Originally Published October 2000
New Clarity Marks Coronary-Care Developments
More and more Americans know that heart disease is the leading cause of death for both men and women in the United States. References to this "number-one killer" have become quasi-ubiquitous in popular culture, and are used to sell everything from rolled oats to ab rollers. Supermarkets—their shelves stocked with wholesome products stamped with little red hearts—resemble Valentine's Day boutiques. Baby boomers have taken to name-dropping the latest statin formulations with an avidity and brand snobbery heretofore reserved for SUVs or espresso machines.
Included in this growing awareness is a recognition of the paradoxical nature of the disease. Risk factors—high blood cholesterol, diabetes, elevated blood pressure, obesity, smoking, family history—are well-known. To a certain extent, the disease can be prevented through measures like diet and exercise, which appeals to our work-ethic mentality of personal improvement.
At the same time, heart disease can be frighteningly unpredictable. People in superb physical condition (the late tennis great Arthur Ashe comes to mind) can succumb, and at least a third of those who suffer heart attacks have no prior symptoms—such as chest pain—that might warn them of their imminent peril. In spite of tremendous progress in diagnosis and treatment, there is an urgent need for technologies that can more accurately assess just who is at risk. A flurry of recent research developments are taking aim at the disease in a kind of "inside-outside" offensive—offering up both novel imaging modalities and blood tests that search for newly elaborated disease markers.
Last spring's Annual Scientific Session of the American College of Cardiology included 349 papers on noninvasive imaging. The intensity of the research effort is prompted in part by statistics showing that traditional angiography—which supplies limited information regarding the walls of the coronary arteries—can miss up to 70% of potential cardiac problems. Among the most promising of the techniques under investigation are magnetic resonance imaging (MRI), ultrafast computed tomography (CT) scanning, and contrast echocardiography. (Another process, optical coherence tomography (OCT), is among the technologies discussed in this issue in New Imaging Techniques Detect Diminutive Danger Signs).
The reason a technique like MRI stands to benefit high-risk but asymptomatic patients is that it provides a more precise picture of a patient's coronary arteries and the morphology of potentially life-threatening obstructions. Advances in image generation are enabling researchers to mask out blood flow and the motion of the beating heart, and to obtain—for the first time—high-resolution images of coronary artery plaque in humans. It turns out that not all plaque is created equally dangerous: mature lesions anchored by collagen are less threatening, whereas younger, softer plaque deposits—like teenage drivers—are more apt to break loose and create havoc in an artery.
In addition to innovative imaging technologies, a number of new blood tests are being examined as a means to more-definitive risk evaluation. Disease markers under study include homocysteine, an amino acid whose levels appear to correlate with risk; C-reactive protein (CRP), which is indicative of vascular inflammation and thus may presage plaque formation; and lipoprotein (a) or Lp(a), an obscure form of cholesterol that in elevated amounts increases the chance of a heart attack. Though none of these tests are yet recommended for widespread use, the hope is that their presence, coupled with further discoveries, will someday make the heart grow fonder.
Back to the MDDI October table of contents | Back to the MDDI home page