Risk of Atrial Fibrillation in Masked and White Coat Uncontrolled Hypertension

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.