Clinical outcome in cardiorenal patients related to coronary computed tomography angiography and serum adrenomedullin

Background: Adrenomedullin is present in numerous human body tissues and its powerful vasodilatatory activity is thought to play role in cardiovascular/renal homeostasis and possibly in atherosclerosis. We conducted a prospective 2-year study of one hundred twenty-three patients with chronic kidney disease (CKD). Clinical outcome was analyzed to coronary computed tomography angiography (CCTA) findings and serum adrenomedullin levels. Methods: We determined plasma mid-regional pro-adrenomedullin (MR-proADM) levels using sandwich immunoassay in patients (pts) on stage 2 to 5 CKD (glomerular filtration rate - GFR < 90 ml/min/1.73 m2). Coronary artery calcification (CAC) and noninvasive coronary angiograms were performed by 64-multi-detector computed tomography (Siemens, Germany). The presence of stenosis ≥ 50% during CCTA was considered as significant. The degree of coronary artery calcification was assessed using the Agatston calcium score method. Results: We studied consecutive 123 pts with suspected coronary artery disease (mean age 62.5±10.7 years, 57.7% male, arterial hypertension 89.2%, type 2 diabetes 25.2%, 29.0% had a history of tobacco use and 38.2% were on regular haemodialysis- mean 51.7 months, ranging from 3 to 252 months). On CCTA, 76 pts (65.0%) had no coronary artery disease (CAD),in 29 pts (24.8%) one significant epicardial stenosis and in 12 (10.3%) multivessel disease were documented. The mean MR-proADM plasma levels and CAC score were 1.4 nmol/l and 472.8, respectively. MR-proADM correlated with CAC (r=0.20; p=0.02), GFR (r=-0.75; p<0.001), total cholesterol and LDL-cholesterol (r=-0.36; p=0.02 and r=-0.34; p= 0.001). During follow-up period (18.4±6.2 months) 7 cardiovascular deaths were occurred and 1 patient underwent percutaneous coronary intervention for unstable angina. The main characteristics in pts with cardiac events or eventfree survival were the following: serum MR-proADM (2.5 vs 1.3 nmol/l), CAC (663.7 vs 462.5). When we compared these variables to cardiac events only significant difference was documented in MR-proADM levels (p=0,04). Otherwise, areas under receiver operating characteristic curve (AUC) for prediction of cardiovascular mortality were 0.82 (95% CI 0.67-0.97), 0.75 (95% CI 0.50-0.99) and 0.64 (95% CI 0.29-0.99) for MR-proADM vs duration of hemodialysis and CAC. Conclusions: Coronary computed tomography angiography and serum adrenomedullin represent new alternative diagnostic tools for risk stratification in special group of cardiorenal patients.