Methods
hypertension
WEST, HYPERTENSION, BLOOD, ADVERSE EVENT
Ethical approval was obtained from North West Haydock Research Committee (16/NW/0557). The trial protocol was approved a priori by the Medicines and Healthcare products Regulatory Agency, the Trial Management Team, Trial Steering Committee and Data Monitoring Committee, and the trial was registered prospectively (EudraCT 2015-005792-25 and ISRCTN12695929). Trial management was overseen by the Liverpool Clinical Trials Research Centre, University of Liverpool. Adverse events were assessed by the study team and Trial Sponsor as described in the trial protocol.Women referred to the Manchester Antenatal Vascular Service (MAViS) translational research clinic with a diagnosis of chronic hypertension were recruited following informed consent. Inclusion criteria were as follows: viable singleton pregnancy; gestation 12At baseline (pre-treatment; Visit 1), and at 4 weekly study visits (Visit 2 during treatment and Visit 3 at the end of the treatment period), side effects were reviewed, blood samples were obtained, and clinical measurements were recorded: BP (× 3 at rest; Alere Microlife, Waltham, USA), PWV via cuff-based oscillometry arteriograph (TensioMed Ltd., Budapest, Hungary), cardiac output and peripheral vascular resistance (Non-Invasive Cardiac Output Monitor (NICOM); Cheetah Medical, Watford, UK) and uterine artery Doppler. Ambulatory BP monitoring (ABPM) was fitted for 24 h at Visits 1 and 3. To assess compliance at Visits 2 and 3, women were asked to report how often they had missed treatment doses and to return bottles for estimation of discrepancies between the volume of study drug utilised and the reported number of missed doses. The percentage of missed doses was estimated as (100 × number of reported missed doses) / expected number of doses between baseline and the week 8 visit, to account for participants whose Visit 3 was later or earlier than the specified 8 weeks. Due to the 2-week window for visits, some women completed their allocated treatment several days prior to Visit 3. At the end of the treatment period, women completed an acceptability questionnaire. All study measurements were performed at St Mary’s Hospital, Manchester. All measurements, participant characteristics and pregnancy outcomes were recorded using a secure Web-based database (COLLECT; MedSciNet) [Blood samples collected in serum gel and EDTA tubes were stored on ice and centrifuged within 4 h at 4 °C for 10 min at 3000 rpm, prior to aliquoting and storage at − 80 °C for future biochemical analysis. Plasma samples were deproteinised using sulphosalicylic acid solution containing norvaline as internal standard, and the free amino acids were derivatised using AccQ-Tag Ultra reagent (6-aminoquinolyl-N-hydroxysuccinimidyl carbamate; Waters Corporation, Milford, USA). The derivatives were separated with gradient elution on an AccQ-Tag Ultra column (Waters Corporation) using the Waters Acquity UPLC system with UV detection at 260 nm. Batched enzyme-linked immunosorbent assays were performed on serum samples at the end of the study according to manufacturer instructions to quantify placental growth factor (PlGF; R&D Systems, Minneapolis, USA), soluble fms-like tyrosine kinase 1 (sFlt-1; R&D Systems) and ADMA (Immundiagnostik AG, Bensheim, Germany).