The Importance of Out-of-Office Blood Pressure Measurement, as Highlighted by the Correlation with Left Ventricular Hypertrophy in an Untreated Hypertensive Population

Background and Objectives: Hypertensive heart disease, especially left ventricular hypertrophy (LVH), is considered to be one of the main types hypertension-mediated organ damage. Hence, the purpose of this study was to examine which method of measuring BP (office BP measurement (OBPM), 24 h ambulatory BP monitoring (ABPM), or home BP monitoring (HBPM)), can be better correlated with echocardiographic LVH in the untreated hypertensive population. Materials and Methods: This study’s population consisted of 202 patients 58 ± 15 years old (40.8% males). All patients reported elevated home BP measurements for at least 3 months, but they had never been treated before for hypertension. Office and out-of-office BP measurements, including ABPM on a usual working day and seven-day HBPM, as well as 2D echocardiography, were performed. Results: In the univariate analysis, LVH was associated (p < 0.05) with a mean 24 h systolic BP (OR: 1.93, CI: 1.29–2.91), a mean 24 h diastolic BP (OR: 1.30, CI: 1.16–1.80), ambulatory daytime systolic (OR: 1.11, CI:1.01–1.82) and diastolic BP (OR: 1.13, CI:1.09–1.17), ambulatory nighttime systolic BP (OR: 2.11, CI: 1.04–4.31), and mean home systolic BP (OR: 1.05, CI:1.01–1.12). Pearson’s correlation analysis showed a significant correlation between the LV mass index and the mean 24 h systolic BP (r = 0.58, p < 0.05), daytime systolic BP (r = 0.59, p < 0.05), and nighttime systolic BP (r = 0.57, p < 0.05). Most of the population with confirmed LVH presented confirmed hypertension (based on ABPM, 48.1% or HBPM, 40%). The second most dominant phenotype was masked hypertension (ABPM, 32.7% and HBPM, 23.7%). The majority (59.3%) had non-dipping status, 20.4% had a reverse dipping pattern, 13% had a dipping pattern, and only 7.3% had extreme dipping BP. Conclusions: Out-of-office BP measurement devices seemed to be superior compared to in-office. This advantage is highlighted by better correlations in the identification of LVH as well as the diagnosis of masked hypertension, a condition also highly correlated with LVH.