Medical Device Daily

In the U.S., nearly 35% of the females who are heart attack survivors will go into cardiac arrest a second time within the same year. Males have a 20% chance of this occurring. But one company is hoping to reduce these statistics by developing an implantable device that can monitor and alert the patient when he or she is on the onset of a heart attack.

Angel Medical Systems (Shrewsbury, New Jersey) has developed the AngelMed Guardian – which is currently going through a pivotal study now called ALERTS. The device will be implanted in 1,000 patients throughout 50 sites.

"[Guardian] is implanted like a pacemaker in the patient," Jonathan Harwood Angel Medical Systems COO told Medical Device Daily. "It is in the patient and it gives a real time stress test of the patient's heart."

The cardiac monitor and alert system is comprised of an internal implantable device about the size of a standard pacemaker with a lead into the heart, a pager device, and a programmer that aids physicians in evaluating heart signals. The device is implanted under the skin near the collarbone and using a wire placed in the right chamber of the heart. Patients wear the pager at all times and are alerted by a combination of vibration, beeps, and a flashing light to notify them to see their doctor or go immediately to the ER.

Typically when patients have heart attacks it is the result of a blood clot closing one of the three major coronary arteries. When this occurs there is a shift in the ST segment of the heart signal caused by the electrical difference between the portion of the heart muscle fed by the closed artery and the rest of the heart that is still receiving oxygen.

The Guardian IMD is designed to recognize a potential heart attack by detecting a shift in the ST segment level of a patient's electrogram sensed using a standard pacemaker lead. The ST segment level is continually compared to the normal patient electrogram using a patented Angel Medical Systems detection algorithm.

According to the company, if there are three abnormal electrical signals that are detected in a row within less than two minutes time, the patients will get a warning.

"It compares the signals to a baseline that is taken over a 24 hour period," Hardwood said. "If there is any change then it lets off a signal."

Most recently the company reported implanting two patients at Memorial Care Heart and Vascular Institute at Long Beach Memorial Medical Center (LBMMC; Long Beach, California) with Guardian. The center is one of 16 U.S. hospitals currently participating in the pilot study for the AngelMed Guardian device.

"A second heart attack within the first year of survival is very common and unfortunately, most patients don't go to the emergency room until three hours after symptoms start," said John Messenger, MD at LBMMC in a statement "Alerting patients that they need immediate medical attention before its too late could profoundly change heart attack survival rates."

Harwood is hopeful of the device and says that it has gotten pretty positive response.

"There are success stories, and this is a huge market the device is entering," he said.

Harwood pointed out that the market could grow to include people who are simply at risk for heart attacks, such as diabetics and smokers.

The Guardian will probably be launched in about two to three years in the U.S. for commercial use, depending on FDA approval. It already has approval in Brazil and there are plans to gain CE mark approval for the system in the near future.

Omar Ford, 404-262-5546;