Office blood pressure and 24-hour ambulatory blood pressure measurements: high proportion of disagreement in resistant hypertension

Resistant hypertension, secondary hypertension, and hypertensive crises: diagnostic evaluation and treatment

Hypertension is a very common modifiable risk factor for cardiovascular morbidity and mortality. Patients with hypertension represent a diverse group. In addition to those with primary hypertension, there are patients whose hypertension is attributable to secondary causes, those with resistant hypertension, and patients who present with a hypertensive crisis. Secondary causes of hypertension account for less than 10% of cases of elevated blood pressure (BP), and screening for these causes is warranted if clinically indicated. Patients with resistant hypertension, whose BP remains uncontrolled in spite of use of 3 or more antihypertensive agents, are at increased cardiovascular risk compared with the general hypertensive population. After potentially correctible causes of uncontrolled BP (pseudoresistance, secondary causes, and intake of interfering substances) are eliminated, patients with true resistant hypertension are managed by encouraging therapeutic lifestyle changes and optimizing the antihypertensive regimen, whereby the clinician ensures that the medications are prescribed at optimal doses using drugs with complementary mechanisms of action, while adding an appropriate diuretic if there are no contraindications. Mineralocorticoid receptor antagonists are formidable add-on agents to the antihypertensive regimen, usually as a fourth drug, and are effective in reducing BP even in patients without biochemical evidence of aldosterone excess. In the setting of a hypertensive crisis, the BP has to be reduced within hours in the case of a hypertensive emergency (elevated BP with evidence of target organ damage) using parenteral agents, and within a few days if there is hypertensive urgency, using oral antihypertensive agents.

Confirmed hypertension and plasma 25(OH)D concentrations amongst elderly men

OBJECTIVES

the results of experimental studies suggest that vitamin D deficiency activates the renin-angiotensin system and predisposes to hypertension. Results of previous epidemiological studies investigating the association between 25-hydroxyvitamin D [25(OH)D] status and hypertension have not been consistent, perhaps because of their sole reliance on office blood pressure (BP) measurements leading to some misclassification of hypertension status. No previous studies have examined the association between 25(OH)D status and confirmed hypertension assessed with both office and 24-h BP measurements.

DESIGN

in this cross-sectional study, we investigated 833 Caucasian men, aged 71 ± 0.6 years, to determine the association between plasma 25(OH)D concentrations, measured with high-pressure liquid chromatography mass spectrometry, and the prevalence of hypertension. We used both supine office and 24-h BP measurements for classifying participants as normotensive or confirmed hypertensive; participants with inconsistent classifications were excluded.

RESULTS

in a multivariable adjusted logistic regression model, men with 25(OH)D concentrations <37.5 nmol L(-1) had a 3-fold higher prevalence of confirmed hypertension compared to those with ≥ 37.5 nmol L(-1) 25(OH)D (odds ratio = 3.3, 95% CI: 1.0-11.0).

CONCLUSIONS

our results show that low plasma 25(OH)D concentration is associated with a higher prevalence of confirmed hypertension.

Reduction of blood pressure in patients with treatment-resistant hypertension

BACKGROUND

Resistant hypertension is a common clinical problem, and patients with resistant hypertension have increased cardiovascular risk. It is a subset of the hypertensive population that is little studied and poorly characterized.

OBJECTIVE

The purpose of this review is to discuss resistant hypertension, its recognition and diagnostic workup and management, and to present current data about the disease from the latest research.

METHODS

We define resistant hypertension and differentiate it from pseudoresistance. We identify diagnostic tests that may be done on patients with resistant hypertension. Last, we discuss therapeutic approaches to resistant hypertension, focusing on pharmacological treatment, and present an algorithm that may be used by the clinician in treating a patient with resistant hypertension.

CONCLUSION

Resistant hypertension is a significant clinical problem commonly encountered by clinicians. Patients with resistant hypertension have increased cardiovascular risk. In evaluating for resistant hypertension, it is important to recognize elements that contribute to pseudoresistance to treatment. Secondary causes of hypertension are common in patients with resistant hypertension and should be included in the diagnostic workup. Pharmacological treatment for resistant hypertension entails choosing medications with complementary mechanisms of action, optimizing diuretic use, and considering the use of mineralocorticoid antagonists as an add-on agent to the antihypertensive regimen.

Relationship of Resting Baroreflex Activity to 24-Hour Blood Pressure and Mood in Healthy People

Objectives: Previous research suggests that mechanisms related to afferent and efferent components of the baroreflex are associated with blood pressure level and mood, and that mood as a component of subjective well-being may be mediated by changes in blood pressure. This study examines these mechanisms in 213 healthy women and men. Methods: Evaluation of spontaneous baroreflex activity using the sequence technique under resting conditions in the laboratory was followed by 2 days of 24-h ambulatory blood pressure recording and diary ratings of mood. Results: Patterns of components of the baroreflex loop were significant predictors of 24-h ambulatory blood pressure mean level, its circadian variability, and daily ratings of mood. Three mechanisms were found to be involved in the regulation: (1) interaction between gains of afferent and efferent cardiac components of the baroreflex, (2) gain of afferent signals related to fast cardiac responses to baroreceptor activation, and (3) gain of afferent signals related to late cardiac responses to baroreceptor inhibition. The interaction of afferent/efferent components of baroreflex loop appears to independently determine mean levels of systolic blood pressure and positive (happy) mood. The effect of the baroreceptor activation mechanism on subjective well-being (indexed by happy and alert moods) was mediated by the wake/sleep systolic blood pressure difference. Additionally, the baroreceptor inhibitory mechanism effect on subjective well-being (indexed by stressed and sleepy moods) was mediated by the wake/sleep diastolic blood pressure difference. Conclusions: Evaluation of the baroreflex components and their interaction provides important information about blood pressure and mood beyond that provided by baroreflex sensitivity and potential for the evaluation of risk for hypertension and mood disturbance in healthy people.