Incidence, Location, Magnitude, and Clinical Correlates of Saphenous Vein Graft Calcification

Abstract

Background— The pattern of saphenous vein graft (SVG) calcification before percutaneous intervention has not been studied. Methods and Results— We used diagnostic and preintervention intravascular ultrasound (IVUS) to determine the incidence and magnitude of SVG calcification in 334 SVG lesions in 274 consecutive patients. Calcium was found in 133 SVGs (40%). Calcium was uniformly distributed among 48 lesion sites (14%), 43 proximal references (13%), and 42 distal references (13%). Calcium was superficial in 20 (40%) and deep in 28 (60%). Over the entire length of the SVGs, the maximum arc and length of calcium (in calcium-containing SVGs) averaged 174±107° and 6.8±4.8 mm, respectively. In calcium-containing SVGs, lesion site arc and length of calcium measured 151±107° and 4.1±3.7 mm, similar to the proximal and distal references (175±121° and 4.0±2.3 mm and 177±121° and 4.1±2.5 mm, respectively). Graft age (7.5±4.7 versus 10.5±4.7 years, P P =0.02), and tobacco use (44% versus 55%, P =0.06) were clinical independent predictors of SVG calcification. Conclusions— Sixty-five percent of calcium-containing SVGs had reference calcium in the absence of lesion calcium. Calcium was located primarily in SVG wall and not at the plaque. These data suggest that SVG calcium is not just part of lesion formation and maturation. SVG calcium occurred more commonly in older grafts, in insulin-treated diabetic patients, and in smokers.