Masked hypertension and cardiovascular outcomes: an updated systematic review and meta-analysis

BACKGROUND: As many as one-third of individuals with normal office blood pressure (BP) are diagnosed with masked hypertension (HTN) based on ambulatory BP measurements (ABPM). Masked HTN is associated with higher risk of sustained HTN (SH) and increased cardiovascular morbidity. METHODS: The present study was designed to systematically review cohort studies and assess the effects of masked HTN compared to normotension and SH on cardiovascular events and all-cause mortality. We systematically searched the electronic databases, such as MEDLINE, PubMed, Embase, and Cochrane for prospective cohort studies, which evaluated participants with office and ambulatory and/or home BP. RESULTS: We included nine studies with a total number of 14729 participants (11245 normotensives, 3484 participants with masked HTN, 1984 participants with white-coat HTN, and 5143 participants with SH) with a mean age of 58 years and follow-up of 9.5 years. Individuals with masked HTN had significantly increased rates of cardiovascular events and all-cause mortality than normotensives and white-coat HTN and had lower rates of cardiovascular events than those with SH (odds ratio 0.61, 95% confidence interval 0.42–0.89; P=0.010; I(2)=84%). Among patients on antihypertensive treatment, masked HTN was associated with higher rates of cardiovascular events than in those with normotension and white-coat HTN and similar rates of cardiovascular events in those with treated SH. CONCLUSION: Prompt screening of high-risk individuals with home BP measurements and ABPM, the diagnosis of masked HTN, and the initiation of treatment, may mitigate the adverse cardiovascular effects of masked HTN.