2005 Canadian Hypertension Education Program Recommendations

2005 marks the sixth consecutive year that the Canadian Hypertension Education Program has updated recommendations for the management of hypertension. The goal of this effort has been two-fold:

1) to offer those in clinical practice a consensus view of how to manage the more than 5 million Canadians with hypertension (based on a critical analysis of the most recent clinical trials data in the field) and
2) to utilize these updates as an opportunity to reiterate the key components of an optimal management program in hypertension.

In some ways, the most notable aspect of the 2005 process is the appreciation that despite the advances made in the management of hypertension, there remains a substantial gap at the "front-end" of disease management, that is, in the detection and diagnosis of hypertension. Thus for 2005 we have focused on the evidence supporting expedited assessment of both the hypertension-related risk of atherosclerotic disease as well as a more "global" atherosclerotic risk assessment. In addition, the 2005 recommendations support the increasingly held belief that, in the choice of antihypertensive drugs, consideration of the effectiveness of blood pressure control supersedes consideration of "pleiotropic" effects for the 5 major antihypertensive classes.

The new key messages identified in the 2005 Recommendations are:

  • The diagnosis of hypertension should be expedited (especially in the setting of increased risk)
  • Practitioners can utilize any of the 3 validated technologies (office, ambulatory and self/home measurements) to diagnose hypertension
  • Reducing hypertension-related complications in the "general" population of patients with hypertension depends more on the extent of blood pressure lowering achieved than on the choice of any specific "first-line" drug class.

However, these "new messages" need to be incorporated into what remain as the "older but still really important" considerations for the management of the patient with hypertension, namely:

  • The management plan for patients with hypertension must be based on their global cardiovascular risk
  • Lifestyle modifications are the cornerstone of both antihypertensive and antiatherosclerotic therapy
  • Combinations of therapies (both drug and lifestyle) are generally necessary to achieve target blood pressures
  • Focus on adherence

WHAT ARE THE NEW KEY MESSAGES IN THE 2005 RECOMMENDATIONS?

KEY NEW MESSAGE 1

The diagnosis of hypertension should be expedited (Figure 1) Previous years' recommendations have outlined strategies to make the diagnosis of hypertension over up to 6 office visits and over a 6-month period. Although minimizing the risk of misdiagnosing (or mislabeling) patients as hypertensive, this approach a) is not practical, given the current realities of health care delivery in Canada and b) may expose hypertensive patients to undue risk of hypertensive complications. Thus in 2005, the Recommendations emphasize an updated algorithm for the expedited diagnosis of hypertension. For patients with hypertensive urgencies/emergencies a diagnosis of hypertension can be made at an initial visit where hypertension is comprehensively assessed.

For patients with one of the following: a) target organ damage, b) chronic kidney disease, c) diabetes mellitus, or d) BP > 180/110, a diagnosis of hypertension can be made at the second visit made to assess blood pressure. For patients with BP between 160-179/100-109 (and not already diagnosed based on the criteria above), a diagnosis can be made at the third visit. It should be noted that in this diagnostic algorithm, preliminary visits where elevated blood pressures are noted (but in the absence of any specific assessment for the causes of hypertension or for hypertensive complications) would not be considered as an "initial" hypertension-related visit.

KEY NEW MESSAGE 2

Practitioners can utilize any of the 3 validated technologies to diagnose hypertension (Figure 1). Office-based diagnosis of hypertension has remained the "gold standard" for the diagnosis of hypertension - notwithstanding the increasing concerns regarding the variability in accuracy of measurements taken in the clinic setting. However, it is now firmly established that "out-of-office" modalities for blood pressure measurement are as, or more, effective in assessing the prognostic importance of blood pressure elevations1-5. To be effective, these technologies, including automatic ambulatory blood pressure monitoring and home/self blood pressure monitoring must be used by properly educated practitioners (for automatic ambulatory blood pressure monitoring) or patients (for self/home monitoring) and assumes the use of validated, properly calibrated equipment. However, when available (and properly used) these modalities are effective and can expedite the diagnosis of hypertension - especially for those patients with Level I hypertension (and without diabetes, chronic kidney disease or target organ damage) that would otherwise require up to six visits and six months prior to a diagnosis being made.

KEY NEW MESSAGE 3

Reducing hypertension-related complications in the "general" population of patients with hypertension is more dependent on the extent of blood pressure lowering achieved than on the choice of any specified "first-line drug". Studies considered for the 2005 Recommendations confirmed our previous recommendations that any one of the five drug classes shown to reduce cardiovascular outcomes in hypertensive patients is an appropriate choice for first line monotherapy in hypertensive individuals. These drug classes include the thiazide (and thiazide-like) diuretics, beta-adrenergic antagonists (in patients younger than 60 years), ACE inhibitors (in non-black patients), longer-acting dihydropyridine calcium channel blockers, and angiotensin II receptor blockers. For 2005 the major change in the list of "validated" first line therapies is the inclusion of longer-acting non-dihydropyridine calcium channel blockers (verapamil and diltiazem).

WHAT ARE THE "OLD BUT STILL IMPORTANT" MESSAGES IN THE 2005 RECOMMENDATIONS?

1. The management plan for patients with hypertension must be based on their global cardiovascular risk. The treatment of hypertension can only be seen as part of a global cardiovascular risk management. A patient's global cardiovascular risk (and recognition of risk factors beyond hypertension) has important implications both in terms of the management of those other risk factors, but as well as in the management of their hypertension - both in terms of their target blood pressures as well as in terms of specific drug therapies. Recommendations that continue to be critical in the management of the patient with hypertension include:

  • Initial consideration of lifestyle modifications (including dietary modifications, weight loss, exercise and obesity) as strategies that are not only effective in reducing blood pressure but are critical in a global cardiovascular protection prescription.
  • Consideration of both statins and ASA as part of a cardiovascular protection strategy for patients with hypertension.
  • ACE-inhibitors for patients with established atherosclerotic disease.
  • Beta-adrenergic antagonists, ACE-inhibitors and aldosterone antagonists recommended for patients with hypertension and congestive heart failure.
  • ACE-inhibitors or angiotensin II receptor blockers for patients with diabetes, and kidney disease

2. Lifestyle modifications are the cornerstone of both antihypertensive and antiatherosclerotic therapy. Lifestyle modifications need to be emphasized (and re-emphasized). Lifestyle interventions are effective in the management of hypertension. Further, and as noted above, patients need to appreciate that lifestyle modification is the cornerstone of "global" management of many atherosclerotic risk factors. For example, exercising 30 to 60 minutes four to seven days a week (i.e., walking) will reduce the possibility of becoming hypertensive and reduce blood pressure in those already hypertensive6 (as well as having beneficial effects on serum lipids). Moderation of alcohol and keeping the waist circumference below 102 cm for men and 88 cm for women will also reduce the possibility of becoming hypertensive and developing the metabolic syndrome. It is appreciated that it is difficult to implement lifestyle change given the factors in our society that discourage physical activity and healthy eating. Notwithstanding, even brief health care professional interventions increases the probability of a patient adhering to some lifestyle changes. Multidisciplinary comprehensive approaches are most successful. However, it must be recognized that our environments largely determine lifestyles. Thus health care professional and volunteer organizations, local, provincial and federal governments, communities and the health care and food industries all need to advocate for change - in order to develop policies, create infrastructure and provide resources to support healthy lifestyles.

3. Combinations of therapies (both drug and lifestyle) are generally necessary to achieve target blood pressures Combination therapy needs to be a "given" in the management of the patient with hypertension. Most patients require more than one antihypertensive drug to achieve recommended blood pressure targets. This is also true in the context of combining pharmacological and lifestyle modification interventions and in the consideration of "global" strategies for atherosclerotic risk reduction.

4. Focus on adherence Lastly (and perhaps most importantly) optimal management prescriptions are only of utility when there is patient "buy-in". We must move our patients from awareness through to adaptation to their new lifestyle and drug therapy. Failure to achieve this adaptation is probably the most important factor leading to our ongoing challenge to improve blood pressure control and reduce the epidemic of hypertension-related morbidity and mortality.

Table 1: Target Values for Blood Pressure
Condition Target (SBP/DBP mmHg)
Diastolic ± systolic hypertension < 140/90
Isolated systolic hypertension < 140
Diabetes < 130/80
Renal disease < 130/80
Proteinuria >1g/day < 125/75

 

Table 2: Useful Antihypertensive Drug Combinations
For additive hypotensive effect in dual therapy, combine an agent from Column 1 with any in Column 2.
Column 1 Column 2
Thiazide diuretic Beta-blocker*
Long-acting calcium channel blocker* ACE Inhibitor, ARB
 
**Caution should be exercised in combining a non-DHP-CCB and a beta-blocker

 

Table 3: Recommendations To Improve Adherence To Antihypertensive Prescriptions

Adherence can be improved by a multi-pronged approach:

  • adherence to pharmacological and nonpharmacological therapy should be assessed at every visit
  • simplify medication regimens to once daily dosing and utilizing electronic medication compliance aids
  • tailor pill-taking to fit patients' daily habits
  • encourage greater patient responsibility/autonomy in monitoring their blood pressure and adjusting their prescriptions
  • coordinate with work-site health care givers to improve monitoring of adherence with pharmacological and lifestyle modification prescriptions
  • educate patients and patients' families about their disease/treatment regimens

 

References:

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  5. Clement DL, De Buyzere ML, De Bacquer DA, et al for the Office versus Ambulatory (OvA) Pressure Study Investigators. Prognostic value of ambulatory blood pressure recordings in patients with treated hypertension. N Engl J Med 2003;348:2407-15.
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  7. Staessen JA, Thijs L, Fagard R, et al for the Systolic Hypertension in Europe Trial Investigators. Predicting cardiovascular risk using conventional vs. ambulatory blood pressure in older patients with systolic hypertension. JAMA 1999;282:539-46.
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  9. Thijs L, Staessen JA, Celis H, et al. Reference values for self-recorded blood pressure: a meta-analysis of summary data. Arch Intern Med 1998;158:481-88.
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  11. Ishikawa-Takata, K., T. Ohta, H. Tanaka. How much exercise is required to reduce blood pressure in essential hypertension: a dose-response study. Am. J. Hypertens. 2003;16:629-633

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