Investigating silent strokes in hypertensives: a magnetic resonance imaging study (ISSYS): rationale and protocol design.

BACKGROUND: Silent brain infarcts are detected by neuroimaging in up to 20% of asymptomatic patients based on population studies. They are five times more frequent than stroke in general population, and increase significantly both with advancing age and hypertension. Moreover, they are independently associated with the risk of future stroke and cognitive decline.Despite these numbers and the clinical consequences of silent brain infarcts, their prevalence in Mediterranean populations is not well known and their role as predictors of future cerebrovascular and cardiovascular events in hypertensive remains to be determined.ISSYS (Investigating Silent Strokes in Hypertensives: a magnetic resonance imaging study) is an observational cross-sectional and longitudinal study aimed to: 1- determine the prevalence of silent cerebrovascular infarcts in a large cohort of 1000 hypertensives and to study their associated factors and 2-to study their relationship with the risk of future stroke and cognitive decline. METHODS/DESIGN: Cohort study in a randomly selected sample of 1000 participants, hypertensive aged 50 to 70 years old, with no history of previous stroke or dementia.On baseline all participants will undergo a brain MRI to determine the presence of brain infarcts and other cerebrovascular lesions (brain microbleeds, white matter changes and enlarged perivascular spaces) and will be also tested to determine other than brain organ damage (heart-left ventricular hypertrophy, kidney-urine albumin to creatinine ratio, vessels-pulse wave velocity, ankle brachial index), in order to establish the contribution of other subclinical conditions to the risk of further vascular events. Several sub-studies assessing the role of 24 hour ambulatory BP monitoring and plasma or genetic biomarkers will be performed.Follow-up will last for at least 3 years, to assess the rate of further stroke/transient ischemic attack, other cardiovascular events and cognitive decline, and their predictors. DISCUSSION: Improving the knowledge on the frequency and determinants of these lesions in our setting might help in the future to optimize treatments or establish new preventive strategies to minimize clinical and socioeconomic consequences of stroke and cognitive decline.

Obstructive sleep apnoea and 24-h blood pressure in patients with resistant hypertension.

Obstructive sleep apnoea (OSA) is common in patients with resistant hypertension, but understanding of the pathogenic mechanisms linking both conditions is limited. This study assessed the prevalence of OSA and the relationships between OSA and 24-h blood pressure (BP) in 62 consecutive patients with resistant hypertension, defined as clinic BP values ≥ 140/90 despite the prescription of at least three drugs at adequate doses, including a diuretic. In order to exclude a 'white coat effect', only patients with ambulatory 24-h BP values ≥ 125/80 were recruited. Patients underwent polysomnography, 24-h ambulatory BP monitoring and completed the Epworth sleepiness scale (ESS). OSA was defined as an apnoea-hypopnoea index (AHI) ≥ 5 and excessive daytime sleepiness (EDS) by an ESS ≥ 10. A multiple linear regression analysis was used to assess the association of anthropometric data, OSA severity measures and ESS with 24-h systolic and diastolic BP. Mean 24-h BP values were 139.14/80.98 mmHg. Ninety per cent of patients had an AHI ≥ 5 and 70% had an AHI ≥ 30. Only the ESS was associated with 24-h diastolic BP [slope 0.775, 95% confidence interval (CI) 0.120-1.390, P < 0.02); age was associated negatively with 24-h diastolic BP (slope -0.64, 95% CI -0.874 to -0.411, P < 0.001). Compared with those without EDS, patients with EDS showed a significantly higher frequency of diastolic non-dipping pattern (69.2% versus 34.7%, P < 0.032). Our results demonstrate a high prevalence of severe OSA in patients with resistant hypertension and suggest that EDS could be a marker of a pathogenetic mechanism linking OSA and hypertension.

De novo nephrotic syndrome following pegylated interferon alfa 2b/ribavirin therapy for chronic hepatitis C infection.

This paper describes the case of a patient with HCV, without previous evidence of nephropathy, who following two well-tolerated cycles of treatment with interferon alone developed nephrotic syndrome after a third attempt with ribavirin associated with peginterferon alfa 2b. The patient exhibited a total remission when the antiviral treatment was discontinued.

High daytime and nighttime ambulatory pulse pressure predict poor cognitive function and mild cognitive impairment in hypertensive individuals.

High blood pressure accelerates normal aging stiffness process. Arterial stiffness (AS) has been previously associated with impaired cognitive function and dementia. Our aims are to study how cognitive function and status (mild cognitive impairment, MCI and normal cognitive aging, NCA) relate to AS in a community-based population of hypertensive participants assessed with office and 24-hour ambulatory blood pressure measurements. Six hundred ninety-nine participants were studied, 71 had MCI and the rest had NCA. Office pulse pressure (PP), carotid-femoral pulse wave velocity, and 24-hour ambulatory PP monitoring were collected. Also, participants underwent a brain magnetic resonance to study cerebral small-vessel disease (cSVD) lesions. Multivariate analysis-related cognitive function and cognitive status to AS measurements after adjusting for demographic, vascular risk factors, and cSVD. Carotid-femoral pulse wave velocity and PP at different periods were inversely correlated with several cognitive domains, but only awake PP measurements were associated with attention after correcting for confounders (beta = -0.22, 95% confidence interval (CI) -0.41, -0.03). All ambulatory PP measurements were related to MCI, which was independently associated with nocturnal PP (odds ratio (OR) = 2.552, 95% CI 1.137, 5.728) and also related to the presence of deep white matter hyperintensities (OR = 1.903, 1.096, 3.306). Therefore, higher day and night ambulatory PP measurements are associated with poor cognitive outcomes.

Short-Term Blood Pressure Variability Relates to the Presence of Subclinical Brain Small Vessel Disease in Primary Hypertension.

Blood pressure (BP) variability is associated with stroke risk, but less is known about subclinical cerebral small vessel disease (CSVD). We aimed to determine whether CSVD relates to short-term BP variability independently of BP levels and also, whether they improve CSVD discrimination beyond clinical variables and office BP levels. This was a cohort study on asymptomatic hypertensives who underwent brain magnetic resonance imaging and 24-hour ambulatory BP monitoring. Office and average 24-hour, daytime and nighttime BP levels, and several metrics of BP variability (SD, weighted SD, coefficient of variation, and average real variability [ARV]) were calculated. Definition of CSVD was based on the presence of lacunar infarcts and white matter hyperintensity grades. Multivariate analysis and integrated discrimination improvement were performed to assess whether BP variability and levels were independently associated with CSVD and improved its discrimination. Four hundred eighty-seven individuals participated (median age, 64; 47% women). CSVD was identified in 18.9%, related to age, male sex, diabetes mellitus, use of treatment, ambulatory BP monitoring-defined BP levels, and ARV of systolic BP at any period. The highest prevalence (33.7%) was found in subjects with both 24-hour BP levels and ARV elevated. BP levels at any period and ARV (24 hours and nocturnal) emerged as independent predictors of CSVD, and discrimination was incrementally improved although not to a clinically significant extent (integrated discrimination improvement, 5.31%, 5.17% to 5.4%). Ambulatory BP monitoring-defined BP levels and ARV of systolic BP relate to subclinical CSVD in hypertensive individuals.

Prevalence and associated factors of silent brain infarcts in a Mediterranean cohort of hypertensives.

Silent brain infarcts (SBIs) are detected by neuroimaging in approximately 20% of elderly patients in population-based studies. Limited evidence is available for hypertensives at low cardiovascular risk countries. Investigating Silent Strokes in Hypertensives: a Magnetic Resonance Imaging Study (ISSYS) is aimed to assess the prevalence and risk factors of SBIs in a hypertensive Mediterranean population. This is a cohort study in randomly selected hypertensives, aged 50 to 70 years old, and free of clinical stroke and dementia. On baseline, all participants underwent a brain magnetic resonance imaging to assess prevalence and location of silent infarcts, and data on vascular risk factors, comorbidities, and the presence of subclinical cardiorenal damage (left ventricular hypertrophy and microalbuminuria) were collected. Multivariate analyses were performed to determine SBIs associated factors. A total of 976 patients (49.4% men, mean age 64 years) were enrolled, and 163 SBIs were detected in 99 participants (prevalence 10.1%; 95% CI, 8.4%-12.2%), most of them (64.4%) located in the basal ganglia and subcortical white matter. After adjustment, besides age and sex, microalbuminuria and increasing total cardiovascular risk (assessed by the Framingham-calibrated for Spanish population risk function) were independently associated with SBIs. Male sex increased the odds of having SBIs in 2.5 as compared with females. Our results highlight the importance of considering both global risk assessment and sex differences in hypertension and may be useful to design future preventive interventions of stroke and dementia.

Obstructive sleep apnea and thoracic aorta dissection.

Obstructive sleep apnea syndrome (OSAS) is a process that is associated with the development of arterial hypertension, the main risk factor for aortic dissection and during obstructive episodes of the upper airways with marked increases in transmural pressure of the aorta wall. The aim of this work was to study the association between aortic dissection and OSAS. Nineteen consecutive patients with thoracic aorta dissection and 19 hypertensive patients of similar age, sex, and body mass index were studied by clinical questionnaire and polysomnography. Snoring and nonrefreshing sleep were common in both groups. Thirteen patients (68%) from each group showed an apnea-hypopnea index of more than 5 per hour. However, patients with aortic dissection presented a higher apnea-hypopnea index (28 [30.3] versus 11.1 [10.4], p=0.032). Seven patients with dissection presented an apnea-hypopnea index of more than 30 versus 1 patient in the control group (p=0.042). Patients with thoracic aorta dissection presented a high prevalence of previously undiagnosed and frequently severe OSAS. Further studies, including this diagnosis as a prognostic variable in the follow-up of patients with aortic dissection, are required. Our results suggest that in patients with aortic dissection and symptoms consistent with OSAS, a sleep study should be considered in their clinical management.