Time in Target Range of Systolic Blood Pressure and Cardiovascular Disease in Patients with Chronic Kidney Disease: A Korean Nationwide Cohort Study.

Introduction: Time in target range of systolic blood pressure (SBP-TTR) is the percentage of time that the SBP remains within 110-130 mm Hg. The association between the SBP-TTR and clinical outcomes in patients with chronic kidney disease (CKD) remains unclear. We evaluated the risks of cardiovascular disease (CVD), all-cause mortality, and renal events across the SBP-TTR groups.

Methods: Overall, 193,289 patients with CKD who underwent at least two health checkups between 2012 and 2015 were selected from the Korean National Health Insurance Database. The patients were categorized into three categories based on their SBP-TTR levels: 76-100%, 26-75%, and 0-25%. The primary outcome was CVD risk and the secondary outcomes were all-cause mortality and progression to end-stage kidney disease (ESKD) according to SBP-TTR using Cox regression analysis.

Results: Compared with patients with SBP-TTR of 76-100%, the adjusted hazard ratios (HRs) for CVD were 1.07 (95% confidence interval [CI], 1.03-1.10) and 1.09 (95% CI: 1.06-1.13) for patients with SBP-TTR of 26-75%, and 0-25%, respectively. The adjusted HR for all-cause mortality was 1.04 (95% CI: 1.003-1.07) and 1.37 (95% CI: 1.28-1.46) for patients with SBP-TTR of 26-75% and 0-25%, respectively. The adjusted HRs for ESKD progression increased gradually: 1.14-fold (95% CI: 1.07-1.21) for the SBP-TTR 26-75% group and 1.37-fold (95% CI: 1.28-1.46) for the SBP-TTR 0-25% group. For patients not taking antihypertensive medications, a lower SBP-TTR was associated with a higher risk of CVD events and ESKD progression than in those taking antihypertensive medications.

Conclusion: Among patients with CKD, those with a lower SBP-TTR had a higher risk of cardiovascular events, mortality, and progression to ESKD.