During the past 10 years, chronic kidney disease (CKD) has been recognized as a major global health problem. Factors leading to decreased renal function are closely related to cardiovascular disease and vice versa. Cardiovascular morbidity and mortality are substantially increased in patients with CKD, even in those with only mild or moderate renal impairment. A better understanding of pathogenesis, risk factors, and genetic conditions is strongly required for more specific treatment strategies in CKD because until now, knowledge is very limited.

The German CAD-REF registry is a prospective observational multicenter national registry. It aims at including >3,300 white patients with angiographically documented coronary artery disease (coronary artery disease [CAD]; ≥50% stenosis in at least 1 coronary artery) being enrolled at 32 centers and assigned to 6 different groups according to their estimated glomerular filtration rate and/or proteinuria. Baseline characteristics, treatment data, and biomaterial including serum, plasma, urine, and DNA samples are collected. Follow-ups are performed at 6, 12, 24, 36, 48, and 60 months.

The CAD-REF registry will establish one of the largest ethnically homogeneous cohorts, to date, of clinically and angiographically well-characterized patients with CAD who have all stages of CKD. This approach offers great opportunities for an improved understanding of the underlying pathophysiologic mechanism and clinical impact of CKD in patients with CAD, especially including the identification of clinically relevant risk factors and (genetic and other bio-) markers as a basis to ameliorate future treatment strategies.