Ambulatory blood pressure variability and risk of cardiovascular events, all-cause mortality, and progression of kidney disease

BACKGROUND: Association between blood pressure (BP) variability and cardiovascular outcome remains unclear in patients with chronic kidney disease (CKD). We evaluated this association between ambulatory BP variability and cardiovascular events, mortality, and kidney disease progression in patients with CKD. METHODS: From the Cardiovascular and Metabolic Disease Etiology Research Center-HIgh Risk study (2013-2018), a total of 470 patients with CKD were analyzed. Ambulatory BP variability was assessed using average real variability (ARV). Primary outcome was composite of nonfatal myocardial infarction, nonfatal stroke, and all-cause mortality. The secondary outcome was rapid kidney function decline [estimated glomerular filtration rate (eGFR), >3 ml/min per 1.73m per year]. RESULTS: During a median follow-up of 51.8 (40.5-56.2) months, the incidences of all-cause death and composite outcomes were higher in the high SBP-ARV group than in the low SBP-ARV group. The Kaplan-Meier analysis showed that a high SBP-ARV, but not a high DBP-ARV and heart rate-ARV, was associated with higher composite outcome risks. In multivariable Cox analysis, a high SBP-ARV correlated with increased composite outcome risks (hazard ratio, 4.53; 95% confidence interval, 1.41-14.58). When subgroup analysis was performed (low vs. high 24-h SBP), this association was only significant in the high 24-h SBP group. The risk stratification for composite outcomes by adding SBP-ARV into the basic model and 24-h SBP, improved by 1.3%. Furthermore, the mean eGFR decline rate was faster, and the rapid eGFR decline risk was 1.68-fold higher in the high SBP-ARV group. CONCLUSION: Greater ambulatory SBP variabilities were associated with increased risks for nonfatal cardiovascular diseases, all-cause mortality, and rapid kidney function decline in patients with CKD.