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Commentary
The Burden of “Vulnerable Plaque”: More Plaque Burden
December 2008
Plaque begets plaque is a lesson to be learned from the article by Okabe and colleagues.1 It sounds tautological, and certainly simplistic, yet may be missed in a time where a great deal of attention is focused on strategies to identify “vulnerable plaque.”2–6 In this study, intravascular ultrasound (IVUS) imaging was performed in the left main coronary artery in a series of patients without angiographically significant left main coronary artery disease (mean diameter stenosis of 32%). What is unique about this study was the subsequent long-term follow up, possibly due to the lower severity of stenosis than seen in other studies of left main coronary artery disease assessments, and hence the lack of referral for revascularization.7,8
Viewing the implications of a “vulnerable plaque” over the lens of a longer term provides the clinician with a different perspective. IVUS, or other modalities assessing for short-term implications of a vulnerable plaque, contain implicit or explicit potential revascularization considerations. Thus, the finding of a smaller minimum lumen area as a predictor of 1-year events may reflect the implications of ischemia due to the obstructive disease, or perhaps impending ischemia. In this study, minimum lumen dimensions were less predictive of outcomes, however, plaque burden was predictive, implying that plaque begets plaque. Since virtually all of the patients with an event had a plaque burden at the site of the minimum lumen area > 55%, whereas virtually no one with a measurement
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