Hypertension-mediated organ damage in masked hypertension

Objectives: Masked hypertension – a blood pressure (BP) phenotype characterized by a clinic BP in the normal range but elevated BP outside the office – is associated with early hypertension-mediated organ damage. This study examined early target organ manifestations of masked hypertension diagnosed by home (HBPM) and ambulatory (ABPM) BP monitoring. Methods: Left ventricular (LV) structure and diastolic function measured by echocardiography, microalbuminuria, and coronary artery calcification were evaluated in 420 patients with high clinic BP (SBP 120–150 mmHg or DBP 80–95 mmHg). Evidence of hypertension-mediated organ damage was compared in patients with sustained normotension, masked hypertension, and sustained hypertension based on measurements by HBPM, daytime ABPM, and 24-h ABPM. Results: The 420 participants averaged 48 (12) [mean (SD)] years of age; the average clinic BP was 130 (13)/81 (8) mmHg. In individuals with masked hypertension diagnosed by HBPM, indexed LV mass, relative wall thickness, and e′ and E/e′ (indices of LV relaxation), were generally intermediate between values observed in normotensives and sustained hypertensive patients, and were significantly greater in masked hypertension than normotensives. Similar trends were observed when masked hypertension was diagnosed by ABPM but a diagnosis of masked hypertension was not as reliably associated with LV remodeling or impaired LV relaxation in comparison to normotensives. There were trends towards greater likelihoods of detectable urinary microalbumin and coronary calcification in masked hypertension than in normotensives. Conclusion: These results support previous studies demonstrating early hypertension-mediated organ damage in patients with masked hypertension, and suggest that HBPM may be superior to ABPM in identifying patients with masked hypertension who have early LV remodeling and diastolic LV dysfunction.