Prognostic value of home blood pressure monitoring in patients under antihypertensive treatment

The prognostic value of home blood pressure monitoring (HBPM) has been investigated in several studies in the general population, demonstrating its independent association with cardiovascular events. However, in the case of treated hypertensive subjects, evidence is controversial. Our purpose was to evaluate the prognostic value of HBPM in this population. Medicated hypertensive patients who performed a 4-day HBPM (Omron® HEM-705CP-II) between 2008 and 2015 were followed up for a median of 5.9 years, registering the occurrence of a composite primary outcome of fatal and non-fatal cardiovascular events. Cox regression models were used to analyze the prognostic value of HBPM, considering 4-day measurements, discarding the first day, and analyzing morning, afternoon and evening periods separately. We included 1582 patients in the analysis (33.4% men, median age 70.8 years, on an average of 2.1 antihypertensive drugs). During follow-up, 273 events occurred. HBPM was significantly associated with cardiovascular events in all five scenarios in the unadjusted models. When adjusting for office BP and other cardiovascular risk factors, the association remained marginally significant for the 4-day period, discarding first-day measurements HBPM (HR 1.04 [95% CI 1–1.1] and 1.04 [95% CI 1–1.1], respectively) and statistically significant for all separate periods of measurement: HR 1.32 (95% CI 1.01–1.72); 1.33 (95% CI 1.02–1.72); and 1.30 (95% CI 1.01–1.67), for morning, afternoon and evening, respectively. When analyzing separately fatal and non-fatal events, statistical significance was held for the former only. In conclusion, HBPM is an independent predictor of cardiovascular events in hypertensives under treatment.