Aims
Chronic kidney disease (CKD) is associated with the development and progression of coronary heart disease (CHD), in addition to classic cardiovascular risk factors. We analysed the prevalence of CKD in CHD patients from 24 European countries in the ambulatory setting and in a preceding hospital stay for CHD (index).

Methods and results
A total of 7998 EUROASPIRE IV participants (median 65 years of age, 76% male) attended a study visit 6–36 months after the index hospitalisation. CKD was classified according to stages of estimated glomerular filtration rate (eGFR) and albuminuria (urinary albumin/creatinine ratio). In stable CHD conditions (study visit), 17.3% had CKD (eGFR <60 mL/min/1.73 m2) with variation among participating countries (range 13.1–26.4%). A further 12% presented with preserved eGFR but significant albuminuria. During the hospital stay due to a coronary event, impaired kidney function was observed in 17.6% (range 7.5–38.2%). Risk factors for impaired kidney function included older age, female gender, classic cardiovascular (CV) risk factors, details of CHD history and congestive heart failure (multivariate regression). Of all patients, 38.9% had declined, 31.3% were stable and 29.8% had improved kidney function between hospital discharge and the study visit, dependent on age, gender, CV risk factors, CHD history and cardiac dysfunction (multivariate regression).

Conclusions
Every fifth CHD patient had CKD, while every tenth exhibited albuminuria as the sole indicator of kidney damage. These subjects are at increased risk of progression of CKD and CHD complications. After hospital stays due to CHD, there is potential of recovery of kidney function, but our findings underline the importance of identifying patients who are at high risk of developing CKD in order to counteract disease progression.