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Canadian Hypertension Society

Publications and source records attributed to Canadian Hypertension Society.

6 recordsLinked to original sources

The value of lowering blood pressure.

According to the Canadian Heart Health Survey, only 14% of Canadian hypertensive patients are aware of their disease and are treated appropriately. One of the reasons for this could be that physicians are confused by an excess of confusing and contradictory information regarding the choice of drugs. Two recent publications may contribute to a much-needed simplification of the problem. The Blood Pressure Lowering Treatment Trialists' Collaboration published a meta-analysis based on 29 randomized trials that comprised a total of more that 162,000 participants. The treatment regimens were based on angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, diuretics, beta-blockers and calcium channel blockers. The main finding of the meta-analysis was that treatment with any of the blood pressure-lowering regimens reduced the risk of major cardiovascular events, and the extent of these risk reductions was directly related to the degree of blood pressure lowering. The Valsartan Antihypertensive Long-term Use Evaluation (VALUE) compared valsartan with amlodipine. At the end of the study, the reductions in blood pressure from baseline were 17.3/9.9 mmHg in the amlodipine group and 15.2/8.2 mmHg in the valsartan group (P<0.0001). There was a significantly lower incidence of myocardial infarction in the amlodipine group (4.1%) than in the valsartan group (4.8%). From these two studies, it would be reasonable to conclude that the treatment of elevated blood pressure has two main goals: to achieve a normal blood pressure and to produce a happy patient. The agent or agents used to obtain these goals are relatively unimportant.

Adolescent↗

Losartan reduces the costs associated with nephropathy and end-stage renal disease from type 2 diabetes: Economic evaluation of the RENAAL study from a Canadian perspective.

BACKGROUND: The Reduction of Endpoints in NIDDM [non-insulin-dependent diabetes mellitus] with the Angiotensin II Antagonist Losartan (RENAAL) study demonstrated the renoprotective effects of losartan in patients with nephropathy from type 2 diabetes. OBJECTIVE: To perform an economic evaluation of the costs associated with end-stage renal disease (ESRD) from a Canadian public health perspective, based on the clinical outcomes reported in the RENAAL study. METHODS: ESRD-related costs were determined by estimating the mean number of days with ESRD multiplied by the daily cost of ESRD (140 dollars); mean days with ESRD were calculated by subtracting the area under the Kaplan-Meier survival curve for time to the first event of ESRD or all-cause mortality from the area under the curve for all-cause mortality. Daily ESRD cost was determined using Canadian specific data sources. ESRD-related cost savings with losartan were obtained by subtracting the ESRD-related costs of the losartan group from those of the placebo group. Net cost savings were ESRD-related cost savings with losartan minus the drug cost of losartan. RESULTS: Losartan reduced the number of ESRD days by 33.6 per patient over 3.5 years (95% CI 10.9 to 56.3) compared with placebo. Losartan reduced ESRD-related costs by 4,695 dollars per randomized patient over 3.5 years (95% CI 1,523 dollars to 7,868 dollars). After accounting for the drug cost of losartan, net cost savings with losartan were 3,675 dollars per randomized patient over 3.5 years. CONCLUSION: Losartan therapy for patients with nephropathy from type 2 diabetes reduces the clinical incidence of ESRD and can result in considerable cost savings for the Canadian public health system.

Adult↗

Continuous renal replacement therapy after heart transplantation.

BACKGROUND: Renal failure following heart transplantation carries a poor prognosis. The objectives of this study were to determine risk factors for renal failure requiring continuous renal replacement therapy (CRRT), to describe the management strategies regarding immunosuppressive therapy and to examine the short-term prognosis. METHODS: Fifty-six patients who underwent heart transplantation from 1998 to 2002 at the Montreal Heart Institute were retrospectively analyzed. RESULTS: Six of 56 patients (11%) underwent CRRT after heart transplantation. Patients who underwent CRRT had lower preoperative creatinine clearance than those who did not (median 44 versus 59 mL/min, P=0.04) and lower first two-week postoperative creatinine clearance (median 23 versus 42 mL/min, P<0.01) compared with patients without CRRT. The total duration of CRRT ranged between two and 60 days (median 15 days). Cyclosporine was withheld for 12 days versus two days (P<0.01) and the time to achieve therapeutic levels of cyclosporine averaged 18 days versus nine days (P=0.01) among CRRT versus non-CRRT patients. Patients were administered thymoglobulin or basiliximab during cyclosporine withholding. The time to discharge from hospital after transplantation was longer in patients with CRRT (median 47 days versus 17 days, P<0.01). There was no mortality at three months in the CRRT group. CONCLUSION: Creatinine clearance is an important predictor of renal failure requiring renal replacement therapy. Although renal failure remains a serious complication after transplantation, the use of CRRT and antilymphocyte agents during cyclosporine A withholding is associated with a favourable short-term prognosis following heart transplantation.

Acute Kidney Injury↗

Effects of perindopril on elastic and structural properties of large arteries in essential hypertension.

BACKGROUND: Perindopril, an angiotensin-converting enzyme (ACE) inhibitor, is a well-recognized antihypertensive drug. Its ability to protect against cardiovascular events in hypertension has also been demonstrated. It decreases the stiffness of the larger arteries; questions remain as to the mechanisms involved and whether it is blood pressure (BP) control-dependent. OBJECTIVES: To correlate the BP response to ACE inhibition therapy with changes in arterial stiffness as evaluated by pulse wave velocity (PWV), and to correlate these changes in arterial stiffness with alterations in indicators of vascular collagen metabolism serum levels of metalloproteinase (MMP)-1 and tissue inhibitor of MMP-1 (TIMP-1). METHODS: A total of 162 patients aged 18 to 70 years with stage 1 and 2 essential hypertension (diastolic BP 95 mmHg to 114 mmHg) were enrolled to receive six months (M6) of therapy with the ACE inhibitor, perindopril. Patients were either treatment-naïve or had not received any antihypertensive treatment for at least six months before the study. RESULTS: Mean BP was significantly reduced after two months (M2) of therapy (P=0.00001) and remained stable thereafter. In addition to the significant mean changes in PWV observed at M2 (P=0.00001), further reductions in PWV were noted at M6 (P=0.007). The change in PWV between baseline (M0) and M2 was significantly correlated to all BP parameters at M0 (correlation coefficient at M2 was 0.189 or greater). However, no correlation was seen regarding BP parameters at M2 and further M2 to M6 changes in PWV, suggesting a decrease of arterial stiffness independent of BP reduction. The expression of TIMP-1 and MMP-1 was highly variable and demonstrated no correlation with BP or PWV. CONCLUSIONS: Reductions in BP and PWV appear to be correlated during the first two months of perindopril therapy. After six months, PWV continues to decrease independently of any further reduction in BP, suggesting the occurrence of a pressure-independent pharmacological remodelling of the arterial wall. A long-term, double-blind, randomized trial could be required to confirm that the observed increase in vascular distensibility induced by perindopril is related to a mechanism of action other than a reduction in BP.

Adolescent↗

Lack of association between activity or fitness and loss of control of hypertension.

BACKGROUND: Many treated hypertensive patients have inadequate control of their blood pressure. Physical activity and cardiorespiratory fitness are important in the development and treatment of hypertension. Less is known about their relationships with hypertension control in the context of long-term management. OBJECTIVES: To identify whether patients with lower levels of activity or fitness are at risk for loss of control of hypertension. METHODS: Follow-up blood pressure measurements were recorded over the period of a year in a cohort of initially controlled hypertensive patients, under the care of 50 family physicians in a variety of practice settings. A questionnaire for a one-year recall of leisure time physical activity and the Step Test, an indirect measure of maximal oxygen consumption, were administered to the patients at the end of the period of blood pressure observations. The study group for the activity questionnaire consisted of 385 patients; 310 of whom undertook the fitness test. Sociodemographic, clinical and lifestyle factors were analyzed as potential confounders in the relationships of main interest in this study: between activity and fitness, respectively, with loss of control of hypertension. RESULTS: Sixteen per cent of patients (95% CI 12, 20) had an increase of 20 mmHg systolic or 10 mmHg diastolic from baseline to the average of three follow-up blood pressures, and 14% (95% CI 11, 18) had blood pressures above the entry thresholds on at least two of three follow-up visits. No associations were found between loss of control of hypertension and physical activity or cardiorespiratory fitness. CONCLUSIONS: Lower levels of physical activity and fitness are not associated with loss of hypertension control. The identification of patients at risk for loss of hypertension control, which could be useful in targeting selected groups for increased follow-up and in understanding the high prevalence of uncontrolled hypertension, requires further study.

Adult↗