Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 171
Filtrar
2.
BMJ Open ; 10(7): e036977, 2020 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-32713850

RESUMEN

OBJECTIVE: Obtaining informed consent is a cornerstone requirement of conducting ethical research. Traditional paper-based consent is often excessively lengthy and may fail to achieve the desired participant understanding of study requirements. Multimedia tools including video and audio may be a useful alternative. This study aimed to determine the efficacy, usability and acceptability of self-directed multimedia delivery of participant consent. DESIGN: It is a single-centre, randomised, prospective study to determine the efficacy, usability and acceptability of a self-directed multimedia consent process (intervention) compared with the traditional paper-based approach (control). The intervention was free of research staff, with computer-based finger-signed consent. SETTING: Pathology blood collection services in Tasmania, Australia. PARTICIPANTS: 298 participants (63±8 years; 51% female individuals) referred from general practice were randomised to intervention (n=146) and control (n=152). OUTCOME MEASURES: Efficacy, usability and acceptability of the allocated consent process were assessed by a questionnaire. RESULTS: All participants successfully completed the allocated interventions. Efficacy parameters were higher among intervention participants, including a better understanding of study requirements compared with controls (p<0.05 all). Intervention participants were more likely to engage with the study information and spend more time on the consent process (p=<0.001 and p=0.006, respectively). Both groups reported similar levels of acceptability, although more control participants reported that the study information was too long (24% vs 14%; p=0.020). CONCLUSION: A self-directed multimedia consent process is effective for achieving participant understanding and obtaining consent free of research staff. Thus, multimedia represents a viable method to reduce the burden on researchers, meet participant needs and achieve informed consent in clinical research.

3.
Artículo en Español | PAHO-IRIS | ID: phr-52467

RESUMEN

[RESUMEN]. La hipertensión arterial es una causa modificable muy prevalente de enfermedades cardiovasculares, accidentes cerebrovasculares y muerte. Medir con exactitud la presión arterial es fundamental, dado que un error de medición de 5 mmHg puede ser motivo para clasificar incorrectamente como hipertensas a 84 millones de personas en todo el mundo. En la presente declaración de posición se resumen los procedimientos para optimizar el desempeño del observador al medir la presión arterial en el consultorio, con atención especial a los entornos de ingresos bajos o medianos, donde esta medición se ve complicada por limitaciones de recursos y tiempo, sobrecarga de trabajo y falta de suministro eléctrico. Es posible reducir al mínimo muchos errores de medición con una preparación adecuada de los pacientes y el uso de técnicas estandarizadas. Para simplificar la medición y prevenir errores del observador, deben usarse tensiómetros semiautomáticos o automáticos de manguito validados, en lugar del método por auscultación. Pueden ayudar también la distribución de tareas, la creación de un área específica de medición y el uso de aparatos semiautomáticos o de carga solar. Es fundamental garantizar la capacitación inicial y periódica de los integrantes del equipo de salud. Debe considerarse la implementación de programas de certificación de bajo costo y fácilmente accesibles con el objetivo de mejorar la medición de la presión arterial.


[ABSTRACT]. High blood pressure (BP) is a highly prevalent modifiable cause of cardiovascular disease, stroke, and death. Accurate BP measurement is critical, given that a 5-mmHg measurement error may lead to incorrect hypertension status classification in 84 million individuals worldwide. This position statement summarizes procedures for optimizing observer performance in clinic BP measurement, with special attention given to low-to-middle-income settings, where resource limitations, heavy workloads, time constraints, and lack of electrical power make measurement more challenging. Many measurement errors can be minimized by appropriate patient preparation and standardized techniques. Validated semi-automated/automated upper arm cuff devices should be used instead of auscultation to simplify measurement and prevent observer error. Task sharing, creating a dedicated measurement workstation, and using semi-automated or solar-charged devices may help. Ensuring observer training, and periodic re-training, is critical. Low-cost, easily accessible certification programs should be considered to facilitate best BP measurement practice.


[RESUMO]. A hipertensão é uma causa altamente prevalente de doença cardiovascular, acidente vascular cerebral e morte. A medição precisa da pressão arterial (PA) é um aspecto crítico, uma vez que erros de mensuração da ordem de 5 mmHg podem levar a uma classificação incorreta do status de hipertensão em 84 milhões de pessoas em todo o mundo. O presente posicionamento resume os procedimentos para otimizar o desempenho do observador (o indivíduo responsável pela mensuração da PA) na mensuração clínica da PA, com atenção especial para contextos de baixa a média renda, onde recursos limitados, cargas de trabalho pesadas, restrições de tempo e falta de energia elétrica tornam mais desafiadora a tarefa de medir a PA. Muitos erros de mensuração podem ser minimizados pela preparação adequada do paciente e pelo uso de técnicas padronizadas. Para simplificar a mensuração e evitar erros do observador, devem-se utilizar dispositivos semiautomatizados ou automatizados validados, com manguito para braço, ao invés de auscultação. O compartilhamento de tarefas, a criação de uma estação de trabalho dedicada à mensuração e o uso de dispositivos semiautomatizados ou com carga solar podem ajudar. É essencial que seja assegurado o treinamento e retreinamento periódico do observador. Programas de certificação de baixo custo e de fácil acesso devem ser considerados para facilitar a adoção das melhores práticas na mensuração da PA.


Asunto(s)
Presión Arterial , Equipos de Medición , Consenso , Salud Global , Hipertensión , Oscilometría , Presión Arterial , Equipos de Medición , Consenso , Salud Global , Hipertensión , Oscilometría , Presión Arterial , Equipos de Medición , Salud Global , Hipertensión , Oscilometría
4.
Artículo en Inglés | MEDLINE | ID: mdl-32634288

RESUMEN

The aim of our study was to estimate the size of regression to the mean with home blood pressure (BP) monitoring and compare with that for office BP. Office and home BP measures were obtained from the BP GUIDE (value of central Blood Pressure for GUIDing managEment for hypertension) study, in which 286 patients had BP measured every 3 months for 12 months. Patients were categorized by 10 mm Hg strata of baseline BP, and regression to the mean measures was calculated for home and office BP. High baseline home BP readings tended to be lower on long-term follow-up, and low baseline readings tended to be higher. For example, patients in the group with mean baseline home systolic BP ≥ 150 mm Hg had a mean baseline systolic BP of 156 mm Hg, which fell to 143 mm Hg at 12 months; and patients in the group with mean baseline home systolic BP < 120 mm Hg had a mean baseline systolic BP of 113 mm Hg which rose to 120 mm Hg at 12 months. Similar patterns were seen in intervention and control groups, and for diastolic BP. The regression dilution ratio for home systolic BP and diastolic BP was 0.52 and 0.64, respectively, compared to 0.40 and 0.55 for office systolic BP and diastolic BP, respectively. Home BP is subject to regression to the mean to a similar degree as office BP. These findings have implications for the diagnosis and management of hypertension using home BP.

7.
Hypertension ; 76(1): 244-250, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32475318

RESUMEN

Numerous devices purport to measure central (aortic) blood pressure (BP) as distinct from conventional brachial BP. This validation study aimed to determine the accuracy of the Sphygmocor Xcel cuff device (AtCor Medical, CardieX, Sydney, Australia) for measuring central BP. 296 patients (mean age 61±12 years) undergoing coronary angiography had simultaneous measurement of invasive central BP and noninvasive cuff-derived central BP using the Xcel cuff device (total n=558 individual comparisons). A subsample (n=151) also had invasive brachial BP measured. Methods were undertaken according to the Artery Society recommendations, and several calibration techniques to derive central systolic BP (SBP) were examined. Minimum acceptable error was ≤5±≤8 mm Hg. Central SBP was significantly underestimated, and with wide variability, when using the default calibration of brachial-cuff SBP and diastolic BP (DBP; mean difference±SD, -7.7±11.0 mm Hg). Similar variability was observed using other calibration methods (cuff 33% form-factor mean arterial pressure and DBP, -4.4±11.5 mm Hg; cuff 40% form-factor mean arterial pressure and DBP, 4.7±11.9 mm Hg; cuff oscillometric mean arterial pressure and DBP, -18.2±12.1 mm Hg). Only calibration with invasive central integrated mean arterial pressure and DBP was within minimal acceptable error (3.3±7.5 mm Hg). The difference between brachial-cuff SBP and invasive central SBP was 3.3±10.7 mm Hg. A subsample analysis to determine the accuracy of central-to-brachial SBP amplification showed this to be overestimated by the Xcel cuff device (mean difference 4.3±9.1 mm Hg, P=0.02). Irrespective of cuff calibration technique, the Sphygmocor Xcel cuff device does not meet the Artery Society accuracy criteria for noninvasive measurement of central BP.

8.
J Hypertens ; 38(6): 1033-1039, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32371792

RESUMEN

OBJECTIVES: Accurate assessment of mean arterial pressure (MAP) is crucial in research and clinical settings. Measurement of MAP requires not only pressure waveform integration but can also be estimated via form-factor equations incorporating peripheral SBP. SBP may increase variably from central-to-peripheral arteries (SBP amplification), and could influence accuracy of form-factor-derived MAP, which we aimed to determine. METHODS: One hundred and eighty-eight patients (69% men, age 60 ±â€Š10 years) undergoing coronary angiography had intra-arterial pressure measured in the ascending aorta, brachial and radial arteries. Reference MAP was measured by waveform integration, and form-factor-derived MAP using 33 and 40% form-factors. RESULTS: Reference MAP decreased from the aorta to the brachial (-0.7 ±â€Š4.2 mmHg) and radial artery (-1.7 ±â€Š4.8 mmHg), whereas form-factor-derived MAP increased (33% form-factor 1.1 ±â€Š4.2 and 1.7 ±â€Š4.7 mmHg; 40% form-factor 0.9 ±â€Š4.8 and 1.4 ±â€Š5.4 mmHg, respectively). Form-factor-derived MAP was significantly different to reference aortic MAP (33% form-factor -2.5 ±â€Š4.6 and -1.6 ±â€Š5.8, P < 0.001; 40% form-factor 2.5 ±â€Š5.0 and 3.9 ±â€Š6.4 mmHg, P < 0.001, brachial and radial arteries, respectively), with significant variation in the brachial form-factor required (FFreq) to generate MAP equivalent to reference aortic MAP (FFreq range 20-57% brachial; 17-74% radial). Aortic-to-brachial SBP amplification was strongly related to brachial FFreq (r = -0.695, P < 0.001). The 33% form-factor was most accurate with high aortic-to-brachial SBP amplification (33% form-factor MAP vs. reference aortic MAP difference 0.06 ±â€Š3.93 mmHg, P = 0.89) but overestimated reference aortic MAP with low aortic-to-brachial SBP amplification (+5.8 ±â€Š4.6 mmHg, P < 0.001). The opposite was observed for the 40% form-factor. CONCLUSION: Due to variable SBP amplification, estimating MAP via form-factors produces nonphysiological inaccurate values. These findings have important implications for accurate assessment of MAP in research and clinical settings.

10.
Fam Pract ; 2020 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-32296818

RESUMEN

BACKGROUND: Absolute cardiovascular disease (CVD) risk assessment is recommended for primary prevention of CVD, yet uptake in general practice is limited. Cholesterol requests at pathology services provide an opportunity to improve uptake by integrating absolute CVD risk assessment with this service. OBJECTIVE: This study aimed to assess the feasibility of such an additional service. METHODS: Two-hundred and ninety-nine patients (45-74 years) referred to pathology services for blood cholesterol had measurement of all variables required to determine absolute CVD risk according to Framingham calculator (blood pressure, age, sex, smoking and diabetes status via self-report). Data were recorded via computer-based application. The absolute risk score was communicated via the report sent to the referring medical practitioner as per usual practice. Evaluation questionnaires were completed immediately post visit and at 1-, 3- and 6-month follow-up via telephone (n = 262). RESULTS: Absolute CVD risk reports were issued for 90% of patients. Most patients (95%) reported that the length of time for the pathology service assessment was acceptable, and 91% that the self-directed computer-based application was easy to use. Seventy-eight per cent reported a preference for pathology services to conduct absolute CVD risk assessment. Only 2% preferred a medical practitioner. Of follow-up patients, 202 (75%) had a consultation with a medical practitioner, during which, aspects of CVD risk prevention were discussed (cholesterol and blood pressure 74% and 69% of the time, respectively). CONCLUSIONS: Measurement of absolute CVD risk in pathology services is feasible, highly acceptable among middle-to-older adults and may increase uptake of guideline-directed care in general practice.

11.
Hypertension ; 75(6): 1593-1599, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32275193

RESUMEN

Self-home blood pressure (BP) monitoring is recommended to guide clinical decisions on hypertension and is used worldwide for cardiovascular risk management. People usually make their own decisions when purchasing BP devices, which can be made online. If patients purchase nonvalidated devices (those not proven accurate according to internationally accepted standards), hypertension management may be based on inaccurate readings resulting in under- or over-diagnosis or treatment. This study aimed to evaluate the number, type, percentage validated, and cost of home BP devices available online. A search of online businesses selling devices for home BP monitoring was conducted. Multinational companies make worldwide deliveries, so searches were restricted to BP devices available for one nation (Australia) as an example of device availability through the global online marketplace. Validation status of BP devices was determined according to established protocols. Fifty nine online businesses, selling 972 unique BP devices were identified. These included 278 upper-arm cuff devices (18.3% validated), 162 wrist-cuff devices (8.0% validated), and 532 wrist-band wearables (0% validated). Most BP devices (92.4%) were stocked by international e-commerce businesses (eg, eBay, Amazon), but only 5.5% were validated. Validated cuff BP devices were more expensive than nonvalidated devices: median (interquartile range) of 101.1 (75.0-151.5) versus 67.4 (30.4-112.8) Australian Dollars. Nonvalidated BP devices dominate the online marketplace and are sold at lower cost than validated ones, which is a major barrier to accurate home BP monitoring and cardiovascular risk management. Before purchasing a BP device, people should check it has been validated at https://www.stridebp.org.

12.
Hypertension ; 75(6): 1565-1573, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32336232

RESUMEN

Individuals with type 2 diabetes mellitus (T2DM) have a greater blood pressure (BP) response to acute maximal exercise compared to those without T2DM; however, whether they exhibit a different arterial stiffness response to maximal exercise has yet to be explored. Adults with (n=66) and without T2DM (n=61) underwent an arterial stress test: at rest and immediately postexercise, carotid-femoral pulse wave velocity, the gold standard measure of arterial stiffness, brachial BP, heart rate, and other hemodynamic measurements were assessed. Linear regression models were used to evaluate between-group differences at rest, and the response to exercise (postexercise value), adjusting for covariates including BP and heart rate when relevant, and the corresponding baseline value of each parameter. All participants (mean±SD: age 59.3±10.6 years; body mass index 31.2±3.9 kg/m2) had hypertension (mean BP 130±14/80±9 mm Hg). At rest, participants with T2DM had significantly higher carotid-femoral pulse wave velocity (10.3±2.7 versus 9.1±1.9 m/s), heart rate (69±11 versus 66±10 beats/min), and lower diastolic BP (79±9 versus 83±9 mm Hg), but systolic BP (129±15 versus 131±13 mm Hg) was similar. In response to exercise, participants with T2DM showed greater increases in carotid-femoral pulse wave velocity (1.6 [95% CI, 0.4-2.9 m/s]) and systolic BP (9 [95% CI, 1-17 mm Hg]) than participants without T2DM. A greater proportion of participants with T2DM had a hypertensive response to exercise compared to participants without T2DM (n=23, 35% versus n=11, 18%; P=0.033). By incorporating exercise as a vascular stressor, we provide evidence of a greater increase in arterial stiffness in individuals with T2DM, independently of resting arterial stiffness, and the BP postexercise.

13.
Artículo en Español | PAHO-IRIS | ID: phr-51862

RESUMEN

[RESUMEN]. La Comisión Lancet de Hipertensión determinó que una medida clave para responder a la carga mundial que representa la hipertensión arterial era mejorar la calidad de las mediciones de la presión arterial, mediante la utilización de dispositivos cuya exactitud haya sido validada. En la actualidad existen 3000 dispositivos comercializados, pero muchos no tienen datos publicados sobre pruebas de exactitud conformes a las normas científicas establecidas. La falta de regulación o su ineficiencia, que permiten la autorización de dispositivos para uso comercial sin una validación oficial, posibilitan este problema. Además, han surgido tecnologías nuevas de medición de la presión arterial (por ejemplo, los sensores sin brazalete) sobre las cuales no existe unanimidad en la comunidad científica con respecto a las normas de exactitud de la medición. En conjunto, estos aspectos contribuyen a la disponibilidad generalizada de tensiómetros de consultorio o domiciliarios que ofrecen una exactitud limitada o incierta, que llevan a diagnósticos, manejo y farmacoterapia inapropiados de la hipertensión a escala mundial. Los problemas más importantes relacionados con la exactitud de los dispositivos de medición de la presión arterial se pueden resolver mediante el requisito regulatorio de una validación independiente obligatoria de los dispositivos, en consonancia con la norma ISO universalmente aceptada. Esta es una recomendación básica y constituye una necesidad internacional acuciante. Otras recomendaciones clave son la elaboración de normas de validación específicas para las tecnologías nuevas de medición de la presión arterial y la publicación en línea de listas de los dispositivos nuevos exactos que están a la disposición de los usuarios y los profesionales de salud. Las recomendaciones están en consonancia con las políticas de la Organización Mundial de la Salud sobre los dispositivos médicos y la atención universal de la salud. El cumplimiento de las recomendaciones aumentará la disponibilidad mundial de dispositivos de medición de la presión arterial que sean exactos y tendrá como efecto un mejor diagnóstico y tratamiento, reduciendo así la carga mundial de la hipertensión.


[ABSTRACT]. The Lancet Commission on Hypertension identified that a key action to address the worldwide burden of high blood pressure (BP) was to improve the quality of BP measurements by using BP devices that have been validated for accuracy. Currently, there are over 3 000 commercially available BP devices, but many do not have published data on accuracy testing according to established scientific standards. This problem is enabled through weak or absent regulations that allow clearance of devices for commercial use without formal validation. In addition, new BP technologies have emerged (e.g. cuffless sensors) for which there is no scientific consensus regarding BP measurement accuracy standards. Altogether, these issues contribute to the widespread availability of clinic and home BP devices with limited or uncertain accuracy, leading to inappropriate hypertension diagnosis, management and drug treatment on a global scale. The most significant problems relating to the accuracy of BP devices can be resolved by the regulatory requirement for mandatory independent validation of BP devices according to the universally-accepted International Organization for Standardization Standard. This is a primary recommendation for which there is an urgent international need. Other key recommendations are development of validation standards specifically for new BP technologies and online lists of accurate devices that are accessible to consumers and health professionals. Recommendations are aligned with WHO policies on medical devices and universal healthcare. Adherence to recommendations would increase the global availability of accurate BP devices and result in better diagnosis and treatment of hypertension, thus decreasing the worldwide burden from high BP.


[RESUMO]. A Comissão Lancet sobre Hipertensão Arterial identificou que uma iniciativa central para enfrentar a carga mundial da hipertensão arterial seria a melhoria na qualidade da mensuração da pressão arterial pelo uso aparelhos de pressão arterial validados quanto à acurácia. Atualmente, existem mais de 3 000 aparelhos de pressão arterial disponíveis comercialmente; entretanto, muitos não têm dados publicados sobre testes de acurácia realizados de acordo com padrões científicos estabelecidos. Este problema resulta de regulamentação fraca ou inexistente, o que permite a aprovação para uso comercial de dispositivos sem validação formal. Além disso, surgiram novas tecnologias de mensuração da pressão arterial (por exemplo, sensores sem algemas) sem consenso científico quanto aos padrões de acurácia. No conjunto, essas questões contribuem para a oferta generalizada de dispositivos de pressão arterial clínica e domiciliar com acurácia limitada ou incerta, levando a diagnóstico, gerenciamento e tratamento inadequados da hipertensão em escala global. Os problemas mais significativos relacionados com a acurácia dos dispositivos de pressão arterial podem ser resolvidos por regulamentação que imponha a obrigatoriedade de validação independente dos aparelhos de pressão arterial, de acordo com a norma universalmente aceita pela Organização Internacional de Normalização. Esta é uma recomendação fundamental para a qual existe uma necessidade internacional urgente. Outras recomendações essenciais incluem o desenvolvimento de padrões de validação especificamente para novas tecnologias de mensuração da pressão arterial e listas on-line de aparelhos com acurácia adequada que sejam acessíveis aos consumidores e profissionais de saúde. As recomendações estão alinhadas com as políticas da Organização Mundial da Saúde (OMS) sobre dispositivos médicos e atenção universal à saúde. A adesão às recomendações aumentaria a oferta global de dispositivos de pressão arterial com acurácia adequada e resultaria em melhor diagnóstico e tratamento da hipertensão arterial, diminuindo assim a carga mundial dessa doença.


Asunto(s)
Salud Global , Tecnología Biomédica , Estándares de Referencia , Equipo para Diagnóstico , Salud Global , Tecnología Biomédica , Estándares de Referencia , Equipo para Diagnóstico , Salud Global , Tecnología Biomédica , Estándares de Referencia , Equipo para Diagnóstico
14.
Arterioscler Thromb Vasc Biol ; 40(5): 1420-1428, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32188272

RESUMEN

OBJECTIVE: Impaired baroreflex function is an early indicator of cardiovascular autonomic imbalance. Patients with type 2 diabetes mellitus (T2D) have decreased baroreflex sensitivity (BRS), however, whether the neural BRS (nBRS) and mechanical component of the BRS is altered in those with high metabolic risk (HMR, impaired fasting glucose and metabolic syndrome) or with overt T2D, is unknown. We examined this in a community-based observational study, the Paris Prospective Study III (PPS3). Approach and Results: In 7626 adults aged 50 to 75 years, resting nBRS (estimated by low-frequency gain, from carotid distension rate and RR [time elapsed between two successive R waves] intervals) and mechanical BRS were measured by high-precision carotid echotracking. The associations between overt T2D or HMR as compared with subjects with normal glucose metabolism and nBRS or mechanical BRS were quantified using multivariable linear regression analysis. There were 319 subjects with T2D (61±6 years, 77% male), 1450 subjects with HMR (60±6 years, 72% male), and 5857 subjects with normal glucose metabolism (59±6 years, 57% male). Compared with normal glucose metabolism, nBRS was significantly lower in HMR subjects (ß=-0.07 [95% CI, -0.12 to -0.01]; P=0.029) and in subjects with T2D (ß=-0.18 [95% CI, -0.29 to -0.07]; P=0.002) after adjustment for confounding and mediating factors. Subgroup analysis suggests significant and independent alteration in mechanical BRS only among HMR patients who had both impaired fasting glucose and metabolic syndrome. CONCLUSIONS: In this community-based study of individuals aged 50 to 75, a graded decrease in nBRS was observed in HMR subjects and patients with overt T2D as compared with normal glucose metabolism subjects.


Asunto(s)
Sistema Nervioso Autónomo/fisiopatología , Barorreflejo , Glucemia/metabolismo , Presión Sanguínea , Sistema Cardiovascular/fisiopatología , Diabetes Mellitus Tipo 2/sangre , Neuropatías Diabéticas/fisiopatología , Frecuencia Cardíaca , Anciano , Biomarcadores/sangre , Estudios de Casos y Controles , Estudios Transversales , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/fisiopatología , Neuropatías Diabéticas/sangre , Neuropatías Diabéticas/diagnóstico , Neuropatías Diabéticas/etiología , Femenino , Humanos , Masculino , Síndrome Metabólico/sangre , Síndrome Metabólico/complicaciones , Síndrome Metabólico/fisiopatología , Persona de Mediana Edad , Paris , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo
16.
J Hypertens ; 38(4): 723-730, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32134846

RESUMEN

OBJECTIVE: Reservoir pressure parameters [e.g. reservoir pressure (RP) and excess pressure (XSP)] measured using tonometry predict cardiovascular events beyond conventional risk factors. However, the operator dependency of tonometry impedes widespread use. An operator-independent cuff-based device can reasonably estimate the intra-aortic RP and XSP from brachial volumetric waveforms, but whether these estimates are clinically relevant to preclinical phenotypes of cardiovascular risk has not been investigated. METHODS: The RP and XSP were derived from brachial volumetric waveforms measured using cuff oscillometry (SphygmoCor XCEL) in 1691 mid-life adults from the CheckPoint study (a population-based cross-sectional study nested in the Longitudinal Study of Australian Children). Carotid intima--media thickness (carotid IMT, n = 1447) and carotid--femoral pulse wave velocity (PWV, n = 1632) were measured as preclinical phenotypes of cardiovascular risk. Confounders were conventional risk factors that were correlated with both exposures and outcomes or considered as physiologically important. RESULTS: There was a modest association between XSP and carotid IMT (ß = 0.76 µm, 95% CI, 0.25-1.26 partial R = 0.8%) after adjusting for age, sex, BMI, heart rate, smoking, diabetes, high-density lipoprotein cholesterol and mean arterial pressure. Neither RP nor XSP were associated with PWV in the similarly adjusted models (ß = -0.47 cm/s, 95% CI, -1.15 to 0.20, partial R = 0.2% for RP, and ß = 0.04 cm/s, 95% CI, -0.59 to 0.67, partial R = 0.01% for XSP). CONCLUSION: Cuff-based XSP associates with carotid IMT independent of conventional risk factors, including traditional BP, but the association was weak, indicating that further investigation is warranted to understand the clinical significance of reservoir pressure parameters.

17.
Am J Hypertens ; 33(4): 325-330, 2020 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-32006010

RESUMEN

BACKGROUND: Central artery reservoir-excess pressure parameters are clinically important but impractical to record directly. However, diastolic waveform morphology is consistent across central and peripheral arteries. Therefore, peripheral artery reservoir-excess pressure parameters related to diastolic waveform morphology may be representative of central parameters and share clinically important associations with end-organ damage. This has never been determined and was the aim of this study. METHODS: Intra-arterial blood pressure (BP) waveforms were measured sequentially at the aorta, brachial, and radial arteries among 220 individuals (aged 61 ± 10 years, 68% male). Customized software was used to derive reservoir-excess pressure parameters at each arterial site (reservoir and excess pressure, systolic and diastolic rate constants) and clinical relevance was determined by association with estimated glomerular filtration rate (eGFR). RESULTS: Between the aorta and brachial artery, the mean difference in the diastolic rate constant and reservoir pressure integral was -0.162 S-1 (P = 0.08) and -0.772 mm Hg s (P = 0.23), respectively. The diastolic rate constant had the strongest and most consistent associations with eGFR across aortic and brachial sites (ß = -0.20, P = 0.02; ß = -0.20, P = 0.03, respectively; adjusted for traditional cardiovascular risk factors). Aortic, but not brachial peak reservoir pressure was associated with eGFR in adjusted models (aortic ß = -0.48, P = 0.02). CONCLUSIONS: The diastolic rate constant is the most consistent reservoir-excess pressure parameter, in both its absolute values and associations with kidney dysfunction, when derived from the aorta and brachial artery. Thus, the diastolic rate constant could be utilized in the clinical setting to improve BP risk stratification.

18.
Scand J Med Sci Sports ; 30(6): 1033-1039, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32100896

RESUMEN

PURPOSE: Exaggerated exercise blood pressure (BP) is associated with altered cardiac structure and increased cardiovascular risk. Fitness modifies these associations, but the effect in healthy adolescents is unknown. We performed an observational study to determine the influence of fitness on post-exercise BP, and on its relationship with cardiac structure in adolescents. METHODS: 4835 adolescents from the Avon Longitudinal Study of Parents and Children, (15.4 (0.3) years, 49% male) completed a submaximal cycle test. Fitness was estimated as physical work capacity 170 adjusted for lean body mass and post-exercise BP measured immediately posttest. Cardiovascular structure and function, including left ventricular (LV) mass (n = 1589), left atrium (LA) size (n = 1466), cardiac output (CO, n = 1610), and total peripheral resistance (TPR, n = 1610) were measured at rest by echocardiography 2.4 (0.4) years later. RESULTS: Post-exercise systolic BP increased stepwise by fitness tertile (131.2 mm Hg [130.4, 132.1]; 137.3 mm Hg [136.5, 138.0]; 142.3 mm Hg [141.5, 143.1]). Each 5 mm Hg of post-exercise systolic BP was associated with 2.46 g [1.91, 3.01] greater LV mass, 0.02 cm [0.02, 0.03] greater LA size, and 0.25 g/m2.7 [0.14, 0.36] greater LV mass index. Adjustment for fitness abolished associations (0.29 g [-0.16, 0.74]; 0.01 cm [-0.001, 0.014] and 0.08 g/m2.7 [-0.001, 0.002]). Similar associations between post-exercise systolic BP and each outcome were found between the lowest and highest fitness thirds. CO increased with fitness third (difference 0.06 L/min [-0.05, 0.17]; 0.23 L/min [0.12, 0.34]) while TPR decreased (difference -0.13 mm Hg·min/L [-0.84,0.59]; -1.08 mm Hg·min/L [-0.1.80, 0.35]). CONCLUSIONS: Post-exercise systolic BP increased with fitness, which modified its association with cardiac structure. Higher CO, but lower TPR suggests a physiologically adapted cardiovascular system with greater fitness, highlighting the importance of fitness in adolescence.

19.
Hypertension ; 75(3): 844-850, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31983305

RESUMEN

Blood pressure (BP) is a leading global risk factor. Increasing age is related to changes in cardiovascular physiology that could influence cuff BP measurement, but this has never been examined systematically and was the aim of this study. Cuff BP was compared with invasive aortic BP across decades of age (from 40 to 89 years) using individual-level data from 31 studies (1674 patients undergoing coronary angiography) and 22 different cuff BP devices (19 oscillometric, 1 automated auscultation, 2 mercury sphygmomanometry) from the Invasive Blood Pressure Consortium. Subjects were aged 64±11 years, and 32% female. Cuff systolic BP overestimated invasive aortic systolic BP in those aged 40 to 49 years, but with each older decade of age, there was a progressive shift toward increasing underestimation of aortic systolic BP (P<0.0001). Conversely, cuff diastolic BP overestimated invasive aortic diastolic BP, and this progressively increased with increasing age (P<0.0001). Thus, there was a progressive increase in cuff pulse pressure underestimation of invasive aortic PP with increasing decades of age (P<0.0001). These age-related trends were observed across all categories of BP control. We conclude that cuff BP as an estimate of aortic BP was substantially influenced by increasing age, thus potentially exposing older people to greater chance for misdiagnosis of the true risk related to BP.

20.
Am J Hypertens ; 33(2): 137-145, 2020 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-31419806

RESUMEN

BACKGROUND: Arterial reservoir-wave analysis (RWA)-a new model of arterial hemodynamics-separates arterial wave into reservoir pressure (RP) and excess pressure (XSP). The XSP integral (XSPI) has been associated with increased risk of clinical outcomes. The objectives of the present study were to examine the determinants of XSPI in a mixed cohort of hemodialysis (HD) and peritoneal dialysis (PD) patients, to examine whether dialysis modality and the presence of an arteriovenous fistula (AVF) are associated with increased XSPI. METHOD: In a cross-sectional study, 290 subjects (232 HD and 130 with AVF) underwent carotid artery tonometry (calibrated with brachial diastolic and mean blood pressure). The XSPI was calculated through RWA using pressure-only algorithms. Logistic regression was used for determinants of XSPI above median. Through forward conditional linear regression, we examined whether treatment by HD or the presence of AVF is associated with higher XSPI. RESULTS: Patients with XSPI above median were older, had a higher prevalence of diabetes and cardiovascular disease, had a higher body mass index, and were more likely to be on HD. After adjustment for confounders, HD was associated with a higher risk of higher XSPI (odds ratio = 2.39, 95% confidence interval: 1.16-4.98). In a forward conditional linear regression analysis, HD was associated with higher XSPI (standardized coefficient: 0.126, P = 0.012), but on incorporation of AVF into the model, AVF was associated with higher XSPI (standardized coefficient: 0.130, P = 0.008) and HD was excluded as a predictor. CONCLUSION: This study suggests that higher XSPI in HD patients is related to the presence of AVF.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA