José Alberto Silva

Sequential follow-up clinic and ambulatory blood pressure evaluation in a low risk population of white-coat hypertensive patients and in normotensives.

BackgroundIn subjects with white-coat hypertension (WCH) it is unclear how ambulatory blood pressure (ABPM) progresses over time and whether they exhibit an increased cardiovascular risk. MethodsWe prospectively evaluated the transition of clinic and ABPM values in 39 clinic and ABPM normotensive subjects (NT) (clinic BP<140/90u2009mmHg and awake BP<130/85u2009mmHg, ages 43.4±2.6u2009y) and in 79 untreated subjects (47.2±2.4u2009y) with WCH (clinic BP>140/90, awake ABP<130/85u2009mmHg) with no other major cardiovascular risk factors. Ambulatory blood pressure was evaluated at baseline and on at least two further occasions during follow-up. ResultsAt baseline all subjects were untreated and groups did not differ on values of metabolic parameters, BMI, left ventricular mass index, and ABPM values. Subjects were revaluated for ABPM half way through and at the end of follow-up, 35±3 and 86±4 months in NT and 49±4 and 90±4 months in WCH. Thirty-six WCH were on antihypertensive treatment (AH) after baseline until the end of follow-up (WCH-tr), whereas 43 WCH (WCH-untr) were free from AH throughout the study. In a similar way all groups showed a significant (p<0.01) progressive increase in 24-h ABPM systolic blood pressure (SBP)/diastolic blood pressure (DBP) from baseline throughout the follow-up in NT (+4.9/2.1±0.8/0.9u2009mmHg), average annual increase of 0.72/0.37u2009mmHg/y, in WCH-tr (+u20095.0/1.2±1.1/1.5u2009mmHg), average annual increase of 0.66/0.31u2009mmHg/y and in WCH-untr (+5.4/3.2±0.9/1.1u2009mmHg), average annual increase of 0.74/0.39u2009mmHg/y. During the follow-up office SBP/DBP (mmHg) significantly rose in NT (+5.7/3.9) but was reduced in WCH-tr (−7.8/5.2) and in WCH-untr (−4.7/1.1). Development of ambulatory hypertension (daytime BP >130 and/or >85u2009mmHg) occurred in 15.4% (6/39) of NT, in 22.7% (8/36) of WCH-tr and in 26.1% (11/43) of WCH-untr (NS). First cardiovascular events recorded were three in subjects with WCH and none in NT. ConclusionsAfter 7.4 years of follow-up, both the progressive increase in ABPM and the rate of transition to ambulatory hypertension in subjects with WCH (either treated or untreated), who were selected under strict criteria were similar to that of normotensive subjects. Also there was no evidence that WCH exhibited a clear higher risk of development cardiovascular events.

Different patterns of peripheral versus central blood pressure in hypertensive patients treated with β-blockers either with or without vasodilator properties or with angiotensin receptor blockers.

BackgroundIt is unclear whether the assumed inferiority of atenolol to reduce central (aortic) blood pressure (BP) extends to other β-blockers with vasodilating properties and, within that scope, how these drugs differ from the angiotensin receptor blockers (ARBs). MethodsIn a retrospective study, we compared three groups of hypertensive patients (aged 35–65 years) chronically treated with either ARBs (n=83, group 1), carvedilol/nebivolol (n=75, 25+25u2009mg/day/5u2009mg/day, group 2) or atenolol (n=84, 50–100u2009mg/day, group 3), matched for age (mean 52 years), sex (61% female), brachial BP and concomitant use of diuretics (75–81%)and dihydropyridine calcium antagonists (27–33%). We measured aortic stiffness by pulse wave velocity (Complior), and central BP, central-peripheral pulse pressure amplification, wave reflection [augmentation index (AIx) corrected for heart rate] and augmentation pressure (Sphygmocor). ResultsFor similar age, sex distribution, brachial BP levels (145/85±11/10u2009mmHg) and pulse wave velocity (10±2u2009m/s), the atenolol group showed significantly (P<0.03 analysis of variance) higher central systolic BP (139±9u2009mmHg) versus group 2 (135±10u2009mmHg) and group 1 (132±11u2009mmHg), higher AIx (34±12%) versus group 2 (27±7%) and group 1 (23.0±9%), lower pulse pressure amplification (1.16±0.09) versus group 2 (1.22±0.10) and group 1 (1.31±0.11) and lower heart rate beats/min (61±9) versus group 2 (69±11) and group 1 (82±11). The differences on these values, between group 2 and group 1, were also significant (P<0.04). After adjustment for the heart rate, AIx became similar in groups 2 and 1, but still lower (P<0.04) than the atenolol group. ConclusionThese findings suggest that, for similar brachial BP and aortic stiffness, treatment with either vasodilating β-blockers or angiotensin receptor blockers associates with lower central systolic BP and wave reflections than treatment with atenolol. These findings may suggest that the vasodilating β-blockers may exert more favourable central haemodynamic effects, compared with atenolol, which are more alike, although not completely equal, to those of the ARBs.

Improvement of aortic reflection wave responses 6 months after stopping smoking: a prospective study.

BackgroundCigarette smoking is one important preventable cause of cardiovascular illness that has been associated with increased stiffness of large arteries and wave reflection, which are independent predictors of cardiovascular disease. MethodsWe investigated the effect of a 6-month quitting smoking programme on aortic stiffness, central pressure and wave reflections in chronic heavy smokers. Seventy-one (83% normotensives) long-term heavy smokers [>20 cigarettes/day and exhaled carboxy haemoglobin (COHb) (≥4% and COu2009ppm ≥21)] completed a 6-month psychological-based stop-smoking program. Patients were divided into two groups. Thirty-one patients aged 45±2 years, 71% male, fully quit smoking for 6 months (COHb <2% and COu2009ppm <10 at 1, 3 and 6 months) – group I, whereas 40 patients aged 45±1 years, 73% male, did not change their smoking habits – group II. We measured between baseline and changes after 6 months in aortic stiffness assessed as pulse wave velocity (Complior), central–peripheral pulse pressure (PP) amplification ratio (PPAr), wave reflection (augmentation index corrected for heart rate), augmentation pressure and transit time (Sphygmocor). Ambulatory 24u2009h blood pressure (ABP) data were obtained at baseline and after 6 months in 36 patients (nu2009=u200919) of group I and 17 of group II. ResultsIn group I, but not in group II, there were significant reductions of peripheral systolic BP (baseline: 131±4 to after 6 months: 127±4u2009mmHg, P<0.04) and of systolic BP (baseline: 121±4 to after 6 months: 114±4u2009mmHg, P<0.03). In group I from baseline to after 6 months, PPAr increased by 13.1±4.1% and transit time (ms) by 8.7±2.9%; augmentation index was reduced by 9.2±1.6%, augmentation pressure by 5.7±1.9u2009mmHg (all P<0.03 vs. baseline and vs. group II); and pulse wave velocity by 2.3±2.8% (Pu2009=u20090.062). In group I, only daytime ABP was reduced from baseline to after 6 months (129/82±2/2 to 123/78±2/2u2009mmHg, P<0.03), whereas no change in 24h-ABP was found in group II. ConclusionSix months of smoking cessation is associated with clear improvement of reflected waves, central pressure and aortic stiffness, and with a reduction of daytime BP. This may contribute to the improvement of cardiovascular prognosis attributed to smoking cessation.

Definição de valores de referência da velocidade da onda de pulso arterial numa população portuguesa: uma sub-análise do projecto EDIVA

INTRODUCTIONnAortic pulse wave velocity (PWV) has been associated with cardiovascular risk in different clinical subsets. This subanalysis of the EDIVA project aimed to establish criteria for normality of PWV based on a statistical definition that considers the fundamental physiological role of aging in arterial stiffness.nnnMETHODSnA sample of 668 healthy subjects (412 male) enrolled in the EDIVA Project (a prospective, multicenter, observational study) were studied. Mean age was 40.00 ± 13.42 years, body mass index was 25.90 ± 4.21kg/m(2), and systolic and diastolic blood pressure were respectively 125.47 ± 11.18 and 75.75 ± 9.27mmHg. PWV was determined annually using a Complior device, and mean follow-up was 23.3 ± 3.34 months. Personal and family history, physical examination, electrocardiogram and biochemical analysis were used to determine individual health.nnnRESULTSnIn the overall population PWV was 8.8 ± 1.4m/sec, 8.7 ± 1.6m/sec in men and 8.9 ± 1.5m/sec in women (p=NS). Normal PWV was defined as the 95th percentile adjusted for age and gender, above which PWV was considered abnormal. Serial evaluation of PWV also enabled the annual age-dependent increase in PWV to be estimated at 5%, values above this cut-off being defined as abnormal vascular deterioration.nnnCONCLUSIONnThis study establishes criteria for normality based on a statistical definition that takes into account the fundamental physiological role of aging in arterial stiffness. Additionally, it provides a cut-off for the clinical interpretation of serial PWV measurements.Resumo Introducao A velocidade da onda de pulso carotideo-femoral (VOP) tem constituido um importante marcador de risco cardiovascular, traduzindo o reflexo arterial subsequente a um conjunto de contextos clinicos em que o impacto cardiovascular e manifesto. Este trabalho visou estabelecer parâmetros de normalidade da VOP para a populacao portuguesa, com base numa definicao estatistica. Metodo O presente trabalho corresponde a uma sub-analise do Projecto EDIVA, envolvendo 668 individuos saudaveis (412 do sexo masculino), com idade media 39,73xa0±xa015,6 anos, indice de massa corporal 25,56xa0±xa04,05xa0kgm 2 , pressao arterial sistolica e diastolica respectivamente 125,47xa0±xa011,18 e 75,75xa0±xa09,27xa0mmHg. Estes individuos foram submetidos a um follow-up medio de 23,3xa0±xa03,34 meses, com avaliacao anual da VOP. A normalidade foi definida em termos da historia pessoal e familiar, da avaliacao clinica, do ECG de superficie e da realizacao de exames analiticos de rotina. Resultados A VOP media na amostra foi de 8,8xa0±xa01,4xa0m/s, sendo de 8,7xa0±xa01,6xa0m/s e 8,9xa0±xa01,5 m/s, respectivamente no sexo feminino e masculino (pxa0=xa0ns). A normalidade foi definida a partir do percentil 95 para cada faixa etaria, e por genero. A avaliacao sequencial permitiu ainda avaliar o contributo percentual de agravamento da VOP face ao envelhecimento (5%), definindo-se assim uma variacao positiva da VOP (em avaliacoes sequenciais) inferior a 5% como normal. Conclusao Os resultados obtidos permitem: por um lado, estabelecer criterios de referencia para a VOP tendo em consideracao o papel determinante do envelhecimento na deterioracao fisiologica da funcao das grandes arterias; por outro lado, estabelecer uma medida de valorizacao da variacao longitudinal da VOP, aspecto que se reveste de grande importância face a adopcao desta metodologia em programas integrados de seguimento de doentes com risco cardiovascular manifesto.

[A statistical definition of aortic pulse wave velocity normality in a Portuguese population: a subanalysis of the EDIVA project].

Abstract Introduction Aortic pulse wave velocity (PWV) has been associated with cardiovascular risk in different clinical subsets. This subanalysis of the EDIVA project aimed to establish criteria for normality of PWV based on a statistical definition that considers the fundamental physiological role of aging in arterial stiffness. Methods A sample of 668 healthy subjects (412 male) enrolled in the EDIVA Project (a prospective, multicenter, observational study) were studied. Mean age was 40.00xa0±xa013.42 years, body mass index was 25.90xa0±xa04.21xa0kg/m2, and systolic and diastolic blood pressure were respectively 125.47xa0±xa011.18 and 75.75xa0±xa09.27 mmHg. PWV was determined annually using a Complior device, and mean follow-up was 23.3xa0±xa03.34 months. Personal and family history, physical examination, electrocardiogram and biochemical analysis were used to determine individual health. Results In the overall population PWV was 8.8xa0±xa01.4xa0m/sec, 8.7xa0±xa01.6xa0m/sec in men and 8.9xa0±xa01.5xa0m/sec in women (pxa0=xa0NS). Normal PWV was defined as the 95th percentile adjusted for age and gender, above which PWV was considered abnormal. Serial evaluation of PWV also enabled the annual age-dependent increase in PWV to be estimated at 5%, values above this cut-off being defined as abnormal vascular deterioration. Conclusion This study establishes criteria for normality based on a statistical definition that takes into account the fundamental physiological role of aging in arterial stiffness. Additionally, it provides a cut-off for the clinical interpretation of serial PWV measurements.

Estimates and analysis of investment in information and communication technologies for the deployment of smart Grid in Brazil

This paper aims to scale resources, estimate and analyze the needs of investments in Information Technology and Communication (ICT) for deployment of Smart Grid in Brazil. The methodology consisted of a survey of the current state of electricity distribution, which defined the technological and communication networks requirements to support the deployment of the main Smart Grid functionalities, followed by a financial viability assessment. The results provide a total cost estimate to implement the considered ICT solutions, broken down into Smart Grid functionalities and geographical aspect (urban and rural). In addition, the paper points out the need for regulatory multidisciplinary setting and structuring of public policies.