Does self-measured home blood pressure highlight cardiovascular risk in patients with chronic kidney disease?: HOMED-BP study

Self-measured home blood pressure (BP) is more reproducible and prognostically relevant than office BP in hypertension. Although chronic kidney disease (CKD) is an established major cardiovascular risk factor, no prior study has thoroughly evaluated whether pretreatment and on-treatment HBP predict cardiovascular events differently in hypertensive patients with versus without CKD. 

This analysis included participants in the HOMED-BP study, a prospective, randomized study evaluating home BP-guided antihypertensive therapy among patients with essential hypertension. Home BP was self-measured according to standardized protocols. Of 3,518 randomized patients, 2,980 with available follow-up home BP data were analyzed after excluding those lacking data for CKD diagnosis. In the present study, data on BP value taken before randomization, without antihypertensive drug treatment, and taken at the last available visit in patients without an event or recorded 6 months before an event, were used as baseline and on-treatment BP, respectively. CKD was defined at baseline as either an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² or proteinuria ≥1+ on dipstick testing. Based on this definition, 834 patients were classified into the CKD group, and the remaining 2,146 into the non-CKD group.

Systolic home BP was the primary exposure. The composite cardiovascular events included cardiovascular death, nonfatal myocardial infarction, ischemic or hemorrhagic stroke, subarachnoid hemorrhage, transient ischemic attack, angina pectoris, or hospitalization for heart failure. Associations between home BP and cardiovascular events were assessed separately in CKD and non-CKD groups using Cox proportional hazards models adjusted for age, sex, baseline risk factors, and treatment allocation. Statistical interaction between CKD status and home BP was tested by cross-product terms.

During a mean follow-up of 7.2 years, 98 composite cardiovascular events occurred, 37 in the CKD group and 61 in the non-CKD group. In the untreated period at baseline, each 10 mmHg increase in systolic home BP was associated with a hazard ratio (HR) of 1.76 (95% confidence interval [CI], 1.33–2.32) in the CKD group and 1.17 (95% CI, 0.96–1.43) in the non-CKD group, with no significant interaction (p=0.35). During on-treatment follow-up, systolic home BP remained predictive in both groups (HR 1.25, 95% CI 1.05–1.48 for CKD; HR 1.71, 95% CI 1.40–2.10 for non-CKD; p for interaction=0.55).

In this large prospective observational analysis of hypertensive patients, the prognostic impact of home BP for cardiovascular outcomes did not significantly differ by CKD status. Systolic home BP during antihypertensive treatment remained associated with CV risk in both groups, indicating residual risk despite therapy. These findings emphasize the importance of strict home BP control not only in the general hypertensive population but also in patients with CKD. Self-measured home BP serves as a robust predictor of cardiovascular risk and a useful tool for individual treatment and risk stratification regardless of kidney function.