The clinical significance of medial arterial calcification in end-stage renal disease in women.

Medial arterial calcification is common in advanced kidney disease but its impact on cardiovascular disease is uncertain because imaging techniques used to date cannot reliably distinguish it from atherosclerotic calcification. We have previously shown that breast arterial calcification (BAC) is exclusively medial and is a marker of generalized medial calcification in end-stage renal disease (ESRD). Therefore, the presence of BAC on mammograms in 202 women with ESRD (mean duration 4.1 years) was correlated with cardiovascular events to determine the clinical significance of medial arterial calcification. BAC was found in 58% of the study participants and was significantly associated with age, diabetes, and ESRD duration. Both coronary artery (27 vs. 15%) and peripheral arterial disease (PAD; 19 vs. 4%) were more likely in patients with BAC but only the latter persisted after accounting for other factors (odds ratio 4.6; 95% confidence interval 1.2-15). In 142 women without clinical events before mammography, BAC was associated with a greater incidence of new PAD events (13 vs. 3%) but not coronary artery disease events (11 vs. 11%). Thus, BAC is strongly and independently associated with PAD in women with ESRD and may be predictive of clinical events. This suggests that medial arterial calcification is a clinically significant lesion that may contribute to the accelerated PAD in ESRD.

The risk for medial arterial calcification in CKD.

BACKGROUND AND OBJECTIVES: CKD is a risk factor for medial artery calcification, but the CKD stage at which this risk begins is unknown. Because breast arterial calcification (BAC) is a marker of generalized medial arterial calcification, mammography was used to detect medial arterial calcification in women with different CKD stages. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This was a retrospective, cross-sectional study of women with and without CKD matched for age and diabetes and identified from mammograms obtained in 2006-2011. BAC was scored as present or absent per visual inspection. RESULTS: A total of 146 women with stage 3 CKD and 54 with stage 4/5 CKD were identified. An additional 21 patients with ESRD were identified and added to a previous cohort of 71 patients. Mean age was 64 years for CKD 3, 63 for CKD 4, and 59 for ESRD. Half of each group had diabetes. Compared with controls, the odds ratios for BAC were 1.44 in CKD 3 (95% confidence interval [CI], 0.82-2.53), 2.69 in CKD 4 (95% CI, 1.14-6.33), and 7.19 in ESRD (95% CI, 3.77-13.7) and did not differ with diabetic status or race. In a multivariable logistic model, age (P<0.001) and estimated GFR (P=0.005) were independent predictors of BAC. The odds ratio for BAC increased 4% for each milliliter per minute per 1.73 m(2) decrease in estimated GFR. The prevalence of BAC in CKD was increased in each decade of age over 49 years. CONCLUSIONS: CKD is an independent risk factor for medial arterial calcification.

Breast arterial calcification: a marker of medial vascular calcification in chronic kidney disease.

BACKGROUND AND OBJECTIVES: Because previous studies have not distinguished between intimal (atherosclerotic) and medial vascular calcification, the prevalence and clinical significance of either condition in chronic or end-stage kidney disease (CKD or ESKD) are unknown. We hypothesized that breast arterial calcification (BAC) is exclusively medial and that mammography can serve as a useful marker of generalized medial calcification in CKD and ESKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Arterial calcification was identified histologically in breast tissue or visually in mammograms and radiographs of extremities from patients with CKD or ESKD. RESULTS: Medial calcification but no intimal calcification was present in all 16 specimens from patients with CKD or ESKD. In 71 women with ESKD, BAC was present on mammograms in 63% compared with 17% in women without renal insufficiency matched for age, race, and diabetes (P<0.001). Age and ESKD duration were significant, independent predictors of BAC. BAC was also present in 36% of mammograms from the same patients performed 5.5±0.7 years before the onset of ESKD (P<0.05 versus control) but in only 14% of patients with stage 3 CKD. Comparison of mammograms and extremity radiographs revealed that BAC was present in over 90% of patients with peripheral arterial calcification (PAC), and PAC was observed in less than 6% of patients without BAC. CONCLUSIONS: BAC is a specific and useful marker of medial vascular calcification in CKD, and its prevalence is markedly increased in ESKD and advanced CKD.