Predictive value of coronary calcifications for future cardiac events in asymptomaticpatients with severe chronic kidney disease

Abstract

Abstract Background: Coronary calcification are a well established risk factor for cardiovascular events. The following retrospective study determined the predictive value of coronary calcification in a specific group of patients with chronic kidney disease. Methods: We included 1094 asymptomatic patients (724 men, 370 women, age 62±9.3 years) referred for cardiological examination. Patents were divided into two groups depending on their renal function. Coronary calcification were determined with a multi-slice CT scanner. For quantification of coronary calcification the Agatston score was calculated. Over a mean follow up period of 6.2±1.3 years we observed the rate of cardiovascular events (185 events, 61 myocardial infarctions, 103 revascularisations, 21 cardiac deaths). Results: The calcium score was significantly higher in patients with severe kidney disease (GFR ≤ 30 ml/min/1,72m²) compared with those with normal to moderate reduced renal function (GFR ≥ 30 ml/min/1,72m²) (207±190 vs.121±169 p≤0.001). The event rate in patients with severe impaired renal function was significantly higher compared to patients with normal to moderate reduced renal function. (20.6% vs 14.8% p=0.0001) The hazard ratio for cardiovascular events increased constantly with the calcium score in both groups .Still the hazard ratio in patients with severe kidney disease was significantly lower compared to patients in corresponding groups with regular to moderate reduced renal function.(7.3 vs 9.3 p=0.01). No cardiac events were observed in patients with a calcium score of 0. Conclusions: We could demonstrate that risk prediction with the calcium score is possible in patients with severe chronic kidney disease even if the calcium score overestimates the risk for future cardiovascular events in compare to patients with normal to moderate reduced renal function.