Medical Device Daily

To say that there are issues concerning the safety of implantable cardioverter defibrillator devices would be an understatement.

A massive recall of the Sprint Fidelis lead made by Medtronic (Minneapolis) helped solidify a variety of questions related to their use in the company's ICDs, after five people implanted with the Fidelis ICD leads died because of fracturing, a problem found to be much more frequent than the expected risk parameters. The leads were eventually pulled from the market, with class action lawsuits lined up against the company as a consequence (Medical Device Daily, Oct. 16, 2007).

And more recently, two cardiologists, Dr. Robert Hauser and Dr. Adrian Almquest, in the New England Journal of Medicine, have raised questions concerning the bench-testing proposed for a new type of significantly thinner defibrillator lead, which would require four lead placements in the heart, being developed by major cardio firms (MDD, Dec. 12, 2008).

And, in any case, whatever type of ICD lead is used, the requirement is for insertion in or near the heart.

As an advanced technical response to these issues, two electrophysiologists, Gust Bardy, MD, and Riccardo Cappato, MD, have founded Cameron Health (San Clemente, California) to develop a device that they offer as providing all of the strengths of the ICD lead but none of its weaknesses.

After nearly nine years of development, the company this week reported that it has begun trials of its Subcutaneous Implantable Defibrillator (S-ICD) System, as support for winning CE mark approval, a system that provides ICD shock but without the need of leads inserted in or near the heart.

The company said that 14 patients have received an S-ICD System as part of the CE trial, which will enroll up to 55 patients at 10 centers in Europe and New Zealand.

Richard Sanders, VP of sales and marketing for Cameron, told Medical Device Daily that the device was designed by Bardy and Cappato, "who thought that there must be a better way for ICD procedures."

He added that the therapy "is very effective," while also acknowledging "potholes" in the process of development.

"The original concept was to completely alleviate the need for any lead or electrode and incorporated a shoehorn-shaped can which can be slipped under the skin and over the ribs. The first generation of device, while not leadless, accomplishes the same thing."

Components of the Cameron Health S-ICD System include the SQ-RX Pulse Generator, Q-TRAK Subcutaneous Electrode, Q-GUIDE Electrode Insertion Tool and the Q-TECH Programmer.

The S-ICD System is implanted subcutaneously (just under the skin), with the electrode running parallel and slightly to the left of the sternum. While most functions are automatic, adjustments and data retrieval can be easily achieved through what the company says is an advanced integrated programming system developed specifically for the S-ICD System.

The company says that the Q-TECH programmer is one of the smallest units in the industry, weighing less than three pounds. And the light-weight, portable unit is capable of wireless communication with the SQ-RX Pulse Generator.

To implant Cameron's device, physicians and surgeons need only surface anatomical landmarks, such as the breastbone, without any imaging equipment.

Commenting on the clinical trial and the first CE trial patient to receive the S-ICD System in New Zealand, Margaret Hood, MD, in a release said, "Our initial experience with this new technology has brought positive results. The whole procedure was surgically simple. Once implanted, the S-ICD System can be programmed to automatically optimize the device parameters for monitoring the heart's rhythm while removing some of the complexity inherent in conventional systems. Traditional ICDs are a bit more complicated in their implantation and a bit more costly.

Conventional ICDs require placement of at least one lead in or on the heart. Most frequently, these leads, constructed of thin insulated wires, are threaded through a vein and then placed inside the heart. These conventional transvenous leads allow for sensing of the heart's rhythm and delivery of a life saving electric shock when a harmful arrhythmia is detected.

But the surgical placement and residence of these transvenous leads within the patient's heart are associated with a significant proportion of the complications related to this well-established and highly effective therapy. Those reports include patients receiving constant unnecessary shocks and, in some cases – as with the case of the Fidelis lead – death.

"So far feedback for (S-ICD) System has been extremely favorable," Sanders said.

The company said that that its expectation is to apply for an investigation device exemption by the first quarter of this year.