Cardiovascular events and death in Japanese patients with chronic kidney disease

The incidence of cardiovascular disease (CVD) is higher in patients with chronic kidney disease (CKD) than in the general population, and the risk of CVD increases with reductions in renal function. However, the incidence of CVD in Japanese patients with CKD has not been sufficiently investigated. To measure this we conducted the Chronic Kidney Disease Japan Cohort (CKD-JAC) Study over four years in 2,966 Japanese patients with CKD to examine the incidence of CVD and all-cause death. These patients had an estimated glomerular filtration rate (eGFR) of 10-59 ml/min/1.73 m², were under nephrologist care, and pooled from 17 medical institutions in Japan. At the median follow-up of 3.9 years, 69 patients had died, 217 had cardiovascular events, and 514 started maintenance dialysis therapy. The incidences of cardiovascular events were 11.9, 19.1, 25.0, and 39.4 per 1,000 person-years at eGFRs of 45-59, 30-44, 15-29, and under 15 ml/min/1.73 m², respectively. The adjusted Cox proportional hazards models showed that the risk of cardiovascular events increased as the eGFR decreased, with a significant difference only between CKD stage G5 (eGFR: under 15 ml/min/1.73 m²) and CKD stage G3a (eGFR: 45-59 ml/min/1.73 m²) (hazard ratio 3.16, 95% confidence interval 1.28 to 7.76). Thus, the risk of CVD and all-cause death was related to the decrease in eGFR, but not necessarily elevated in proportion to progression of the CKD stage in Japanese patients with predialysis CKD under a nephrologist's care.