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.

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.

Hypertension management in patients with renal cell cancer treated with anti-angiogenic agents

Inhibitors of the vascular endothelial growth factor (vegf-is) signalling pathway have fundamentally changed the treatment of metastatic renal cell carcinoma (mrcc). Hypertension is one of the most common side effects of vegf-is and has been reported with almost every vegf-i used for treatment to date. The exact mechanism of vegf-i-induced hypertension appears complex and multifactorial, and it remains to be fully explained. No randomized clinical trials are available to guide the management of hypertension during vegf-i treatment in mrcc patients. The guiding principles suggested here summarize the consensus of opinions on the diagnosis and management of vegf-i-induced hypertension during treatment of mrcc obtained from an expert working group composed of 4 Canadian medical oncologists and 5 Canadian hypertension specialists. The Canadian Hypertension Education Program guidelines, available literature, and expert opinion were used to develop the guiding principles.

Randomized controlled trial on the long-term efficacy of a multifaceted, interdisciplinary lifestyle intervention in reducing cardiovascular risk and improving lifestyle in patients at risk of cardiovascular disease

The objective of the study was to evaluate the efficacy of an interdisciplinary intervention known as Educoeur in reducing cardiovascular risk and improving health behaviors in people without evidence of cardiovascular disease and to compare the Educoeur program to interventions in a specialized clinic and in usual care family practice. In a parallel, randomized, controlled trial of 185 adults with at least two modifiable cardiovascular risk factors, patients were randomly assigned to either Educoeur, specialized clinic or usual care. Cardiovascular risk, biological and lifestyle measures were assessed at baseline and at 2 years. In Educoeur, measurements were also taken before and after the lifestyle group treatment program. In 12 weeks, patients in Educoeur significantly lowered their cardiovascular risk, weight, body mass index, waist circumference, systolic blood pressure, kilocalories intake and improved their VO2 Max and mental health. Changes remained significant at 2 years. Between group comparisons at 2 years demonstrated that Educoeur was significantly better in reducing cardiovascular risk than interventions in usual care. Together, these results highlight the importance of providing interdisciplinary programs that optimize cardiovascular risk reduction and promote active lifestyles in patients at risk of cardiovascular disease.

Comparative assessment of four blood pressure measurement methods in hypertensives

INTRODUCTION

Discordance between blood pressure (BP) measurement methods can occur and create ambiguity. New automated office BP monitors (AOBPs) are widely available, but their role is presently unclear. The objectives of this study are to quantify concordance among BP measurement methods and to define the diagnostic sensitivity, specificity, and predictive value of AOBPs in a population of hypertensive patients.

METHODS

The office mercury sphygmomanometer, the AOBP, an ambulatory BP monitor (ABPM), and home self-measurement with an automatic device were compared in a randomized, crossover study. BP averages and achievement of therapeutic goals were defined. Comparisons and agreement tests were performed. Diagnostic indices were calculated for the AOBP.

RESULTS

A total of 101 patients were enrolled. Average BP results were similar between measurement methods with the exception of daytime ABPM, which was significantly higher; figures are mean ± standard deviation (SD): sphygmomanometer, 129.9 ± 13.7/80.9 ± 9.3 mm Hg; AOBP, 128.4 ± 13.9/80.0 ± 9.4 mm Hg; 24-hour ABPM, 131.4 ± 11.7/78.7 ± 9.7 mm Hg; day ABPM, 135.5 ± 11.4/82.0 ± 11.9 mm Hg; home self-measurement, 131.0 ± 14.3/82.5 ± 8.2 mm Hg. Discordance in the achievement of therapeutic goals was observed in 58 patients, with only 26 cases being explained by masked hypertension or "white coat syndrome" according to all measurements. Disagreement was greater when office methods were compared with ambulatory methods.

CONCLUSIONS

This study shows that the 4 measurement strategies provide similar average BP estimates but generate many discordant results. The AOBP device can be very valuable as a replacement for the sphygmomanometer.

Hypertension in people with type 2 diabetes: Update on pharmacologic management

OBJECTIVE

To summarize the evidence for the need to improve pharmacologic management of hypertension in people with type 2 diabetes and to provide expert advice on how blood pressure (BP) treatment can be improved in primary care.

SOURCES OF INFORMATION

Studies were obtained by performing a systematic review of the literature on hypertension and diabetes, from which management recommendations were developed, reviewed, and voted on by a group of experts selected by the Canadian Hypertension Education Program and the Canadian Diabetes Association; authors' expert opinions on optimal pharmacologic management were also considered during this process.

MAIN MESSAGE

The pathogenesis of hypertension in patients with diabetes is complex, involving a range of biological and environmental factors and genetic predisposition; as a result, hypertension in people with diabetes incurs higher associated risks and adverse events. Mortality and morbidity are heightened in diabetes patients who do not achieve BP control (ie, a target value of less than 130/80 mm Hg). Large randomized controlled trials and meta-analyses of randomized controlled trials have shown that reducing BP pharmacologically is single-handedly the most effective way to reduce rates of death and disability in patients with diabetes, particularly associated cardiovascular risks. Often, combinations of 2 or more drugs (diuretics, angiotensin-converting enzyme inhibitors, β-blockers, angiotensin receptor blockers, calcium channel blockers, spironolactone, etc) are required for pharmacotherapy to be effective, particularly for patients in whom BP is difficult to control. However, the health care costs associated with extensively lowering BP are substantially less than the costs associated with treating the complications that can be prevented by lowering BP.

CONCLUSION

Detecting and managing hypertension in people with diabetes is one of the most effective measures to prevent adverse events, and pharmacotherapy is one of the most effective ways to maintain target BP levels in primary care.

The 2010 Canadian Hypertension Education Program recommendations for the management of hypertension: part 2 - therapy

OBJECTIVE

To update the evidence-based recommendations for the prevention and treatment of hypertension in adults for 2010.

OPTIONS AND OUTCOMES

For lifestyle and pharmacological interventions, randomized trials and systematic reviews of trials were preferentially reviewed. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. However, for lifestyle interventions, blood pressure lowering was accepted as a primary outcome given the general lack of long-term morbidity and mortality data in this field. Progressive renal impairment was also accepted as a clinically relevant primary outcome among patients with chronic kidney disease.

EVIDENCE

A Cochrane Collaboration librarian conducted an independent MEDLINE search from 2008 to August 2009 to update the 2009 recommendations. To identify additional studies, reference lists were reviewed and experts were contacted. All relevant articles were reviewed and appraised independently by both content and methodological experts using prespecified levels of evidence.

RECOMMENDATIONS

For lifestyle modifications to prevent and treat hypertension, restrict dietary sodium to 1500 mg (65 mmol) per day in adults 50 years of age or younger, to 1300 mg (57 mmol) per day in adults 51 to 70 years of age, and to 1200 mg (52 mmol) per day in adults older than 70 years of age; perform 30 min to 60 min of moderate aerobic exercise four to seven days per week; maintain a healthy body weight (body mass index 18.5 kg/m(2) to 24.9 kg/m(2)) and waist circumference (less than 102 cm for men and less than 88 cm for women); limit alcohol consumption to no more than 14 standard drinks per week for men or nine standard drinks per week for women; follow a diet that emphasizes fruits, vegetables and low-fat dairy products, dietary and soluble fibre, whole grains and protein from plant sources, and that is low in saturated fat and cholesterol; and consider stress management in selected individuals with hypertension. For the pharmacological management of hypertension, treatment thresholds and targets should be predicated on the patient's global atherosclerotic risk, target organ damage and comorbid conditions. Blood pressure should be decreased to less than 140/90 mmHg in all patients, and to less than 130/80 mmHg in patients with diabetes mellitus or chronic kidney disease. Most patients will require more than one agent to achieve these target blood pressures. Antihypertensive therapy should be considered in all adult patients regardless of age (caution should be exercised in elderly patients who are frail). For adults without compelling indications for other agents, considerations for initial therapy should include thiazide diuretics, angiotensin- converting enzyme (ACE) inhibitors (in patients who are not black), long-acting calcium channel blockers (CCBs), angiotensin receptor blockers (ARBs) or beta-blockers (in those younger than 60 years of age). A combination of two first-line agents may also be considered as initial treatment of hypertension if systolic blood pressure is 20 mmHg above target or if diastolic blood pressure is 10 mmHg above target. The combination of ACE inhibitors and ARBs should not be used, unless compelling indications are present to suggest consideration of dual therapy. Agents appropriate for first-line therapy for isolated systolic hypertension include thiazide diuretics, long-acting dihydropyridine CCBs or ARBs. In patients with coronary artery disease, ACE inhibitors, ARBs or betablockers are recommended as first-line therapy; in patients with cerebrovascular disease, an ACE inhibitor/diuretic combination is preferred; in patients with proteinuric nondiabetic chronic kidney disease, ACE inhibitors or ARBs (if intolerant to ACE inhibitors) are recommended; and in patients with diabetes mellitus, ACE inhibitors or ARBs (or, in patients without albuminuria, thiazides or dihydropyridine CCBs) are appropriate first-line therapies. In selected high-risk patients in whom combination therapy is being considered, an ACE inhibitor plus a long-acting dihydropyridine CCB is preferable to an ACE inhibitor plus a thiazide diuretic. All hypertensive patients with dyslipidemia should be treated using the thresholds, targets and agents outlined in the Canadian lipid treatment guidelines. Selected patients with hypertension who do not achieve thresholds for statin therapy, but who are otherwise at high risk for cardiovascular events, should nonetheless receive statin therapy. Once blood pressure is controlled, low-dose acetylsalicylic acid therapy should be considered.

VALIDATION

All recommendations were graded according to the strength of the evidence and voted on by the 63 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 80% consensus. These guidelines will continue to be updated annually.

SPONSORS

The Canadian Hypertension Education Program process is sponsored by the Canadian Hypertension Society, Blood Pressure Canada, the Public Health Agency of Canada, the College of Family Physicians of Canada, the Canadian Pharmacists Association, the Canadian Council of Cardiovascular Nurses, and the Heart and Stroke Foundation of Canada.

Increasing the detection and response to adherence problems with cardiovascular medication in primary care through computerized drug management systems: a randomized controlled trial

BACKGROUND

Adherence with antihypertensive and lipid-lowering therapy is poor, resulting in an almost 2-fold increase in hospitalization. Treatment side effects, cost, and complexity are common reasons for nonadherence, and physicians are often unaware of these potentially modifiable problems.

OBJECTIVE

To determine if a cardiovascular medication tracking and nonadherence alert system, incorporated into a computerized health record system, would increase drug profile review by primary care physicians, increase the likelihood of therapy change, and improve adherence with antihypertensive and lipid-lowering drugs.

METHODS

There were 2293 primary care patients prescribed lipid-lowering or antihypertensive drugs who were randomized to the adherence tracking and alert system or active medication list alone to determine if the intervention increased drug profile review, changes in cardiovascular drug treatment, and refill adherence in the first 6 months. An intention to treat analysis was conducted using generalized estimating equations to account for clustering within physician.

RESULTS

Overall, medication adherence was below 80% for 36.3% of patients using lipid-lowering drugs and 40.8% of patients using antihypertensives at the start of the trial. There was a significant increase in drug profile review in the intervention compared to the control group (44.5% v. 35.5%; P < 0.001), a nonsignificant increase in drug discontinuations due to side effects (2.3% v. 2.0%; P = 0.61), and a reduction in therapy increases (28.5% v. 29.1%; P = 0.86). There was no significant change in refill adherence after 6 months of follow-up.

CONCLUSION

An adherence tracking and alert system increases drug review but not therapy changes or adherence in prevalent users of cardiovascular drug treatment. Targeting incident users where adverse treatment effects are more common and combining adherence tracking and alert tools with motivational interventions provided by multidisciplinary primary care teams may improve the effectiveness of the intervention.

Effect of Ketoprofen on Blood Pressure, Endocrine and Renal Responses to Chronic Dosing with Captopril in Patients with Essential Hypertension

The effects of non-steroidal anti-inflammatory drugs (NSAIDs) on the blood pressure and renal function of essential hypertensive patients depend on the specific type of NSAID and antihypertensive drug administered. Twelve patients with essential hypertension, aged 35 to 59 years, stabilized (blood pressure less than 140/90 mmHg) with captopril, received ketoprofen (100 mg bid for 7 days) or matching placebo in a randomized double-blind cross-over fashion. A 3-week wash-out period was included between treatment periods. Blood pressure on the first and last days of the placebo treatment period (137 +/- 7 (SD)/80 +/- 8 and 139 +/- 11/81 +/- 9 mmHg) was similar to respective values during ketoprofen therapy (136 +/- 10/79 +/- 7 and 143 +/- 10/81 +/- 9 mmHg). The mean differences in systolic and diastolic blood pressures, at the end of the treatment periods, between ketoprofen and placebo were 4 (95% confidence intervals -5, +13) and 0 (-8, +8) mmHg, respectively. Ketoprofen had no effect on 24-h urinary sodium excretion (160 +/- 33 and 147 +/- 39 mmol/24 h for ketoprofen and placebo, respectively). Ketoprofen was without effect on glomerular filtration rate, renal plasma flow and filtration fraction. In conclusion, our data suggest that ketoprofen is a safe choice when short-term treatment with a NSAID is indicated in an essential hypertensive patient treated with a converting enzyme inhibitor such as captopril.

Hypertension in diabetes: a call to action

The Canadian Hypertension Education Program, Blood Pressure Canada, Canadian Hypertension Society, Heart and Stroke Foundation of Canada, Canadian Diabetes Association, College of Family Physicians of Canada, Canadian Pharmacists Association and the Canadian Council of Cardiovascular Nurses call on Canadian health care professionals to redouble efforts to help patients achieve treatment targets (blood pressure less than 130 mmHg systolic and less than 80 mmHg diastolic) in people with diabetes. Treatment of high blood pressure in people with diabetes results in large reductions in death and disability within a short period of time and needs to be a therapeutic priority. Achieving blood pressure targets requires sustained lifestyle modification, and three or more drugs including a diuretic are often required. Antihypertensive treatment in people with diabetes is one of the few medical treatments estimated to reduce overall health costs. The cost of treatment is less than the cost of complications prevented. Blood pressure needs to be assessed at all visits and home blood pressure assessment is encouraged. Management strategies need to include assessment and management of cardiovascular risks including smoking, unhealthy eating, physical inactivity, abdominal obesity, dyslipidemia as well as dysglycemia. The risks and benefits of acetylsalicylic acid in primary prevention of cardiovascular disease are uncertain in people with hypertension and diabetes. Intensive individualized lifestyle modification is recommended to prevent and treat hypertension, dyslipidemia, dysglycemia and other vascular risks in people with diabetes.

Antihydrogen production within a Penning-Ioffe trap

Slow antihydrogen (H) is produced within a Penning trap that is located within a quadrupole Ioffe trap, the latter intended to ultimately confine extremely cold, ground-state H[over ] atoms. Observed H[over ] atoms in this configuration resolve a debate about whether positrons and antiprotons can be brought together to form atoms within the divergent magnetic fields of a quadrupole Ioffe trap. The number of detected H atoms actually increases when a 400 mK Ioffe trap is turned on.

The 2007 Canadian Hypertension Education Program recommendations for the management of hypertension: part 2 - therapy

OBJECTIVE

To provide updated, evidence-based recommendations for the prevention and management of hypertension in adults.

OPTIONS AND OUTCOMES

For lifestyle and pharmacological interventions, evidence was reviewed from randomized controlled trials and systematic reviews of trials. Changes in cardiovascular morbidity and mortality were the primary outcomes of interest. However, for lifestyle interventions, blood pressure lowering was accepted as a primary outcome given the lack of long-term morbidity and mortality data in this field. For treatment of patients with kidney disease, the progression of kidney dysfunction was also accepted as a clinically relevant primary outcome.

EVIDENCE

A Cochrane collaboration librarian conducted an independent MEDLINE search from 2005 to August 2006 to update the 2006 Canadian Hypertension Education Program recommendations. In addition, reference lists were scanned and experts were contacted to identify additional published studies. All relevant articles were reviewed and appraised independently by both content and methodological experts using prespecified levels of evidence.

RECOMMENDATIONS

Dietary lifestyle modifications for prevention of hypertension, in addition to a well-balanced diet, include a dietary sodium intake of less than 100 mmol/day. In hypertensive patients, the dietary sodium intake should be limited to 65 mmol/day to 100 mmol/day. Other lifestyle modifications for both normotensive and hypertensive patients include: performing 30 min to 60 min of aerobic exercise four to seven days per week; maintaining a healthy body weight (body mass index of 18.5 kg/m2 to 24.9 kg/m2) and waist circumference (less than 102 cm in men and less than 88 cm in women); limiting alcohol consumption to no more than 14 units per week in men or nine units per week in women; following a diet reduced in saturated fat and cholesterol, and one that emphasizes fruits, vegetables and low-fat dairy products, dietary and soluble fibre, whole grains and protein from plant sources; and considering stress management in selected individuals with hypertension. For the pharmacological management of hypertension, treatment thresholds and targets should take into account each individual's global atherosclerotic risk, target organ damage and any comorbid conditions: blood pressure should be lowered to lower than 140/90 mmHg in all patients and lower than 130/80 mmHg in those with diabetes mellitus or chronic kidney disease. Most patients require more than one agent to achieve these blood pressure targets. In adults without compelling indications for other agents, initial therapy should include thiazide diuretics; other agents appropriate for first-line therapy for diastolic and/or systolic hypertension include angiotensin-converting enzyme (ACE) inhibitors (except in black patients), long-acting calcium channel blockers (CCBs), angiotensin receptor blockers (ARBs) or beta-blockers (in those younger than 60 years of age). First-line therapy for isolated systolic hypertension includes long-acting dihydropyridine CCBs or ARBs. Certain comorbid conditions provide compelling indications for first-line use of other agents: in patients with angina, recent myocardial infarction, or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with cerebrovascular disease, an ACE inhibitor plus diuretic combination is preferred; in patients with nondiabetic chronic kidney disease, ACE inhibitors are recommended; and in patients with diabetes mellitus, ACE inhibitors or ARBs (or, in patients without albuminuria, thiazides or dihydropyridine CCBs) are appropriate first-line therapies. All hypertensive patients with dyslipidemia should be treated using the thresholds, targets and agents outlined in the Canadian Cardiovascular Society position statement (recommendations for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease). Selected high-risk patients with hypertension who do not achieve thresholds for statin therapy according to the position paper should nonetheless receive statin therapy. Once blood pressure is controlled, acetylsalicylic acid therapy should be considered.

VALIDATION

All recommendations were graded according to strength of the evidence and voted on by the 57 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 95% consensus. These guidelines will continue to be updated annually.

Effects of valsartan or amlodipine alone or in combination on plasma catecholamine levels at rest and during standing in hypertensive patients

To compare the effects of valsartan and amlodipine alone or in combination on plasma norepinephrine (NE) at rest and standing for 10 minutes in patients with hypertension, 47 patients with a sitting diastolic blood pressure (BP) (DBP)>95 mm Hg and<110 mm Hg were randomized in a double-blind fashion to either valsartan or amlodipine. During the first 4 weeks of treatment, patients received a low dose of either valsartan (80 mg) or amlodipine (5 mg). The patients were force-titrated to the high dose of either drug (160 or 10 mg) for 4 weeks. After 8 weeks of therapy, those who still had a DBP>90 mm Hg (nonresponders) received combination therapy with the other drug, whereas patients with a DBP<90 mm Hg (responders) continued on monotherapy. Decreases in ambulatory BP and clinic systolic BP and DBP were significant (P<.05) after 8 weeks' therapy with no difference between the 2 groups. Amlodipine but not valsartan as monotherapy consistently increased NE levels at rest and enhanced NE levels during standing. Valsartan decreased basal NE in responders. Combination therapy with valsartan and amlodipine did not attenuate the rise in NE levels induced by amlodipine. This study indicates that therapy with amlodipine increases peripheral sympathetic basal tone and reactivity to standing in patients with hypertension, whereas valsartan does not. Combined therapy with amlodipine/valsartan did not attenuate the sympathetic activation induced by amlodipine. The hypotensive action of valsartan may be mediated in part by an inhibition of the sympathetic baroreflex in patients with hypertension.

Antiproton confinement in a Penning-Ioffe trap for antihydrogen

Antiprotons (p[over]) remain confined in a Penning trap, in sufficient numbers to form antihydrogen (H[over ) atoms via charge exchange, when the radial field of a quadrupole Ioffe trap is added. This first demonstration with p[over] suggests that quadrupole Ioffe traps can be superimposed upon p[over] and e(+) traps to attempt the capture of H[over] atoms as they form, contrary to conclusions of previous analyses.

Effects of valsartan compared to amlodipine on preventing type 2 diabetes in high-risk hypertensive patients: the VALUE trial

CONTEXT

Type 2 diabetes is emerging as a major health problem, which tends to cluster with hypertension in individuals at high risk of cardiovascular disease.

OBJECTIVE

To test for the first time the hypothesis that treatment of hypertensive patients at high cardiovascular risk with the angiotensin-receptor blocker (ARB) valsartan prevents new-onset type 2 diabetes compared with the metabolically neutral calcium-channel antagonist (CCA) amlodipine.

DESIGN

Pre-specified analysis in the VALUE trial. Follow-up averaged 4.2 years. The risk of developing new diabetes was calculated as an odds ratio (OR) with 95% confidence intervals (CI) for different definitions of diabetes.

PATIENTS

A sample of 9995 high-risk, non-diabetic hypertensive patients.

INTERVENTIONS

Valsartan or amlodipine with or without add-on medication [hydrochlorothiazide (HCTZ) and other add-ons, excluding other ARBs, angiotensin-converting enzyme (ACE) inhibitors, CCAs].

MAIN OUTCOME MEASURE

New diabetes defined as an adverse event, new blood-glucose-lowering drugs and/or fasting glucose > 7.0 mmol/l.

RESULTS

New diabetes was reported in 580 (11.5%) patients on valsartan and in 718 (14.5%) patients on amlodipine (OR 0.77, 95% CI 0.69-0.87, P < 0.0001). Using stricter criteria (without adverse event reports) new diabetes was detected in 495 (9.8%) patients on valsartan and in 586 (11.8%) on amlodipine (OR 0.82, 95% CI 0.72-0.93, P = 0.0015).

CONCLUSION

Compared with amlodipine, valsartan reduces the risk of developing diabetes mellitus in high-risk hypertensive patients.

The 2005 Canadian Hypertension Education Program recommendations for the management of hypertension: part II - therapy

OBJECTIVE

To provide updated, evidence-based recommendations for the management of hypertension in adults.

OPTIONS AND OUTCOMES

For lifestyle and pharmacological interventions, evidence from randomized controlled trials and systematic reviews of trials was preferentially reviewed. While changes in cardiovascular morbidity and mortality were the primary outcomes of interest, for lifestyle interventions, blood pressure lowering was accepted as a primary outcome given the lack of long-term morbidity/mortality data in this field, and for certain comorbid conditions, other relevant outcomes, such as development of proteinuria or worsening of kidney function, were considered.

EVIDENCE

MEDLINE searches were conducted from November 2003 to October 2004 to update the 2004 recommendations. Reference lists were scanned, experts were contacted, and the personal files of the subgroup members and authors were used to identify additional published studies. All relevant articles were reviewed and appraised independently, using prespecified levels of evidence, by content and methodology experts. As per previous years, only studies that had been published in the peer-reviewed literature were included; evidence from abstracts, conference presentations and unpublished personal communications was not included.

RECOMMENDATIONS

Lifestyle modifications to prevent and/or treat hypertension include the following: perform 30 min to 60 min of aerobic exercise on four to seven days of the week; maintain a healthy body weight (body mass index of 18.5 kg/m2 to 24.9 kg/m2) and waist circumference (less than 102 cm for men and less than 88 cm for women); limit alcohol consumption to no more than 14 units per week in men or nine units per week in women; follow a reduced fat, low cholesterol diet with an adequate intake of potassium, magnesium and calcium; restrict salt intake; and consider stress management (in selected individuals). Treatment thresholds and targets should take into account each individual's global atherosclerotic risk, target organ damage and any comorbid conditions. Blood pressure should be lowered to 140/90 mmHg or less in all patients, and to 130/80 mmHg or less in those with diabetes mellitus or chronic kidney disease. Most adults with hypertension require more than one agent to achieve target blood pressures. For adults without compelling indications for other agents, initial therapy should include thiazide diuretics. Other agents appropriate for first-line therapy for diastolic hypertension with or without systolic hypertension include beta-blockers (in those younger than 60 years), angiotensin-converting enzyme (ACE) inhibitors (except in black patients), long-acting calcium channel blockers and angiotensin receptor antagonists. Other agents appropriate for first-line therapy for isolated systolic hypertension include long-acting dihydropyridine calcium channel blockers and angiotensin receptor antagonists. Certain comorbid conditions provide compelling indications for first-line use of other agents: in patients with angina, recent myocardial infarction or heart failure, beta-blockers and ACE inhibitors are recommended as first-line therapy; in patients with diabetes mellitus, ACE inhibitors or angiotensin receptor antagonists (or thiazides in patients with diabetes mellitus without albuminuria) are appropriate first-line therapies; and in patients with nondiabetic chronic kidney disease, ACE inhibitors are recommended. All hypertensive patients should have their fasting lipids screened, and those with dyslipidemia should be treated using the thresholds, targets and agents recommended by the Canadian Hypertension Education Program Working Group on the management of dyslipidemia and the prevention of cardiovascular disease. Selected patients with hypertension, but without dyslipidemia, should also receive statin therapy and/or acetylsalicylic acid therapy.

VALIDATION

All recommendations were graded according to the strength of the evidence and voted on by the 43 members of the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. All recommendations reported here achieved at least 95% consensus. These guidelines will continue to be updated annually.

Effect of the renin–angiotensin system or calcium channel blockade on the circadian variation of heart rate variability, blood pressure and circulating catecholamines in hypertensive patients

OBJECTIVE

To determine the effects of 8 weeks of therapy with amlodipine, ramipril or telmisartan on the autonomic system over 24 h in hypertensives.

METHODS

After a placebo run-in, 57 patients were included in a prospective randomized open-label design protocol for therapy with amlodipine (5 mg for 4 weeks followed by 10 mg for 4 weeks, n = 22), or ramipril (2.5 mg for 1 week, 5.0 mg for 3 weeks and 10 mg for 4 weeks, n = 17) or telmisartan (80 mg for 8 weeks, n = 18). Autonomic functions were assessed by norepinephrine (NE) and epinephrine (E), as well as by the spectral analysis of heart rate variability (HRV).

RESULTS

The 24-h ambulatory blood pressure, plasma NE and HRV demonstrated the characteristic day-night circadian rhythm in hypertensives. Higher values for SBP and DBP and for NE levels, as well as for spectral analysis components - low frequency band (LF) and low frequency/high frequency (LF/HF) ratio - were found during the day, whereas the HF was higher during the night. In patients treated with amlodipine, the HF decreased significantly during the night, while the LF and the LF/HF ratio increased during the day in association with the rise in NE. The therapy with telmisartan did increase the HF during the night and the day, while ramipril did not influence all HRV components during the night but significantly increased the HF, and decreased the LF/HF ratio during the day. No changes were observed in plasma NE with telmisartan or ramipril, but a 50% increase in NE levels throughout the 24-h period was found in amlodipine-treated patients.

CONCLUSION

These data suggest a sympathetic activation during the day and a decrease in parasympathetic activity during the night after therapy with amlodipine, correlated with increases in plasma NE. In contrast, the therapy with telmisartan significantly increased parasympathetic activity without changes in NE during the night and day. The therapy with ramipril increased the parasympathetic activity only during the day.

A comparison of the efficacy and duration of action of telmisartan, amlodipine and ramipril in patients with confirmed ambulatory hypertension

OBJECTIVES

The aim of the study was to compare the antihypertensive effects and the duration of action of telmisartan, amlodipine and ramipril in patients with mild-to-moderate hypertension using ambulatory blood pressure (ABP) monitoring.

METHODS

After a 2-4-week single-blind, placebo run-in period, qualifying patients were randomized to receive telmisartan 80 mg (n=18); amlodipine 5 mg (n=22); titrated to 10 mg after 4 weeks; or ramipril 2.5 mg (n=17); titrated to 5 mg and 10 mg after 1 and 3 weeks, respectively, administered once daily in the morning (0700 h). Ambulatory blood pressure monitoring was performed at baseline and at the end of the 8-week treatment period. Plasma renin activity was measured over 24 h at the same time points.

RESULTS

Telmisartan and amlodipine provided significant reductions from baseline (P<0.0001) and not statistically different reductions between treatments in ABP during daytime (9.3/6.0 and 14.7/9.4 mmHg, respectively) and night-time (12.4/7.7 and 13.3/8.6 mmHg, respectively) at the end of 8 weeks' treatment. In contrast, although ramipril provided significant reductions in ambulatory systolic and diastolic BP from 2-6 h post dose (peak effect), it failed to induce significant reductions in mean daytime (4.5/1.6 mmHg) and night-time (1.8/0.1 mmHg) ambulatory BP. In addition, the greater reductions in ABP with telmisartan and amlodipine were associated with a significant rise in plasma renin activity whereas ramipril only increased renin during the first 4 h of the administration interval.

CONCLUSION

The results of the present study confirm the efficacy of both telmisartan and amlodipine in reducing ABP during each period of the 24-h interval. Because ABP reduction with ramipril was restricted to its peak effect, the present data do not support the use of this agent when administered once daily in the morning.

Effects of circadian rhythms, posture, and medication on renin-aldosterone interrelations in essential hypertensives

BACKGROUND

The aldosterone-to-renin ratio (ARR) is frequently used to screen primary hyperaldosteronism. This study, part of a clinical trial, was designed to measure the influence of circadian rhythms, antihypertensive drugs, and body posture on plasma renin, on aldosterone, and on their interrelation.

METHODS

In a prospective, randomized, open-label, parallel-designed protocol, 57 essential hypertensives (41 men, 16 women) were randomized to a morning dose of telmisartan (80 mg), ramipril (10 mg), or amlodipine (10 mg) for 8 weeks. At baseline and after 8 weeks of therapy, blood pressure (BP), plasma renin (in nanograms per liter), and plasma aldosterone (in picomoles per liter) concentrations were assessed in the supine position every 4 h for 24 h and after 10 min of standing at 9 am.

RESULTS

There was no significant association between renin, aldosterone, the ARR and demographic factors, or BP. Circadian variations of plasma renin and aldosterone were clearly present. Aldosterone variations were of greater relative amplitude with earlier-occurring peaks than renin. The ARR exhibited statistically and clinically significant circadian variations with the low and peak values averaging 55.9 +/- 32.3 and 161.84 +/- 85.4 pmol/L/ng/dL, respectively. Telmisartan, ramipril, and amlodipine significantly decreased the ARR. Telmisartan had the greatest influence on the ARR. Posture had a clinically significant but statistically nonsignificant effect on the ARR.

CONCLUSIONS

Renin, aldosterone, and their interrelation are influenced by circadian rhythms, telmisartan, ramipril, and amlodipine in patients with essential hypertension. Telmisartan has a greater impact on these parameters than ramipril and amlodipine. Measurement of the ARR in treated hypertensive patients should take these influences into account.

Does QTc interval predict the response to beta-blockers and calcium channel blockers in hypertensives?

The QT interval corrected for heart rate (QTc) is believed to reflect sympathovagal balance. It has also been established that beta-blockers and dihydropyridine-type calcium channel blockers (DHPCCB) influence the autonomic nervous system. This study tested the hypothesis that QTc interval length is a predictor of the blood pressure reduction induced by beta1-selective beta-blockers or DHPCCB. The predictive values of pretreatment heart rate and of the heart rate change with therapy were also evaluated. The authors conducted an historical reanalysis of 5 clinical trials that looked at the antihypertensive effects of beta-blockers (nebivolol) or DHPCCB (amlodipine, felodipine, isradipine, nifedipine). Correlation and quintile analyses were performed to measure the association between QTc interval, heart rate, or heart rate change and therapeutic blood pressure response. Separate analyses were undertaken for beta-blockers and DHPCCB. Seventy-three and 98 hypertensive subjects respectively were included in the beta-blocker and DHPCCB analyses. QTc interval, pretreatment heart rate, and heart rate change with therapy were not associated with therapeutic blood pressure response. In this study, QTc interval length, pretreatment heart rate, and heart rate change with therapy were not good predictors of the blood pressure response to beta1-selective beta-blockers or DHPCCB in hypertensive subjects.

Circadian variation in blood pressure: dipper or nondipper

Awareness of an increased incidence of cardiovascular events shortly after awakening has heightened interest in the chronopathology of cardiovascular diseases. Blood pressure varies according to cycles characterized by a reduction during sleep and an increase on awakening. The surge in blood pressure coincides with the circadian nature of various endocrine and hematologic parameters that also have a putative role in triggering the onset of cardiovascular events. The nighttime decrease is absent or blunted in some hypertensive patients (termed nondippers), an effect associated with increased morbidity. Drugs can influence the effect of these circadian patterns. Research efforts are focused on clarifying an underlying pathophysiologic process that could be modified by pharmacologic or other means. Long-acting angiotensin II receptor blockers have an effect on blood pressure over 24 hours due to their long half-life, but could also limit the morning surge in blood pressure through an effect on the renin-angiotensin-aldosterone and noradrenergic systems.

The 2001 Canadian recommendations for the management of hypertension: Part two--Therapy

OBJECTIVE

To provide updated, evidence-based recommendations for the therapy of hypertension in adults.

OPTIONS

For patients with hypertension, a number of antihypertensive agents may control blood pressure. Randomized trials evaluating first-line therapy with thiazides, beta-adrenergic antagonists, angiotensin-converting enzyme inhibitors, calcium channel blockers, alpha-blockers, centrally acting agents or angiotensin II receptor antagonists were reviewed.

OUTCOMES

The health outcomes that were considered were changes in blood pressure, cardiovascular morbidity, and cardiovascular and/or all-cause mortality rates. Economic outcomes were not considered due to insufficient evidence.

EVIDENCE

MEDLINE was searched for the period March 1999 to October 2001 to identify studies not included in the 2000 revision of the Canadian Recommendations for the Management of Hypertension. Reference lists were scanned, experts were polled, and the personal files of the subgroup members and authors were used to identify other published studies. All relevant articles were reviewed and appraised, using prespecified levels of evidence, by content experts and methodological experts.

VALUES

A high value was placed on the avoidance of cardiovascular morbidity and mortality.

BENEFITS, HARMS AND COSTS

Various antihypertensive agents reduce the blood pressure of patients with sustained hypertension. In certain settings, and for specific classes of drugs, blood-pressure lowering has been associated with reduced cardiovascular morbidity and/or mortality.

RECOMMENDATIONS

The present document contains detailed recommendations pertaining to treatment thresholds, target blood pressures, and choice of agents in various settings in patients with hypertension. The main changes from the 2000 Recommendations are the addition of a section on the treatment of hypertension in patients with diabetes mellitus, the amalgamation of the previous sections on treatment of hypertension in the young and old into one section, increased emphasis on the role of combination therapies over repeated trials of single agents and expansion of the section on the treatment of hypertension after stroke. Implicit in the recommendations for therapy is the principle that treatment for an individual patient should take into consideration global cardiovascular risk, the presence and/or absence of target organ damage, and comorbidities.

VALIDATION

All recommendations were graded according to strength of the evidence and voted on by the Canadian Hypertension Recommendations Working Group. Individuals with potential conflicts of interest relative to any specific recommendation were excluded from voting on that recommendation. Only those recommendations achieving high levels of consensus are reported here. These guidelines will continue to be updated annually.

Design of the Omapatrilat in Persons with Enhanced Risk of Atherosclerotic events (OPERA) trial

The Omapatrilat in Persons with Enhanced Risk of Atherosclerotic events (OPERA) trial is a large clinical trial of omapatrilat, a vasopeptidase inhibitor, in patients with stage 1 isolated systolic hypertension (ISH). OPERA is the first study to examine whether effective antihypertensive treatment can provide survival and clinical end point benefits in older persons with this common condition. This 5-year multinational, randomized, double-blind, parallel-group, placebo-controlled, forced-titration study will be conducted in approximately 12,600 subjects randomized by approximately 1100 study centers worldwide over a recruitment period of approximately 2 years. The primary objective of OPERA is to determine whether treatment with once-daily omapatrilat (target dose 40 mg) will reduce cardiovascular (CV) morbidity and mortality in older (> or = 65 years) men and women with enhanced risk for atherosclerotic events due to stage 1 ISH plus other risk factors for which currently there is no evidence-based requirement for treatment. Blood pressure inclusion criteria are systolic blood pressure (SBP) 140 to 159 mm Hg (SBP 125 to 139 mm Hg in diabetic individuals) and diastolic blood pressure (DBP) <90 mm Hg. The primary end point is defined as the composite of fatal/nonfatal stroke, fatal/nonfatal myocardial infarction, fatal/nonfatal heart failure, and other CV mortality. Secondary end points include the individual components of the primary end point, CV mortality, and major cardiovascular end points, as well as effects on cognitive function and initiation of treatment for diabetes. Additional analyses will be conducted in men and women, in diabetic patients, in different risk classes and according to prior evidence of vascular disease.

Effects of individual risk factors on the incidence of cardiovascular events in the treated hypertensive patients of the Hypertension Optimal Treatment Study. HOT Study Group

BACKGROUND

The Hypertension Optimal Treatment (HOT) Study has provided information about cardiovascular events in 18790 hypertensives, subjected to pronounced blood pressure (BP) lowering for a mean of 3.8 years. The HOT study data have subsequently been analysed after stratification of the patients according to global cardiovascular risk, and it has been found that, despite intensive blood pressure lowering in all risk strata, morbid event rates increased with increasing risk stratum.

OBJECTIVES

Previously analysed global risk strata were based on combinations of risk factors. The analyses presented here were intended to provide information on the relative role that the presence of each individual factor may have in increasing cardiovascular risk, despite good BP control.

METHODS

Risk ratios (RR) for patients with and those without a risk factor were calculated with 95% confidence intervals (CI) using a Cox proportional hazard model, and adjusted for all variables except the one under examination.

RESULTS

For all risk factors considered and for all types of event, RR were always greater than 1, indicating a greater risk in the presence, compared with that in the absence of each factor. The male gender was a statistically significant risk for cardiovascular (CV) events, CV and total mortality and particularly for myocardial infarction (MI); age > or = 65 years for CV events, stroke, CV and particularly total mortality; smoking for all events analysed, but particularly for total mortality (twice higher in smokers than in non-smokers); high serum cholesterol (> 6.8 mmol/l) for CV events, MI and CV mortality; high serum creatinine (> 155 micromol/l) for CV events, stroke, CV and total mortality; diabetes for CV events, stroke, total mortality and particularly CV mortality; and ischaemic heart disease for all events analysed. Adjusted RR were often close to or greater than 2.

CONCLUSIONS

Each of the risk factors considered was found to be an important cause of residual risk, despite good BP control. These findings emphasize the importance of addressing other correctable risk factors, e.g. smoking, hypercholesterolaemia and diabetes, as well as rigorous control of blood pressure, and of initiating antihypertensive therapy before cardiovascular and renal damage becomes manifest.

Adverse events associated with prescription drug cost-sharing among poor and elderly persons

CONTEXT

Rising costs of medications and inequities in access have sparked calls for drug policy reform in the United States and Canada. Control of drug expenditures by prescription cost-sharing for elderly persons and poor persons is a contentious issue because little is known about the health impact in these subgroups.

OBJECTIVES

To determine (1) the impact of introducing prescription drug cost-sharing on use of essential and less essential drugs among elderly persons and welfare recipients and (2) rates of emergency department (ED) visits and serious adverse events associated with reductions in drug use before and after policy implementation.

DESIGN AND SETTING

Interrupted time-series analysis of data from 32 months before and 17 months after introduction of a prescription coinsurance and deductible cost-sharing policy in Quebec in 1996. Separate 10-month prepolicy control and postpolicy cohort studies were conducted to estimate the impact of the drug reform on adverse events.

PARTICIPANTS

A random sample of 93 950 elderly persons and 55 333 adult welfare medication recipients.

MAIN OUTCOME MEASURES

Mean daily number of essential and less essential drugs used per month, ED visits, and serious adverse events (hospitalization, nursing home admission, and mortality) before and after policy introduction.

RESULTS

After cost-sharing was introduced, use of essential drugs decreased by 9.12% (95% confidence interval [CI], 8.7%-9.6%) in elderly persons and by 14.42% (95% CI, 13.3%-15.6%) in welfare recipients; use of less essential drugs decreased by 15.14% (95% CI, 14.4%-15.9%) and 22.39% (95% CI, 20.9%-23.9%), respectively. The rate (per 10 000 person-months) of serious adverse events associated with reductions in use of essential drugs increased from 5.8 in the prepolicy control cohort to 12.6 in the postpolicy cohort in elderly persons (a net increase of 6.8 [95% CI, 5.6-8.0]) and from 14.7 to 27.6 in welfare recipients (a net increase of 12.9 [95% CI, 10.2-15.5]). Emergency department visit rates related to reductions in the use of essential drugs also increased by 14.2 (95% CI, 8.5-19.9) per 10 000 person-months in elderly persons (prepolicy control cohort, 32.9; postpolicy cohort, 47.1) and by 54.2 (95% CI, 33.5-74.8) among welfare recipients (prepolicy control cohort, 69.6; postpolicy cohort, 123.8). These increases were primarily due to an increase in the proportion of recipients who reduced their use of essential drugs. Reductions in the use of less essential drugs were not associated with an increase in risk of adverse events or ED visits.

CONCLUSIONS

In our study, increased cost-sharing for prescription drugs in elderly persons and welfare recipients was followed by reductions in use of essential drugs and a higher rate of serious adverse events and ED visits associated with these reductions.

[Calcium channel blocking agents and albuminuria in diabetic and hypertensive patients. A pilot study]

Diltiazem tends to decrease proteinuria in hypertensive diabetic subjects in comparison to amlodipine that does not modify it. Since estimated glomerular pressure is identical in amlodipine treated and diltiazem treated subjects, differences in albuminuria may be explained by different renal tubular reabsorption rates.

OBJECTIVES

To compare plasma clearances (PC) of technetium labeled albumin (albumin-Tc99m) obtained by serial plasma measurements with PC obtained by urinary excretion measurements. Indirectly evaluate tubular reabsorption of albumin-Tc99m. Test the hypothesis that amlodipine decreases renal tubular reabsorption of albumin in diabetic hypertensive subjects.

METHODS

Fourteen diabetic and hypertensive subjects (DH) (average plasma creatinine: 94 mmol/L) and 6 normal subjects (average plasma creatinine: 82 mmol/L) had previously been assessed for albumin-Tc99m PC. Eleven of these 14 DH subjects were then randomized to diltiazem 300 mg/daily (6 subjects) or amlodipine 10 mg/daily (5 subjects). Their glomerular filtration, glomerular pressure and albumin-Tc99m PC were then assessed on the 3rd, 6th, and 12th month of the study.

RESULTS

Albumin-Tc99m PC obtained from serial blood draws: A decrease in PC between months 0 and 3 from 14 to 10.6 cc/min was observed in subjects treated with amlodipine but subjects on diltiazem showed PC stability (from 11.9 to 12 cm3/min). PC obtained from urinary excretion: Amlodipine and diltiazem treated subjects showed PC stability. Plasma volume in amlodipine treated subjects decreased from 156 to 127% and diltiazem treated subjects from 128 to 117%.

CONCLUSION

A decrease in PC obtained with plasma measurements and stability of PC based on urinary excretion measurements tends to identify a decrease in plasma volume. A decrease in albumin-Tc99m tubular reabsorption was not observed. The estimate of albumin PC with Tc 99m labelled albumin measurements still needs to be validated.

Role of tumor necrosis factor-alpha gene locus in obesity and obesity-associated hypertension in French Canadians

Obesity represents a serious risk factor for the development of cardiovascular diseases, including hypertension. Segregation studies suggest that obesity and obesity-associated hypertension may share some genetic determinants. The results of the present candidate gene investigation suggest that in hypertensive pedigrees of French-Canadian origin, one such determinant is the tumor necrosis factor (TNF)-alpha gene locus. Gender-pooled quantitative sib-pair analysis demonstrated a significant effect of the gene locus on 3 global and 7 regional measures of obesity (P=0.05 to 0.0004). Gender-separate quantitative sib-pair analyses showed that the impact of the locus on obesity is most significant in the abdominal region in men and in the thigh region in women. Furthermore, the haplotype relative-risk test demonstrated a significant association between the TNF-alpha gene locus and both obesity (P=0.006) and obesity-associated hypertension (P=0.02). These effects were most significant in individuals with nonmorbid obesity. In conclusion, the results of linkage and association analyses suggest that in hypertensive pedigrees of French-Canadian origin, the TNF-alpha gene locus contributes to the determination of obesity and obesity-associated hypertension. In addition, the data indicate that gender modifies the effect of the locus on the regional distribution of body fat.

1999 Canadian recommendations for the management of hypertension. Task Force for the Development of the 1999 Canadian Recommendations for the Management of Hypertension

OBJECTIVE

To provide updated, evidence-based recommendations for health care professionals on the management of hypertension in adults.

OPTIONS

For patients with hypertension, there are both lifestyle options and pharmacological therapy options that may control blood pressure. For those patients who are using pharmacological therapy, a range of antihypertensive drugs is available. The choice of a specific antihypertensive drug is dependent upon the severity of the hypertension and the presence of other cardiovascular risk factors and concurrent diseases.

OUTCOMES

The health outcomes considered were changes in blood pressure and in morbidity and mortality rates. Because of insufficient evidence, no economic outcomes were considered.

EVIDENCE

MEDLINE searches were conducted from the period of the last revision of the Canadian Recommendations for the Management of Hypertension (January 1993 to May 1998). Reference lists were scanned, experts were polled and the personal files of the authors were used to identify other studies. All relevant articles were reviewed, classified according to study design and graded according to levels of evidence.

VALUES

A high value was placed on the avoidance of cardiovascular morbidity and premature death caused by untreated hypertension.

BENEFITS

Harms and costs: The diagnosis and treatment of hypertension with pharmacological therapy will reduce the blood pressure of patients with sustained hypertension. In certain settings, and for specific drugs, blood pressure lowering has been associated with reduced cardiovascular morbidity and mortality.

RECOMMENDATIONS

This document contains detailed recommendations pertaining to all aspects of the diagnosis and pharmacological therapy of hypertensive patients. With respect to diagnosis, the recommendations endorse the greater use of non-office-based measures of blood pressure control (i.e., using home blood pressure and automatic ambulatory blood pressure monitoring equipment) and greater emphasis on the identification of other cardiovascular risk factors, both in the assessment of prognosis in hypertension and in the choice of therapy. On the treatment side, lower targets for blood pressure control are advocated for some subgroups of hypertensive patients, in particular, those with diabetes and renal disease. Implicit in the recommendations for therapy is the principle that for the vast majority of hypertensive patients treated pharmacologically, practitioners should not follow a stepped-care approach. Instead, therapy should be individualized, based on consideration of concurrent diseases, both cardiovascular and noncardiovascular.

VALIDATION

All recommendations were graded according to the strength of the evidence and the consensus of all relevant stakeholders.

SPONSORS

The Canadian Hypertension Society and the Canadian Coalition for High Blood Pressure Prevention and Control.

Clinical problem solving based on the 1999 Canadian recommendations for the management of hypertension

The 1999 Canadian Recommendations for the Management of Hypertension are notable for the trends that they represent with regard to the evolution of the management of hypertension. Diagnostically, the Recommendations endorse the greater use of non-office-based measures of blood pressure control and greater emphasis on the assessment of other atherosclerotic risk factors, both when considering prognosis in hypertension and in the choice of therapy. On the treatment side of the equation, lower targets for blood pressure control have been advocated in subgroups of hypertensive patients, particularly in those with diabetes and renal disease. In conjunction with the recently published recommendations on lifestyle management, there is a greater emphasis on lifestyle modification, both as initial and adjunctive therapy in hypertension. Implicit in the recommendations for therapy is the principle that for the vast majority of hypertensive patients treated pharmacologically, practitioners should not follow a stepped-care approach. Instead, therapy should be individualized, primarily based on consideration of concurrent diseases, both cardiovascular and noncardiovascular (Tables 1 and 2). Through the consensus process, there was a general appreciation of how far we have come in the development of evidence-based recommendations for hypertension management. However, there was also an increasing appreciation of how far we have to go in effectively translating these recommendations into better blood pressure control.

Sibling resemblance of erythrocyte ion transporters in French-Canadian sibling-pairs affected with essential hypertension

OBJECTIVES

Erythrocyte Na+/Li+ countertransport and Na+,K+ cotransport are increased in some Caucasians with essential hypertension. This study examines the relative contributions of genetic and shared environmental factors to the activity of these ion carriers in French-Canadian sibling-pairs affected with essential hypertension.

DESIGN

The activity of Na+/Li+ countertransport and Na+,K+ cotransport (rate of Na+ o-dependent Li+ efflux and bumetanide-sensitive 86Rb influx, respectively) was measured in 122 French-Canadian siblings with essential hypertension, including 36 brother/brother and 48 sister/sister pairs. Sibling/sibling correlations were estimated using the FCOR program of the S.A.G.E. package.

RESULTS

Na+/Li+ countertransport and Na+,K+ cotransport were respectively higher by 27% (P = 0.002) and 42% (P = 0.0009) in erythrocytes from men compared with women. Intra-individual correlation analysis did not reveal a significant effect of age on the activity of these ion transporters in both males and females, and an influence of plasma lipids (triglycerides, cholesterol, low-density lipoprotein, high-density lipoprotein) in females. In males, Na+,K+ cotransport was correlated with the level of serum triglycerides only (P = 0.01). Familial correlation analysis showed that sibling resemblance of Na+/Li+ countertransport and Na+,K+ cotransport was higher in men (r = 0.26 and 0.39) than in women (r = 0.01 and 0.03, respectively).

CONCLUSION

The present data indicate that different factors contribute to the regulation of monovalent ion carriers in erythrocytes from Caucasian men and women with essential hypertension. The activity of erythrocyte Na+/Li+ countertransport and Na+,K+ cotransport appears to be more strongly determined by inheritable factors in men than in women.

Lifestyle modifications to prevent and control hypertension. 5. Recommendations on dietary salt. Canadian Hypertension Society, Canadian Coalition for High Blood Pressure Prevention and Control, Laboratory Centre for Disease Control at Health Canada, Heart and Stroke Foundation of Canada

OBJECTIVE

To provide updated, evidence-based recommendations concerning the effects of dietary salt intake on the prevention and control of hypertension in adults (except pregnant women). The guidelines are intended for use in clinical practice and public education campaigns.

OPTIONS

Restriction of dietary salt intake may be an alternative to antihypertensive medications or may supplement such medications. Other options include other nonpharmacologic treatments for hypertension and no treatment.

OUTCOMES

The health outcomes considered were changes in blood pressure and in morbidity and mortality rates. Because of insufficient evidence, no economic outcomes were considered.

EVIDENCE

A MEDLINE search was conducted for the period 1966-1996 using the terms hypertension, blood pressure, vascular resistance, sodium chloride, sodium, diet, sodium or sodium chloride dietary, sodium restricted/reducing diet, clinical trials, controlled clinical trial, randomized controlled trial and random allocation. Both trials and review articles were obtained, and other relevant evidence was obtained from the reference lists of the articles identified, from the personal files of the authors and through contacts with experts. The articles were reviewed, classified according to study design and graded according to level of evidence. In addition, a systematic review of all published randomized controlled trials relating to dietary salt intake and hypertension was conducted.

VALUES

A high value was placed on the avoidance of cardiovascular morbidity and premature death caused by untreated hypertension.

BENEFITS, HARMS AND COSTS

For normotensive people, a marked change in sodium intake is required to achieve a modest reduction in blood pressure (there is a decrease of 1 mm Hg in systolic blood pressure for every 100 mmol decrease in daily sodium intake). For hypertensive patients, the effects of dietary salt restriction are most pronounced if age is greater than 44 years. A decrease of 6.3 mm Hg in systolic blood pressure and 2.2 mm Hg in diastolic blood pressure per 100 mmol decrease in daily sodium intake was observed in people of this age group. For hypertensive patients 44 years of age and younger, the decreases were 2.4 mm Hg for systolic blood pressure and negligible for diastolic blood pressure. A diet in which salt is moderately restricted appears not to be associated with health risks.

RECOMMENDATIONS

(1) Restriction of salt intake for the normotensive population is not recommended at present, because of insufficient evidence demonstrating that this would lead to a reduced incidence of hypertension. (2) To avoid excessive intake of salt, people should be counselled to choose foods low in salt (e.g., fresh fruits and vegetables), to avoid foods high in salt (e.g., pre-prepared foods), to refrain from adding salt at the table and minimize the amount of salt used in cooking, and to increase awareness of the salt content of food choices in restaurants. (3) For hypertensive patients, particularly those over the age of 44 years, it is recommended that the intake of dietary sodium be moderately restricted, to a target range of 90-130 mmol per day (which corresponds to 3-7 g of salt per day). (4) The salt consumption of hypertensive patients should be determined by interview.

VALIDATION

These recommendations were reviewed by all of the sponsoring organizations and by participants in a satellite symposium of the fourth International Conference on Preventive Cardiology. They have not been clinically tested.

SPONSORS

The Canadian Hypertension Society, the Canadian Coalition for High Blood Pressure Prevention and Control, the Laboratory Centre for Disease Control at Health Canada, and the Heart and Stroke Foundation of Canada.

Effects of antihypertensive therapies on the sympathetic nervous system

The sympathetic nervous system is a major modulator of cardiovascular function. Over the past three decades, numerous studies, using various methodologies, have reported the existence of a variety of pre- and postsynaptic sympathetic dysfunctions in essential hypertension. Most of these abnormalities facilitate sympathetic neurotransmission, resulting in a chronic increase in the sympathetic tone and reactivity in a significant proportion of hypertensive patients. Chronic sympathetic activation is also associated with major alterations in the balance among postsynaptic adrenergic receptors in cardiovascular tissues. Indeed, an attenuation of beta-adrenergic function and a potentiation of alpha1-adrenergic function has been demonstrated in cardiovascular tissues in hypertensive patients, suggesting the development of a sympathetic postsynaptic alpha1 dominance during the development and evolution of hypertension. Chronic activation of the sympathetic system is deleterious and could contribute to the development of most cardiovascular complications associated with hypertension. One of the major aims of antihypertensive therapy should thus be to attenuate pre- or postsynaptic sympathetic tone. Most antihypertensive drugs have been found to improve either pre- or postsynaptic sympathetic function in hypertensive patients. At the presynaptic level, diuretics were found to increase the liberation of noradrenalin, presumably through baroreflex sympathetic activation. In contrast, beta-blockers were shown to attenuate noradrenalin release from sympathetic nerves by blocking presynaptic facilitatory beta-receptors, thus reducing the sympathetic tone on postsynaptic receptors. Similarly, angiotensin-converting enzyme inhibitors or angiotensin II type 1 (AT1) receptor antagonists have been found to reduce sympathetic reactivity by acting on the central nervous system, but also by blocking AT1-mediated facilitatory mechanisms located on sympathetic fibres and in the adrenal medulla. Short acting dihydropyridine calcium channel blockers (CCBs) were found to enhance noradrenalin release from sympathetic nerves, but longer acting CCBs seems to have variable effects. Indeed, while the chronic slow release formulation of nifedipine gastrointestinal therapeutic system (GITS) did not raise circulating noradrenalin levels, treatment with amlodipine increased circulating noradrenalin levels, suggesting that nifedipine GITS is neutral on the sympathetic tone but that amlodipine chronically activates the sympathetic system. At the postsynaptic level, however, dihydropyridine CCBs were shown to attenuate the sympathetic tone on alpha1-adrenoceptors. In conclusion, it appears that most antihypertensive drugs interfere with pre- or postsynaptic sympathetic mechanisms and that these mechanisms could contribute to their hypotensive effects.