PREVALENCE OF CORONARY ARTERY CALCIFICATION IN PATIENTS WITH CHRONIC RENAL INSUFFICIENCY NOT UNDERGOING DIALYSIS

Calcifications in coronary arteries (CAC) may contribute to the high rate of cardiovascular morbidity and mortality in patients with chronic kidney insufficiency (CKI) undergoing dialysis. The prevalence of CAC has never been evaluated in patients with CKI not receiving hemodialysis. In the present study the prevalence of CAC was assessed in patients with different degree of CKI not yet in dialysis. Out-patients with CKI who had no prior clinically documented coronary artery disease were evaluated. Renal function had been stable during the previous 12 months; no patients had rapidly progressive renal disease. The following parameters were gathered: calcium, phosphorus, urea, creatinine, glucose, total protein, albumin, serum electrolytes, cholesterol, triglycerides, total alkaline phosphatase, homocysteine, CPR, PTH. Other data were: renal disease, onset of CKI, blood pressure, traditional cardiovascular risk factors. CT scan was performed with multi-slice spiral scanner (GE Medical Systems). Parameters used for data acquisition were: 140 kVp, 360 mAs, slice width 2.5 mm, gantry rotation time 0.5 s, thick/speed 2.5 mm/4i. Data were reconstructed with a standard algorithm, prospective Gating, 512 X 512 matrix, SFOV 50 cm2, DFOV 25 cm2. The left main coronary artery (LMA), left anterior descending artery (LAD), circumflex artery (Cx), right coronary artery (RCA) were scored; total calcium score was reported as the sum of plaques found in all coronaries. Eighty-three (73 male, 10 female; mean age 51.3±13, range 18-70 years) consecutive patients with CKI (mean Ccr 32.5±16.6, range 10-70 ml/min) were evaluated. CAC was found in 33 pts (39,7%); mean calcium score was 400±500 mm3 (range: 12-2370). Clinical and biochemical data were not significantly different among calcified and not calcified patients; in particular, BMI: 27±4, duration of CKI: 5.3±4.1 years, PTH: 140±110 pg/ml, serum calcium: 9.5± 0.5 mg/dL, serum P: 4.0±0.7 mg/dL, Ca x P product: 36.7±7.3 mg2dL2, homocysteine: 39±37 uM, total cholesterol: 190±40 mg/dL, triglycerides: 160±90, HDL cholesterol: 46±8 mg/dL, PAS 132±11 mmHg, PAD: 81±4.5 mmHg. The mean age of calcified patients was significantly higher (59±8 vs. 46±12; p<0.01). To exclude a role of age, CAC were also seek in a control group of 30 normal subjects (patients without CKI or healthy subjects) homogenous per age with calcified patients. The prevalence of CAC in the control group was 5%. The data of the present study clearly indicate that CAC is already present in early phases of CKI in asymptomatic patients and that their prevalence is eight times higher than that of general population (39% vs. 5%) indicating an evident causal relation between plaque and CKI. This relationship may exist even in absence of any correlation with degree of renal failure, duration of renal impairment, parameters of bone mineral metabolism, PTH. Therefore, the assessment of CAC in pre-dialysis patients is clinically relevant; it is mandatory in order to earlier prevent or reduce cardiovascular outcomes. Finally the presence of CAC points out the need of changes in our therapeutic policy in pre-dialysis patients even in absence of evident alteration of lipids and/or calcium/phosphorus metabolism. Keywords: calcium; hyperparathyroidism; imaging techniques; renal failure: chronic Session: Poster Session II: Calcification