ABSTRACT
Coronary artery disease (CAD) is the leading cause of death
in the United States, accounting for approximately 540,000
myocardial infarctions, ~515,000 total deaths, and ~250,000
sudden deaths per year, most of which result from ruptured
vulnerable plaques.1 Initial diagnostic evaluation of sympto-
matic patients with suspected CAD includes risk assessment
and stress testing.2,3 Coronary angiography with diagnostic
catheterization remains the cornerstone for detecting flow-
limiting lesions (>75% stenosis) and is paramount for percu-
taneous coronary interventions (PCI). While there is
concern regarding the expense and potential complications
of diagnostic catheterization, the major limitation of coro-
nary angiography is its inability to visualize atherosclerotic
plaque within the vessel wall. This is of critical importance
since the majority of patients with acute coronary syn-
dromes (unstable angina, myocardial infarction, sudden
death) have plaques that did not have a hemodynamically
significant stenosis prior to rupture and thrombosis. Indeed,
more than 60% of myocardial infarctions are caused by
lesions, which are previously associated with a less than 50%
luminal narrowing of coronary arteries.4
