T he leading cause of death in the U.S. remains cardiovascular disease, and there is nothing within sight to change this everyday reality of healthcare. Smoking, nutrition, exercise, and weight are the contributing factors, and our healthcare systems will be seriously challenged to contain this epidemic.
The worldwide situation is forcing cardiovascular M.D.s to therefore pay close attention to the latest developments arising from the research, science and commercial fields. The magic bullet for this disease is nowhere to be found on the radar screens today. Fortunately, we are now beginning to understand how pervasive this disease has become. There have been some recent noteworthy developments as manufacturers, patients and M.D.s respond to the opportunities for improving care and outcomes.
D-E-S spells success
April 24, 2003 dawned as the day that interventional cardiologists and patients in the U.S., and especially staffers at Johnson & Johnson’s Cordis Corp. have been waiting for — marketing clearance by the FDA of the CYPHER Drug Eluting Stent for use in treating lesions in coronary arteries. This stent contains a drug coating that (in general) delivers greatly reduced restenosis rates, thereby reducing cardiac events and the need for repeat interventional procedures. There are reports of patients delaying their interventional procedures these last few months in order to wait for the approval of these stents. Johnson and Johnson is expected to generate more than $1.5 billion in sales in the U.S. alone, while Boston Scientific continues to diligently pursue approval of its competing DES stent. For now, CYPHER stands alone.
So the more interesting question now that DES is available to every interventional cath lab becomes “What’s next?” The notion of diagnosing and treating vulnerable plaque (VP), the mild lesions that can rupture and cause heart attacks in patients that previously had mild or no symptoms (which includes about half of the annual heart attacks in the U.S.) seems to be struggling. Presentations at the recent Society of Cardiac Angiography and Interventions meeting in Boston, Mass. (May 7-10, 2003) indicated that these lesions in selected patients may be numerous and better described as vulnerable patients instead. Finding the risky lesion that, if treated, will prevent a heart attack seems to be losing momentum. The cause of these lesions is linked to atherosclerosis, which is now being considered a systemic disease, and VP may find its role limited to research, an important application that requires better understanding. The clinical role for VP detection and treatment seems more limited.
However, based on other SCAI presentations, the extent of atherosclerosis across the population as an extra-luminal disease is now being quantified. Cath labs have provided many millions of patient studies regarding both the intra-luminal appearance of coronary artery disease using x-ray angiography imaging, and during the last decade the extra-luminal appearance of CAD using intravascular ultrasound. For most people, the first sign that they have CAD is a heart attack, reported as the case for 62 percent of men and 46 percent of women. Imaging the vessel walls (for now via IVUS, interventional MRI or optical coherence tomography) is currently the only way to understand the extent of CAD for an individual patient. Additional information regarding already ruptured plaques (that did not cause heart attacks) may be gained from CRP (C-Reactive Protein) lab tests.
The potential extent of coronary plaque in the population is now becoming a real concern. The presentation at SCAI by Steve Nissen, M.D., provided an early look on age-based proliferation of coronary plaque in a study of consecutive heart transplant patients. While 17 percent of the people under age 20 already have measurable extra-luminal plaque, the figure rapidly rises to 60 percent of 30 year olds and 85 percent of the people over 50. Dr. Nissen suggested that cardiologists may need to revisit the recommended cholesterol targets, as his study proceeded to demonstrate that the plaque area could be reduced over time, responding to drugs and lifestyle modifications.
This leads to the thought that cath lab procedures are focused currently on diagnosing and treating the end stage of CAD, assuming that intra-luminal blockages occur after the extra-luminal plaque burden has begun to close down the vessel lumen. There will certainly be no fall-off of need for these treatments in the near future, and DES has an important role to play. The focus now seems to be shifting towards the large number of (potential) patients that have CAD with no symptoms, where diagnostic and treatment regimens could have a real impact. This group represents over half of the heart attack victims, for whom today there is no organized plan for screening or detection. One presentation suggested that Interleukin 6 may be a marker with promise, along with high-sensitivity CRP.
In conclusion, IVUS usage in the U.S.A. may be poised for an increase, despite the widely publicized recent financial problems of Jomed. Not only can IVUS define the extent of CAD, but its routine use in assessing significant lesions to confirm optimal treatment strategy is well-founded. Not every cardiologist agrees with this approach, but an increasing number seem ready to better understand the extent of CAD.
Doug Orr, president of J&M Group (Ridgefield, Conn.), consults with medical device companies in strategy and business development for emerging growth markets, notably radiology and cardiology. Comments and suggestions can be sent to [email protected].
