255 JNEPHROL 2009; 22: 255-262 ORIGINAL ARTICLE www.sin-italy.org/jnonline – www.jnephrol.com INTRODUCTION The high prevalence (1-4) along with the recognition of the unfavorable impact of cardiovascular calcification on outcomes (5-7) has led to a great effort to understand the pathogenesis and natural history of this condition in uremia. Furthermore, several published studies have shown that progression of coronary artery calcification (CAC) can be slowed (2, 8, 9) and that the use of a calci- um-based phosphate binder is associated with a worse outcome (7, 10). Although it has been reported that sev- eral patients do not have calcification at screening and do not develop it after a short follow-up, it remains to be determined whether these patients remain free of calcifi- cation long-term (what is the warranty period?) and what factors predict progression. Accordingly, we conducted the current analysis in the context of a randomized trial with phosphate binders, to evaluate rate and severity of CAC progression in patients new to hemodialysis and with minimal or absent baseline CAC, followed for a pe- riod of 30 months. SUBJECTS AND METHODS Subjects and study design Patients were originally randomized in the Renagel in New Dialysis (RIND) study (2). RIND was designed to evalu- ate the impact of calcium-based phosphate binders and sevelamer on CAC progression in incident dialysis patients (2). Briefly, patients were recruited from September 2000 through December 2002 and randomized within the first 120 days of beginning dialysis to receive either sevelamer Antonio Bellasi 1,2 , Laura Kooienga 3 , Geoffrey A. Block 4 , Emir Veledar 2 , David M. Spiegel 3 , Paolo Raggi 2 1 Department of Nephrology, San Paolo Hospital, Universi- ty of Milan, Milan - Italy 2 Division of Cardiology, Emory University, Atlanta, Georgia - USA 3 Division of Nephrology, University of Colorado Health Sciences Center, Denver, Colorado - USA 4 Denver Nephrology, Denver, Colorado - USA How long is the warranty period for nil or low coronary artery calcium in patients new to he- modialysis? ABSTRACT Background: Coronary artery calcification (CAC) is common in patients with advanced chronic kidney dis- ease on dialysis. A sizeable proportion of patients has no or minimal CAC at the inception of dialysis, but it is unclear how long they remain free of it. Methods: For the purpose of this study, 36 incident hemodialysis patients were submitted to sequential chest computed tomography to quantify CAC at base- line, 6, 12, 18 and 30 months. Results: Among them, 15 had absent or minimal CAC score (CACS 0 to 30) and 21 had a CACS >30 at base- line. Overall, the median baseline CACS was 129 (in- terquartile range [IQR] = 0-709) and it increased to 364 (IQR=8.3-1683) at study completion (182% increase). Among the 15 patients with minimal CACS, only 3 pro- gressed and the median CACS increase was 20, as op- posed to 15 of 21 patients with a baseline CACS >30 whose median progression was 431 (p<0.02). The 18 patients who had CACS progression were older (68.5 vs. 57.3 years, p=0.0081) and exhibited a poorer con- trol of mineral metabolism (phosphorus 5.2 vs. 4.9 mg/ dL, p=0.048; corrected calcium × phosphorus product [Ca×P] 49.3 vs. 46.2 mg 2 /dL 2 , p=0.001) than the pa- tients without progression. On multivariable analysis, independent predictors of progression were baseline CACS (p=0.038) and time-averaged Ca×P (p=0.077). Conclusion: These data suggest that absent or low CAC at baseline is associated with minimal progres- sion even up to 30 months. Careful management of mineral metabolism appears to be one of the main fac- tors that limit progression of CAC. Key words: Arteriosclerosis, Coronary calcium, Hemo- dialysis, Mineral metabolism, Progression Bellasi.indd 255 14-04-2009 15:40:17