Risks of untreated and treated isolated systolic hypertension in the elderly: meta-analysis of outcome trials

Pulse pressure and risk of cardiovascular events in the systolic hypertension in the elderly program

Pulse pressure has been related to higher risk of cardiovascular events in older persons. Isolated systolic hypertension is common among the elderly and is accompanied by elevated pulse pressure. Treatment of isolated systolic hypertension may further increase pulse pressure if diastolic pressure is lowered to a greater extent than systolic pressure. Little is known regarding pulse pressure as a predictor of cardiovascular outcomes in elderly persons with isolated systolic hypertension, and the influence of treatment on the pulse pressure effect. We assessed the relation between pulse pressure, measured throughout the follow-up period, and the incidence of coronary heart disease (CHD), heart failure (HF), and stroke in 4,632 participants in the Systolic Hypertension in the Elderly Program, a 5-year randomized, placebo-controlled clinical trial of treatment of isolated systolic hypertension in older adults. In the treatment group, a 10-mm Hg increase in pulse pressure was associated with a statistically significant 32% increase in risk of HF and a 24% increase in risk of stroke after controlling for systolic blood pressure and other known risk factors, as well as with a 23% increase in risk of HF and a 19% increase in risk of stroke after controlling for diastolic blood pressure and other risk factors. Pulse pressure was not significantly associated with HF or stroke in the placebo group, nor with incidence of CHD in either the placebo or treatment group. These results suggest that pulse pressure is a useful marker of risk for HF and stroke among older adults being treated for isolated systolic hypertension.

One-year study of felodipine or placebo for stage 1 isolated systolic hypertension

Asubstantial number of older hypertensive patients have stage 1 isolated systolic hypertension (systolic blood pressure between 140 and 159 mm Hg and diastolic blood pressure <90 mm Hg), but there are currently no data showing that drug treatment is effective, safe, and/or beneficial. To compare the effects of active treatment compared with placebo on blood pressure, left ventricular hypertrophy, and quality of life among older stage 1 isolated systolic hypertensive patients, a randomized, double-blind, parallel-group, multicenter clinical trial comparing felodipine (2.5, 5, or 10 mg once daily) and matching placebo was performed in 171 patients (49% male, average age 66+/-7 years, with 49% white and 30% Hispanic) with a baseline blood pressure of 149+/-7/83+/-6 mm Hg. During 52 weeks of treatment, patients randomized to active treatment achieved significantly lower blood pressures (137.0+/-11.7/80.2+/-7.6 mm Hg for extended-release felodipine versus 147.5+/-16.0/83.5+/-9.7 mm Hg for placebo, P<0.01 for each), a reduced incidence of left ventricular hypertrophy (7% for extended release felodipine versus 24% for placebo, P<0.04), and improved quality of life (change in Psychological General Well-Being index, 3.0+/-6.8 for extended-release felodipine versus -0.8+/-10.3 for placebo, P<0.01) versus baseline. There were no clinically significant differences between treatments in tolerability or adverse effects. Stage 1 isolated systolic hypertension can be effectively and safely treated pharmacologically. Treatment reduced progression to the higher stages of hypertension, reduced the incidence of left ventricular hypertrophy, and improved an overall measure of the quality of life. Larger and longer studies will be needed to document any long-term reduction in cardiovascular event rates associated with treating stage 1 systolic hypertension.

Cardiovascular protection and blood pressure reduction: a meta-analysis

BACKGROUND

Whether antihypertensive drugs offer cardiovascular protection beyond blood pressure lowering has not been established. We aimed to investigate whether pharmacological properties of antihypertensive drugs or reduction of systolic pressure accounted for cardiovascular outcome in hypertensive or high-risk patients.

METHODS

In a meta-analysis we extracted summary statistics from published reports, and calculated pooled odds ratios for experimental versus reference treatment. We correlated across-trials odd ratios for differences in systolic pressure between groups.

FINDINGS

We analysed nine randomised trials comparing treatments in 62605 hypertensive patients. Compared with old drugs (diuretics and b-blockers), calcium-channel blockers and angiotensin converting-enzyme inhibitors offered similar overall cardiovascular protection, but calcium-channel blockers provided more reduction in the risk of stroke (13.5%, 95% CI 1.3-24.2, p=0.03) and less reduction in the risk of myocardial infarction (19.2%, 3.5-37.3, p=0.01). Heterogeneity was significant between trials because of high risk of cardiovascular events on doxazosin in one trial, and high risk of stroke on captopril in another; but systolic pressure differed between groups in these two trials by 2-3 mm Hg. Similar systolic differences occurred in a trial of diltiazem versus old drugs, and in three trials of converting-enzyme inhibitor against placebo in high-risk patients. Meta-regression across 27 trials (136124 patients) showed that odds ratios could be explained by achieved differences in systolic pressure.

INTERPRETATION

Our findings emphasise that blood pressure control is important. All antihypertensive drugs have similar long-term efficacy and safety. Calcium-channel blockers might be especially effective in stroke prevention. We did not find that converting-enzyme inhibitors or a-blockers affect cardiovascular prognosis beyond their antihypertensive effects.

Pulse pressure, arterial stiffness, and drug treatment of hypertension

Epidemiological studies in the past decade have stressed the importance of pulse pressure as an independent risk factor for cardiovascular morbidity and mortality. We briefly review the epidemiological evidence and discuss in more detail the pathophysiological basis for this observation and the therapeutic consequences. We focus on the vascular determinants of increased pulse pressure. Both longitudinal and cross-sectional components of the vascular system contribute to the shape of the arterial pressure wave and, thereby, to pulse pressure. The primary longitudinal component is the architecture of the arterial tree, which determines the major reflection sites for the pressure wave. The cross-sectional architecture of the vascular system consists of a geometric (diameter) and a structural (composition vessel wall) component. Both diameter and composition of the vessel wall vary greatly when going from central to more peripheral arteries. We review the implications for the functional properties of various arterial segments. Finally, we discuss the therapeutic consequences of targeting pulse pressure rather than mean blood pressure with various drug classes. Among the antihypertensive agents, nitrates, NO donors, and drugs that interfere with the renin-angiotensin-aldosterone system may offer useful tools to lower pulse pressure, in addition to mean blood pressure. Future developments may include non-antihypertensive agents that target collagen or other components of the arterial wall matrix. However, large-scale clinical trials will have to confirm the therapeutic value of these agents in the treatment of increased pulse pressure and arterial stiffness.

[Cerebral complications of hypertension in the elderly]

PURPOSE

This review focuses on cerebral complications of hypertension, which include stroke, impairment of cognitive function, dementia, and possibly depression and anxiety. These conditions are major causes of morbidity and mortality in the elderly.

CURRENT KNOWLEDGE AND KEY POINTS

Not only elevated diastolic blood pressure, but also isolated systolic hypertension and elevated pulse pressure play an important role in the development of brain complications. Randomised placebo-controlled trials have provided evidence that reduction of hypertension decreases safely and effectively morbidity and mortality rates in the elderly. The new classes of drugs, in particular calcium-channels blockers and angiotensin-converting enzyme inhibitors, have been shown to be as effective as the originally used diuretics and beta-blockers.

FUTURE PROSPECTS AND PROJECTS

Several trials are currently in progress and should provide more information on the benefit of antihypertensive treatment in very elderly persons (Hypertension in the Very Elderly Trial, HYVET) and secondary prevention of stroke (PROGRESS). The importance of assessing new dosages of the presently used antihypertensive drugs as well as the benefit of new classes of drugs is emphasised. Further trials specifically focusing on the prevention of dementia by antihypertensive drugs are needed to confirm the results of the Syst-Eur Vascular Dementia Project. The benefit of calcium antagonists in the prevention of dementia in elderly hypertensive patients should be assessed in the Dementia Prevention in Hypertension trial (DEPHY).

Improvement in blood pressure, arterial stiffness and wave reflections with a very-low-dose perindopril/indapamide combination in hypertensive patient: a comparison with atenolol

International guidelines recommend that antihypertensive drug therapy should normalize not only diastolic (DBP) but also systolic blood pressure (SBP). Therapeutic trials based on cardiovascular mortality have recently shown that SBP reduction requires normalization of both large artery stiffness and wave reflections. The aim of the present study was to compare the antihypertensive effects of the very-low-dose combination indapamide (0.625 mg) and perindopril (2 mg) (Per/Ind) with the beta-blocking agent atenolol (50 mg) to determine whether Per/Ind decreases SBP and pulse pressure (PP) more than does atenolol and, if so, whether this decrease is predominantly due to reduction of aortic pulse wave velocity (PWV) (automatic measurements) and reduction of wave reflections (pulse wave analysis, applanation tonometry). In a double-blind randomized study, 471 patients with essential hypertension were followed for 12 months. For the same DBP reduction, Per/Ind decreased brachial SBP (-6.02 mm Hg; 95% confidence interval, -8.90 to -3.14) and PP (-5.57; 95% confidence interval, -7.70 to -3.44) significantly more than did atenolol. This difference was significantly more pronounced for the carotid artery than for the brachial artery. Whereas the 2 antihypertensive agents decreased PWV to a similar degree, only Per/Ind significantly attenuated carotid wave reflections, resulting in a selective decrease in SBP and PP. The very-low-dose combination Per/Ind normalizes SBP, PP, and arterial function to a significantly larger extent than does atenolol, a hemodynamic profile that is known to improve survival in hypertensive populations with high cardiovascular risk.

Comparative efficacy of olmesartan, losartan, valsartan, and irbesartan in the control of essential hypertension

In a multicenter, randomized, double-blind trial, the authors compared the antihypertensive efficacy of once-daily treatment with the new angiotensin II type 1 receptor blocker (ARB) olmesartan (20 mg) with recommended starting doses of losartan (50 mg), valsartan (80 mg), and irbesartan (150 mg) in 588 patients with a cuff diastolic blood pressure (DBP) of greater than or equal to 100 and less than or equal to 115 mm Hg and a mean daytime DBP of greater than or equal to 90 mm Hg and less than 120 mm Hg, as measured by ambulatory blood pressure monitoring. Cuff and ambulatory blood pressures were monitored at baseline and after 8 weeks of treatment. All groups were predominantly white and approximately 62% male, and their mean age was approximately 52 years. In all groups, mean baseline DBP and systolic blood pressure (SBP) were approximately 104 and 157 mm Hg, respectively. The reduction of sitting cuff DBP with olmesartan (11.5 mm Hg), the primary efficacy variable of this study, was significantly greater than with losartan, valsartan, and irbesartan (8.2, 7.9, and 9.9 mm Hg, respectively). Reductions of cuff SBP with the four ARBs ranged from 8.4-11.3 mm Hg and were not significantly different. The reduction in mean 24-hour DBP with olmesartan (8.5 mm Hg) was significantly greater than reductions with losartan and valsartan (6.2 and 5.6 mm Hg, respectively) and showed a trend toward significance when compared to the reduction in DBP with irbesartan (7.4 mm Hg; p=0.087). The reduction in mean 24-hour SBP with olmesartan (12.5 mm Hg) was significantly greater than the reductions with losartan and valsartan (9.0 and 8.1 mm Hg, respectively) and equivalent to the reduction with irbesartan (11.3 mm Hg). All drugs were well tolerated. The authors conclude that olmesartan, at its starting dose, is more effective than the starting doses of the other ARBs tested in reducing cuff DBP in patients with essential hypertension.

Blood pressure control and benefits of antihypertensive therapy: does it make a difference which agents we use?

This article debates the important question of whether blood pressure lowering alone is responsible for the benefits accrued from antihypertensive therapy as demonstrated in many multicenter randomized clinical trials with different antihypertensive agents or whether there is evidence that some agents have special properties that result in benefits that go beyond those resulting from lowering blood pressure. Over the past >/=30 years, it has been demonstrated beyond any doubt that lowering blood pressure in severe forms of hypertension, and more recently in systolic and even mild hypertension, will result in reduced incidence of stroke and slower progression of heart and renal failure. These effects have been easier to demonstrate in sicker patients, because enough end points may be counted in the 3 to 5 years that these clinical trials last. However, risk attributable to high blood pressure comes, to a greater degree, from the much larger group of hypertensive individuals who have less severe forms of hypertension. Blood pressure lowering offers less protection from coronary heart disease, which is highly prevalent in hypertensive patients, than from stroke. With the introduction of agents such as renin-angiotensin system inhibitors or calcium channel blockers, it has been demonstrated that hypertensive vascular remodeling and endothelial dysfunction may be corrected. It has therefore been suggested that benefits beyond blood pressure lowering may be achieved with the use of specific drugs to lower blood pressure. Although some evidence suggests that this may be the case, it is difficult to extrapolate from mechanistic studies to prevention of hard end points in outcome trials and vice versa. The question remains for the time being largely unanswered.

Hypertension in the Very Elderly Trial (HYVET): protocol for the main trial

A number of trials and meta-analyses have demonstrated clear benefits of blood pressure (BP) reduction in patients aged <80 years with regard to the reduction in stroke and cardiovascular events. However, a variety of studies have suggested that the positive relationship between BP and cardiovascular mortality is weakened or indeed reversed in the very elderly. Most intervention trials to date have either excluded or not recruited sufficient patients aged > or =80 years to determine whether there is a significant benefit from treatment in this age group. A meta-analysis of intervention trials that recruited patients aged > or =80 years has suggested a benefit in terms of stroke reduction but has also raised the possibility of an increase in total mortality. The benefit to risk ratio therefore needs to be clearly established before recommendations can be made for treating very elderly patients with hypertension. The Hypertension in the Very Elderly Trial (HYVET) pilot recruited 1283 patients aged > or =80 years and showed the feasibility of performing such a trial in this age group. It was a Prospective Randomised Open Blinded End-Points (PROBE) design but the main trial has additional pharmaceutical sponsorship to run a double-blind trial. Therefore, the main trial is a randomised, double-blind, placebo-controlled trial designed to assess the benefits of treating very elderly patients with hypertension. It compares placebo with a low dose diuretic (indapamide sustained release 1.5mg daily) and additional ACE inhibitor (perindopril) therapy if required. As in the pilot trial, the primary end-point is stroke events (fatal and non-fatal) and the trial is designed to determine whether or not a 35% difference occurs between placebo and active treatment. The main objective will be achieved with 90% power at the 1% level of significance. Secondary outcome measures will include total mortality, cardiovascular mortality, cardiac mortality, stroke mortality and skeletal fracture. 2100 patients aged > or =80 years are to be recruited and followed up for an average of 5 years. Entry BP criteria after 2 months of a single-blind placebo run-in period are a sustained sitting systolic BP (SBP) of 160 to 199mm Hg and a diastolic BP of 90 to 109mm Hg. The standing SBP must be >140mm Hg. The trial will be carried out in accordance with the principles of Good Clinical Practice. We describe in detail the protocol for the main trial and discuss the reasons for the changes from the pilot, the use of the drug regimen, and the BP criteria to be used in the trial.

The benefit of treating isolated systolic hypertension

Isolated systolic hypertension affects over 15% of all people older than 60 years of age. In the elderly, systolic hypertension is a major modifiable cardiovascular risk factor. Systolic blood pressure is associated with higher risk of an adverse outcome. Diastolic blood pressure is inversely correlated with total mortality, independent of systolic blood pressure, highlighting the role of pulse pressure as risk factor. Three placebo-controlled outcome trials on antihypertensive drug treatment in older patients with isolated systolic hypertension have been published: the Systolic Hypertension in the Elderly Program (SHEP), the Systolic Hypertension in Europe (Syst-Eur) Trial, and the Systolic Hypertension in China (Syst-China) Trial. These three trials showed the benefit of antihypertensive drug treatment. A meta-analysis was done by pooling the patients from these three trials with a subset of patients with isolated systolic hypertension from five other trials in the elderly. The pooled results of 15,693 older patients with isolated systolic hypertension prove that antihypertensive drug treatment is justified if systolic blood pressure on repeated clinic measurements is 160 mm Hg or higher.

Hypertension trials: 1990 to 2000

A large number of randomized controlled trials have been published over the past decade. The earlier ones established the benefits of low-dose diuretic-based therapy. The more recent ones have documented the equal overall effectiveness of therapy based on an angiotensin-converting enzyme inhibitor or a calcium antagonist. The comparative data do not clearly define a single superior drug for most hypertensive patients, so the initial choice should be individualized, on the basis of the concomitant conditions. For the rapidly increasing population of diabetic hypertensive patients, similar conclusions are obvious, with the caveat that an angiotensin-converting enzyme inhibitor should usually be the initial choice, with diuretics and calcium antagonists usually needed to accomplish adequate control. There are no concerns about the use of calcium antagonists in diabetic patients.

Non-invasive assessment of local arterial pulse pressure: comparison of applanation tonometry and echo-tracking

OBJECTIVES

Pulse pressure is not constant throughout the arterial tree. Use of pulse pressure at one arterial site as surrogate for pulse pressure at another arterial site may be erroneous. The present study compares three non-invasive techniques to measure local pulse pressure: (i) internally calibrated readings from applanation tonometry, (ii) alternative calibration of pressure waves obtained with applanation tonometry and (iii) alternative calibration of arterial distension waves obtained with echo-tracking. Alternative calibration assumes mean and diastolic blood pressure constant throughout the large artery tree.

DESIGN AND METHODS

Study 1 used invasive measurements in the ascending aorta as a reference method and internally calibrated tonometer readings and alternatively calibrated pressure waves at the common carotid artery as test methods. Study 2 used alternatively calibrated pressure waves as a reference method and alternatively calibrated distension waves and internally calibrated applanation tonometer readings as test methods.

RESULTS

In study 1, pulse pressure from internally calibrated tonometer readings was 10.2+/-14.3 mmHg lower and pulse pressure from alternatively calibrated pressure waves was 1.8+/-5.2 mmHg higher than invasive pulse pressure. Pulse pressure from calibrated distension waves was 3.4+/-6.9 mmHg lower than pulse pressure from alternatively calibrated pressure waves. According to British Hypertension Society criteria, pulse pressure from the internally calibrated tonometer achieved grade D and pulse pressure from alternatively calibrated pressure waves achieved grade A. Pulse pressure from calibrated distension waves achieved grade B when alternatively calibrated pressure waves were used as a reference method.

CONCLUSIONS

Pulse pressure obtained from alternatively calibrated tonometer-derived pressure waves and echo-tracking-derived distension waves demonstrates good accuracy. Accuracy of pulse pressure from internally calibrated applanation tonometer readings at the carotid artery is poor.

Different prognostic impact of 24-hour mean blood pressure and pulse pressure on stroke and coronary artery disease in essential hypertension

BACKGROUND

We tested the hypothesis that the steady and pulsatile components of blood pressure (BP) exert a different influence on coronary artery disease and stroke in subjects with hypertension.

METHODS AND RESULTS

We analyzed data on 2311 subjects with essential hypertension. All subjects (mean age 51 years, 47% women) underwent off-therapy 24-hour ambulatory BP monitoring. Over a follow-up period of up to 14 years (mean 4.7 years), there were 132 major cardiac events (1.20 per 100 person-years) and 105 cerebrovascular events (0.90 per 100 person-years). After adjustment for age, sex, diabetes, serum cholesterol, and cigarette smoking (all P<0.01), for each 10 mm Hg increase in 24-hour pulse pressure (PP), there was an independent 35% increase in the risk of cardiac events (95% CI 17% to 55%). Twenty-four-hour mean BP was not a significant predictor of cardiac events after controlling for PP. After adjustment for age, sex, and diabetes (all P<0.05), for every 10 mm Hg increase in 24-hour mean BP, the risk of cerebrovascular events increased by 42% (95% CI 19% to 69%), and 24-hour PP did not yield significance after controlling for 24-hour mean BP. Twenty-four-hour PP was also an independent predictor of fatal cardiac events, and 24-hour mean BP was an independent predictor of fatal cerebrovascular events.

CONCLUSIONS

In subjects with predominantly systolic and diastolic hypertension, ambulatory mean BP and PP exert a different predictive effect on the cardiac and cerebrovascular complications. Although PP is the dominant predictor of cardiac events, mean BP is the major independent predictor of cerebrovascular events.

Update in pharmacologic treatment of hypertension

Initial pharmacologic therapy for hypertension is low-dose thiazide diuretics, beta-blockers, and ACE inhibitors. Increasing data have confirmed that ACE inhibitors have specific benefit in patients with diabetes, atherosclerosis, left ventricular dysfunction, and renal insufficiency. CCBs are alternative agents for ISH in the elderly and appear to decrease stroke with perhaps less protection against progression of renal insufficiency and proteinuria, CAD mortality and new onset heart failure versus other initial agents, especially ACE inhibitors. ARBs are well tolerated and effective blood pressure lowering agents but have not been confirmed as effective as ACE inhibitors for reducing renal progression, clinical events, or mortality from heart failure. Effective pharmacologic antihypertensive therapy may avoid disabling and undetected cerebrovascular disease, cognitive dysfunction, and disturbing symptoms of elevated blood pressure. Vasopeptidase inhibitor, such as omapatrilat, and endothelin-1 antagonist, such as bosentan, may become future agents approved for the reduction of morbidity and mortality with hypertension. The ALLHAT trial continues to examine the potential benefits and harms of amlodipine versus chlorthalidone and lisinopril in a diverse high-risk population. Based on ALLHAT data, however, doxazosin is no longer an acceptable initial pharmacological agent. Intensive pharmacologic treatment with blood pressure lowering to less than 130/85 mm Hg is recommended with diabetes, renal insufficiency, and heart failure with additional goal of less than 125/75 mm Hg with renal failure and proteinuria greater than 1 g/24 h, based on multiple outcome studies.

Recent clinical trial highlights in hypertension

Clinical trials continue to guide patient management. However, the hypotheses generally come from observational studies. Studies on women continue to be too little and too few, particularly in light of the fact that most elderly hypertensive patients are likely to be women. Attention has been drawn to the possibility that hypertension per se may engender symptoms such as headache for example, in addition to harder endpoints such as death. The MICROHOPE study, which was not a blood pressure-lowering study, showed that angiotensin converting enzyme inhibition with ramipril in diabetic patients provided the same beneficial effects previously published for the HOPE study. The doxazosin arm of the ALLHAT study was terminated by the data monitoring and safety board because the doxazosin-treated patients developed congestive heart failure at a greater rate than diuretic-treated patients. Two extensive studies testing two different classes of calcium antagonists against primarily diuretic-based treatment showed that the calcium antagonists were no less effective in terms of preventing hard endpoints. A small, but impressive cross-over study testing the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, pravastatin, against placebo showed that statin treatment lowers blood pressure in hypercholesterolemic patients with hypertension. Meta- analyses emphasized the value of blood pressure reduction in the elderly and added to the controversy and confusion about the role of calcium antagonists in the first-line treatment of hypertension. The point may be moot since with the current recommendations few hypertensive patients will be adequately treated with a single agent.

Hypertension in older adults

The high prevalence of hypertension in older persons (nearly one of two subjects aged 60 years and older) suggests that the recognition and treatment should be a priority for physicians. Although diastolic blood pressure is regarded as an important risk factor, it is now clear that isolated systolic hypertension and elevated pulse pressure also play an important role in the development of cerebrovascular disease, congestive heart failure, and coronary heart disease, which are the major causes of cardiovascular morbidity and mortality in the population aged older than 65 years. Controlled, randomized trials have shown that treatment of systolic as well as systolodiastolic hypertension decreases the incidence of cardiovascular and cerebrovascular complications in older adults. The question of whether treatment of hypertension should be maintained in very old persons, those older than 80 years, is still undecided.

Pulse pressure--a review of mechanisms and clinical relevance

The goal of this study was to review the origin, clinical relevance and treatment of pulse pressure (PP). Elevated PP is increasingly being recognized as a risk factor for cardiovascular, particularly coronary, disease. Pulse pressure is discussed in terms of both Windkessel and distributive models of the arterial circulation. Pulse pressure arises from the interaction of cardiac ejection (stroke volume) and the properties of the arterial circulation. An increased stiffness of the aorta and large arteries leads to an increase in PP through a reduction in arterial compliance and effects on wave reflection. A number of factors are known to influence arterial wall behavior and, therefore, PP. In addition to the effects of aging and blood pressure on arterial wall elasticity, there is some evidence that atherosclerosis, per se, amplifies these effects. Thus, the relationship between PP and coronary disease may be bidirectional. A number of dietary and lifestyle interventions have been shown to modify large artery behavior. These include aerobic exercise training and consumption of n-3 fatty acids. Conversely, strength training is associated with an increase in arterial stiffness and a higher PP. The effects of antihypertensive medication have been extensively studied, but many studies are difficult to interpret because of concomitant change in blood pressure, and to a lesser degree, heart rate. However a number of studies do suggest direct arterial wall effects, particularly for angiotensin-converting enzyme inhibitors. A distributed compliance model of the arterial circulation provides a framework for understanding the causes, effects and potential treatment of elevations in PP.

Cyclooxygenase-2--specific inhibitors and cardiorenal function: a randomized, controlled trial of celecoxib and rofecoxib in older hypertensive osteoarthritis patients

BACKGROUND

Arthritis and hypertension are common comorbid conditions affecting elderly adults. Use of nonsteroidal anti-inflammatory drugs in patients treated with antihypertensive medication can lead to destabilization of blood pressure control and other cardiorenal events. The potential for similar interactions with cyclooxygenase-2-specific inhibitors has not been fully explored. The authors evaluated the cardiorenal safety of two new cyclooxygenase-2-specific inhibitors, celecoxib and rofecoxib.

METHODS

This study was a 6-week, randomized, parallel-group, double-blind trial in patients with osteoarthritis who were > or =65 years of age and were taking antihypertensive agents. Patients received once-daily celecoxib 200 mg or rofecoxib 25 mg. The primary endpoints were the development of edema, changes in systolic blood pressure, and changes in diastolic blood pressure as measured at any time point in the study. Measurements occurred at baseline and after 1, 2, and 6 weeks of treatment.

FINDINGS

Eight hundred ten patients received study medication (celecoxib, n = 411; rofecoxib, n = 399). Nearly twice as many rofecoxib- compared with celecoxib-treated patients experienced edema (9.5% vs. 4.9%, P = 0.014). Systolic blood pressure increased significantly in 17% of rofecoxib- compared with 11% of celecoxib-treated patients (P = 0.032) at any study time point. Diastolic blood pressure increased in 2.3% of rofecoxib- compared with 1.5% of celecoxib-treated patients (P = 0.44). At week 6, the change from baseline in mean systolic blood pressure was +2.6 mmHg for rofecoxib compared with -0.5 mmHg for celecoxib (P = 0.007).

CONCLUSIONS

Patients taking antihypertensive therapy and receiving cyclooxygenase-2-specific inhibitors should be monitored for the development of cardiorenal events. Patients receiving celecoxib experienced less edema and less destabilization of blood pressure control compared with those receiving rofecoxib.

Antihypertensive drug therapy in older patients

Elevated pulse pressure is an important cardiovascular risk factor in the elderly, and it remains to be determined whether this can be reversed. Drug treatment is justified in older patients with isolated systolic hypertension whose systolic blood pressure is 160 mmHg or higher on repeated measurement. Absolute benefit is greater in men, in patients aged 70 years or more, and in those with previous cardiovascular complications or greater pulse pressure. In the recently published comparative trials blood pressure gradients largely accounted for most, if not all, of the differences in outcome. In hypertensive patients, calcium-channel blockers may offer greater protection against stroke than against myocardial infarction, resulting in an overall cardiovascular benefit similar to that provided by older drug classes. The hypothesis that angiotensin-converting enzyme inhibitors or alpha-blockers might influence outcome over and beyond that expected on the basis of their blood pressure lowering effects still remains to be proved.

A comparison of indapamide SR 1.5 mg with both amlodipine 5 mg and hydrochlorothiazide 25 mg in elderly hypertensive patients: a randomized double-blind controlled study

OBJECTIVE

To analyse the efficacy of indapamide sustained-release (SR) 1.5 mg in reducing blood pressure versus amlodipine 5 mg and hydrochlorothiazide 25 mg, in elderly hypertensive patients.

DESIGN

Double-blind, randomized, 12 week study using three parallel groups.

SETTING

European teaching hospitals and general practices.

PATIENTS

Randomized patients, (n = 524) including 128 patients with isolated systolic hypertension (ISH); mean age: 72.4 years; mean systolic/diastolic blood pressures (SBP/DBP): 174.5/97.9 mmHg.

MAIN OUTCOME MEASURES

Clinic systolic and diastolic blood pressure variations.

RESULTS

Indapamide SR 1.5 mg demonstrates a similar efficacy to that of amlodipine 5 mg, as well as to that of hydrochlorothiazide 25 mg (equivalence P < 0.001); the mean decreases in SBP/DBP were -22.7/-11.8 mmHg, -22.2/-10.7 mmHg and -19.4/-10.8 mmHg, respectively. In the ISH subgroup, indapamide SR 1.5 mg tends to have greater efficacy than hydrochlorothiazide 25 mg in reducing the SBP (-24.7 versus -18.5 mmHg, respectively; equivalence P = 0.117), while similar results are obtained with amlodipine 5 mg (-23 mmHg, equivalence P < 0.001). The normalization rate was relatively high for indapamide SR 1.5 mg (75.3%), when compared with amlodipine (66.9%) and hydrochlorothiazide (67.3%), especially in the subgroup of isolated systolic hypertensive patients: 84.2 versus 80.0% for amlodipine, and versus 71.4% for hydrochlorothiazide.

CONCLUSIONS

Indapamide SR 1.5 mg shows similar antihypertensive efficacy to amlodipine 5 mg and hydrochlorothiazide 25 mg in elderly hypertensive patients, while in patients with isolated systolic hypertension, indapamide SR 1.5 mg shows a similar efficacy to amlodipine 5 mg but a greater efficacy than hydrochlorothiazide 25 mg.

Arterial elastance and wave reflection augmentation of systolic blood pressure: deleterious effects and implications for therapy

Systolic and pulse blood pressures are stronger predictors of stroke, coronary heart disease, myocardial infarction, heart failure, end-stage renal disease, and cardiovascular mortality than diastolic pressure. Furthermore, diastolic pressure is inversely related to coronary heart disease and cardiovascular mortality. Increased elastance (or stiffness, inverse of compliance) of the central elastic arteries is the primary cause of increased systolic and pulse pressure with advancing age and in patients with cardiovascular disease, including hypertension, and is due to degeneration and hyperplasia of the arterial wall; diastolic pressure decreases as arterial elastance increases. As elastance increases, transmission velocity of both forward and backward (or reflected) traveling waves increases, which causes the reflected wave to arrive earlier in the central aorta and augments pressure in late systole. These changes in arterial wall properties cause an increase in left ventricular afterload and myocardial oxygen consumption and a decrease in myocardial perfusion pressure, which may induce an imbalance in the supply-demand ratio, especially in hypertrophied hearts with coronary artery disease. Also, an increase in systolic pressure increases arterial wall circumferential stress, which promotes fatigue and development of atherosclerosis. Vasodilator drugs have little direct active effect on large elastic arteries but can markedly reduce wave reflection amplitude and augmentation index by decreasing elastance of the muscular arteries and reducing pulse wave velocity of the reflected wave from the periphery to the heart. This decrease in intensity (or amplitude) and increase in travel time (or delay) of the reflected wave causes a generalized decrease in systolic pressure and arterial wall stress and an increase in ascending aortic flow during the deceleration phase. The decrease in systolic pressure brought about by this mechanism is grossly underestimated when systolic pressure is measured in the brachial artery.

Recent advances in the management of hypertension in the elderly

Important new advances have occurred in our understanding and approach to management of high blood pressure in the elderly. New clinical trials have re-emphasized the risk of development of cardiovascular and cerebrovascular complications associated with isolated elevations in systolic blood pressure as well as the safety and efficacy of interventions to reduce blood pressure. These trials have shown that systolic blood pressure can be reduced by interventions such as weight loss, restriction of dietary sodium intake, and drugs. In several new trials, the long-acting dihydropyridine calcium channel blockers have been found to be safe and effective in these patients but not superior to other drugs. As in younger individuals with hypertension, drug therapy should be targeted to address comorbidity. Education of primary care physicians concerning these new findings is the next step in reducing the morbidity and mortality of this common problem in the elderly.

Therapeutic studies and arterial stiffness in hypertension: recommendations of the European Society of Hypertension. The Clinical Committee of Arterial Structure and Function. Working Group on Vascular Structure and Function of the European Society of Hypertension

BACKGROUND

Increased pulse pressure and arterial stiffness are identified as predictors of cardiovascular risk in older hypertensive populations, particularly that of myocardial infarction. Because increased pulse pressure involves an increase in systolic (SBP) and a decrease in diastolic blood pressure (DBP), and because the former promotes cardiac hypertrophy and the latter alters coronary perfusion, a drug regimen reducing pulse pressure and decreasing arterial stiffness might further reduce cardiovascular risk. Under conventional treatment, normalization of DBP (< or = 90 mmHg) is not consistently associated with normalization of SBP (< or = 140 mmHg).

THERAPEUTIC DESIGNS

In individuals older than 50 years, the goal of antihypertensive treatment should be, not only to decrease mean blood pressure (to less than 100 mmHg), but also to decrease pulse pressure (to less than 50 mmHg). Using appropriate pharmacological tools, trials should test whether an active decrease in arterial stiffness might produce an attenuation of the age-related increase in SBP and decrease in DBP, thus delaying the age-related increase in pulse pressure and decreasing further cardiovascular risk. This procedure requires concomitant non-invasive evaluations of aortic stiffness.

CONCLUSION

The studies that are required in hypertension should use two different approaches: novel titrations of conventional drugs to achieve a decrease in either SBP or pulse pressure, and development of new drugs acting selectively on the large artery wall, to facilitate the conduct of subsequent controlled trials.

Atherosclerotic renal artery stenosis: surgery, percutaneous transluminal angioplasty, or medical therapy?

Atherosclerotic renal artery stenosis typically occurs in high-risk patients with coexistent vascular disease elsewhere. Patients with atherosclerotic renal artery stenosis may develop progressive renal failure but have a much higher risk of dying of stroke or myocardial infarction than of progressing to endstage renal disease. Recent controlled trials comparing medication to revascularization have shown that only a minority of such patients can expect hypertension cure, whereas trials designed to document the ability of revascularization to prevent progressive renal failure are not yet available. Revascularization should be undertaken in patients with atherosclerotic renal artery stenosis and resistant hypertension or heart failure, and probably in those with rapidly deteriorating renal function or an increase in plasma creatinine levels during angiotensin converting enzyme inhibition. With or without revascularization, medical therapy using antihypertensive agents, statins, and aspirin is necessary in almost all cases.

A multicenter, randomized, double-blind study of the antihypertensive efficacy and tolerability of irbesartan in patients aged > or = 65 years with mild to moderate hypertension

BACKGROUND

Blockade of the renin-angiotensin-aldosterone system (RAAS) is the preferred mechanism of action for controlling hypertension in select groups of patients, including those with diabetic nephropathy and heart failure. Currently, 2 classes of drugs work by blocking the RAAS, albeit by differing mechanisms: angiotensin-converting enzyme (ACE) inhibitors and angiotensin II angiotensin type 1 receptor blockers (ARBs).

OBJECTIVE

The goal of this study was to assess the comparative efficacy and tolerability of the ARB irbesartan and the ACE inhibitor enalapril in patients > or = 65 years of age with mild to moderate hypertension (sitting diastolic blood pressure [DBP], 95 to 110 mm Hg).

METHODS

Elderly (> or = 65 years of age) patients were recruited from 26 Canadian study centers for a randomized, double-blind, 8-week clinical trial. Exclusion criteria included sitting DBP >110 mm Hg or sitting systolic blood pressure (SBP) >200 mm Hg, angina pectoris, myocardial infarction, cardiac procedure, stroke, or transient ischemic attack within 6 months of randomization, as well as other preexisting or present severe medical or psychologic conditions. Patients were randomly assigned to receive a single daily dose of irbesartan 150 mg (n = 70) or enalapril 10 mg (n = 71) with treatment doses of study drugs doubled at week 4 for sitting DBP > or = 90 mm Hg. Reductions from baseline blood pressure measurements at trough (24 +/- 3 hours after the last dose of medication) were assessed for sitting DBP and sitting SBP. Comparative tolerability to study drugs was also assessed.

RESULTS

The intent-to-treat analysis demonstrated similar reductions at week 8 in both DBP and SBP for both groups. For the primary efficacy analysis of sitting DBP, there was a mean reduction from baseline of 9.6 mm Hg and 9.8 mm Hg for the irbesartan and enalapril groups, respectively (P = 0.93). The mean reduction from baseline in sitting SBP was 10.1 mm Hg and 11.6 mm Hg for the irbesartan and enalapril groups, respectively (P = 0.54). Normalization rates (sitting DBP <90 mm Hg) at week 8 did not differ between groups (52.9% in the irbesartan group and 54.9% in the enalapril group; P = 0.81). No statistical difference existed between the 2 groups with respect to serious adverse events or discontinuations due to adverse events. Irbesartan was associated with a significantly lower incidence of cough than was enalapril (4.3% vs 15.5%, respectively; P = 0.046).

CONCLUSIONS

Irbesartan is an effective and well-tolerated antihypertensive for elderly patients with mild to moderate hypertension. This study establishes that irbesartan has better tolerability than enalapril with respect to cough and suggests that irbesartan is as effective at lowering blood pressure but better tolerated than an ACE inhibitor in hypertensive patients > or = 65 years of age.

Is there a preferred antihypertensive therapy for isolated systolic hypertension and reduced arterial compliance?

Isolated systolic hypertension (ISH) is the most common type of hypertension and the most difficult type to control with antihypertensive therapy. ISH, by definition, is wide pulse pressure hypertension resulting largely from excessive large artery stiffness and representing an independent risk factor for cardiovascular disease in the older aged population. Two major intervention studies of ISH have shown significant benefit in reducing systolic blood pressure with active drug therapy, including thiazide diuretics and calcium receptor antagonists. The optimal treatment strategy is to maximize reduction in systolic blood pressure and to minimize reduction in diastolic blood pressure, thereby reducing pulse pressure. All classes of antihypertensive drugs reduce pulse pressure by means of lowering peripheral resistance, but certain drugs like nitrates, angiotensin converting enzyme inhibitors, and other drugs affecting the renin-angiotensin system have multiple actions that improve large artery stiffness and early wave reflection and are especially useful in treating ISH in the elderly.