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1.
BMJ Open ; 12(10): e062602, 2022 10 07.
Article in English | MEDLINE | ID: mdl-36207050

ABSTRACT

INTRODUCTION: Inflammation plays a critical role in the pathogenesis of atherosclerosis, the leading cause of ischaemic heart disease (IHD). Studies in preclinical models have demonstrated that an increase in regulatory T cells (Tregs), which have a potent immune modulatory action, led to a regression of atherosclerosis. The Low-dose InterLeukin 2 (IL-2) in patients with stable ischaemic heart disease and Acute Coronary Syndromes (LILACS) study, established the safety of low-dose IL-2 and its biological efficacy in IHD. The IVORY trial is designed to assess the effects of low-dose IL-2 on vascular inflammation in patients with acute coronary syndromes (ACS). METHODS AND ANALYSIS: In this study, we hypothesise that low-dose IL-2 will reduce vascular inflammation in patients presenting with ACS. This is a double-blind, randomised, placebo-controlled, phase II clinical trial. Patients will be recruited across two centres, a district general hospital and a tertiary cardiac centre in Cambridge, UK. Sixty patients with ACS (unstable angina, non-ST elevation myocardial infarction or ST elevation myocardial infarction) with high-sensitivity C reactive protein (hsCRP) levels >2 mg/L will be randomised to receive either 1.5×106 IU of low-dose IL-2 or placebo (1:1). Dosing will commence within 14 days of admission. Dosing will comprise of an induction and a maintenance phase. 2-Deoxy-2-[fluorine-18] fluoro-D-glucose (18F-FDG) positron emission tomography/CT (PET/CT) scans will be performed before and after dosing. The primary endpoint is the change in mean maximum target to background ratios (TBRmax) in the index vessel between baseline and follow-up scans. Changes in circulating T-cell subsets will be measured as secondary endpoints of the study. The safety and tolerability of extended dosing with low-dose IL-2 in patients with ACS will be evaluated throughout the study. ETHICS AND DISSEMINATION: The Health Research Authority and Health and Care Research Wales, UK (19/YH/0171), approved the study. Written informed consent is required to participate in the trial. The results will be reported through peer-reviewed journals and conference presentations. TRIAL REGISTRATION NUMBER: NCT04241601.


Subject(s)
Acute Coronary Syndrome , Atherosclerosis , Coronary Artery Disease , Myocardial Infarction , Myocardial Ischemia , Acute Coronary Syndrome/drug therapy , C-Reactive Protein/metabolism , Clinical Trials, Phase II as Topic , Double-Blind Method , Fluorodeoxyglucose F18/therapeutic use , Glucose/therapeutic use , Humans , Inflammation/drug therapy , Interleukin-2/therapeutic use , Myocardial Ischemia/drug therapy , Positron Emission Tomography Computed Tomography , Randomized Controlled Trials as Topic , Treatment Outcome
2.
NEJM Evid ; 1(1): EVIDoa2100009, 2022 01.
Article in English | MEDLINE | ID: mdl-38319239

ABSTRACT

Regulatory T-Cell Response to Low-Dose Interleukin-2 in Ischemic Heart Disease This phase 1b/2a, randomized, double-blind, placebo-controlled, dose-escalation trial tested low-dose subcutaneous aldesleukin (recombinant IL-2) in patients with ischemic heart disease. Low-dose IL-2 expanded Tregs, without adverse events of major concern. Single-cell RNA-sequencing of circulating immune cells was used to provide mechanistic assessment of the treatment's effects.


Subject(s)
Interleukin-2 , Interleukin-2/analogs & derivatives , Myocardial Ischemia , T-Lymphocytes, Regulatory , Humans , Interleukin-2/administration & dosage , Interleukin-2/therapeutic use , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/drug effects , Myocardial Ischemia/immunology , Myocardial Ischemia/drug therapy , Double-Blind Method , Male , Middle Aged , Female , Recombinant Proteins
3.
BMJ Open ; 11(4): e037457, 2021 04 13.
Article in English | MEDLINE | ID: mdl-33849844

ABSTRACT

INTRODUCTION: Elevated low-density lipoprotein cholesterol (LDL-C) is a strong independent risk predictor of cardiovascular (CV) events, while interventions to reduce it remain the only evidence-based approach to reduce CV morbidity and mortality. Secondary prevention statin trials in combination with ezetimibe and/or proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors showed that there is no 'J shaped curve' in LDL-C levels with regard to CV outcomes. The lowest threshold beyond which reduction of LDL-C confers no further CV benefits has not been identified.The INTENSITY-HIGH study seeks to explore physiological mechanisms mediating CV benefits of LDL-C lowering by PCSK9 inhibition in patients with established cardiovascular disease (CVD). The study examines the changes in measures of endothelial function and vascular inflammation imaging following intervention with PCSK9 and against standard of care. METHODS AND ANALYSIS: This is a single-centre, randomised, open label, parallel group, mechanistic physiological study. It will include approximately 60 subjects with established CVD, with LDL-C of <4.1 mmol/L on high-intensity statins. All eligible participants will undergo 18-fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) scanning of the aorta and carotid arteries, as well as baseline endothelial function assessment. Subsequently, they will be randomised on a 1:1 basis to either alirocumab 150 mg or ezetimibe 10 mg/day. Repeat FDG-PET/CT scan and vascular assessments will be undertaken after 8 weeks of treatment. Any changes in these parameters will be correlated with changes in lipid levels and systemic inflammation biomarkers. ETHICS AND DISSEMINATION: The study received a favourable opinion from the Wales Research Ethics Committee 4, was registered on clinicaltrials.gov and conformed to International Conference for Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use Good Clinical Practice. The results of this study will be reported through peer-reviewed journals and conference presentations. TRIAL REGISTRATION NUMBER: NCT03355027.


Subject(s)
Cardiovascular Diseases , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Antibodies, Monoclonal , Antibodies, Monoclonal, Humanized , Cardiovascular Diseases/drug therapy , Cardiovascular Diseases/prevention & control , Cholesterol, LDL , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Positron Emission Tomography Computed Tomography , Proprotein Convertase 9 , Randomized Controlled Trials as Topic , Wales
5.
Trials ; 21(1): 604, 2020 Jul 02.
Article in English | MEDLINE | ID: mdl-32616067

ABSTRACT

OBJECTIVES: PRIMARY OBJECTIVE: To determine whether chemoprophylaxis with hydroxychloroquine versus placebo increases time to contracting coronavirus disease 2019 (COVID-19) in frontline healthcare workers. SECONDARY OBJECTIVES: 1) To determine whether chemoprophylaxis with daily versus weekly dosing of hydroxychloroquine increases time to contracting COVID-19 disease in frontline healthcare workers. 2) To compare the number of COVID-19 cases between each trial arm on the basis of positive tests (as per current clinical testing methods and/or serology) 3) To compare the percentage of COVID-19 positive individuals with current testing methods versus serologically-proven COVID-19 in each trial arm 4) To compare COVID-19 disease severity in each trial arm 5) To compare recovery time from COVID-19 infection in each trial arm EXPLORATORY OBJECTIVES: 1) To determine compliance (as measured by trough pharmacokinetic hydroxychloroquine levels) on COVID-19 positive tests 2) To determine if genetic factors determine susceptibility to COVID-19 disease or response to treatment 3) To determine if blood group determines susceptibility to COVID-19 disease 4) To compare serum biomarkers of COVID-19 disease in each arm TRIAL DESIGN: Double-blind, multi-centre, 2-arm (3:3:2 ratio) randomised placebo-controlled trial PARTICIPANTS: National Health Service (NHS) workers who have direct patient contact delivering care to patients with COVID-19. Participants in the trial will be recruited from a number of NHS hospitals directly caring for patients with COVID-19. INCLUSION CRITERIA: To be included in the trial the participant MUST: 1) Have given written informed consent to participate 2) Be aged 18 years to 70 years 3) Not previously have been diagnosed with COVID-19 4) Work in a high-risk secondary or tertiary healthcare setting (hospitals accepting COVID-19 patients) with direct patient-facing care EXCLUSION CRITERIA: The presence of any of the following will mean participants are ineligible: 1) Known COVID-19 positive test at baseline (if available) 2) Symptomatic for possible COVID-19 at baseline 3) Known hypersensitivity reaction to hydroxychloroquine, chloroquine or 4-aminoquinolines 4) Known retinal disease 5) Known porphyria 6) Known chronic kidney disease (CKD; eGFR<30ml/min) 7) Known epilepsy 8) Known heart failure or conduction problems 9) Known significant liver disease (Gilbert's syndrome is permitted) 10) Known glucose-6-phosphate dehydrogenase (G6PD) deficiency 11) Currently taking any of the following contraindicated medications: Digoxin, Chloroquine, Halofantrine, Amiodarone, Moxifloxacin, Cyclosporin, Mefloquine, Praziquantel, Ciprofloxacin, Clarithromycin, Prochlorperazine, Fluconazole 12) Currently taking hydroxychloroquine or having a clinical indication for taking hydroxychloroquine 13) Currently breastfeeding 14) Unable to be followed-up during the trial 15) Current or future involvement in the active treatment phase of other interventional research studies (excluding observational/non-interventional studies) before study follow-up visit 16) Not able to use or have access to a modern phone device/web-based technology 17) Any other clinical reason which may preclude entry in the opinion of the investigator INTERVENTION AND COMPARATOR: Interventions being evaluated are: A) Daily hydroxychloroquine or B) Weekly hydroxychloroquine or C) Placebo The maximum treatment period is approximately 13 weeks per participant. Hydroxychloroquine-identical matched placebo tablets will ensure that all participants are taking the same number and dosing regimen of tablets across the three trial arms. There is no variation in the dose of hydroxychloroquine by weight. The dosing regimen for the three arms of the study (A, B, C) are described in further detail below. Arm A: Active Hydroxychloroquine (- daily dosing and placebo-matched hydroxychloroquine - weekly dosing). Form: Tablets Route: Oral. Dose and Frequency: Active hydroxychloroquine: Days 1-2: Loading phase - 400mg (2 x 200mg tablets) taken twice a day for 2 days Days 3 onwards: Maintenance Phase - 200mg (1 x 200mg tablet) taken once daily, every day for 90 days (~3 months) Matched Placebo hydroxychloroquine: Days 3 onwards: Maintenance Phase - 2 tablets taken once a week on the same day each week (every 7th day) for 90 days (~3 months) Arm B: Active Hydroxychloroquine (- weekly dosing and placebo matched hydroxychloroquine - daily dosing.) Form: Tablets Route: Oral. Dose and Frequency: Active hydroxychloroquine: Days 1-2: Loading Phase - 400mg (2 x 200mg tablets) taken twice daily for 2 days Days 3 onwards: Maintenance Phase - 400mg (2 x 200mg tablets) taken once a week on the same day each week (every 7th day) for 90 days (~3 months) Matched Placebo hydroxychloroquine: Days 3 onwards: Maintenance Phase - 1 tablet taken once daily for 90 days (~3 months) Arm C: Matched placebo Hydroxychloroquine (- daily dosing and matched placebo hydroxychloroquine - weekly dosing.) Form: Table. Route: Oral. Frequency: Matched placebo hydroxychloroquine - daily dosing: Days 1-2: Loading Phase - 2 tablets taken twice daily for 2 days Days 3 onwards: Maintenance Phase - 1 tablet taken once daily for 90 days (~3 months) Matched placebo hydroxychloroquine - weekly dosing: Days 3 onwards: Maintenance Phase - 2 tablets taken once a week on the same day each week (every 7th day) for 90 days (~3 months) A schematic of the dosing schedule can be found in the full study protocol (Additional File 1). MAIN OUTCOMES: Time to diagnosis of positive COVID-19 disease (defined by record of date of symptoms onset and confirmed by laboratory test) RANDOMISATION: Participants will be randomised to either hydroxychloroquine dosed daily with weekly placebo, HCQ dosed weekly with daily placebo, or placebo dosed daily and weekly. Randomisation will be in a 3:3:2 ratio [hydroxychloroquine-(daily), hydroxychloroquine-(weekly), placebo], using stratified block randomisation. Random block sizes will be used, and stratification will be by study site. BLINDING (MASKING): Participants and trial investigators consenting participants, delivering trial assessments and procedures will be blinded to intervention. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): A sufficient number of participants will be enrolled so that approximately 1000 participants in total will have data suitable for the primary statistical analysis. It is anticipated that approximately 1,200 participants will need to be enrolled in total, to allow for a 20% dropout over the period of the trial. This would result in approximately 450:450:300 participants randomised to hydroxychloroquine daily, hydroxychloroquine weekly+daily matched placebo or matched-placebo daily and weekly. TRIAL STATUS: V 1.0, 7th April 2020 EU Clinical Trials Register EudraCT Number: 2020-001331-26 Date of registration: 14th April 2020 Trial registered before first participant enrolment. Trial site is Cambridge University Hospitals NHS Foundation Trust. Recruitment started on 11th May 2020. It is anticipated that the trial will run for 12 months. The recruitment end date cannot yet be accurately predicted. FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest of expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2).


Subject(s)
Antiviral Agents/administration & dosage , Betacoronavirus/drug effects , Chemoprevention , Coronavirus Infections/prevention & control , Health Personnel , Hydroxychloroquine/administration & dosage , Occupational Health , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Adolescent , Adult , Aged , Antiviral Agents/adverse effects , Antiviral Agents/pharmacokinetics , Betacoronavirus/pathogenicity , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Coronavirus Infections/drug therapy , Coronavirus Infections/transmission , Coronavirus Infections/virology , Drug Administration Schedule , England , Female , Host-Pathogen Interactions , Humans , Hydroxychloroquine/adverse effects , Hydroxychloroquine/pharmacokinetics , Male , Medication Adherence , Middle Aged , Pneumonia, Viral/diagnosis , Pneumonia, Viral/transmission , Pneumonia, Viral/virology , Protective Factors , Randomized Controlled Trials as Topic , Remission Induction , Risk Assessment , Risk Factors , SARS-CoV-2 , Severity of Illness Index , Time Factors , Treatment Outcome , Young Adult , COVID-19 Drug Treatment
7.
J Drug Assess ; 8(1): 167-174, 2019.
Article in English | MEDLINE | ID: mdl-31692938

ABSTRACT

Objective: Whether reducing low density lipoprotein cholesterol (LDL-C) is associated with cardiovascular benefits in low risk normocholesterolaemic subjects is unknown. The INTENSITY LOW [Investigating the lowest threshold of vascular benefits from LDL-cholesterol lowering with a PCSK9 mAb inhibitor (alirocumab) in healthy volunteers] study aims to assess whether lowering LDL-C by alirocumab monotherapy can improve endothelial-dependent vascular function compared with placebo (primary objective) in low-risk normocholesterolaemic healthy individuals. Changes in endothelial-dependent or endothelial-independent vascular function, arterial stiffness and biomarkers of systemic inflammation by alirocumab, atorvastatin or their combination are secondary objectives. Study design and methods: This is a single-center, randomized, two-period, single-blind, placebo-controlled clinical trial. The study was registered on clinicaltrials.gov (N03273972). It will include 30 healthy low-risk subjects with LDL-C < 4.1 mmol/l. After passing the screening visit (Visit 1), eligible participants will be randomized 1:1 to either subcutaneous alirocumab 150 mg or placebo. These will be administered as single doses in 2 visits 14 days apart (Visits 2 and 3). Atorvastatin 20 mg once nightly will be prescribed for 14 days at Visit 3 in both groups through to Visit 4. At baseline (Visit 2) and during all post-dose visits (Visits 3-4), endothelial function will be assessed using venous occlusion plethysmography. Specifically, changes in forearm blood flow responses to intra-arterial infusions of acetylcholine, sodium nitroprusside and L-NG-monomethyl-arginine acetate will be assessed as surrogates of endothelial-dependent and -independent vasodilatation. Additionally, arterial stiffness and carotid intima-media thickness will be evaluated at the same timepoints. The above-mentioned changes will be correlated with changes in lipid and systemic inflammation biomarkers.

8.
J Am Heart Assoc ; 7(22): e010321, 2018 11 20.
Article in English | MEDLINE | ID: mdl-30571482

ABSTRACT

Background The mechanism underlying the beneficial cardiovascular effects of the incretin GLP-1 (glucagon-like peptide 1) and its analogues in humans is elusive. We hypothesized that activating receptors located on vascular smooth muscle cells to induce either peripheral or coronary vasodilatation mediates the cardiovascular effect of GLP -1. Methods and Results Ten stable patients with angina awaiting left anterior descending artery stenting underwent forearm blood flow measurement using forearm plethysmography and post-percutaneous coronary intervention coronary blood flow measurement using a pressure-flow wire before and after peripheral GLP -1 administration. Coronary sinus and artery bloods were sampled for GLP -1 levels. A further 11 control patients received saline rather than GLP -1 in the coronary blood flow protocol. GLP -1 receptor (GLP-1R) expression was assessed by immunohistochemistry using a specific GLP -1R monoclonal antibody in human tissue to inform the physiological studies. There was no effect of GLP -1 on absolute forearm blood flow or forearm blood flow ratio after GLP -1, systemic hemodynamics were not affected, and no binding of GLP -1R monoclonal antibody was detected in vascular tissue. GLP -1 reduced resting coronary transit time (mean [ SD ], 0.87 [0.39] versus 0.63 [0.27] seconds; P=0.02) and basal microcirculatory resistance (mean [ SD ], 76.3 [37.9] versus 55.4 [30.4] mm Hg/s; P=0.02), whereas in controls, there was an increase in transit time (mean [SD], 0.48 [0.24] versus 0.83 [0.41] seconds; P<0.001) and basal microcirculatory resistance (mean [SD], 45.9 [34.7] versus 66.7 [37.2] mm Hg/s; P=0.02). GLP -1R monoclonal antibody binding was confirmed in ventricular tissue but not in vascular tissue, and transmyocardial GLP -1 extraction was observed. Conclusions GLP -1 causes coronary microvascular dilation and increased flow but does not influence peripheral tone. GLP -1R immunohistochemistry suggests that GLP -1 coronary vasodilatation is indirectly mediated by ventricular-coronary cross talk.


Subject(s)
Coronary Vessels/drug effects , Glucagon-Like Peptide 1/pharmacology , Vasodilation/drug effects , Vasodilator Agents/pharmacology , Aged , Female , Humans , Male , Microvessels/drug effects , Middle Aged , Plethysmography
9.
BMJ Open ; 8(9): e022452, 2018 09 17.
Article in English | MEDLINE | ID: mdl-30224390

ABSTRACT

INTRODUCTION: Inflammation and dysregulated immune responses play a crucial role in atherosclerosis, underlying ischaemic heart disease (IHD) and acute coronary syndromes (ACSs). Immune responses are also major determinants of the postischaemic injury in myocardial infarction. Regulatory T cells (CD4+CD25+FOXP3+; Treg) induce immune tolerance and preserve immune homeostasis. Recent in vivo studies suggested that low-dose interleukin-2 (IL-2) can increase Treg cell numbers. Aldesleukin is a human recombinant form of IL-2 that has been used therapeutically in several autoimmune diseases. However, its safety and efficacy is unknown in the setting of coronary artery disease. METHOD AND ANALYSIS: Low-dose interleukin-2 in patients with stable ischaemic heart disease and acute coronary syndromes is a single-centre, first-in-class, dose-escalation, two-part clinical trial. Patients with stable IHD (part A) and ACS (part B) will be randomised to receive either IL-2 (aldesleukin; dose range 0.3-3×106 IU) or placebo once daily, given subcutaneously, for five consecutive days. Part A will have five dose levels with five patients in each group. Group 1 will receive a dose of 0.3×106 IU, while the dose for the remaining four groups will be determined on completion of the preceding group. Part B will have four dose levels with eight patients in each group. The dose of the first group will be based on part A. Doses for each of the subsequent three groups will similarly be determined after completion of the previous group. The primary endpoint is safety and tolerability of aldesleukin and to determine the dose that increases mean circulating Treg levels by at least 75%. ETHICS AND DISSEMINATION: The study received a favourable opinion by the Greater Manchester Central Research Ethics Committee, UK (17/NW/0012). The results of this study will be reported through peer-reviewed journals, conference presentations and an internal organisational report. TRIAL REGISTRATION NUMBER: NCT03113773; Pre-results.


Subject(s)
Acute Coronary Syndrome/drug therapy , Immunologic Factors/adverse effects , Interleukin-2/analogs & derivatives , Myocardial Ischemia/drug therapy , Randomized Controlled Trials as Topic , T-Lymphocytes, Regulatory/drug effects , Acute Coronary Syndrome/blood , C-Reactive Protein/metabolism , Clinical Trials, Phase I as Topic , Clinical Trials, Phase II as Topic , Double-Blind Method , Humans , Immunologic Factors/administration & dosage , Immunologic Factors/blood , Interleukin-2/administration & dosage , Interleukin-2/adverse effects , Interleukin-2/blood , Interleukin-6/blood , Lymphocyte Count , Myocardial Ischemia/blood , Natriuretic Peptide, Brain/blood , Recombinant Proteins/administration & dosage , Recombinant Proteins/adverse effects , Recombinant Proteins/blood , Troponin/blood
10.
PLoS One ; 9(6): e99070, 2014.
Article in English | MEDLINE | ID: mdl-24911964

ABSTRACT

AIMS: The mechanisms by which a 'Mediterranean diet' reduces cardiovascular disease (CVD) burden remain poorly understood. Lycopene is a potent antioxidant found in such diets with evidence suggesting beneficial effects. We wished to investigate the effects of lycopene on the vasculature in CVD patients and separately, in healthy volunteers (HV). METHODS AND RESULTS: We randomised 36 statin treated CVD patients and 36 healthy volunteers in a 2∶1 treatment allocation ratio to either 7 mg lycopene or placebo daily for 2 months in a double-blind trial. Forearm responses to intra-arterial infusions of acetylcholine (endothelium-dependent vasodilatation; EDV), sodium nitroprusside (endothelium-independent vasodilatation; EIDV), and NG-monomethyl-L-arginine (basal nitric oxide (NO) synthase activity) were measured using venous plethysmography. A range of vascular and biochemical secondary endpoints were also explored. EDV in CVD patients post-lycopene improved by 53% (95% CI: +9% to +93%, P = 0.03 vs. placebo) without changes to EIDV, or basal NO responses. HVs did not show changes in EDV after lycopene treatment. Blood pressure, arterial stiffness, lipids and hsCRP levels were unchanged for lycopene vs. placebo treatment groups in the CVD arm as well as the HV arm. At baseline, CVD patients had impaired EDV compared with HV (30% lower; 95% CI: -45% to -10%, P = 0.008), despite lower LDL cholesterol (1.2 mmol/L lower, 95% CI: -1.6 to -0.9 mmol/L, P<0.001). Post-therapy EDV responses for lycopene-treated CVD patients were similar to HVs at baseline (2% lower, 95% CI: -30% to +30%, P = 0.85), also suggesting lycopene improved endothelial function. CONCLUSIONS: Lycopene supplementation improves endothelial function in CVD patients on optimal secondary prevention, but not in HVs. TRIAL REGISTRATION: ClinicalTrials.gov NCT01100385.


Subject(s)
Antioxidants/therapeutic use , Cardiovascular Diseases/drug therapy , Cardiovascular Diseases/physiopathology , Carotenoids/therapeutic use , Administration, Oral , Adult , Aged , Aged, 80 and over , Antioxidants/administration & dosage , Blood Pressure/drug effects , Cardiovascular Diseases/blood , Carotenoids/administration & dosage , Dietary Supplements/analysis , Double-Blind Method , Female , Humans , Lycopene , Male , Middle Aged , Regional Blood Flow/drug effects , Vascular Stiffness/drug effects
11.
J Hypertens ; 31(1): 77-85, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23079681

ABSTRACT

OBJECTIVES: The Vicorder is a new brachial cuff-based device that estimates central blood pressure (cBP) using a brachial-to-aortic transfer function. The aim of this study was to evaluate cBP estimated by the Vicorder. METHODS: During cardiac angiography, cBP estimated by the Vicorder and the SphygmoCor was evaluated against simultaneous invasive cBP in 50 patients. The two devices were also compared noninvasively in a separate group of 90 healthy individuals. RESULTS: Central SBP (cSBP) obtained with each device satisfied the American Association for the Advancement of Medical Instrumentation accuracy criteria when peripheral waveforms were calibrated to invasive mean arterial pressure (MAP)/DBP: estimated - invasive cSBP difference, -4.0 ±â€Š7.4 mmHg, Vicorder, P < 0.001; -1.4 ±â€Š7.9 mmHg, SphygmoCor, P = 0.21. When oscillometric brachial SBP/DBP was used for peripheral waveform calibration, cSBP was underestimated by Vicorder (Δ -6.4 ±â€Š7.4 mmHg, P < 0.001 versus invasive) and more so by SphygmoCor (Δ -11.9 ±â€Š7.2 mmHg, P < 0.001 versus invasive). Conversely, cSBP was more closely estimated by SphygmoCor when waveforms were calibrated to brachial MAP/DBP (Δ -2.8 ±â€Š9.4 mmHg, P = 0.04 versus invasive). In the noninvasive study, Vicorder cSBP correlated well with SphygmoCor cSBP when SphygmoCor waveforms were calibrated to brachial MAP/DBP (121 ±â€Š16 versus 121 ±â€Š17 mmHg, P = 0.2) but not when brachial SBP/DBP was used for calibration (115 ±â€Š19 mmHg, P < 0.001). CONCLUSION: The Vicorder and SphygmoCor devices provide reliable estimates of cSBP when calibrated to invasive pressure. When calibrated to brachial BP, both devices underestimated cSBP, although this was attenuated when SphygmoCor was calibrated to brachial MAP/DBP. Vicorder may be a simple alternative to tonometry-based methods for noninvasive assessment of cBP.


Subject(s)
Blood Pressure Determination/instrumentation , Blood Pressure/physiology , Aged , Blood Pressure Determination/methods , Female , Humans , Male , Middle Aged
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