To provide updated, evidence-based recommendations for the therapy of hypertension in adults.
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.
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.
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.
A high value was placed on the avoidance of cardiovascular morbidity and mortality.
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.
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.
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.
We updated the evidence-based recommendations for the diagnosis, assessment, prevention, and treatment of hypertension in adults for 2011. The major guideline changes this year are: (1) a recommendation was made for using comparative risk analogies when communicating a patient's cardiovascular risk; (2) diagnostic testing issues for renal artery stenosis were discussed; (3) recommendations were added for the management of hypertension during the acute phase of stroke; (4) people with hypertension and diabetes are now considered high risk for cardiovascular events if they have elevated urinary albumin excretion, overt kidney disease, cardiovascular disease, or the presence of other cardiovascular risk factors; (5) the combination of an angiotensin-converting enzyme (ACE) inhibitor and a dihydropyridine calcium channel blocker (CCB) is preferred over the combination of an ACE inhibitor and a thiazide diuretic in persons with diabetes and hypertension; and (6) a recommendation was made to coordinate with pharmacists to improve antihypertensive medication adherence. We also discussed the recent analyses that examined the association between angiotensin II receptor blockers (ARBs) and cancer.
To determine whether statins are underprescribed in the Canadian military. The cost effectiveness of statin therapy in patients identified by the 1998 Canadian cholesterol interim guidelines was also explored.
Charts of 1424 Canadian military personnel (age 45 or older) were reviewed at 11 Canadian bases. Risk factors and cholesterol values were used to identify drug therapy candidates. Cost effectiveness ratios and health benefits in terms of years of life saved for statin therapy were estimated for the candidates using a validated cardiovascular disease life expectancy model.
Of the 1313 personnel not on lipid lowering medication, 172 were identified as drug therapy candidates. An average of 2.89 years of life saved was forecast for the identified personnel, at an average cost of less than 10,000 dollars per year of life saved.
The health benefits of statin therapy in this population are substantial and the cost effectiveness is acceptable. Statin therapy warrants greater attention as a preventive strategy for coronary artery disease.
Recent studies suggest that the benefit of lipid-lowering treatment for the primary and secondary prevention of cardiovascular disease (CVD) extends to individuals with average cholesterol levels, to women and to the elderly. However, the proportion of the general population for which treatment is cost-effective has not been evaluated.
Using data provided by the Canadian Heart Health Survey, the level of CVD risk was estimated for a random sample of the total population. A cost-effectiveness ratio for simvastatin was then calculated for each individual in the sample. Lastly, the proportion of the total population for which lipid-lowering therapy would be cost-effective for primary and secondary prevention of CVD was estimated according to total cholesterol (TC) levels.
Among the surveyed individuals who were 30 to 74 years of age, 2212 had CVD and 12,982 did not. Among those with a TC level higher than 6.2 mmol/L, the proportions of individuals for which lipid-lowering therapy was cost-effective (at a level of less than 50,000 dollars per year of life saved) were 85.6% of men and 28.7% of women for primary prevention, and 99.8% of men and 86.1% of women for secondary prevention. The estimated cost of one year of lipid-lowering treatment for all individuals in the population with a TC level higher than 6.2 mmol/L and for all individuals regardless of TC levels for whom treatment would be cost-effective was $1 billion and 3.9 billion dollars, respectively.
Lipid-lowering treatment for CVD prevention is cost-effective for a high proportion of the population, even for primary prevention. As a result, the cost of population-wide treatment for only one year is high even among individuals with a TC level higher than 6.2 mmol/L. Such costs should be considered in health care policy decisions.
Economic analyses of randomized clinical trials often focus only on the results that are observed during the study. However, for many preventive interventions, associated costs and benefits will accrue over a patient's remaining lifetime. To determine the importance of the chosen time horizon, the cost-effectiveness (C/E) of ramipril therapy was calculated and compared in the Heart Outcomes Prevention Evaluation (HOPE), the Microalbuminuria, Cardiovascular, and Renal Outcomes in HOPE (MICRO-HOPE) and the Acute Infarction Ramipril Efficacy (AIRE) study versus the entire life expectancy (L/E) of potential patients.
The Cardiovascular Disease Life Expectancy model, a validated Markov model, was calibrated to accurately forecast the results of each trial. These results were then extrapolated over the remaining L/E of hypothetical patients 55 to 75 years of age. The predicted change in L/E and associated direct health care costs for Canadians were calculated and discounted 3% annually.
In HOPE, the forecasted increased L/E averaged 0.06 years during the five-year study versus 1.3 years over the remaining years of L/E. The associated C/E of ramipril was $15,000 per year of life saved (YOLS) over the study duration and $8,500/YOLS over the remaining lifetime. For hypothetical patients, the C/E of ramipril over 4.5 years ranged from $6,700/YOLS to more than $58,300/YOLS and was lowest among elderly men. When the remaining L/E was considered, the C/E of ramipril was similar for men and women of all ages, ranging from $8,100/YOLS to $10,200/YOLS. The analyses of MICRO-HOPE and AIRE provided similar results.
The estimated efficacy and associated C/E of ramipril in HOPE, MICRO-HOPE and the AIRE study is extremely sensitive to the selected time horizon. Economic analyses beyond the duration of randomized clinical trials are required to fully evaluate the potential costs and benefits of long-term preventive therapies.
Cites: Arch Intern Med. 1998 Mar 23;158(6):655-629521231
Economic analyses of drug therapies are highly dependent on the clinical indications for treatment. The cost effectiveness of ramipril has been evaluated in numerous studies, usually based on the results of one specific clinical trial. We estimated the cost effectiveness of this drug across a range of currently accepted therapeutic indications, using a single health economic model and adjusted for quality of life, to compare the different outcomes observed in four clinical trials.
The cardiovascular life expectancy model, a validated Markov model, was calibrated to accurately forecast the results of four trials including AIRE, HOPE, Micro-HOPE, and REIN. We then extrapolated these results over the remaining life expectancy of the patients enrolled in each study and adjusted for the quality of life associated with the observed outcomes. The cost per quality-adjusted life-year (QALY) was then calculated from the perspective of the Canadian healthcare system incorporating the estimated direct healthcare costs associated with treatments and outcomes.
After discounting all costs and outcomes 3% annually, the benefits associated with ramipril ranged from 0.74 QALYs in the AIRE study to 1.22 QALYs in Micro-HOPE. Treatment was estimated to be cost-saving for some patient groups, such as those in REIN. The highest cost-effectiveness ratio was observed among individuals enrolled in HOPE ($Can20 000 per QALY in 2002).
Treatment with ramipril appears to be economically attractive across a wide range of patient groups, including those with increased coronary risk and/or diabetes mellitus (HOPE and Micro-HOPE), those with congestive heart failure (AIRE), and those with non-diabetic nephropathy (REIN).
Hypertension is associated with lower health-related quality of life (HRQOL). Similar association may be found for dyslipidemia. However, controversies exist regarding the HRQOL with dyslipidemia. We evaluated the HRQOL of cardiac patients with and without dyslipidemia and hypertension.
In a cross-sectional study, 284 cardiac patients rated their HRQOL using SF-36 Health Survey (SF-36), and three preference-based measures (Rating Scale, Time Trade-off and Standard Gamble).
Compared to those without dyslipidemia, those with dyslipidemia reported better HRQOL on all preference-based measures and most SF-36 scales particularly on the physical health scales. Adjusted mean differences and 95% confidence interval (95% CI) were equal to 4.5 (0.5, 8.5), 10.8 (2.8, 18.8), and 2.2 (0.2, 4.2) on the Physical Functioning, the Role-Physical and the Physical Component Summary scales, respectively. Exactly the opposite trends were observed among patients with hypertension. The adjusted mean differences (95% CI) were equal to -2.7 (-6.7, 1.4), -10.9 (-19.1, -2.8), and -2.9 (-4.9, -0.9) on the Physical Functioning, the Role-Physical and the Physical Component Summary scales, respectively.
Cardiac patients with hypertension reported lower physical health than those without hypertension while cardiac patients with dyslipidemia reported better physical health than those without dyslipidemia. The reason for these different trends is not known. Possible explanations are discussed.
The losses in productivity due to cardiovascular disease (CVD) are substantial but rarely considered in health economic analyses. We compared the cost-effectiveness of lipid level modification in the primary prevention of CVD with and without these indirect costs.
We used the Cardiovascular Life Expectancy Model to estimate the long-term benefits and cost-effectiveness of lipid level modification with atorvastatin calcium, including 28% and 38% reductions in total cholesterol and low-density lipoprotein cholesterol levels, respectively, and a 5.5% increase in high-density lipoprotein cholesterol level. The direct costs included all medical care costs associated with CVD. The indirect costs represented the loss of employment income and the decreased value of housekeeping services after different manifestations of CVD. All costs were expressed in 2000 Canadian dollars.
When only direct medical care costs were considered, the incremental cost-effectiveness ratios for lifelong therapy with atorvastatin calcium, 10 mg/d, were generally positive, ranging from a few thousand to nearly $20 000 per year of life saved. When the societal point of view was adopted and indirect costs were included, the total costs were generally negative, representing substantial cost savings (up to $50 000) and increased life expectancy for most groups of individuals.
Lipid therapy with statins can reduce CVD morbidity and mortality as demonstrated in a number of clinical trials. Adding the indirect CVD costs associated with productivity losses at work and home can result in forecasted cost savings to society as a whole such that lipid therapy could potentially save lives and money.
The prevalence of erectile dysfunction (ED) and associated risk factors has been described in many clinical settings, but there is little information regarding men seen by primary care physicians. We sought to identify independent factors associated with ED in a primary care setting.
We surveyed a cross-sectional sample of 3921 Canadian men, aged 40 to 88 years, seen by primary care physicians. Participants completed a full medical history, physical examination, and measurement of fasting blood glucose and lipid levels. We used the International Index of Erectile Function to define ED as a score of less than 26 on the erectile function domain.
The overall prevalence of ED was 49.4%. The presence of cardiovascular disease (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.16-1.81; P
Comment In: Arch Intern Med. 2006 Jun 26;166(12):1322-316801517
Treatments for hypertension and dyslipidemia to prevent the development of cardiovascular disease compete for the same finite number of health care dollars. Therefore, the potential benefits of treating Canadians without cardiovascular disease or diabetes who would currently be targeted by the national treatment guidelines were estimated and compared.
Canadian Heart Health Surveys data were used to estimate the number of Canadians requiring intervention. The Cardiovascular Life Expectancy Model, a previously validated Markov model, was used to calculate the increased life expectancy and decreased morbidity associated with treating risk factors to target.
Among 8.44 million adults 40 to 74 years of age without cardiovascular disease or diabetes, it was estimated that approximately 2.33 million would require treatment for dyslipidemia and 2.34 million for hypertension. The estimated Framingham 10-year coronary risk averaged 12.4% versus 9.6%, respectively. Treating dyslipidemia was associated with an average increased life expectancy of 1.67 years and 1.81 years of life free of cardiovascular disease. Treating hypertension was expected to increase life expectancy by 0.94 years and years of life free of cardiovascular disease by 1.29 years. The population benefits associated with treating dyslipidemia or hypertension would be 2.5 million and 1.4 million person years of life saved, respectively. Overall, the person years of treatment required to save one year of life was estimated to average 20 years for dyslipidemia therapy and 38 years for hypertension.
The potential benefits associated with treating hypertension or dyslipidemia to prevent cardiovascular disease are substantial. However, compared with hypertension guidelines, dyslipidemia guidelines target higher-risk patients. Accordingly, given the relative efficacy of each treatment, the forecasted benefits associated with treating dyslipidemia are substantially greater than those associated with hypertension therapy.
Cites: Arch Intern Med. 2000 Feb 28;160(4):459-6710695686
Cites: Arch Intern Med. 2006 Jan 23;166(2):213-916432091