SBP-hyper-burden: a novel predictor of cardiovascular mortality in patients undergoing maintenance hemodialysis
J Tang, J L Sha, S K Yu, G Q Chen, Y ZhangAbstract
Background
Neither the traditional systolic blood pressure (SBP) index SBP-mean nor SBP-Time in Target Range (SBP-TTR) adequately captures the combined impact of blood pressure fluctuations and the proportion of time spent above the target level on mortality risk. SBP-Hyper-Burden is a novel parameter that quantifies the temporal cumulative effect of SBP exceeding the target threshold.
Purpose
This study aimed to evaluate the predictive utility of SBP-Hyper-Burden for all-cause and cardiovascular (CV) mortality in patients undergoing maintenance hemodialysis (MHD).
Methods
A total of 100 MHD patients were enrolled and underwent 24-hour ambulatory blood pressure monitoring (ABPM). SBP-mean, SBP variability indices, and SBP burden indices (including SBP-TTR and SBP-Hyper-Burden) were calculated using a dedicated application developed by our team. The primary endpoints were all-cause death and CV death.
Results
Over a median follow-up of 4.3 years, 38 all-cause deaths and 25 CV deaths were recorded. After full adjustment for confounders, only SBP-mean and SBP-Hyper-Burden remained significantly associated with CV mortality among all SBP indices examined. Compared with survivors, only SBP-Hyper-Burden was significantly elevated in the endpoint event group (p < 0.05), while SBP-mean showed no statistically significant difference. Although higher SBP-mean, lower SBP-TTR, and higher SBP-Hyper-Burden were all associated with increased mortality, only SBP-Hyper-Burden demonstrated statistically significant between-group differences in Kaplan-Meier analysis (log-rank p < 0.05). Restricted cubic spline analysis revealed a significant linear relationship between SBP-Hyper-Burden and CV mortality risk (p < 0.05). Each standard deviation increase in SBP-Hyper-Burden was associated with a 52% higher risk of all-cause mortality (HR = 1.52, 95% CI: 1.03–2.26, p = 0.035) and a 122% higher risk of CV mortality (HR = 2.22, 95% CI: 1.27–3.88, p = 0.005). In LASSO regression with the λ = 1 SE criterion, SBP-Hyper-Burden was the only blood pressure index retained in the final model.
Conclusion
SBP-Hyper-Burden, a novel metric reflecting the cumulative temporal burden of elevated systolic pressure, serves as a strong and independent predictor of both all-cause and cardiovascular mortality in MHD patients, outperforming traditional SBP indices in risk stratification.