CORONARY ARTERY CALCIFICATION IN PRE-DIALYSIS PATIENTS

Coronary artery calcification (CAC) are frequent in dialysis patients and regarded as independent risk factor responsible for cardiovascular events. This study evaluates prevalence of CAC and pathogenetic factors in a cohort of pre-dialysis patients. Exclusion criteria were: heart failure or coronary artery disease, previous history of MI, coronary bypass surgery or angioplasty, stroke, arrhythmia. Patients were divided in: (A) patients with CKI without diabetes; (B) type II diabetic patients with CKI; (C): hypertensive patients without CKI and diabetes (Controls). The following parameters were evaluated: calcium, phosphorus, urea, creatinine, glucose, total protein, albumin, serum electrolytes, cholesterol, triglycerides, total alkaline phosphatase, homocysteine, C-reactive protein (CRP), i-PTH, urinary protein excretion (UAE). Systolic and diastolic blood pressure and biochemical data recorded during 6 months preceding the study were collected and averaged for statistical analysis. CAC were sought and scored by spiral CT. Left main coronary artery, left anterior descending artery, circumflex artery, right coronary artery were scored and values were added (total calcium score, TCS) N. 168 consecutive patients were evaluated: 51% had CKI, 10% had CKI and diabetes; 39% hypertension without CKI and diabetes. Biochemical parameters in patients with CKI were: GFR = 32±17 ml/min, i-PTH = 117±114 pg/ml, serum calcium = 9.5±0.5 mg/dL, phosphorus = 4.0±0.8, Ca x P product = 37.6±7.6, cholesterol = 195±43. Mean blood pressure was 98±7 mm Hg. Biochemical data were not significantly different among patients with CKI except for significantly higher triglycerides and UAE in diabetic patients (219±128 mg/dL Vs 145±72, p<0.001 and 3.1±3.8 gr/24h Vs 1.5± 1.6 gr/24 h, p< 0.01, respectively). Age was significantly higher in diabetics than other groups. CAC were found in 71% of diabetics, in 40% of non diabetic patients with CKI, and in 27% of Controls. TCS was higher in patients with CKI and mostly in diabetics (group A: 402±539; group B: 231±241; group C: 70±65); 52% of diabetics, 23% of CKI patients, and only 8% of controls were at very high cardiovascular risk according to Rumberger's classification (TCS >100 = highest risk). The present study indicates that CAC are present in asymptomatic pre-dialysis; diabetes increases both prevalence of CAC and cardiovascular risk. The higher prevalence of CAC in CKI patients indicates a causal role of renal failure in the pathogenesis of CAC even in absence of alterations of parameters regulating bone mineral metabolism. In addition the data suggests that aggressive clinical atherosclerosis prevention is warranted, especially in diabetics with CKI. Session: Poster: Cardiovascular / soft tissue calcification - cardiovascular risk factors