Risk of Atrial Fibrillation in Masked and White Coat Uncontrolled Hypertension

Risk of atrial fibrillation (AF) in masked and white coat uncontrolled hypertension (MUCH and WUCH, respectively) has not yet been investigated. We assessed the risk of new-onset AF in MUCH and WUCH detected by ambulatory blood pressure (BP) monitoring.

The occurrence of AF was evaluated in 2,135 treated hypertensive patients aged >40 years, with baseline sinus rhythm, by electrocardiogram. Controlled hypertension (CH) was defined as clinic BP <140/90 mm Hg and daytime BP, regardless of nighttime BP, <135/85 mm Hg, MUCH as clinic BP <140/90 mm Hg and daytime BP ≥135 and/or ≥85 mm Hg, WUCH as clinic BP ≥140 and/or ≥90 mm Hg and daytime BP <135/85 mm Hg, and sustained uncontrolled hypertension (SUCH) as clinic BP ≥140 and/or ≥90 mm Hg and daytime BP ≥135 and/or ≥85 mm Hg.

MUCH was identified in 203 patients (9.5% of all the population, 29% of those with normal clinic BP) and WUCH in 503 patients (23.5% of all the population, 35% of those with high clinic BP). During the follow-up (mean 9.7 years), 116 cases of AF occurred. After adjustment for covariates, patients with MUCH (hazard ratio 2.02, 95% confidence interval, 1.06-3.85) and SUCH (hazard ratio 1.83, 95% confidence interval, 1.04-3.21) had higher risk of new-onset AF than those with CH, whereas those with WUCH (hazard ratio 1.12, 95% confidence interval, 0.59-2.13) did not.

When compared with patients with CH, those with MUCH and SUCH are at higher risk (approximately doubled) of new-onset AF, whereas those with WUCH are not.