909-24 Intravascular Ultrasound Validation of a Semiquantitative Angiographic Classification of Coronary Artery Target Lesion Calcium

• Published in: Journal of the American College of Cardiology 1995-02, Vol.25 (2), p.61A-61A
• Main Authors: Mintz, Gary S., Popma, Jeffrey J., Pichard, Augusto D., Kent, Kenneth M., Satler, Lowell F., Chuang, Ya Chien, Griffin, Jennifer, Leon, Martin B.
• Format: Article
• Language: English
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/0735-1097(95)91706-4

We used pre-intervention intravascular ultrasound (IVUS) imaging to validate a semiquantitative coronary angiographic classification of target lesion calcium (Ca) in 1155 native vessel lesions (47LM, 487LAD, 180LCX, 441 RCA) in 1117 pts (862 males, 255 females, ages 61±11 yrs). The are, length, distribution (superficial vs deep), and location (lesion vs reference) of IVUS Ca were compared to the following angiographic classification: “None/Mild” Ca, “Moderate” Ca (radiopacities only noted during the cardiac cycle prior to contrast injection), and “Severe” Ca (radiopacities noted without cardiac motion prior to contrast injection generally involving both sides of the arterial lumen).Coronary Angiographic CapNone/MildModerateSevereN=715N=306N=134Intravascular UltrasoundTarget lesion Ca # (%)436 (61%)274 (90%)141 (98%)<0.0001Arc of Ca(°)71±83165±106238±104<0.0001Length of Ca (mm)2.5±3.24.5±3.56.2±4.7<0.0001Superficial Ca # (%)261(37%)219(72%)123(92%)<0.0001Arc of superficial Ca (°)44±74124±110215±119<0.0001Length of superficial Ca (mm)1.5±2.63.2±3.187±98<0.0001Arc of reference Ca (°)1.0±2.66.1±933.3±4.1<0.0001Length of reference Ca (mm)1.0±2.62.6±4.83.3±4.1<0.0001Total length of Ca (mm)3.6±4.47.2±6.49.7±6.4<0.0001 Using discriminant analysis (variables are listed in the Table), a predictive model of the angiographic classification of lesion Ca was constructed; this model included the arc of target lesion Ca, the arc of superficial Ca, the length of reference segment Ca, and the distribution of Ca within the lesion. It correctly predicted the angiographic classification of lesion-associated Ca in 62.8% of lesions. Pre-intervention IVUS imaging validates a semiquantitative angiographic classification of target lesion Ca. Importantly, the presence of “Severe” angiographic Ca is a highly sensitive marker not only for target lesion Ca (sensitivity=98% with a mean arc of 238°), but also for superficial lesion Ca (sensitivity=92% with a mean arc of 215°)