Hypertension Canada's 2016 Canadian Hypertension Education Program Guidelines for Blood Pressure Measurement, Diagnosis, Assessment of Risk, Prevention, and Treatment of Hypertension

Hypertension Canada's Canadian Hypertension Education Program Guidelines Task Force provides annually updated, evidence-based recommendations to guide the diagnosis, assessment, prevention, and treatment of hypertension. This year, we present 4 new recommendations, as well as revisions to 2 previous recommendations. In the diagnosis and assessment of hypertension, automated office blood pressure, taken without patient-health provider interaction, is now recommended as the preferred method of measuring in-office blood pressure. Also, although a serum lipid panel remains part of the routine laboratory testing for patients with hypertension, fasting and nonfasting collections are now considered acceptable. For individuals with secondary hypertension arising from primary hyperaldosteronism, adrenal vein sampling is recommended for those who are candidates for potential adrenalectomy. With respect to the treatment of hypertension, a new recommendation that has been added is for increasing dietary potassium to reduce blood pressure in those who are not at high risk for hyperkalemia. Furthermore, in selected high-risk patients, intensive blood pressure reduction to a target systolic blood pressure ≤ 120 mm Hg should be considered to decrease the risk of cardiovascular events. Finally, in hypertensive individuals with uncomplicated, stable angina pectoris, either a β-blocker or calcium channel blocker may be considered for initial therapy. The specific evidence and rationale underlying each of these recommendations are discussed. Hypertension Canada's Canadian Hypertension Education Program Guidelines Task Force will continue to provide annual updates.

Does pragmatically structured outpatient dietary counselling reduce sodium intake in hypertensive patients? Study protocol for a randomized controlled trial

Background

Hypertension is highly prevalent among adults, and is the most important modifiable risk factor for cardiovascular events, in particular stroke. Decreasing sodium intake has the potential to prevent or delay the development of hypertension and improve blood pressure control, independently of blood pressure lowering drugs, among hypertensive patients. Despite guidelines recommending a low sodium diet, especially for hypertensive individuals, sodium intake remains higher than recommended. A recent systematic review indicated that the efficacious counselling methods described in published trials are not suitable for hypertension management by primary care providers in Canada in the present form. The primary reason for the lack of feasibility is that interventions for sodium restriction in these trials was not limited to counselling, but included provision of food, prepared meals, or intensive inpatient training sessions.

Methods/design

This is a parallel, randomized, controlled, open-label trial with blinded endpoints. Inclusion criteria are adult patients with hypertension with high dietary sodium intake (defined as ≥100 mmol/day). The control arm will receive usual care, and the intervention arm will receive usual care and an additional structured counselling session by a registered dietitian, with four follow-up telephone support sessions over four weeks. The two primary outcomes are change in sodium intake from baseline, as measured by a change in 24-hour urinary sodium measurements at four weeks and one year. Secondary outcomes include change in blood pressure (as measured by 24-hour ambulatory monitoring), change in 24-hour urinary potassium, and change in body weight at the same time points.

Discussion

Though decreasing sodium intake has been reported to be efficacious in lowering blood pressure, there exists a gap in the evidence for an effective intervention that could be easily translated into clinical practice. If successful, our intervention would be suitable for outpatient programs such as hypertension clinics or interprofessional family practices (family health teams). A negative, or partially negative (positive effect at four weeks with attrition by 12 months) trial outcome also has significant implications for healthcare delivery and use of resources.

Trial registration

The trial was registered with Clinicaltrials.gov (identifier: NCT02283697) on 2 November 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-0794-y) contains supplementary material, which is available to authorized users.

Autonomic nervous system dysregulation in pediatric hypertension

Historically, primary hypertension (HTN) has been prevalent typically in adults. Recent data however, suggests an increasing number of children diagnosed with primary HTN, mainly in the setting of obesity. One of the factors considered in the etiology of HTN is the autonomous nervous system, namely its dysregulation. In the past, the sympathetic nervous system (SNS) was regarded as a system engaged mostly in buffering major acute changes in blood pressure (BP), in response to physical and emotional stressors. Recent evidence suggests that the SNS plays a much broader role in the regulation of BP, including the development and maintenance of sustained HTN by a chronically elevated central sympathetic tone in adults and children with central/visceral obesity. Consequently, attempts have been made to reduce the SNS hyperactivity, in order to intervene early in the course of the disease and prevent HTN-related complications later in life.

Short daily versus conventional hemodialysis for hypertensive patients: a randomized cross-over study

Background

Treatment of end stage renal disease patients with short daily hemodialysis has been associated with an improvement in blood pressure. It is unclear from these studies if anti-hypertensive management had been optimized prior to starting short daily hemodialysis. Also, the potential mechanism(s) of blood pressure improvement remain to be fully elucidated.

Study Design, Setting and Participants

We undertook a randomized cross-over trial in adult hypertensive patients with ESRD treated with conventional hemodialysis to determine: 1) if short-daily hemodialysis is associated with a reduction in systolic blood pressure after a 3-month blood pressure optimization period and; 2) the potential mechanism(s) of blood pressure reduction. Blood pressure was measured using Canadian Hypertension Education Program guidelines. Extracellular fluid volume (ECFV) was assessed with bioimpedance. Serum catecholamines were used to assess the sympathetic nervous system. Interleukin-6 (IL-6) and thiobarbituric acid reactive substances (T-BARS) were used as markers of inflammation and oxidative stress respectively.

Results

After a 3-month run-in phase in which systolic blood pressure improved, there was no significant difference in pre-dialysis systolic pressure between short-daily and conventional hemodialysis (p = 0.39). However, similar blood pressures were achieved on fewer anti-hypertensive medications with short daily hemodialysis compared to conventional hemodialysis (p = 0.01). Short daily hemodialysis, compared to conventional hemodialysis, was not associated with a difference in dry weight or ECFV (p = 0.77). Sympathetic nervous system activity as assessed by plasma epinephrine (p = 1.0) and norepinephrine (p = 0.52) was also not different. Markers of inflammation (p = 0.42) and oxidative stress (p = 0.83) were also similar between the two treatment arms.

Conclusions

Patients treated with short daily, compared to conventional hemodialysis, have similar blood pressure control on fewer anti-hypertensive medications. The mechanism(s) by which short daily hemodialysis allows for decreased anti-hypertensive medication use remains unclear but effects on sodium balance and changes in peripheral vascular resistance require further study.

Trial Registration

ClinicalTrials.gov NCT00759967

The Canadian Society of Nephrology methods in developing and adapting clinical practice guidelines: a review

INTRODUCTION

The Canadian Society of Nephrology (CSN) was established to promote the highest quality of care for patients with renal diseases and to encourage research related to the kidney and its disorders. The CSN Clinical Practice Guideline (CPG) Committee develops guidelines with clear recommendations to influence physicians' practice and improve the health of patients with kidney disease in Canada.

REVIEW

In this review we describe the CSN process in prioritizing CPGs topics. We document the CSN experience using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. We then detail the CSN process in developing de novo CPGs and in adapting existing CPGs and developing accompanying commentaries. We also discuss challenges faced during this process and suggest solutions. Furthermore, we summarize the CSN effort in disseminating and implementing their guidelines. Additionally, we describe recent development and partnerships that allow evaluation of the effect of the CSN guidelines and commentaries.

CONCLUSION

The CSN follows a comprehensive process in identifying priority areas to be addressed in CPGs. In 2010, the CSN adopted GRADE, which enhanced the rigor and transparency of guideline development. This process focuses on systematically identifying best available evidence and carefully assessing its quality, balancing benefits and harms, considering patients' and societies' values and preferences, and when possible considering resource implications. Recent partnership allows wider dissemination and implementation among end users and evaluation of the effects of CPG and commentaries on the health of Canadians.

Canadian Society of Nephrology commentary on the 2012 KDIGO clinical practice guideline for the management of blood pressure in CKD

The KDIGO (Kidney Disease: Improving Global Outcomes) 2012 clinical practice guideline for the management of blood pressure (BP) in chronic kidney disease (CKD) provides the structural and evidence base for the Canadian Society of Nephrology (CSN) commentary on this guideline's relevancy and application to the Canadian health care system. While in general agreement, we provide commentary on 13 of the 21 KDIGO guideline statements. Specifically, we agreed that nonpharmacological interventions should play a significant role in the management of hypertension in patients with CKD. We also agreed that the approach to the management of hypertension in elderly patients with CKD should be individualized and take into account comorbid conditions to avoid adverse outcomes from excessive BP lowering. In contrast to KDIGO, the CSN Work Group believes there is insufficient evidence to target a lower BP for nondiabetic CKD patients based on the presence and severity of albuminuria. The CSN Work Group concurs with the Canadian Hypertension Education Program (CHEP) recommendation of a target BP for all non-dialysis-dependent CKD patients without diabetes of ≤140 mm Hg systolic and ≤90 mm Hg diastolic. Similarly, it is our position that in diabetic patients with CKD and normal urinary albumin excretion, raising the threshold for treatment from <130 mm Hg systolic BP to <140 mm Hg systolic BP could increase stroke risk and the risk of worsening kidney disease. The CSN Work Group concurs with the CHEP and the Canadian Diabetic Association recommendation for diabetic patients with CKD with or without albuminuria to continue to be treated to a BP target similar to that of the overall diabetes population, aiming for BP levels < 130/80 mm Hg. Consistent with this, the CSN Work Group endorses a BP target of <130/80 mm Hg for diabetic patients with a kidney transplant. Finally, in the absence of evidence for a lower BP target, the CSN Work Group concurs with the CHEP recommendation to target BP<140/90 mm Hg for nondiabetic patients with a kidney transplant.

Percutaneous renal sympathetic denervation: 2013 and beyond

Systemic hypertension affects almost a quarter of Canadian adults. Although most can achieve adequate blood pressure control using a combination of medical and lifestyle interventions, many have resistant hypertension and are unable to reach their target. Percutaneous renal sympathetic denervation has been developed to address a crucial mechanism in the pathophysiology of hypertension: renal sympathetic overactivity. In 2009, the first-in-man experience with renal denervation was published. Several studies followed, including the randomized Symplicity HTN-2 trial of 106 patients: 6-month mean blood pressure reduction was 32/12 mm Hg in those who underwent renal denervation, vs a change of +1/0 Hg in those who did not. However, all the evidence to date suffers from the same drawbacks: studies are small, and follow-up is short and largely incomplete. The future of renal denervation will be determined by 3 factors. First, there will be more and better evidence. Symplicity HTN-3 has randomized 530 patients to renal denervation vs a sham procedure; 24-hour ambulatory blood pressure monitoring will be assessed in all participants. Other quality trials will follow, including ones that will assess clinical end points. Second, other indications for this treatment will be investigated. Sympathetic overactivity is implicated in many other conditions, including heart failure and arrhythmia; sympathetic denervation might benefit these patients as well. Third, myriad devices, using different methods to achieve renal denervation, are being developed. The first renal denervation system was approved for clinical use in Canada in March 2012. Until more data are available, patients undergoing this procedure should be carefully screened and, ideally, enrolled in research protocols.

The 2013 Canadian Hypertension Education Program recommendations for blood pressure measurement, diagnosis, assessment of risk, prevention, and treatment of hypertension

We updated the evidence-based recommendations for the diagnosis, assessment, prevention, and treatment of hypertension in adults for 2013. This year's update includes 2 new recommendations. First, among nonhypertensive or stage 1 hypertensive individuals, the use of resistance or weight training exercise does not adversely influence blood pressure (BP) (Grade D). Thus, such patients need not avoid this type of exercise for fear of increasing BP. Second, and separately, for very elderly patients with isolated systolic hypertension (age 80 years or older), the target for systolic BP should be < 150 mm Hg (Grade C) rather than < 140 mm Hg as recommended for younger patients. We also discuss 2 additional topics at length (the pharmacological treatment of mild hypertension and the possibility of a diastolic J curve in hypertensive patients with coronary artery disease). In light of several methodological limitations, a recent systematic review of 4 trials in patients with stage 1 uncomplicated hypertension did not lead to changes in management recommendations. In addition, because of a lack of prospective randomized data assessing diastolic BP thresholds in patients with coronary artery disease and hypertension, no recommendation to set a selective diastolic cut point for such patients could be affirmed. However, both of these issues will be examined on an ongoing basis, in particular as new evidence emerges.

White coat hypertension in children: not rare and not benign?

The clinical significance of white coat hypertension (WCH) remains uncertain. We aimed to evaluate the target organ damage (TOD) in children with essential hypertension (HTN) and WCH. We retrospectively analyzed the body mass index (BMI) and ambulatory blood pressure monitoring (ABPM) in 183 untreated children aged 5 to 19 years who were referred for assessment of hypertension and had secondary hypertension ruled out. Left ventricular mass index (LVMi) and carotid intima media thickness (CIMT) were analyzed in a subset of 106 children. WCH was found in 54/183 children (29.5%) who had normal mean arterial pressure (MAP), MAP load, and MAP day/night ratio. However, the mean+/-SD LVMi (g/m(2.7)) was identical in HTN and WCH patients (38.2+/-10.9 vs. 37.0+/-11.3, P=.59); it exceeded the 95th percentile in 40% HTN and 36% WCH patients (NS). The mean CIMT was significantly higher compared with normal, but not different between HTN and WCH; it exceeded the 95th percentile in 26% HTN and 29% WCH patients. WCH was found in up to 30% of children referred for HTN. Patients with WCH have TOD comparable to that found in HTN patients despite similar BMI, significantly lower average BP and BP load and a well-preserved BP dipping pattern.

Adipocytes produce aldosterone through calcineurin-dependent signaling pathways: implications in diabetes mellitus-associated obesity and vascular dysfunction

We reported aldosterone as a novel adipocyte-derived factor that regulates vascular function. We aimed to investigate molecular mechanisms, signaling pathways, and functional significance of adipocyte-derived aldosterone and to test whether adipocyte-derived aldosterone is increased in diabetes mellitus-associated obesity, which contributes to vascular dysfunction. Studies were performed in the 3T3-L1 adipocyte cell line and mature adipocytes isolated from human and mouse (C57BL/6J) adipose tissue. Mesenteric arteries with and without perivascular fat and mature adipocytes were obtained from obese diabetic db/db and control db/+ mice. Aldosterone synthase (CYP11B2; mRNA and protein) was detected in 3T3-L1 and mature adipocytes, which secrete aldosterone basally and in response to angiotensin II (Ang II). In 3T3-L1 adipocytes, Ang II stimulation increased aldosterone secretion and CYP11B2 expression. Ang II effects were blunted by an Ang II type 1 receptor antagonist (candesartan) and inhibitors of calcineurin (cyclosporine A and FK506) and nuclear factor of activated T-cells (VIVIT). FAD286 (aldosterone synthase inhibitor) blunted adipocyte differentiation. In candesartan-treated db/db mice (1 mg/kg per day, 4 weeks) increased plasma aldosterone, CYP11B2 expression, and aldosterone secretion were reduced. Acetylcholine-induced relaxation in db/db mesenteric arteries containing perivascular fat was improved by eplerenone (mineralocorticoid receptor antagonist) without effect in db/+ mice. Adipocytes possess aldosterone synthase and produce aldosterone in an Ang II/Ang II type 1 receptor/calcineurin/nuclear factor of activated T-cells-dependent manner. Functionally adipocyte-derived aldosterone regulates adipocyte differentiation and vascular function in an autocrine and paracrine manner, respectively. These novel findings identify adipocytes as a putative link between aldosterone and vascular dysfunction in diabetes mellitus-associated obesity.

Spironolactone for difficult to control hypertension in chronic kidney disease: an analysis of safety and efficacy

Spironolactone is effective at treating difficult to control hypertension in the general population, and it is unknown if it is safe or effective for those with chronic kidney disease (CKD) and difficult-to-control hypertension. In a retrospective cohort design, 88 patients with difficult-to-control hypertension study were assessed for blood pressure (BP) response to spironolactone as well as for biochemical changes. In the CKD group (34 patients), the average systolic BP (SBP) fell from 153 ± 18 to 143 ± 20 mm Hg (P = .006) compared with a fall in SBP from 150 ± 17 to 135 ± 17 mm Hg (P < .0001) in the non-CKD group (P < .0001). In 44% of those with CKD and 59% of those without CKD, SBP decreased by >10 mm Hg (defined as responders; P = .22). Potassium rose by 0.5 ± 0.6 mmol/L in the CKD group and 0.3 ± 0.5 mmol/L in the non-CKD group (P = .12). The overall incidence of hyperkalemia was 5.7% in the CKD group and 0% in the non-CKD group (P = .07). Spironolactone is associated with a significant fall in BP among those with CKD and difficult-to-control BP. It is associated with a modest rise in serum potassium, which is more pronounced among those with glomerular filtration rate below 45 mL/minute.

Effects of ACE inhibitors on cardiac angiotensin II and aldosterone in humans: "Relevance of lipophilicity and affinity for ACE"

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors differ in their lipophilic/hydrophilic index that determines their tissue bioavailability and affinity to ACE, which may result in major differences in the degree of blockade of cardiac ACE. We evaluated the hypothesis that in patients with chronic heart failure (CHF) and activated cardiac renin-angiotensin-aldosterone system (RAAS), lipophilic ACE inhibitors with high affinity for ACE (perindopril and quinapril) will cause marked blockade of cardiac angiotensin (Ang) II and aldosterone generation, but not a hydrophilic ACE inhibitor with low affinity for ACE (lisinopril).

METHODS

Patients were randomized to receive perindopril (8 mg/day), quinapril (40 mg/day), or lisinopril (20 mg/day) for 3-4 weeks before cardiac catheterization. The coronary sinus-aortic root gradients for Ang I and II, and aldosterone were determined.

RESULTS

A total of 19 patients completed the study. Compared to a healthy control group, all three ACE inhibitors decreased circulating Ang II and aldosterone to a similar extent. There were only minor differences between the three ACE inhibitors for the Ang II gradient between the coronary sinus and aortic root. The gradient for aldosterone tended to be positive in the quinapril group and absent/negative in the lisinopril and perindopril groups. Despite the lowest pulmonary capillary wedge pressure (PCWP), gradients between the coronary sinus and aortic root for Ang II and aldosterone were actually the highest in the quinapril group.

CONCLUSIONS

These findings do not support the concept that a hydrophilic ACE inhibitor is less effective in blocking the cardiac RAAS as compared to lipophilic ACE inhibitors.

The 2010 Canadian Hypertension Education Program recommendations for the management of hypertension: part I - blood pressure measurement, diagnosis and assessment of risk

OBJECTIVE

To provide updated, evidence-based recommendations for the diagnosis and assessment of adults with hypertension.

EVIDENCE

MEDLINE searches were conducted from November 2008 to October 2009 with the aid of a medical librarian. Reference lists were scanned, experts were contacted, and the personal files of authors and subgroup members were used to identify additional studies. Content and methodological experts assessed studies using prespecified, standardized evidence-based algorithms. Recommendations were based on evidence from peer-reviewed full-text articles only.

RECOMMENDATIONS

Recommendations for blood pressure measurement, criteria for hypertension diagnosis and follow-up, assessment of global cardiovascular risk, diagnostic testing, diagnosis of renovascular and endocrine causes of hypertension, home and ambulatory monitoring, and the use of echocardiography in hypertensive individuals are outlined. Changes to the recommendations for 2010 relate to automated office blood pressure measurements. Automated office blood pressure measurements can be used in the assessment of office blood pressure. When used under proper conditions, an automated office systolic blood pressure of 135 mmHg or higher or diastolic blood pressure of 85 mmHg or higher should be considered analogous to a mean awake ambulatory systolic blood pressure of 135 mmHg or higher and diastolic blood pressure of 85 mmHg or higher, respectively.

VALIDATION

All recommendations were graded according to strength of the evidence and voted on by the 63 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. To be approved, all recommendations were required to be supported by at least 70% of task force members. These guidelines will continue to be updated annually.