Which is more important: cholesterol or coronary plaque?
Ask whatDr. Michael Eades'calls "statinators," and you will likely receive a befuddled look. Or, you might receive comments like "Measuring plaque has never been shown to reduce mortality."
While risk factors for heart disease are important, no doubt (my office practice is about half lipid consultation and complex hyperlipidemia management), for many they have become an end in themselves. In other words, LDL cholesterol in particular dominates thinking so much that it has caused many to exclude thefactthat plaque---coronary atherosclerotic plaque---isthe disease itself.
Dozens of studies, from theSt. Francis Heart Studyto the 25,000-participantUCLA registry, to the recently-released MESA database (ethic differences,women, as well assuperiority to carotid measures)have repeatedly shown that heart scan scores (coronary artery calcium scores) are superior to conventional risk factors (usually via the Framingham risk score) for predicting future heart attack and other events. And the differences are not minor incremental differences. The predictive power of plaque measurement via heart scanning ismultiplesbetter: 4 times, 10 times, 20 times or more in various subgroups.
Much of what we do in medicine is not based on long-term studies of outcome, pitting some diagnostic measure or treatment against placebo. It is already standard practice to measure plaque via heart catheterization, crudely via stress testing, and increasingly popular CT coronary angiography. None of these methods have been subjected to studies comparing testing vs. not testing in a large population, followed by some program of prevention to assess differences in mortality, heart attack, and other events.
Why should heart scan be held to such a standard?
Dr. Scott Grundy, lipid guru and one of the experts who sat on the Adult Treatment Panel-II for lipid management guidelines,recently stated[emphasis added]:
"Imaging has at least 3 virtues. Itindividualizes risk assessmentbeyond use of age, which is a less reliable surrogate for atherosclerosis burden; it providesan integrated assessment of the lifetime exposureto risk factors; and it identifies individuals who are susceptible to developing atherosclerosisbeyond established risk factors. Also of importance, in the absence of detectable atherosclerosis, short-term risk appears to be very low."
Well said, and from a vocal statinator, to boot.
Sadly, Dr. Grundy goes on to say how plaque imaging can serve to better determine who will benefit from statin drug use.
Of course, you and I know that there is far more to reduction of cardiovascular risk applied to a framework of serial plaque quantification ("tracking plaque"!) than statin drugs. I doubt that a man as intelligent as Dr. Grundy truly believes this. I suspect that he is simply stating what he knows what will be published without resistance in the standard medical literature, trying to achieve a modest incremental success just by raising consciousness about heart scanning and plaque imaging: first things first.
Maybe next will be a plaque-tracking, or even a plaque-reducing, mainstream conversation, just like the one we've been conducting for the past four years.