Management of essential hypertension

Threshold and Target for Blood Pressure Lowering in the Elderly

PURPOSE OF REVIEW

Detection of elevated blood pressure values in elderly patients represents a common clinical condition associated with an increased cardiovascular risk. This has been shown to be the case in both systodiastolic and isolated systolic hypertension as well. However, despite the evidence of the benefits of the blood pressure lowering intervention in terms of reduction of cardiovascular morbidity and mortality, at least two issues related to antihypertensive drug treatment in aged individuals are still undefined: (1) the blood pressure threshold at which antihypertensive drug should be initiated and (2) the blood pressure goals of the therapeutic intervention.

RECENT FINDINGS

The present paper will critically review the evidence available so far on these two issues as well as the position of current guidelines and consensus statements. Emphasis will be given to the analysis of the new data of the Systolic Blood Pressure Interventional Trial (SPRINT), which have recently demonstrated the benefits, even in individuals aged more than 75 years, of a tight blood pressure reduction to systolic blood pressure to 120 mmHg or less. The potential limitations of the trial will be also critically addressed and the expectations of ongoing clinical studies investigating the issue in elderly patients properly emphasized. Although of interest, the results of the SPRINT trial encompass a number of limitations which limit their applicability to the general elderly hypertensive population. A prudent approach will be to adopt in clinical practice the less intensive and more conservative targets recommended by current guidelines.

Chronic vagal nerve stimulation prevents high-salt diet-induced endothelial dysfunction and aortic stiffening in stroke-prone spontaneously hypertensive rats

Parasympathetic activity is often reduced in hypertension and can elicit anti-inflammatory mechanisms. Thus we hypothesized that chronic vagal nerve stimulation (VNS) may alleviate cardiovascular end-organ damage in stroke-prone spontaneously hypertensive rats. Vagal nerve stimulators were implanted, a high-salt diet initiated, and the stimulators turned on (VNS, n = 10) or left off (sham, n = 14) for 4 wk. Arterial pressure increased equally in both groups. After 4 wk, endothelial function, assessed by in vivo imaging of the long posterior ciliary artery (LPCA) after stimulation (pilocarpine) and inhibition (N(ω)-nitro-l-arginine methyl ester) of endothelial nitric oxide synthase (eNOS), had significantly declined (-2.3 ± 1.2 μm, P < 0.05) in sham, but was maintained (-0.7 ± 0.8 μm, nonsignificant) in VNS. Furthermore, aortic eNOS activation (phosphorylated to total eNOS protein content ratio) was greater in VNS (0.83 ± 0.07) than in sham (0.47 ± 0.08, P < 0.05). After only 3 wk, ultrasound imaging of the aorta demonstrated decreased aortic strain (-9.7 ± 2.2%, P < 0.05) and distensibility (-2.39 ± 0.49 1,000/mmHg, P < 0.05) and increased pulse-wave velocity (+2.4 ± 0.7 m/s, P < 0.05) in sham but not in VNS (-3.8 ± 3.8%, -0.70 ± 1.4 1,000/mmHg, and +0.1 ± 0.7 m/s, all nonsignificant). Interleukin (IL)-6 serum concentrations tended to be higher in VNS than in sham (34.3 ± 8.3 vs. 16.1 ± 4.6 pg/ml, P = 0.06), and positive correlations were found between NO-dependent relaxation of the LPCA and serum levels of IL-6 (r = +0.70, P < 0.05) and IL-10 (r = +0.56, P < 0.05) and between aortic eNOS activation and IL-10 (r = +0.48, P < 0.05). In conclusion, chronic VNS prevents hypertension-induced endothelial dysfunction and aortic stiffening in an animal model of severe hypertension. We speculate that anti-inflammatory mechanisms may contribute to these effects.

The influence of proximity to city parks on blood pressure in early pregnancy

This study investigated the effect of proximity to city parks on blood pressure categories during the first trimester of pregnancy. This cross-sectional study included 3,416 female residents of the city of Kaunas, Lithuania, who were enrolled in the FP7 PHENOTYPE project study. The women were classified into four blood pressure categories: optimal, normal, high-normal blood pressure, and hypertension. Multinomial regression models were used to investigate the association between three women's groups with respect to the residence distances from city parks (300, >300-1,000, and >1,000 m) and four blood pressure categories. When using the optimal blood pressure as the reference group, the crude and adjusted odds ratios (OR) for normal blood pressure and for high-normal blood pressure proved to be statistically significantly higher after the inclusion of the selected covariates into the regression analysis. The probability of normal blood pressure increased by 9%, and that of high-normal blood pressure-by 14% for every 300 m increase in the distance to green spaces. The findings of this study suggest a beneficial impact of nearby city parks on blood pressure amongst 20- to 45-year-old women. This relationship has important implications for the prevention of hypertension and the reduction of hypertension-related morbidity.

Lisinopril Indifferently Improves Heart Rate Variability During Day and Night Periods in Spontaneously Hypertensive Rats

The aim of this work was to investigate the effect of 10 weeks of lisinopril treatment to spontaneously hypertensive rats (SHRs) on day/night variations of blood pressure, heart rate and autonomic cardio-regulation parameters. Male SHR with surgically implanted radio-telemetry implant that provided direct measurements of arterial pressure and electrocardiogram wave were used. Animals were allocated to two groups (n=5 each). The first group was treated with lisinopril (20 mg/kg by gavage) daily for 10 weeks (treated group); whereas the second was gavaged daily with tap water (untreated group). Arterial blood pressure, ECG and other telemetry parameters were recorded at the start and at the end of 10-week treatment. Collected data were analyzed using specialized software and were statistically tested. In addition to the expected lowering of blood pressure, spectral analysis of R-R intervals revealed that lisinopril treatment for 10 weeks significantly caused 2-3 fold increase in heart rate variability (HRV) during both active and inactive periods. However, R-R interval durations demonstrated variable distribution patterns during those periods. The cause of observed distribution pattern of R-R intervals during active and inactive periods may be of significance to better understand HRV changes and warrants further investigations.

Azilsartan medoxomil: a review of its use in hypertension

Azilsartan medoxomil (Edarbi®; Ipreziv™) is an orally administered angiotensin II receptor type 1 antagonist (blocker) used in the treatment of adults with essential hypertension. This article reviews data on the clinical efficacy and tolerability of azilsartan medoxomil in adults with essential hypertension and provides a summary of its pharmacological properties. Azilsartan medoxomil is a prodrug that undergoes rapid hydrolysis in the gastrointestinal tract after oral administration to the bioactive moiety azilsartan, before systemic absorption. Azilsartan medoxomil produces antihypertensive effects by selectively blocking the binding of angiotensin II to the angiotensin type 1 (AT(1)) receptor, thereby antagonizing the pressor response activity of angiotensin II. In vitro, azilsartan produced greater and more sustained AT(1) receptor binding/blockade activity than several comparator angiotensin II receptor antagonists. Azilsartan medoxomil reduces blood pressure (BP) in hypertensive adults. In addition, the drug has been shown to have pleiotropic effects (i.e. effects beyond AT(1) receptor blockade). In adults with essential hypertension, azilsartan medoxomil 20, 40 or 80 mg effectively reduced BP over a 24-hour period with once-daily administration in three major, randomized, controlled trials in which the primary endpoints were changes from baseline in 24-hour mean systolic BP (SBP) at week 6 (two trials) or week 24, assessed by ambulatory BP monitoring (ABPM). In the two 6-week trials, azilsartan medoxomil showed dose-dependent efficacy over all evaluated dosages and was more effective than placebo in lowering SBP. At the maximum approved dosage of 80 mg once daily, azilsartan medoxomil was significantly more effective than maximum dosages of olmesartan medoxomil (40 mg once daily) or valsartan (320 mg once daily), based on primary endpoint assessments. Mean reductions in clinic measurements of SBP and diastolic BP (DBP) measurements were also generally greater with azilsartan medoxomil 80 mg once daily than with the comparator drugs in these 6-week studies. Over a longer treatment period of 24 weeks, azilsartan medoxomil showed sustained BP-lowering efficacy, with the reduction in 24-hour mean SBP at week 24 significantly greater with azilsartan medoxomil 40 or 80 mg once daily than with valsartan 320 mg once daily. Mean reductions from baseline in mean clinic SBP and DBP as well as DBP by ABPM were also significantly greater with azilsartan medoxomil 40 or 80 mg once daily than with valsartan. Azilsartan medoxomil was generally well tolerated, with a tolerability profile similar to that of placebo in the 6-week trials. Across the three major trials, headache and dizziness were among the most common adverse events. Overall, rates of treatment discontinuation as a result of adverse events were low in the 6-week and 24-week trials. In conclusion, once-daily azilsartan medoxomil effectively lowers BP in adults with essential hypertension and has shown better antihypertensive efficacy than maximum therapeutic dosages of olmesartan medoxomil or valsartan in major trials of up to 24 weeks' duration. Azilsartan medoxomil is generally well tolerated and the low rates of discontinuation due to adverse events suggest that patients are likely to persist with long-term treatment. Azilsartan medoxomil is therefore a useful and attractive new option for lowering BP in patients with essential hypertension, particularly for those not able to tolerate other antihypertensive drugs. Further studies are required to evaluate the effects of azilsartan medoxomil on cardiovascular morbidity and mortality.

Optimizing blood pressure control in hypertension: the need to use ABPM

Hypertension is the most prevalent, treatable cause of cardiovascular (CV) disease. Patients with hypertension and one or more comorbidities increasingly form a significant part of the primary care practitioner's caseload. The emphasis on intensive blood pressure (BP) lowering has softened, encouraging any degree of BP lowering, since any fall in BP is beneficial for reducing CV risk. Consistency of BP control during long-term therapy (i.e. low visit-to-visit variability) and decreasing BP variability over 24-h may be as, if not more, important than degree of BP lowering per se. Fluctuations in BP between visits as well as within a 24-h period have been associated with increased CV risk. Ambulatory BP monitoring (ABPM) is a crucial element of the clinician's armamentarium not only for assessing the "true" BP load and fluctuations under real-life conditions but for identification of various abnormal BP patterns that may require attention, including white- coat hypertension, masked hypertension, non-dipping and the morning BP surge. ABPM provides accurate assessment of treatment effectiveness over 24-h and may lead to better tailoring of therapy. This article reviews the benefits of ABPM and discusses the importance of selecting long-acting antihypertensive agents for optimizing BP control.

Are there new threshold and goals in the treatment of arterial hypertension?

BACKGROUND

About half of the global burden of cardiovascular disease has been attributed to high blood pressure (BP). Worldwide, 7·6 million premature deaths (about 13·5% of the global total), 54% of strokes, and 47% of cases of ischemic heart disease were caused by high BP in 2001.

METHODS AND RESULTS

All guidelines agree that pharmacological treatment of patients with hypertension should be initiated as soon as BP rises >140/90 mmHg. Available data support the reduction of BP to values to <140/90 mmHg, but do not favor a reduction to <130/80 mmHg in patients with diabetes or a history of cardiovascular disease because of the absence of evidence obtained in prospective studies.

CONCLUSIONS

This review updates the controversies and challenges involved in the treatment of patients with established arterial hypertension, such as the progression of high-normal BP to overt hypertension, the choice of appropriate threshold and goal BP levels, the adequate number of drugs to be used since the early stages of hypertension, and which type of combination therapy offers most advantages to the patient.

Current challenges in the clinical management of hypertension

Elevated blood pressure (BP) is probably the most-important modifiable risk factor for cardiovascular disease (CVD). BP influences the development of CVD, even if levels of BP are well below the usual cut-off point that defines the presence of arterial hypertension. Adequate measurement of BP is the most-important requirement for the diagnosis and treatment of patients with suspected hypertension. The use of methodologies such as ambulatory and home BP monitoring have become powerful tools for defining the 'real' BP of patients, discarding the white-coat effect, and discovering masked hypertension. Early intervention with life-style changes and antihypertensive drugs is required to obtain the best outcome for the patient. In this sense, early use of combination antihypertensive drug therapy is recommended. The treatment of resistant hypertension-the type of elevated BP that is most difficult to control-has clearly improved over the past decade. Further studies are required to define how antihypertensive therapy should be used in the earliest stages of hypertension and for the treatment of patients with a mild-to-moderate increase in global cardiovascular risk.