PATTERNS OF CALCIFICATION IN CORONARY-ARTERY DISEASE - A STATISTICAL-ANALYSIS OF INTRAVASCULAR ULTRASOUND AND CORONARY ANGIOGRAPHY IN 1155 LESIONS

Background Target lesion calcium is a marker for significant coronary artery disease and a determinant of the success of transcatheter thera py. Methods and Results Eleven hundred fifty-five native vessel target lesions in 1117 patients were studied by intravascular ultrasound (IV US) and coronary angiography. The presence, magnitude, location, and d istribution of IVUS calcium were analyzed and compared with the detect ion and classification (none/mild, moderate, and severe) by angiograph y. Angiography detected calcium in 440 of 1155 lesions (38%): 306 (26% ) moderate calcium and 134 (12%) severe. IVUS detected lesion calcium in 841 of 1155 (73%, P<.0001 versus angiography). The mean are of lesi on calcium measured 115+/-110 degrees; the mean length measured 3.5+/- 3.7 mm. Target lesion calcium was only superficial in 48%, only deep i n 28%, and both superficial and deep in 24%. The mean are of superfici al calcium measured 85+/-108 degrees; the mean length measured 2.4+/-3 .4 mm. Three hundred seventy-three of 1155 reference segments (32%) co ntained calcium (P<.0001 compared with lesion site). The mean are of r eference calcium measured 42+/-80 degrees; the mean length measured 1. 7+/-3.6 mm. Only 44 (4%) had reference calcium in the absence of lesio n calcium. Angiographic detection and classification of calcium depend ed on arcs, lengths, location, and distribution of lesion and referenc e segment calcium. By discriminant analysis, the classification functi on for predicting angiographic calcium included the are of target lesi on calcium, the are of superficial calcium, the length of reference se gment calcium, and the location of calcium within the lesion. This mod el correctly predicted the angiographic detection of calcification in 74.4% of lesions and the angiographic classification (none/moderate/se vere) of calcium in 62.8% of lesions. Conclusions IVUS detected calciu m in >70% of lesions, significantly more often than standard angiograp hy. Although angiography is moderately sensitive for the detection of extensive lesion calcium (sensitivity, 60% and 85% for three- and four -quadrant calcium, respectively), it is less sensitive for the presenc e of milder degrees.