Subsequent silent plaque rupture of nonculprit lesion in a patient with acute myocardial infarction

The lesions responsible for acute coronary syndrome (ACS) are pathologically sudden ruptures of vulnerable plaques with superimposed thrombosis. Vulnerable plaques are generally characterized as those having a thin inflamed fibrous cap over a very large lipid core with activated macrophages near the fibrous cap [ [1] Fuster V. Stein B. Ambrose J.A. Badimon L. Badimon J.J. Chesebro J.H. Atherosclerotic plaque rupture and thrombosis. Evolving concepts. Circulation. 1990; 82: II47-II59 PubMed Google Scholar ]. An intravascular ultrasound (IVUS) report have suggested that the presence of positive vascular remodeling and hypoechoic regions corresponding to lipid rich tissue in coronary plaques were related to acute coronary events [ [2] Yamagishi M. Terashima M. Awano K. et al. Morphology of vulnerable coronary plaque: insights from follow-up of patients examined by intravascular ultrasound before an acute coronary syndrome. J Am Coll Cardiol. 2000; 35: 106-111 Abstract Full Text Full Text PDF PubMed Scopus (397) Google Scholar ]. A ST-segment elevation myocardial infarction caused by plaque rupture was associated with a large degree of myocardial damage and poor functional recovery as compared with that without plaque rupture, even after successful primary angioplasty [ [3] Tanaka A. Shimada K. Namba M. et al. Ruptured plaque is associated with larger infarct size following successful percutaneous coronary intervention in ST segment elevation acute myocardial infarction. Coron Artery Dis. 2009; 20: 260-266 Crossref PubMed Scopus (13) Google Scholar ]. ACS patients may harbor multiple complex coronary plaques, which are associated with adverse clinical outcomes [ [4] Goldstein J.A. Demetriou D. Grines C.L. Pica M. Shoukfeh M. O'Neill W.W. Multiple complex coronary plaques in patients with acute myocardial infarction. N Engl J Med. 2000; 343: 915-922 Crossref PubMed Scopus (896) Google Scholar ]. Plaque instability is thus not merely a local vascular accident but probably reflects more generalized pathophysiologic processes with the potential to destabilize atherosclerotic plaques throughout the coronary tree [ [5] Rioufol G. Finet G. Ginon I. et al. Multiple atherosclerotic plaque rupture in acute coronary syndrome: a three-vessel intravascular ultrasound study. Circulation. 2002; 106: 804-808 Crossref PubMed Scopus (658) Google Scholar ]. Therefore, it is very important to detect silent plaque rupture, because detection of a rupture at a nonculprit site could indicate a plaque that is at high risk of thrombotic complication, and could be used as a prognostic indicator.