Detection of a Vulnerable Coronary Plaque
A Treatment Dilemma
A 34-year-old man who experienced a 30-minute episode of chest pain at rest was admitted to the coronary care unit after becoming symptom free. His ECG was normal. A few hours later, he suffered a 5-minute period of recurrent chest pain with transient ST-segment elevation (Figure 1). The level of creatine phosphokinase reached its peak at 800 IU (upper limit=199 IU), and the maximum troponin T level was 1.85 μg/L. Noninvasive coronary imaging with a 16-slice spiral computed tomography scanner (MSCT) (Sensation 16, Siemens AG; Forchheim, Germany) suggested a nonobstructive lesion in the mid-left anterior descending artery (LAD) (Figure 2), which was confirmed with coronary angiography. Coronary spasm was excluded by methergin provocation test, which only showed general vasoconstriction (31% reduction of reference diameter) but no focal spasm. Intravascular ultrasound (IVUS) (CVIS Atlantis 40-MHz 3F catheter, Boston Scientific, TOMTEC ECG-gated acquisition system) demonstrated a local plaque with vessel remodeling in the mid-LAD. The plaque was covered by a thin layer of speckling, which was different from the plaque and blood speckles, suggesting clot formation (Figure 3B). A small rupture was visible at the proximal shoulder of the plaque (Figure 3A), which was better delineated with a 4D reconstruction image (Movie I). Coronary flow reserve was 4.3, indicating a non–flow-limiting plaque. IVUS palpography demonstrated a strain pattern, which strongly suggested the presence of a vulnerable plaque (Figure 4A and 4B; Movie II). Given the clinical presentation and ultrasound findings, and despite the non–flow-limiting obstruction, we decided after considerable deliberation to implant a drug-eluting stent in the diseased part of the mid-LAD. The procedure and recovery after stent implantation were uneventful.
Movies I and II are available in the online-only Data Supplement at http://www.circulationaha.org.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
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