Blood Pressure Load Does Not Add to Ambulatory Blood Pressure Level for Cardiovascular Risk Stratification

• Published in: Hypertension (Dallas, Tex. 1979) Vol. 63; no. 5; pp. 925 - 933
• Main Authors: Li, Yan, Thijs, Lutgarde, Boggia, José, Asayama, Kei, Hansen, Tine W., Kikuya, Masahiro, Björklund-Bodegård, Kristina, Ohkubo, Takayoshi, Jeppesen, Jørgen, Torp-Pedersen, Christian, Dolan, Eamon, Kuznetsova, Tatiana, Stolarz-Skrzypek, Katarzyna, Tikhonoff, Valérie, Malyutina, Sofia, Casiglia, Edoardo, Nikitin, Yuri, Lind, Lars, Sandoya, Edgardo, Kawecka-Jaszcz, Kalina, Filipovský, Jan, Imai, Yutaka, Ibsen, Hans, O’Brien, Eoin, Wang, Jiguang, Staessen, Jan A.
• Format: Journal Article
• Language: English
• Published: United States 01.05.2014
• Subjects: Adult; Aged; ambulatory blood pressure monitoring; Area Under Curve; Blood Pressure - physiology; Blood Pressure Monitoring, Ambulatory; Cardiovascular Diseases - epidemiology; Circadian Rhythm - physiology; epidemiology; Female; Humans; Hypertension - complications; Hypertension - physiopathology; Incidence; Male; Middle Aged; Multivariate Analysis; Predictive Value of Tests; Prospective Studies; Retrospective Studies; Risk Factors; ambulatory blood pressure monitoring; epidemiology; risk factors
• ISSN: 0194-911X; 1524-4563; 1524-4563
• DOI: 10.1161/HYPERTENSIONAHA.113.02780

Experts proposed blood pressure (BP) load derived from 24-hour ambulatory BP recordings as a more accurate predictor of outcome than level, in particular in normotensive people. We analyzed 8711 subjects (mean age, 54.8 years; 47.0% women) randomly recruited from 10 populations. We expressed BP load as percentage (%) of systolic/diastolic readings ≥135/≥85 mm Hg and ≥120/≥70 mm Hg during day and night, respectively, or as the area under the BP curve (mm Hg×h) using the same ceiling values. During a period of 10.7 years (median), 1284 participants died and 1109 experienced a fatal or nonfatal cardiovascular end point. In multivariable-adjusted models, the risk of cardiovascular complications gradually increased across deciles of BP level and load ( P <0.001), but BP load did not substantially refine risk prediction based on 24-hour systolic or diastolic BP level (generalized R 2 statistic ≤0.294%; net reclassification improvement ≤0.28%; integrated discrimination improvement ≤0.001%). Systolic/diastolic BP load of 40.0/42.3% or 91.8/73.6 mm Hg×h conferred a 10-year risk of a composite cardiovascular end point similar to a 24-hour systolic/diastolic BP of 130/80 mm Hg. In analyses dichotomized according to these thresholds, increased BP load did not refine risk prediction in the whole study population ( R 2 ≤0.051) or in untreated participants with 24-hour ambulatory normotension ( R 2 ≤0.034). In conclusion, BP load does not improve risk stratification based on 24-hour BP level. This also applies to subjects with normal 24-hour BP for whom BP load was proposed to be particularly useful in risk stratification.