130/80 mmHg as a unifying hypertension threshold for office brachial, office central, and ambulatory daytime brachial blood pressure

Abstract

The present study investigated the prognostic values for office brachial (OB), office central (OC), and ambulatory daytime brachial (AmDB) hypertension, as defined by a unifying threshold of 130/80 mmHg, and the incremental value of either OC or AmDB hypertension to OB hypertension. A total of 1219 community residents without receiving anti-hypertensive treatment (671 men and 548 women, aged ≥ 30 years old) from central Taiwan and Kinmen islands had OB, OC, and AmDB blood pressure measurements during a cardiovascular survey conducted in 1992-1993. OB hypertension, OC hypertension, and AmDB hypertension were all defined in retrospect at the threshold of 130/80 mmHg. They were followed up for nonfatal and fatal cardiovascular events until December 31, 2017, by linking the baseline database to the National Health Insurance Research dataset and the National Death Registry. During a follow-up of 25 612.5 person-years (Average event-free time: 21.0 years), there were 368 fatal and nonfatal cardiovascular events. In multivariable analyses, OB hypertension, OC hypertension, and AmDB hypertension had similar hazard ratios for cardiovascular events [2.03, 95% confidence interval: 1.47-2.80]; 1.92 (1.47-2.51); and 1.79 (1.41-2.29), respectively. Using OB normotension as the reference, either the concordant OB and OC hypertension [2.24 (1.61-3.12)], or the concordant OB and AmDB hypertension [2.52 (1.80-3.54)] was significantly associated with cardiovascular events. Moreover, OB hypertension plus AmDB normotension was also significantly associated with increased risk for cardiovascular events. We concluded that OB hypertension, OC hypertension, and AmDB hypertension defined by a unifying threshold of 130/80 mmHg may provide similar estimates of long-term risk for cardiovascular events. Cross-classification analyses suggest that addition of OC hypertension or AmDB hypertension may improve the prognostic value of OB hypertension.

Keywords: epidemiology; hypertension-general; risk assessment; unifying hypertension threshold.

FIGURE 1

The hazard ratios and 95% confidence intervals of office brachial hypertension ●, office central hypertension ■ and daytime ambulatory brachial hypertension ▲ for fatal and nonfatal cardiovascular events at the follow‐up years of 10, 15, 20, and more than 20 years

FIGURE 2

Survival curves of (A) office brachial hypertension versus office brachial normotension, (B) office central hypertension versus office central normotension, and (C) ambulatory daytime brachial hypertension versus daytime ambulatory brachial normotension, for fatal and nonfatal cardiovascular events. All P values less than .05 by log‐rank test for homogeneity of the survival curves. No data was available for the first 5 years

FIGURE 3

Survival curves of (A) the concordant office brachial hypertension and office central hypertension (Brachial HT plus Central HT, solid line) versus isolated office brachial hypertension (Brachial HT plus Central NT, long‐dash line) and versus office brachial normotension (Brachial NT, short‐dash line) ; and (B) the concordant office brachial hypertension and ambulatory daytime brachial hypertension (Brachial HT plus Daytime HT, solid line) versus isolated office brachial hypertension (Brachial HT plus Daytime NT, long‐dash line) and versus office brachial normotension (Brachial NT, short‐dash line). All P values less than .05 by log‐rank test for homogeneity of the survival curves. No data was available for the first 5 years