Resistant Hypertension and Mortality: An Observational Cohort Study

Abstract

Background: Resistant hypertension is characterized by elevated blood pressure (BP) despite using 3 antihypertensive agents. Ambulatory BP monitoring (ABPM) detects the presence of white-coat resistant hypertension (24-hour BP <130/80 mm Hg). The aim of the study was to evaluate risks of death in resistant hypertension compared with controlled hypertension, as well as in ABPM-confirmed (24-hour BP ≥130 or 80 mm Hg), versus white-coat resistant hypertension.

Methods: We selected 8146 patients with controlled hypertension (office BP <140/90 mm Hg while being treated with ≤3 antihypertensive drugs) and 8577 with resistant hypertension (BP ≥140 or ≥90 mm Hg while being treated with ≥3 drugs). All-cause and cardiovascular mortalities (median follow-up, 9.7 years) were compared between groups, as well as between patients with white-coat (3289) and ABPM-confirmed (5288) resistant hypertension. Hazard ratios (HRs) from Cox models after adjustment for clinical confounders were used for comparisons.

Results: Compared with controlled hypertension, resistant hypertension was associated with an increased risk in all-cause (HR, 1.21 [95% CI, 1.12-1.30]) and cardiovascular mortalities (HR, 1.33 [95% CI, 1.17-1.51]) in confounder-adjusted models. Compared with white-coat, ABPM-confirmed resistant hypertension was associated with an increased risk of all-cause (HR, 1.45 [95% CI, 1.32-1.60]) and cardiovascular (HR, 1.68 [95% CI, 1.43-1.98]) mortalities. When ABPM-confirmed and white-coat resistant hypertension were separately compared with controlled hypertension, only the former was associated with an increased risk of death and cardiovascular death (HR, 1.36 [95% CI, 1.26-1.48] and 1.56 [95% CI, 1.36-1.79]), respectively.

Conclusions: ABPM-confirmed resistant hypertension is associated with an increased risk of death and cardiovascular death with respect to both controlled hypertension and white-coat resistant hypertension.

Keywords: blood pressure; blood pressure monitoring, ambulatory; hypertension; mortality; population.