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 & Johnsons 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 Whats 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 dforr@aol.com.