Intravascular Ultrasound Study of Patterns of Calcium in Ruptured Coronary Plaques

Coronary calcium is intimately associated with coronary atherosclerotic plaque development, although it is controversial as to whether coronary calcium is associated with plaque instability. We analyzed 101 IVUS-detected ruptured plaques and compared them with 101 computer-matched control plaques without evidence of plaque rupture. The arc of calcium was measured every 0.5 mm within 10-mm-long segments that spanned the minimum lumen cross-sectional area, and the number and length of calcium deposits were assessed. Ruptured plaques had a significantly larger number of individual calcium deposits than control plaques (3.5 ± 1.7 vs 1.8 ± 1.1, p