Vascular calcification as a cardiovascular risk factor in hemodialyzed and undialyzed patients with chronic renal failure

Abstract EN

Background : Vascular calcification is common in chronic renal failure patients (CRF).

Two distinct forms of calcification are recognized.

Intimal calcification occurs within athermanous plaques.

It is a disease of ischemia related occlusion in which inflammatory cells play an early role.

Whereas medial calcification occurs in the matrix between smooth muscle cells and result in increased arterial stiffness resulting in elevation of systolic blood pressure, left ventricular hypertrophy and altered coronary perfusion.

The aim of this work: was to study vascular calcifications in (CRF) patients either undialyzed or on maintenance hem dialysis (HD), its relation to some possible underlying factors, and correlation of these calcifications with cardiovascular disease.

Material and methods: The present study included 30 patients with (stage 4 and 5) for whom dialysis was not performed, 30 patients CRF on HD, 20 healthy subjects of matched age and sex as control.

creatinine, albumin, triglycerides and cholesterol (total, LDL, HDL), calcium (total and ionized), phosphorus.

Intact parathyroid hormone C-reactive protein (CRP).

ultrasonography of the carotid artery for measurement of intima media thickness (IMT) and the presence of atherosclerotic plaques Echocardiography for detection of cardiac valves calcification, and Left ventricular mass index.

Measurement of carotid and femoral arteries compliance and distensibility using ultrasound.

Plain radio-graphy of the pelvis and hands to detect calcification in iliac, femoral, radial and digital arteries and calculate a vascular calcification score.

Result : Valve calcification was present in 4 out of the 30 undialyzed patients (13.3%) and in 7 out of the 30 dialyzed patients (23.3%).There was a positive correlation between valve calcification and age, IMT, ischemic heart disease (IHD) and atherosclerotic plaques.

Carotid atherosclerotic plaques were demonstrated in 4 patients (13.33%) in the undialyzed group and in 9 out of the 30 dialyzed patients (30%) and it were positively correlated with IHD, IMT, CRP, serum creatinine and valve calcification.

Ankle / Brachial pressure Index (ABI) showed a significant decrease from one group to another and was abnormal (<1) in 6 and 9 undialyzed and dialyzed groups respectively.

There was a significant decrease in carotid artery distensibility coefficient between the 3 groups while its compliance coefficient was decreased from one group to another but this decrease was significant only between the dialyzed and the control groups.

Carotid (Distensibility Coefficient) DC & Compliance Coefficient (CC ) was negatively correlated with Systolic Blood Pressure.

(SBP) (Pulse Pressure )PP, P, Ca X P product; carotid DC with serum creatinine, the duration of dialysis and LVMI ; and carotid CC with age.

For the femoral artery distensibility coefficient: there was a significant difference between both undialyzed and dialyzed and the control group and for its compliance coefficient, there was a significant difference between only the dialyzed and the control group.

Femoral DC and CC was negatively correlated with duration of dialysis, SBP, PP, CRP, and calcification score ; femoral DC with IHD, Ca X P product ; and femoral CC with PTH.

13 Patients (43%) out of the 30 dialyzed patients showed vascular calcification in nays of pelvis and hands.

Calcification score was found to be positively correlated with duration of dialysis, SBP, PP, PTH and was negatively correlated with femoral CC and DC Conclusions : Cardiovascular calcifications were evident in CRF patients, which starts early in CKD before reaching the ESRD and is more marked in HD patients.

Vascular calcification was present in its two types either atherosclerosis or arteriosclerosis.