| 1. |
- Adiyaman, Ahmet, et al.
(författare)
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Determinants of the ambulatory arterial stiffness index in 7604 subjects from 6 populations
- 2008
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Ingår i: Hypertension. - 1524-4563. ; 52:6, s. 1038-44
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Tidskriftsartikel (refereegranskat)abstract
- The ambulatory arterial stiffness index (AASI) is derived from 24-hour ambulatory blood pressure recordings. We investigated whether the goodness-of-fit of the AASI regression line in individual subjects (r(2)) impacts on the association of AASI with established determinants of the relation between diastolic and systolic blood pressures. We constructed the International Database on the Ambulatory Blood Pressure in Relation to Cardiovascular Outcomes (7604 participants from 6 countries). AASI was unity minus the regression slope of diastolic on systolic blood pressure in individual 24-hour ambulatory recordings. AASI correlated positively with age and 24-hour mean arterial pressure and negatively with body height and 24-hour heart rate. The single correlation coefficients and the mutually adjusted partial regression coefficients of AASI with age, height, 24-hour mean pressure, and 24-hour heart rate increased from the lowest to the highest quartile of r(2). These findings were consistent in dippers and nondippers (night:day ratio of systolic pressure >or=0.90), women and men, and in Europeans, Asians, and South Americans. The cumulative z score for the association of AASI with these determinants of the relation between diastolic and systolic blood pressures increased curvilinearly with r(2), with most of the improvement in the association occurring above the 20th percentile of r(2) (0.36). In conclusion, a better fit of the AASI regression line enhances the statistical power of analyses involving AASI as marker of arterial stiffness. An r(2) value of 0.36 might be a threshold in sensitivity analyses to improve the stratification of cardiovascular risk.
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| 2. |
- Hansen, Tine W., et al.
(författare)
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Prognostic value of ambulatory heart rate revisited in 6928 subjects from 6 populations
- 2008
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Ingår i: Hypertension. - 0194-911X .- 1524-4563. ; 52:2, s. 229-235
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Tidskriftsartikel (refereegranskat)abstract
- The evidence relating mortality and morbidity to heart rate remains inconsistent. We performed 24-hour ambulatory blood pressure monitoring in 6928 subjects (not on beta-blockers; mean age: 56.2 years; 46.5% women) enrolled in prospective population studies in Denmark, Belgium, Japan, Sweden, Uruguay, and China. We computed standardized hazard ratios for heart rate, while stratifying for cohort, and adjusting for blood pressure and other cardiovascular risk factors. Over 9.6 years (median), 850, 325, and 493 deaths accrued for total, cardiovascular, and noncardiovascular mortality, respectively. The incidence of fatal combined with nonfatal end points was 805, 363, 439, and 324 for cardiovascular, stroke, cardiac, and coronary events, respectively. Twenty-four-hour heart rate predicted total (hazard ratio: 1.15) and noncardiovascular (hazard ratio: 1.18) mortality but not cardiovascular mortality (hazard ratio: 1.11) or any of the fatal combined with nonfatal events (hazard ratio: < or =1.02). Daytime heart rate did not predict mortality (hazard ratio: < or =1.11) or any fatal combined with nonfatal event (hazard ratio: < or =0.96). Nighttime heart rate predicted all of the mortality outcomes (hazard ratio: > or =1.15) but none of the fatal combined with nonfatal events (hazard ratio: < or =1.11). The night:day heart rate ratio predicted total (hazard ratio: 1.14) and noncardiovascular mortality (hazard ratio: 1.12) and all of the fatal combined with nonfatal events (hazard ratio: > or =1.15) with the exception of stroke (hazard ratio: 1.06). Sensitivity analyses, in which we stratified by risk factors or from which we excluded 1 cohort at a time or the events occurring within 2 years of enrollment, showed consistent results. In the general population, heart rate predicts total and noncardiovascular mortality. With the exception of the night:day heart rate ratio, heart rate did not add to the risk stratification for fatal combined with nonfatal cardiovascular events. Thus, heart rate adds little to the prediction of cardiovascular risk.
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| 3. |
- Li, Yan, et al.
(författare)
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Is blood pressure during the night more predictive of cardiovascular outcome than during the day?
- 2008
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Ingår i: Blood Pressure Monitoring. - 1359-5237 .- 1473-5725. ; 13:3, s. 145-147
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to investigate the prognostic significance of the ambulatory blood pressure (BP) during night and day and of the night-to-day BP ratio (NDR). We studied 7458 participants (mean age 56.8 years; 45.8% women) enrolled in the International Database on Ambulatory BP in relation to Cardiovascular Outcome. Using Cox models, we calculated hazard ratios (HR) adjusted for cohort and cardiovascular risk factors. Over 9.6 years (median), 983 deaths and 943 cardiovascular events occurred. Nighttime BP predicted mortality outcomes (HR, 1.18-1.24; P<0.01) independent of daytime BP. Conversely, daytime systolic (HR, 0.84; P<0.01) and diastolic BP (HR, 0.88; P<0.05) predicted only noncardiovascular mortality after adjustment for nighttime BR Both daytime BP and nighttime BP consistently predicted all cardiovascular events (HR, 1.11-1.33, P<0.05) and stroke (HR, 1.21-1.47; P<0.01). Daytime BP lost its prognostic significance for cardiovascular events in patients on antihypertensive treatment. Adjusted for the 24-h BP, NDR predicted mortality (P<0.05), but not fatal combined with nonfatal events. Participants with systolic NDR of at least 1 compared with participants with normal NDR (>= 0.80 to < 0.90) were older, at higher risk of death, but died at higher age. The predictive accuracy of the daytime and nighttime BP and the NDR depended on the disease outcome under study. The increased mortality in patients with higher NDR probably indicates reverse causality. Our findings support recording the ambulatory BP during the whole day.
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