Is there a role for coronary angiography in the early detection of the vulnerable plaque?

The identification of the coronary "vulnerable plaque" that is prone to disruption and thrombosis remains a "holy grail" in the treatment of coronary artery disease. The widespread use of coronary angiography for the identification of coronary atherosclerotic disease has led to numerous earlier studies exploring the role of angiography in the early detection of the vulnerable plaque. Some of the angiographic features explored for risk of plaque rupture include the degree of luminal stenosis, presence of plaque calcification, complex lesions with plaque disruption and thrombosis, and coronary artery movement patterns. However, a major limiting factor with coronary angiography is that it is a "luminogram", and provides little characterization of plaque morphology or vessel wall, both of which play an important role in the development of plaque vulnerability. Newer intravascular imaging techniques have been developed to permit more detailed interrogation of plaque morphology and vessel wall, potentially allowing for more accurate detection of plaque vulnerability. Whilst coronary angiography may be increasingly superseded by these advances in imaging technologies, it is likely that it will continue to play an important complementary role in the quest for the early detection of the vulnerable plaque. The prospective identification of the vulnerable plaque currently remains elusive, as definitive tools for its detection do not exist. Hence, further prospective studies on the natural history of the atherosclerotic plaque, as well as validation of imaging modalities in clinical studies are needed before the notion of early detection of the vulnerable plaque becomes a clinical reality.