMonitor 2 is not currently available for clinical use in Australia. It is awaiting approval by the Australian Therapeutic Goods Administration.

The first-in-human study evaluated the implantation tools, the R-wave sensing amplitude, and the reliability of the remote monitoring transmissions. In all three respects, the BioMonitor 2 performed exceptionally well. Though the volume of the device is greater than others on the market, its flexible antenna design, thinness, and deeper insertion depth create a comfortable experience for the patient. The noise burden detected was minimal. It remains to be seen whether the increased R-wave sensing amplitude and noise reduction translate into greater diagnostic abilities and, in particular, improve the diagnostic accuracy of atrial activations. This question is the subject of a subsequent, ongoing BioMonitor study.

Disclosure: The author has no conflicts of interest to report regarding the content herein.