By Beulah Devadason

Cardiovascular diseases account for 30% of deaths and continue to remain the leading cause of death globally. WHO statistics predict an estimated 20 million death toll due to cardiovascular disease (mainly from heart attacks and strokes) by 2015. A build-up of fatty deposits blocks the flow of blood to the heart or brain. This results in heart attacks and stroke. Coronary Artery Bypass Graft surgery (CABG) and Percutaneous Coronary Interventions (PCI) are two treatment methods used to deal with constricted and occluded arteries. PCI or coronary angioplasty is a procedure wherein a catheter in inserted through the groin and a balloon, or a balloon-stent combination are used to enlarge an occluded artery.

The evolution of angioplasty has diversified the interventional cardiovascular devices market. Balloon angioplasty was the first intervention technology to be used in this field. This involved the introduction of a deflated and folded balloon into the partially occluded artery followed by dilation of the balloon. The weakening of the arterial walls seen post angioplasty using the balloon procedure led to the invention of the stent. The stent is a metal scaffolding mounted on a balloon that is expanded and fitted onto the arterial wall when the balloon is dilated. Bare metal stents (BMS) were the first generation of stents to be used. Drug-eluting stents (DES) were conceived and implemented as a measure to combat the re-stenosis of arteries seen after a BMS intervention. The DES is coated with an anti-stenosis drug that is delivered over a period of time at the site of the stent placement. However, the incidence of late stent thrombosis and the need for dual platelet therapy to tolerate the DES have spawned a new generation of bio-absorbable stents as well as drug-eluting balloons (DEB).

The implantable cardiovascular devices market can be divided into three main segments – cardiac rhythm management, interventional cardiology, and cardiac surgery. Cardiac rhythm management includes pacemakers, implantable cardioveter defibrillators, and cardiac resynchronization therapy devices, while cardiac surgery devices include mechanical and tissue valves. The interventional cardiology devices include bare-metal stents (BMS), drug-eluting stents (DES), bio-absorbable stents, and drug-eluting balloons (DEB). The interventional cardiology devices market has seen rapid growth and diversification in terms of technology in the last 10 years.

Initially, drug-eluting stents were widely accepted and attained rapid market penetration, doubling the world market for stents to $5 billion annually. In what is termed as “the fall of 2006”, DES was linked to higher incidences of late stent thrombosis, the market had shrunk and resulted in the resurgence of the use of BMS. The DES manufacturers have emerged leaner and meaner with advances in technical and pharmacological fields, two to four year clinical trials with increasing number of test subjects to prove their products' safety and efficacy, and innovative bundling and marketing strategies to combat the financial downturn.

The level of competition and technical innovation required to survive in this market has been a challenge for new entrants thus, limiting major market share to key players such as Boston Scientific, Abbott, Cordis, and Medtronic. In their efforts to tackle the late stent thrombosis, companies have come up with innovative technologies such as bio-absorbable stents. As inhibition of re-stenosis is one of the primary goals of angioplasty, technological advances include a new twist, drug-eluting balloons (DEB).

The DES market is facing the emergence of disruptive technology in the form of bio-absorbable stents and drug-eluting balloons. Bio-absorbable stents, in studies published by Abbott in March this year, have demonstrated their potential to prevent re-stenosis following angioplasty. They are made of polymers that can dissolve and be absorbed by the body within six months to two years. Such devices could address the inflammatory risk associated with permanently implanted stents and be advantageous in cases where repeat procedures are required. Bio-absorbable stents could also be bare or drug coated. Several companies including Abbott, Medtronic, and AMS (Biotronic) have applied for or received CE marking for their bio-absorbable DES products. Bio-absorbable stents are believed to be the fourth generation of stents and the technology that shows most promise for the stent market.

Balloons have been the silent winner in the longstanding battle for market share in the interventional cardiology devices market. From the time when balloons were first used as a standalone measure to combat coronary occlusions, through the stent wars, and the eventual consideration of the balloon as a drug eluting device, the balloons remain a steady source of income for manufacturers in the ever changing implantable coronary devices market. Key market players have adopted marketing strategies that focus on stent systems as opposed to individual stents. A stent system consists of all necessary medical devices for angioplasty including the stent, balloon, guide wires, etc. Such marketing strategies have been largely successful with increasing stress on reducing procurement costs by hospitals.

Drug eluting balloon catheters are being hailed as the most promising technology to overcome in-stent re-stenosis. The technology is based on the premise that short-term, localized release of anti re-stenosis drugs is more beneficial than DES. Initial studies have confirmed this hypothesis. Some current offerings in the DEB market include B.Braun's SeQuent Please, Aachen Resonance's Elutax, EuroCor's DIOR and Invatec's IN.PACT Falcon. Placlitaxel is the drug of choice for DEB technology though several other therapies are also being investigated. The application of more than one drug-coating to interfere with the multiple pathways of re-stenosis is also being investigated. The use of DEB in the treatment of coronary artery disease (CAD) could cause a further downward slide in angioplasty costs, further intensifying competition in the highly competitive implantable coronary devices market.