title: Novel description of the 24-hour circadian rhythms of brachial versus central aortic blood pressure and the impact of blood pressure treatment in a randomized controlled clinical trial: The Ambulatory Central Aortic Pressure (AmCAP) Study.
abstract: Elevated brachial blood pressure (BP) is associated with increased cardiovascular risk and predicts morbidity and mortality in humans. Recently, 24-hour ambulatory BP monitoring and assessment of central aortic BP have been introduced to improve BP phenotyping. The Ambulatory Central Aortic Pressure (AmCAP) study combines these approaches and describes, for the first time, the diurnal patterns of simultaneously measured 24-hour ambulatory brachial and central pressures in a prespecified substudy embedded within a clinical trial of BP lowering in patients with hypertension. Twenty-four-hour ambulatory brachial and central pressure measurements were acquired using a tonometer mounted into the articulating strap of a wristwatch-like device (BPro) in 171 participants with hypertension recruited into the ASSERTIVE (AliSkiren Study of profound antihypERtensive efficacy in hyperTensIVE patients) trial. Participants were randomly assigned to BP lowering with either aliskiren 300 mg QD or telmisartan 80 mg QD for 12 weeks. Ambulatory brachial and central BP was measured in all participants both at baseline and at study end. Brachial and central BP both demonstrated typical diurnal patterns with lower pressures at night. However, night time was associated with smaller reductions in central relative to brachial pressure and decreased pulse pressure amplification (P<0.0001 for both). These effects were not modulated after BP lowering and were maintained after adjustment for day and night-time BP and heart rate (P=0.02). This study demonstrates that brachial and central pressure show different diurnal patterns, which are not modulated by BP-lowering therapy, with relatively higher night-time central pressures. These novel data indicate that night-time central BP may provide prognostic importance and warrants further investigation. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00865020.
authors: Institute of Cardiovascular Science, University College London, 170 Tottenham Court Rd, London W1T 7HA, UK. bryan.williams@ucl.ac.uk
authors: Bryan
authors: B
authors: Williams
authors: Peter S
authors: PS
authors: Lacy
authors: Fabio
authors: F
authors: Baschiera
authors: Patrick
authors: P
authors: Brunel
authors: Rainer
authors: R
authors: Düsing
mesh_terms: D000577:Amides / Q000008:administration & dosage* / Q000627:therapeutic use; D047228:Angiotensin II Type 1 Receptor Blockers / Q000008:administration & dosage; D000959:Antihypertensive Agents / Q000008:administration & dosage; D001013:Aorta, Thoracic / Q000503:physiopathology*; D001562:Benzimidazoles / Q000008:administration & dosage*; D001565:Benzoates / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods; D001916:Brachial Artery / Q000503:physiopathology*; D002940:Circadian Rhythm / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D005650:Fumarates / Q000008:administration & dosage* / Q000627:therapeutic use; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D000077333:Telmisartan; D000092502:Renin Inhibitors
chemical_list: D000577:Amides; D047228:Angiotensin II Type 1 Receptor Blockers; D000959:Antihypertensive Agents; D001562:Benzimidazoles; D001565:Benzoates; D005650:Fumarates; D000077333:Telmisartan; D000092502:Renin Inhibitors; C446481:aliskiren
keywords: ambulatory blood pressure monitoring; blood pressure; central aortic pressure; hypertension