#1200 Coronary artery calcium modifies the relationship between blood pressure and adverse kidney outcome: results from KNOW-CKD

Abstract

Abstract Background and Aims Previous studies evidenced that elevated coronary artery calcium (CAC) score is associated with higher chronic kidney disease (CKD) progression. However, the use of CAC score to guide CKD management has not been adequately evaluated. Here, we evaluated whether presence of CAC modify the association between systolic blood pressure (SBP) and CKD progression in patients with CKD. Method We analyzed 1693 participants with CKD stages G1 to G5 from the KoreaN cohort study for Outcome in patients With Chronic Kidney Disease (KNOW-CKD). Key exclusion criteria were kidney failure with replacement therapy (KFRT) and missing data for CAC and SBP information. We categorized participants according to baseline SBP and CAC score (Controlled BP, SBP < 120 mmHg; Elevated BP without CAC, SBP 120-140 mmHg and CAC score = 0; Elevated BP with CAC, SBP 120-140 mmHg and CAC score >0; Uncontrolled BP, SBP >140 mmHg) and compared the CKD progression. The CKD progression was defined as a composite of halving eGFR from baseline value or onset of KFRT. Results During 10,023 person-years of follow-up (median 6.2 years), the composite outcome occurred in 689 (40.7%) participants, and 108 (6.4%) participants died among the KNOW-CKD participants. There was significant interaction between CAC score and SBP for CKD progression (P < 0.001). There were 181/568 (31.9%), 167/424 (39.4%), 128/314 (40.8%) 213/387 (55.0%), composite outcomes in controlled BP, elevated BP without CAC, elevated BP with CAC, uncontrolled BP group, respectively. In crude Cox regression, compared to controlled BP, elevated BP with CAC group showed similar CKD progression risk (Hazard ratio [HR], 1.17; 95% confidence interval [CI], 0.95-1.44), whereas other strata group showed increased risk of CKD progression (elevated BP with CAC; HR, 1.59; 95% CI 1.31-1.94 and uncontrolled BP, HR, 1.94; 95% CI 1.56-2.41). Similar elevated risk in elevated BP with CAC was observed even after adjustment of age, sex, diabetes mellitus, estimated glomerular filtration ratio, and proteinuria (HR, 1.26; 95% CI, 1.02-1.56). However, the risk of CKD progression in elevated BP without CAC group was comparable to controlled BP group (HR, 1.20; 95% CI, 0.87-1.66). Conclusion Elevated SBP was more strongly associated with an increased risk of adverse kidney outcomes in patients with coronary calcification.