The effect of pulse rate and blood pressure dipping status on the risk of stroke and cardiovascular disease in Japanese hypertensive patients.

BACKGROUND: There have been few reports on the relationship between variation in the diurnal pulse rate (PR) in relation to a nondipper blood pressure (BP) pattern and cardiovascular events in elderly hypertensives.

METHODS: Ambulatory BP monitoring (ABPM) was conducted at baseline in 811 older Japanese hypertensives (clinical BP >140/90 mm Hg; age >50 years old) enrolled in the Jichi Medical School ABPM study, wave 1. They were followed up for an average of 41 months, and the incidence of subsequent cardiovascular event and death was evaluated. PR nondipping status was defined as (awake PR - sleep PR)/awake PR <0.1.

RESULTS: The mean age of patients was 72.3 +/- 9.8 years (311 men and 500 women). The nondipper patients had a higher risk of cardiovascular events (11.5% vs. 6.1%, P = 0.006) and stroke (9.9% vs. 5.7%, P = 0.039) than the dippers. Patients were classified into four subgroups: BP dipping plus PR dipping status (n = 471), BP dipping plus PR nondipping (n = 37), BP nondipping plus PR dipping (n = 250), and BP nondipping plus PR nondipping (n = 53). The combination of BP and PR nondipping constituted a higher risk of cardiovascular events and stroke than the other three combinations combined (cardiovascular events: 17.0% vs. 7.5%, P = 0.015; stroke: 17.0% vs. 6.6%, P = 0.005). On Cox proportional hazards modeling, BP nondipping with PR nondipping led to a significant synergistic increase in the risk of stroke (hazard ratio: 8.92; 95% confidence interval: 1.03-77.5, P = 0.048).

CONCLUSIONS: A blunted PR dip might predict a stroke in elderly hypertensives with a nondipping BP status.