Abstract
Major adverse cardiovascular events are closely associated with 24-hour blood pressure (BP). We determined outcome-driven thresholds for 24-hour mean arterial pressure (MAP), a BP index estimated by oscillometric devices.
We assessed the association of major adverse cardiovascular events with 24-hour MAP, systolic BP (SBP), and diastolic BP (DBP) in a population-based cohort (n=11 596). Statistics included multivariable Cox regression and the generalized R-2 statistic to test model fit.
Baseline office and 24-hour MAP averaged 97.4 and 90.4 mm Hg. Over 13.6 years (median), 2034 major adverse cardiovascular events occurred.
Twenty-four-hour MAP levels of = 96 (stage-2 hypertension, n=2960) mm Hg yielded equivalent 10-year major adverse cardiovascular events risks as office MAP categorized using 2017 American thresholds for office SBP and DBP. Compared with 24-hour MAP normotension, hazard ratios were 0.96 (95% CI, 0.80-1.16), 1.32 (1.15-1.51), and 1.77 (1.59-1.97), for elevated and stage-1 and stage-2 hypertensive MAP.
On top of 24-hour MAP, higher 24-hour SBP increased, whereas higher 24-hour DBP attenuated risk (P<0.001). Considering the 24-hour measurements, R-2 statistics were similar for SBP (1.34) and MAP (1.28), lower for DBP than for MAP (0.47), and reduced to null, if the base model included SBP and DBP; if the ambulatory BP indexes were dichotomized according to the 2017 American guideline and the proposed 92 mm Hg for MAP, the R-2 values were 0.71, 0.89, 0.32, and 0.10, respectively.
In conclusion, the clinical application of 24-hour MAP thresholds in conjunction with SBP and DBP refines risk estimates.