Study: Mammo may help assess cardiac risk in kidney disease patients
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Although arterial calcification is prevalent among patients with chronic kidney disease and end-stage kidney disease, diagnostic tools to assess vascular calcification are lacking. The process is further hampered by the distinct pathology, possible differing clinical significance and possible differing therapeutic approach associated with intimal layer or medial layer calcification.
Previous research demonstrated that arterial calcification can be detected on mammograms, and should be exclusively medial on the basis of vessel size and histologic exam, offered the authors. The research team, based at Emory University in Atlanta, sought to evaluate the role of mammography in determining the prevalence and risk factors for medial calcification in chronic kidney disease.
The study incorporated histologic examination of breast tissue, retrospective mammogram analysis and correlation with peripheral x-rays in patients with chronic kidney disease, according to lead researcher Valerie S. Duhn, MD, from the internal medicine department at Emory, and colleagues.
The histologic exam of 16 breast tissue samples found medial calcification, but no intimal calcification, in all samples. The researchers also age-matched 71 patients with end-stage kidney disease with subjects without renal insufficiency. The retrospective comparison of mammograms showed breast arterial calcification in 63 percent of the patients with kidney disease versus 17 percent in women without renal insufficiency.
The researchers selected a subset of 25 women with end-stage kidney disease and 44 women with stage III chronic kidney disease and reviewed mammograms acquired before disease onset. They found breast arterial calcification in 36 percent of pre end-stage kidney disease subjects and 14 percent of stage III subjects.
Finally, Duhn and colleagues compared arterial calcification on mammograms with peripheral arterial calcification on x-rays of 62 patients to determine if breast arterial calcification is a marker of generalized medial vascular calcification. “Of the 21 that showed diffuse, linear calcification indicative of medial calcification, breast arterial calcification was also present in 19,” wrote Duhn.
The researchers suggested that the detection of early stages of calcification that were not apparent on x-rays indicates that the prevalence of medial calcification is greater than that indicated by x-ray. “The fact that this peripheral arterial calcification correlated strongly with breast arterial calcification indicated that breast arterial calcification is a marker of generalized medial vascular calcification,” they wrote.
Duhn and colleagues acknowledged the limitations of the study: subjective detection of breast arterial calcification, a small sample and retrospective design. Yet, they concluded “the results demonstrate the utility of mammography as a specific tool for examining medial vascular calcification in chronic kidney disease.”
Because most women with chronic kidney disease are at an age where yearly mammograms are recommended, mammograms may be a useful tool for studying the development and progression of medial calcifications without additional radiation exposure or imaging costs, offered the researchers.