Coronary calcification in patients with chronic kidney disease and coronary artery disease

Abstract

Background and objectives: A close linkage between chronic kidney disease (CKD) and cardiovascular disease (CVD) has been demonstrated. Coronary artery calcification (CAC) is considered to be the causal link connecting them. The aim of the study is to determine the relationship between level of kidney function and the prevalence of CAC.

Design, setting, participants, & measurements: Autopsy subjects known to have coronary artery disease and a wide range of kidney function were studied. Patients without CKD were classified into five groups depending on estimated GFR (eGFR) and proteinuria: eGFR > or =60 ml/min/1.73 m(2) without proteinuria; CKD1/2: eGFR > or =60 ml/min/1.73 m(2) with proteinuria; CKD3: 60 ml/min/1.73 m(2) >eGFR > or =30 ml/min/1.73 m(2); CKD4/5: eGFR <30 ml/min/1.73 m(2); and CKD5D: on hemodialysis. Intimal and medial calcification of the coronary arteries was evaluated. Risk factors for CVD and uremia were identified as relevant to CAC using logistic regression analysis.

Results: Intimal calcification of plaques was present in all groups, but was most frequent and severe in the CKD5D group and less so in the CKD4/5 and CKD3 groups. Risk factors included luminal stenosis, age, smoking, diabetes, calcium-phosphorus product, inflammation, and kidney function. Medial calcification was seen in a small number of CKD4/5 and CKD5D groups. Risk factors were use of calcium-containing phosphate binders, hemodialysis treatment, and duration.

Conclusions: It was concluded that CAC was present in the intimal plaque of both nonrenal and renal patients. Renal function and traditional risks were linked to initimal calcification. Medial calcification occurred only in CKD patients.

Figure 1.

Coronary artery pathologic findings (A) A representative left anterior descending coronary artery proximal segment of CKD5D case with acute myocardial infarction. Large calcification of intimal atheromatous plaque (surrounded by arrow) (HE). (B) Distal segment of the same case as (A). Severe stenosis with calcified hard plaque (HE). (C) Osteopontin-positive calcified plaque (crop area from A) (immunohistochemistry, DAB). (D) RCA proximal segment of case without CKD. Large necrotic core with minute foci of calcification (HE). (E) Distal segment of the same case as (D) shows no stenosis (HE). (F) Significant CD68-positive macrophages accumulation in atheromatous plaque with lymphocyte (arrow) infiltration (crop area from D) (immunohistochemistry, DAB).