CD&D

The implantable cardiac monitoring (ICM) sector saw an uptick of activity inb mid-February as two companies competing in the space reported regulatory/commercialization achievements with their respective technologies. Transoma Medical (St. Paul, Minnesota) received FDA clearance for its second-generation ICM product, Sleuth AT (Advanced Trending) cardiac monitoring system.

And Medtronic (Minneapolis) reported the commercial availability of its Reveal XT insertable cardiac monitor in the U.S. and the first U.S. implant of that device.

Transoma said its new device allows physicians to program the capture of electrocardiogram (ECG) strips at more frequent intervals than its previous device, putting more control in the hands of the physician.

The first-generation Sleuth product had three ways of capturing an ECG, Nestor Jaramillo, VP of sales and marketing at Transoma, told Cardiovascular Devices & Drugs. First, when a patient felt a symptom (such as lightheadedness) they could push a button to tell the system to store the ECG strip during the time of the symptom; second, the system automatically captured and stored the ECG strip when the patient's heart rate is above or below physician-programmed limits; and third, the Sleuth would automatically capture an ECG every four hours.

The Sleuth AT captures an ECG the same as the predecessor device except that the new Sleuth can be programmed to capture a 20-second ECG strip every 7.5 minutes, or every 15 minutes, or every four hours, Jaramillo said. So, he said, if the physician wanted to monitor a patient for complex arrhythmias, including atrial fibrillation (AF), he will get a monthly report, looking at the patient for 20 seconds as often as every 7.5 minutes.

Transoma said the system includes an implantable loop recorder, a personal diagnostic manager (PDM), a base station and a 24/7 monitoring center operated by Medicomp (Chantilly, Virginia) and staffed by certified cardiac technicians who classify and notify physicians of the presence of a wide variety of cardiac arrhythmias such as ventricular tachycardia, bradycardia, supraventricular tachycardia and AF. If the cardiac technician observes a particularly concerning arrhythmia, the patient's physician will be contacted immediately, the company said.

Transoma describes the ICM as a small, thin device, about the size of a 50-cent piece (or the size of the smallest pacemakers), which continuously monitors the electrical activity of the heart. The cardiac monitor is implanted under the skin during a brief, simple, outpatient procedure, the company noted. The PDM is a hand-held, multipurpose device that automatically retrieves and stores relevant ECG data from the ICM, securely relays the information to the base station and then to the monitoring center. The physician also uses the PDM to program the ICM.

Similarly, Medtronic's Reveal XT and its Reveal DX insertable cardiac monitors are placed just under the skin of the chest area in a short outpatient procedure, and are also designed to capture an ECG during the actual episode. The patient can store an ECG by placing a hand-held, pager-sized assistant over the device, and pressing a button. Later, a physician analyzes the stored information, transmitted via the Medtronic CareLink Network or during an in-office patient visit, and determines whether the episode was caused by an abnormal heart rhythm.

Medtronic received Japanese regulatory approval for the Reveal DX in July, a device the size of a memory stick. The company said the device provides insight into syncope, unexplained fainting episodes.

Another Minnesota company in the ICM sector is St. Jude Medical (St. Paul, Minnesota), which reported FDA clearance of its Confirm ICM in September. That device is the size of a computer thumb drive and St. Jude said at the time that it is the smallest cardiac monitor available. St. Jude's device is also approved for syncope.

Despite facing competition from Medtronic and St. Jude, Jaramillo said Transoma's device stands out against both of those companies' devices in its design and, importantly, memory capacity. According to Transoma the Sleuth AT has a "virtually unlimited memory capacity," which Jaramillo said is a significant advantage over competing devices.

"We think the market is significantly underpenetrated," Jaramillo told CD&D. "Based on the calculations we have made, 100 to 150 patients come in every year with a syncope that, after the conventional testing, continue to be undiagnosed and that's just by the nature of the syncope."

Syncope is difficult to diagnose as episodes are often too infrequent and unpredictable for detection with conventional monitoring techniques such as ECG Holter monitors or external loop recorders.

"Some of these patients only faint two or three times a year," Jaramillo said. "They are in their normal routine, they could be driving, they could be at work. The physician wants to capture the ECG when it happens."

According to Peter Kowey, MD, chief of cardiology for Main Line Health, William Wikoff Smith Chair in CV Research at the Lankenau Institute (Wynnewood, Pennsylvania), the Sleuth AT "promises to provide an improved approach."

"The concept of the device, without memory constraints, automatically capturing frequent ECG strips which are then over-read at the monitoring center, may address the limitations and inaccuracies of existing devices used to assess complex arrhythmias such as atrial fibrillation," Kowey said in a Transoma news release.

Jaramillo said Transoma believes its technology brings a "totally new approach" to cardiac monitoring. "We are redefining cardiac monitoring in a way that physicians would be more attracted to implant this technology," he said.

The nation's first implant of Medtronic's Reveal XT Insertable Cardiac Monitor device was conducted by Blair Grubb, MD, a professor of medicine and pediatrics at the University of Toledo Medical Center in Ohio.

The company said the Reveal XT joins the Reveal DX ICM as the first insertable cardiac monitors that offer comprehensive remote monitoring capabilities via the Medtronic CareLink Network, and which allow doctors to confirm or rule out an abnormal heart rhythm.

"The Reveal XT Insertable Cardiac Monitor is really like a black box in an airplane; it captures vital information 24/7 ... for up to three years," Elizabeth Hoff, VP and general manager of the Subcutaneous Diagnostics and Monitoring unit of Medtronic's Cardiac Rhythm Disease Management business, told CD&D.

The company said doctors may choose the Reveal XT ICM for patients with suspected arrhythmias, and in difficult-to-diagnose patients for whom long-term cardiac rhythm trending data may aid in a more informed diagnosis. The Reveal XT device is also an option for physicians seeking to detect the presence of atrial arrhythmias (irregular heart rhythms in the upper chambers), including asymptomatic episodes, or to monitor the amount of time a patient is in atrial fibrillation (AF) to assess whether medical treatment is necessary or should be adjusted, the company said.

Hoff said Reveal XT is Medtronic's first and only ICM in the U.S. and the XT is specifically used to diagnose and monitor for up to three years AF, one of the leading causes of stroke. Both the Reveal XT and the Reveal DX can be used in the Syncope populations, she said, but the Reveal XT is primarily used to evaluate AF. Both devices can be used with Medtronic's CareLink Network, Hoff added.

ICMs can have a significant advantage over external monitors, she said, noting that one of the biggest issues with external monitors is poor patient compliance. "One of the advantages of an insertable monitor for something as serious as AF is guaranteed patient compliance for a longer period time."

Hoff said the Reveal XT may be used to diagnose AF in patients, or it may be used in patients with known AF to monitor the length and frequency of episodes. Such information allows the physician to make better treatment decisions, she said. "It's like having your doctor with you 24 hours a day."

"I see many patients desperately seeking answers for their unexplained symptoms," Grubb said. "By adding AF detection capabilities and greater diagnostic reporting, I expect the Reveal XT device to be an even more effective tool to help monitor and diagnose my patients' cardiac conditions."

Placed just under the skin of the chest area in a short outpatient procedure, the Reveal XT and DX devices capture an electrocardiogram (ECG) during the actual episode, Medtronic said. The patient can store an ECG by placing a hand-held, pager-sized assistant over the device, and pressing a button. Later, a physician analyzes the stored information, transmitted via the Medtronic CareLink Network or during an in-office patient visit, and determines whether the episode was caused by an abnormal heart rhythm.

Reveal device data has been accessible via the Medtronic CareLink Network since fall 2008, which allows patients to stay connected to their healthcare provider from home and offers physicians access to diagnostic data remotely, which may help them make timely, informed decisions, according to the company.

"The Reveal XT monitor offers physicians a proven option for uncovering dangerous cardiac conditions, including atrial fibrillation. For patients experiencing arrhythmias or unexplained fainting episodes, having greater insights into the cause is incredibly valuable for both the patient and physician," Hoff said.

Medtronic received Japanese regulatory approval for the Reveal DX ICM in July. The company said the device provides insight into syncope, unexplained fainting episodes. Syncope is difficult to diagnose as episodes are often too infrequent and unpredictable for detection with conventional monitoring techniques such as ECG Holter monitors or external loop recorders. The Reveal DX ICM is about the size of a memory stick and is capable of monitoring patients for up to three years.