Association of BP with Death, Cardiovascular Events, and Progression to Chronic Dialysis in Patients with Advanced Kidney Disease

Background and objective The optimal BP target to reduce adverse clinical outcomes in patients with CKD is unclear. This study examined the relationship between BP and death, cardiovascular events (CVEs), and kidney disease progression in patients with advanced kidney disease. Design, setting, participants, & measurements The relationship of systolic BP (SBP), diastolic BP (DBP), and pulse pressure (PP) with death, CVE, and progression to long-term dialysis was examined in 1099 patients with advanced CKD (eGFR <= 30 ml/min per 1.7 3m(2); not receiving dialysis) who participated in the Homocysteine in Kidney and ESRD study. That study enrolled participants from 2001 to 2003. Cox proportional hazard models were used to examine the association between BP and adverse outcomes. Results The mean +/- SD baseline eGFR was 18 +/- 7 ml/min per 1.73 m(2). During a median follow-up of 2.9 years, 453 patients died, 215 had a CVE, and 615 initiated long-term dialysis. After adjustment for demographic characteristics and confounders, SBP, DBP, and PP were not associated with a higher risk of death. SBP and DBP were also not associated with CVE. The highest quartile of PP was associated with a substantial higher risk of CVE compared with the lowest quartile (hazard ratio [HR], 1.67; 95% confidence interval [95% CI], 1.10 to 2.52). The highest quartiles of SBP (HR, 1.28; 95% CI, 1.01 to 1.61) and DBP (HR, 1.36; 95% CI, 1.07 to 1.73), but not PP, were associated with a higher risk of progression to long-term dialysis compared with the lowest quartile. Conclusions In patients with advanced kidney disease not undergoing dialysis, higher PP was strongly associated with CVE whereas higher SBP and DBP were associated with progression to long-term dialysis. These results suggest that SBP and DBP should not be the only factors considered in determining antihypertensive therapy; elevated PP should also be considered.