Background: Aortic valve calcification without obstruction (AVC) is common in the elderly and is associated with increased cardiovascular mortality and morbidity. We hypothesized that AVC detected by transthoracic echocardiography (TTE) is a marker for significant coronary artery disease in patients undergoing coronary angiography. Methods: The study group included 388 patients with AVC (259 males, 129 females, mean age 72.2 +/- 9 years) who underwent coronary angiography for various indications. Data were compared with 320, age- and sex-matched patients without AVC who underwent coronary angiography for the same indications. AVC was detected in TTE as focal areas of increased echogenecity and thickening of the aortic-valve leaflets without restriction in motion. Significant obstructive coronary artery disease was defined as either a greater than or equal to 70% reduction of the internal diameter of the left anterior descending, right coronary, or left circumflex artery distribution or a e greater than or equal to 50% reduction of the internal diameter of the left main coronary artery. Risk factors for atherosclerosis including hypertension, smoking, hypercholesterolemia and diabetes were also investigated. Results: Compared with control group, the AVC group had a higher prevalence of significant coronary artery disease (90 vs. 85%, P=0.019), and a trend for lower frequency of coronary arteries without obstruction (6 vs. 9%, P=0.11); a trend was also noted for 3-vessel disease (38 vs. 33%, P=0.14). Multivariate analysis identified age (P=0.0001), sex (P=0.0001), hypercholesterolemia (P=0.005) and AVC (P=0.02) as independent predictors for significant coronary artery disease. Conclusions: There is a significant association between AVC and significant coronary artery disease in patients undergoing coronary angiography. Thus AVC can serve as a window to atherosclerosis of the coronary arteries. These results reinforce a previous observation regarding association between AVC and increased risk of cardiovascular morbidity. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.