Day-by-Day Variability of Blood Pressure and Heart Rate at Home as a Novel Predictor of Prognosis

Abstract

Abstract-Day-by-day blood pressure and heart rate variability defined as within-subject SDs of home measurements can be calculated from long-term self-measurement. We investigated the prognostic value of day-by-day variability in 2455 Ohasama, Japan, residents (baseline age: 35 to 96 years; 60.4% women). Home blood pressure and heart rate were measured once every morning for 26 days (median). A total of 462 deaths occurred over a median of 11.9 years, composing 168 cardiovascular deaths (stroke: nϭ83; cardiac: nϭ85) and 294 noncardiovascular deaths. Using Cox regression, we computed hazard ratios while adjusting for baseline characteristics, including blood pressure and heart rate level, sex, age, obesity, current smoking and drinking habits, history of cardiovascular disease, diabetes mellitus, hyperlipidemia, and treatment with antihypertensive drugs. An increase in systolic blood pressure variability of ϩ1 between-subject SD was associated with increased hazard ratios for cardiovascular (1.27; Pϭ0.002) and stroke mortality (1.41; Pϭ0.0009) but not for cardiac mortality (1.13; Pϭ0.26). Conversely, heart rate variability was associated with cardiovascular (1.24; Pϭ0.002) and cardiac mortality (1.30; Pϭ0.003) but not stroke mortality (1.17; Pϭ0.12). Similar findings were observed for diastolic blood pressure variability. Additional adjustment of heart rate variability for systolic blood pressure variability and vice versa produced confirmatory results. Coefficient of variation, defined as within-subject SD divided by level of blood pressure or heart rate, displayed similar prognostic value. In conclusion, day-by-day blood pressure variability and heart rate variability by self-measurement at home make up a simple method of providing useful clinical information for assessing cardiovascular risk. Key Words: epidemiology Ⅲ cerebrovascular disease/stroke Ⅲ population science Ⅲ risk factors Ⅲ blood pressure measurement/monitoring H ome blood pressure measurement is reportedly more reliable than conventional blood pressure measurement, because this approach avoids both observer and regression dilution biases and eliminates the white coat effect. 1 Home blood pressure measurement offers more prognostic significance than office blood pressure 2 and is more indicative of target organ damage. 3 The clinical significance of home blood pressure measurement is primarily produced by multiple measurements of blood pressure. 2 These multiple measurements also provide information on day-by-day blood pressure variability under relatively controlled conditions. 4 Previous studies of ambulatory blood pressure monitoring have highlighted that circadian variation 5 and short-term blood pressure variability 6 can predict cardiovascular events above and beyond traditional risk factors. However, no studies have investigated associations between home blood pressure variability and cardiovascular events. We hypothesized that day-by-day blood pressure variability derived from self-measurement at home would provide further insights into pro...

The relationship between systolic and diastolic pressures: a possible link between risk-related clinical measures and arterial properties

“…3 These expressions link the above-mentioned prognostic power of slope-related measures to the BP variability. Increased BP variability has already been shown to represent an independent risk factor for future CV complications using 24-h ABPMs, 10 home BP measurements 11 or visit-by-visit office BP measurements. 12 In fact, the data of Stergiou et al show that the SBP variability in the home BP measurements was significantly higher than the SBP variability in the ambulatory BP, and the corresponding home DBP variability was somewhat lower than the ambulatory one.…”

The relationships between visit-to-visit blood pressure variability and renal and endothelial function in chronic kidney disease

“…Recent studies have shown that not only absolute blood pressure (BP) levels, but also fluctuations in these levels have a significant impact on end-organ damage. 6,7 Fluctuations in BP include beat-to-beat, day-to-day and visit-to-visit variability, and circadian and seasonal variations. These fluctuations are influenced by vascular, neurohumoral and environmental factors.…”

Questionable link between normo- to microalbuminuria and home-measured blood pressure variability in hypertension

“…15 Concerning the variability in home BP, a study of the general population of Ohasama showed that high day-by-day BP variability is associated with increases in total, cardiovascular and stroke mortality, independently of the average BP value and other cardiovascular risk factors. 16 A recent study of 1866 Finnish adults also demonstrated that greater variability in morning home BP is an independent predictor of cardiovascular events. 17 With respect to a possible relationship between home BP variability and renal deterioration in hypertensive patients, a previous study demonstrated that home BP variability correlated with macroalbuminuria (urinary albumin excretion (UAE)X 300 mg g À1 creatinine) independently of the known risk factors for type 2 diabetic nephropathy.…”