The past, present and future of hypertension management: a potential role for AT(1)-receptor antagonists

Effect of 24-Week Treatment with Telmisartan on Myocardial Structure and Function: Relationship to Insertion/Deletion Polymorphism of the Angiotensin-Converting Enzyme Gene

The aim of the present study was to assess the effect of treatment with the angiotensin II receptor blocker telmisartan for 24 weeks on myocardial structure and function in patients with essential hypertension, and the relationship between this effect and the structural polymorphism of the angiotensin-converting enzyme (ACE) gene. Thirty-five patients with essential hypertension and left ventricular hypertrophy (LVH) without other associated morbidity were included in an open-label, non-comparative study. The patients were treated with telmisartan 40-80 mg once daily. In the final analysis, there were 29 patients who received the full course of treatment and were evaluated echocardiographically before and after treatment by the same blinded investigator, and myocardial structure and function were analysed. The myocardial mass of the left ventricle was determined in M-mode. Assessment of diastolic function of transmitral blood flow was performed using pulsed Doppler echocardiography. All patients were genotyped for insertion/deletion (I/D) polymorphism of the ACE gene. Telmisartan produced a significant reduction in left ventricular mass index from 140.4 ± 48.6 to 128.7 ± 40.6 g/m2 that was accompanied by an improvement in characteristics of diastolic function. The decrease in LVH was more significant in the ID genotype group than in the II and DD groups. Thus, prolonged treatment with telmisartan is accompanied by an improvement in myocardial structure, expressed as a reduction in left ventricular mass and function that is more marked in patients with ID genotype of the ACE gene.

Rationale and Design of the Cardiac Magnetic Resonance Imaging Substudy of the ONTARGET Trial Programme

Angiotensin-converting enzyme (ACE) inhibitors have been shown to improve cardiovascular disease outcomes in high-risk patients, but evidence for the cardioprotective effects of angiotensin II receptor blockers (ARBs) is less extensive. The ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) and the parallel Telmisartan Randomized AssessmeNt Study in aCE iNtolerant subjects with cardiovascular Disease (TRANSCEND) - which together form The ONTARGET Trial Programme – are long-term, large-scale, double-blind, multinational outcome studies with the primary objectives of determining if the combination of the ARB telmisartan 80 mg and the ACE inhibitor ramipril 10 mg is more effective than ramipril 10 mg alone, and if telmisartan is at least as effective as ramipril (in the case of ONTARGET), and if telmisartan is superior to placebo (in the case of TRANSCEND), in providing cardiovascular protection for high-risk patients. A pre-defined substudy is being conducted within The ONTARGET

Trial Programme to compare the effects of these agents, alone and in combination, on cardiac structure and function. The substudy overcomes criticisms of many previous studies, which have been performed in small numbers of patients using suboptimal methodology, by evaluating changes in left ventricular structure and function using sophisticated technology provided by magnetic resonance imaging (MRI). Some 300 randomized patients within ONTARGET, recruited from selected centres in Australia, Canada, Germany, Hong Kong, New Zealand and Thailand, will have MRI undertaken at baseline and at 2-year follow-up. As this method of assessing left ventricular dysfunction is somewhat time-consuming, expensive and complex, and in the light of current interest in the role of B-type natriuretic peptide (BNP) as a simple, inexpensive diagnostic and prognostic tool, the substudy will also examine whether changes in BNP during follow-up correlated with changes in left ventricular dysfunction.

Comparison between angiotensin-converting enzyme inhibitors and angiotensin receptor blockers on the risk of stroke recurrence and longitudinal progression of white matter lesions and silent brain infarcts on MRI (CEREBRAL study): rationale, design, and methodology

OBJECTIVES

Patients with a history of ischemic stroke are known to develop new ischemic stroke. While asymptomatic, the presence and progression of silent brain infarcts and white matter lesions on magnetic resonance imaging are associated with an increased risk of future strokes. Both angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers are recommended for the primary and secondary prevention of stroke, but there are no direct comparisons of angiotensin-converting enzyme inhibitors versus angiotensin II receptor blockers regarding their cerebroprotective effects, including their effect on asymptomatic cerebral lesions detected by magnetic resonance imaging.

METHODS

Elderly (65 years or older) patients with essential hypertension who underwent cerebral magnetic resonance imaging and were found to have any cerebral ischemic lesions, such as cerebral infarction, silent brain infarct, or white matter lesion, were enrolled in this CEREBRAL study. Patients who agreed to participate were enrolled in the randomized controlled trial portion. Patients who did not agree to participate in the randomized controlled trial were enrolled in the cohort study portion. After two-years of angiotensin-converting enzyme inhibitor or angiotensin II receptor blockers treatment, follow-up magnetic resonance imaging examination will be performed. The primary end-point is the composite of (1) occurrence of a fatal or nonfatal cerebrovascular event or (2) progression of cerebrovascular lesions as evaluated by magnetic resonance imaging, including white matter lesions or silent brain infarcts. After enrollment, cognitive function was evaluated, if possible, using the Mini-Mental State Examination.

CONCLUSIONS

Our study will clarify whether angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers are more effective for preventing primary and recurrence of ischemic stroke, including the progression of asymptomatic cerebral lesions on magnetic resonance imaging, in elderly hypertensive patients.

Burden of illness among patients at high risk versus low risk for major cardiovascular events

OBJECTIVE

This study was designed to compare the burden of illness (BOI) in patients at high risk versus low risk of developing a major cardiovascular (CV) event.

METHODS

This retrospective claims data analysis included commercial health plan members identified with a primary diagnosis on a medical claim for cardiovascular disease (CVD) from January 1, 2001 through December 31, 2002. Patients were categorized as: low risk (LR), high risk (HR), or high risk aged≥55 (HR55), based on the ONTARGET clinical trial.

RESULTS

Most patients (85%) were in the LR category (8% in HR55, 7% in HR). A significantly greater proportion of patients in the HR55 group were hospitalized and experienced a greater number of ambulatory visits compared with LR and HR patients. Controlling for covariates, HR55 patients averaged $22,502 in paid healthcare services over 2 years versus $15,645 for HR patients and $11,423 for LR patients (p<0.001). CV-related costs represented about 46% of costs for the HR55 group, versus 41% for the HR group and 31% for the LR group.

LIMITATIONS

Claims data are collected for the purpose of payment and not research and the presence of a diagnosis code is not proof of disease, due to possible coding errors or the use of a rule-out criterion. Also, patients who died in the follow-up were not included in the analyses, resulting in lower BOI estimates. Finally, the results of this study reflect treatment of CVD in managed-care settings, and may not be applicable to a different type of population.

CONCLUSION

This study demonstrates the high BOI associated with CVD, especially for patients within the high-risk group aged≥55 years. Opportunities exist for reducing costs in this population.

Effects of oral fixed-dose combinations of telmisartan plus ramipril and losartan plus ramipril in hypertension: A multicenter, prospective, randomized, double-blind, phase iii trial in adult indian patients

BACKGROUND

A new oral fixed-dose combination (FDC) of telmisartan plus ramipril is being introduced in India for the treatment of patients with stage 2 hypertension.

OBJECTIVE

The aim of this study was to compare the effectiveness and tolerability of an oral FDC of telmisartan plus ramipril with those of an oral FDC of losartan plus ramipril in adult Indian patients with stage 2 hypertension.

METHODS

This multicenter, prospective, randomized, double-blind, Phase III study was conducted at 5 centers in India. Indian patients aged 18 to 65 years with uncomplicated stage 2 essential hypertension (systolic/diastolic blood pressure [SBP/DBP], >160/>100 mm Hg) were enrolled. After a 2-week placebo run-in period, patients were randomly assigned to receive telmisartan 40 mg plus ramipril 5 mg (T + R) or losartan 50 mg plus ramipril 5 mg (L + R), PO (tablet) QD (before the morning meal) for 8 weeks. Supine blood pressure (BP) was measured at 0 (baseline) and 8 weeks of treatment. The primary end point was the mean reduction from baseline in BP. Responders were classified as patients who had a DBP <90 mm Hg at the end of 8 weeks of therapy. Tolerability was assessed using spontaneous reports of adverse events (AEs) during the follow-up visits and laboratory analyses performed at week 8.

RESULTS

A total of 289 patients were enrolled (155 men, 134 women; mean age, 50.74 years). Of these, 8 patients in the T + R group and 7 in the L + R group were lost to follow-up and considered withdrawals. At the end of week 8, the mean percentage reduction in SBP was significantly greater in the T + R group compared with that in the L + R group (24.1% vs 19.4%; P < 0.05). The mean percentage reduction in DBP was also significantly greater in the T + R group compared with that in the L + R group (17.3% vs 12.5%; P < 0.05). The response rates in the T + R and L + R groups were statistically similar (79.1% vs 68.7%). The most common AEs in the T + R and L + R groups were cough (9 [6.1%] and 11 [7.8%] patients, respectively) and headache (7 [4.7%] and 8 [5.7%] patients, respectively).

CONCLUSIONS

The results in this study in Indian patients with stage 2 essential hypertension suggest that the FDC of T + R controlled BP more effectively compared with the FDC of L + R over 8 weeks. The response rates were similar between the 2 groups. Both treatments were well tolerated.

Rationale, design, and baseline characteristics of 2 large, simple, randomized trials evaluating telmisartan, ramipril, and their combination in high-risk patients: the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial/Telmisartan Randomized Assessment Study in ACE Intolerant Subjects with Cardiovascular Disease (ONTARGET/TRANSCEND) trials

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors reduce mortality, myocardial infarction, stroke, heart failure, need for revascularization, nephropathy, and diabetes and its complications. Although angiotensin-II receptor blockers (ARBs) have been less extensively evaluated, theoretically they may have "protective" effects similar to those of ACE inhibitors, but with better tolerability. Currently, there is uncertainty about the role of ARBs when used alone or in combination with an ACE inhibitor in high-risk populations with controlled hypertension.

OBJECTIVES

Primary objectives of the ONgoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) are to determine if the combination of the ARB telmisartan and the ACE inhibitor ramipril is more effective than ramipril alone, and if telmisartan is at least as effective as ramipril. The Telmisartan Randomized AssessmeNt Study in aCE iNtolerant subjects with cardiovascular Disease (TRANSCEND) will determine if telmisartan is superior to placebo in patients who are intolerant of ACE inhibitors. The primary outcome for both trials is the composite of cardiovascular death, myocardial infarction, stroke, or hospitalization for heart failure.

METHOD

High-risk patients with coronary, peripheral, or cerebrovascular disease or diabetes with end-organ damage are being recruited and followed for 3.5 to 5.5 years in 2 parallel, randomized, double-blind clinical trials.

PROGRESS

Recruitment from 730 centers in 40 countries for ONTARGET (n = 25,620) was completed in July 2003. For TRANSCEND, 5776 patients (out of a projected total of 6000) have been recruited (by May 10, 2004). Baseline patient characteristics are comparable to the Heart Outcomes Prevention Evaluation (HOPE) trial, the basis of the design of the current study, confirming that patients are at high-risk.

Antihypertensive treatment in elderly patients aged 75 years or over: a 24-week study of the tolerability of candesartan cilexetil in relation to hydrochlorothiazide

OBJECTIVE

To assess the safety and tolerability of the AT1-receptor blocker candesartan cilexetil in relation to the diuretic hydrochlorothiazide (HCTZ) in elderly patients.

DESIGN AND SETTING

A multicentre, double-blind, randomised, parallel group study. 32 general practice centres and 3 hospital centres in Denmark and Finland participated in this study.

PATIENTS

185 patients aged > or =75 years with mean sitting diastolic blood pressure (DBP) of 95 to 114mm Hg.

INTERVENTIONS

After a placebo run-in period of 4 to 8 weeks, patients were randomised to once daily treatment with candesartan cilexetil 8mg or HCTZ 12.5mg for 24 weeks. In both treatment groups the dosage could be doubled after > or =2 weeks [according to blood pressure (BP) response] and, if necessary, subsequently decreased if the higher dosage was poorly tolerated.

MAIN OUTCOME MEASURES

Proportion of patients with at least 1 adverse event; changes in laboratory values, electrocardiogram and BP during the double-blind treatment period.

RESULTS

Once daily candesartan cilexetil 8 to 16mg was very well tolerated. The most common adverse events in both treatment groups were dizziness or vertigo and headache. Although the profile of adverse events was generally similar in the 2 treatment groups, it was notable that hypokalaemia and hyperuricaemia were not found in patients treated with candesartan cilexetil but occurred in 8.1 and 6.5%, respectively, of patients treated with HCTZ. At week 24, the adjusted mean changes in sitting DBP (24 hours postdose) from baseline were -12.0mm Hg [95% confidence interval (CI) -1 0.4 to -13.6] in patients treated with candesartan cilexetil and -11.4mm Hg (95% CI -9.3 to -13.6) in patients treated with HCTZ. The difference between treatments in favour of candesartan cilexetil was not statistically significant.

CONCLUSIONS

This study shows that antihypertensive treatment with candesartan cilexetil in elderly patients (aged > or =75 years) is well tolerated with a good safety profile and avoids the metabolic adverse effects of diuretic therapy.