Comparison of active treatment and placebo in older Chinese patients with isolated systolic hypertension. Systolic Hypertension in China (Syst-China) Collaborative Group

The paradigm has shifted to systolic blood pressure

Since the middle of the 20th century, most physicians and epidemiologists assessed the risks associated with hypertension based on the level of diastolic blood pressure (DBP). In a classic paper in 1971, the Framingham Heart Study clearly showed that systolic BP more accurately described the risk of all the complications we attribute to hypertension. It took 22 years until JNC V in 1993 also used systolic blood pressure (SBP) to define hypertension in US national guidelines. Since then, the paradigm has shifted dramatically. In JNC VI (1997) and JNC VII (2003), SBP has become the primary focus of risk stratification and treatment goals. This shift is a result of the Framingham results being confirmed by many others analyses, the most compelling of which is the recently published report of the Prospective Collaborative Study Group, which pooled 61 observational studies in more than 1 million volunteers with a collective experience of more than 12 million person-years. This group showed that the SBP level at baseline was a significantly more informative reading than DBP for predicting strokes and coronary heart disease (CHD). Furthermore, three trials of older individuals with isolated systolic hypertension, SHEP, SYST-Eur, and SYST-China, unambiguously demonstrated that effective antihypertensive therapy lowered the rate of strokes, heart failure, CHD, and even all-cause mortality. Finally, the World Health Organization (WHO)/International Society of Hypertension (ISH) Hypertension Trialists also showed that the level of SBP achieved in clinical trials comparing different antihypertensives with placebo and with each other was the strongest determinant of how effectively strokes and CHD events were reduced, although a similar relationship was not evident for heart failure. A recent metaregression analysis using new trials, many of which were used by the Trialists, and older studies not included in their analysis also showed that small differences in SBP can have a dramatic impact on cardiovascular outcomes. If there is one thing we have learned in the recent past, it is the need for us to focus on lowering SBP and getting it down to a reasonable goal. We have also learned that to do so, we will need to combine a variety of lifestyle and pharmacological approaches, always with combinations of drugs that will usually contain a low-dose thiazide-type diuretic with other antihypertensives.

Nifedipine gastrointestinal therapeutic system--hypertension management to improve cardiovascular outcomes

Hypertension is a major cardiovascular risk factor, and its increasing prevalence is of great clinical concern. Despite the availability of numerous effective therapies, hypertension remains under-diagnosed and under-treated. Hypertension often coexists with other risk factors, and current guidelines recommend a multifactorial approach to management, with the aim of not only controlling blood pressure but also reducing overall cardiovascular risk. Nifedipine gastrointestinal therapeutic system (GITS) is a long-acting formulation of a calcium channel blocker. Once-daily dosing with nifedipine GITS has been shown to achieve smooth and continuous blood pressure control, identical to conventional first-line diuretic therapy. Small-scale clinical trials have also shown that nifedipine GITS positively affects markers of atherosclerotic disease, which may signify an additional clinical benefit, but this is yet to be demonstrated. The recently completed ACTION (A Coronary Disease Trial Investigating Outcome with Nifedipine GITS) trial provides further evidence that nifedipine GITS can be used safely in high-risk patients to treat angina, lower blood pressure and significantly improve clinical outcomes.

The role of calcium antagonists in stroke prevention

Lowering elevated blood pressure significantly reduces the risk of stroke, but whether any specific type of antihypertensive medication is better for this purpose, independent of blood pressure-lowering effects, is controversial. Compared with placebo or no treatment, the point estimate for stroke reduction is the largest with calcium antagonists; all such studies used dihydropyridine compounds. When all clinical trials published through December 2004 are combined in meta-analysis, stroke is not significantly reduced when an initial dihydropyridine or nondihydropyridine calcium antagonist is compared with an initial diuretic or beta blocker, but when the two subclasses are combined, stroke reduction (9%) is significant. The risk of heart failure, however, is significantly increased (by 29%) with the initial calcium antagonist. These estimates may change as newer trials are reported.

Angiotensin-Converting Enzyme Inhibitors and Calcium Channel Blockers for Coronary Heart Disease and Stroke Prevention

We investigated whether protection from coronary heart disease (CHD) and stroke conferred by angiotensin-converting enzyme inhibitors (ACEIs) and calcium channel blockers (CCBs) in hypertensive or high-risk patients may be explained by the specific drug regimen. We extracted summary statistics regarding CHD and stroke from 28 outcome trials that compared either ACEIs or CCBs with diuretics, β-blockers, or placebo for a total of 179 122 patients, 9509 incident cases of CHD, and 5971 cases of stroke. CHD included myocardial infarction and coronary death. In placebo-controlled trials, ACEIs decreased the risk of CHD ( P <0.001), and CCBs reduced stroke incidence ( P <0.001). There were no significant differences in CHD risk between regimens based on diuretics/β-blockers and regimens based on ACEIs ( P =0.46) or CCBs ( P =0.52). The risk of stroke was reduced by CCBs ( P =0.041) but not by ACEIs ( P =0.15) compared with diuretics/β-blockers. Because heterogeneity between trials was significant, we investigated potential sources of heterogeneity by metaregression. Examined covariates were the reduction in systolic blood pressure (BP), drug treatment (ACEIs versus CCBs), their interaction term, sex, age at randomization, year of publication, and duration of treatment. Prevention of CHD was explained by systolic BP reduction ( P <0.001) and use of ACEIs ( P =0.028), whereas prevention of stroke was explained by systolic BP reduction ( P =0.001) and use of CCBs ( P =0.042). These findings confirm that BP lowering is fundamental for prevention of CHD and stroke. However, over and beyond BP reduction, ACEIs appear superior to CCBs for prevention of CHD, whereas CCBs appear superior to ACEIs for prevention of stroke.

The effects of losartan compared to atenolol on stroke in patients with isolated systolic hypertension and left ventricular hypertrophy. The LIFE study

The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study reported that a losartan-based antihypertensive regimen reduced cardiovascular morbidity and mortality (composite of cardiovascular death, stroke, and myocardial infarction) more than therapy based on atenolol in patients with left ventricular hypertrophy and isolated systolic hypertension (ISH). Patients aged 55-80 years with blood pressures 160-200/<90 mm Hg were followed for a mean of 4.7 years. Blood pressure was similarly reduced in the losartan (n=660) and atenolol (n=666) ISH groups. There were 88 (6.6%) patients who experienced a stroke, 18 of which were fatal. Of patients experiencing strokes, 72.7% had an ischemic stroke. ISH patients in LIFE compared to the non-ISH group had a higher incidence of any stroke and embolic stroke, and similar incidences of fatal, atherosclerotic, and hemorrhagic/other strokes. The incidence of any stroke (40% risk reduction [RR], p=0.02), fatal stroke (70% RR, p=0.035), and atherothrombotic stroke (45% RR, p=0.022) was significantly lower in losartan-treated compared to the atenolol-treated patients. The 36% RR for embolic strokes in the losartan group was not statistically significantly (p=0.33) different from the atenolol group. These data suggest that losartan-based treatment is more effective than an atenolol-based treatment for patients with ISH and a high risk for stroke.

Treatment of systolic hypertension: spotlight on recent studies with angiotensin II antagonists

Systolic blood pressure has a continuous, graded, strong, independent, and aetiologically significant relationship to mortality from coronary heart disease, stroke, and all cardiovascular diseases, as well as to all-cause mortality and life expectancy. Angiotensin II (AII) may be intimately involved in the pathogenesis of systolic hypertension through multiple mechanisms, including decreasing the elastin content and increasing the collagen content of the arterial wall, thickening and fibrotic remodelling of the vascular intima, and proliferating smooth muscle cells in the arterial wall, resulting in increased thickness, stiffening, and partial loss of contractility. AII antagonists may therefore offer hitherto unrecognized benefits (independent of blood pressure) on age-related vascular damage and provide particular benefits in patients with systolic hypertension. Recent evidence has demonstrated that losartan offers cardiovascular outcomes benefits in isolated systolic hypertension (ISH) associated with an excellent tolerability profile. This, in patients with ISH, AII antagonists more facilitate systolic BP control, providing cardiovascular protection and offering an excellent risk-benefit profile.

NITRIC OXIDE and SYMPATHETIC NERVE ACTIVITY IN THE CONTROL OF BLOOD PRESSURE

1. Endothelial dysfunction marked by impairment in the release of nitric oxide (NO) is seen very early in the development of hypertension and is considered important in mediating the impaired vascular tone evident in essential hypertensive patients. 2. Recently, a hypothesis has emerged that NO acting as a neurotransmitter in the brain can modulate levels of sympathetic nerve activity and thereby blood pressure. The NO inhibition model of hypertension has been used to explore the possibility that a decrease in levels of NO can cause an increase in levels of sympathetic nerve activity that can mediate the hypertension. 3. In the present review, we examine the literature regarding the role of NO in setting the mean level of sympathetic nerve activity and blood pressure. Although the acute effects of NO inhibition are well understood, the chronic interaction between the sympathetic nervous system and NO has only been investigated using indirect measures of sympathetic nerve activity, such as ganglionic blockade. This has led to inconsistent results regarding the role of NO in modulating sympathetic nerve activity chronically. 4. Some of the conflicting results may be explained by differences in the 'background' levels of angiotensin (Ang) II. Evidence suggests that NO may interact with AngII and baroreceptor afferent inputs in the central nervous system to set the mean level of sympathetic nerve activity. 5. We suggest chronic NO inhibition can increase sympathetic nerve activity if baroreceptor input is intact and AngII levels are elevated. Although studies exploring the actions of NO or AngII in isolation are useful for gathering initial information, future studies should focus on their interactions and their role in setting the long-term levels of sympathetic activity and blood pressure.

Systolic and diastolic blood pressure lowering as determinants of cardiovascular outcome

Based on individual patient data, we performed a quantitative overview of trials in hypertension to investigate to what extent lowering of systolic blood pressure (SBP) and diastolic blood pressure (DBP) contributed to cardiovascular prevention. We selected trials that tested active antihypertensive drugs against placebo or no treatment. Our analyses included 12,903 young (30 to 49 years of age) patients randomized in 3 trials and 14,324 old (60 to 79 years of age) and 1209 very old (> or =80 years of age) patients enrolled in 8 trials. Antihypertensive treatment reduced SBP/DBP by 8.3/4.6 mm Hg in young patients, by 10.7/4.2 mm Hg in old patients, and by 9.4/3.2 mm Hg in very old patients, respectively, resulting in ratios of DBP to SBP lowering of 0.55, 0.39, and 0.32, respectively (P=0.004 for trend with age). In spite of the differential lowering of SBP and DBP, antihypertensive treatment reduced the risk of all cardiovascular events, stroke and myocardial infarction in the 3 age strata to a similar extent. Absolute benefit increased with age and with lower ratio of DBP to SBP lowering. Furthermore, in patients with a larger-than-median reduction in SBP, active treatment consistently reduced the risk of all outcomes irrespective of the decrease in DBP or the achieved DBP. These findings remained consistent if the achieved DBP averaged <70 mm Hg. In conclusion, our overview suggests that antihypertensive drug treatment improves outcome mainly through lowering of SBP.

Evaluation of drug therapy and risk factors in diabetic hypertensives: a study of the quality of care provided in diabetic clinics in Bahrain

OBJECTIVE

To evaluate control of blood pressure (BP) and diabetes and the associated risk factors in diabetic hypertensives treated by diabetic clinic primary care physicians.

METHODS

A retrospective analysis of the medical records of diabetic hypertensives from six primary care diabetic clinics in Bahrain.

RESULTS

The recommended BP target <130/<85 mmHg and of glycosylated haemoglobin (HbA1C) <7% were achieved in 7.5% and 14.5%, respectively. Most of the patients with uncontrolled BP and HbA(1C) were at high cardiovascular risk. More patients were on antihypertensive monotherapy than on combination therapy (60.6% vs. 36.7%; P<0.0001). The recommended two- and three-antihypertensive drug combinations were less often prescribed. In high-risk patients glycaemic control achieved was poor: antidiabetic combination therapy vs. monotherapy did not significantly differ. Inappropriate prescribing practices, such as the use of immediate-release nifedipine monotherapy, use of sulphonylurea instead of metformin in obese patients, and a trend towards prescribing of glyburide rather than a gliclazide in the elderly, were observed. Lipid-lowering (13.5%) and antiplatelet (12.8%) drugs were infrequently prescribed.

CONCLUSIONS

Hypertension and diabetes in patients treated at the primary care diabetic clinics were inadequately controlled. In several instances, mono- and combination antihypertensives prescribed were irrational. Lipid-lowering and platelet aggregation inhibition strategies have received little attention. Intensive antihypertensive and antidiabetic complementary combination therapy should be encouraged. Continuous professional education of diabetic clinic physicians and expert-supervised diabetic clinics are desirable.

Pharmacotherapy and blood pressure control in elderly hypertensives in a primary care setting in Bahrain

BACKGROUND AND AIMS

Antihypertensive treatment in the elderly has important beneficial effects in terms of reduced cardiovascular morbidity and mortality. The aim of this study was to determine, in elderly hypertensives, the adherence of primary care physicians to World Health Organization/International Society of Hypertension (WHO/ISH) guidelines for the drug management of hypertension and extent of blood pressure (BP) control.

METHODS

A multicentric therapeutic audit of medical records of elderly hypertensives was performed in nine primary care health centers in the Kingdom of Bahrain.

RESULTS

In elderly hypertensives (> or =60 years), the WHO/ISH-1999 recommended BP targets of <140/<90 mmHg and BP<130/85 mmHg were achieved in 11.1% of elderly hypertensives and 4.1% of elderly diabetic hypertensives, respectively. Antihypertensive combination therapy was used in approximately half of the elderly. No significant difference in BP was found in elderly hypertensives treated either with monotherapy or combination therapy. As regards mono- and overall drug utilization, beta-blockers were the most frequently prescribed drugs in hypertensives, and angiotensin-converting enzyme (ACE) inhibitors in diabetic hypertensives. Diuretics and calcium channel blockers, the preferred antihypertensives for the elderly, were less often prescribed, particularly in patients with isolated systolic hypertension.

CONCLUSIONS

Approximately one out of 9 elderly hypertensives and one out of 24 diabetic hypertensives achieved optimal BP control. Although preference for antihypertensives was markedly influenced by comorbidity with diabetes, tailoring of drug therapy was suboptimal and did not adhere to the recommended guidelines in elderly hypertensives. Efforts to improve the drug management of hypertension at primary care level, particularly in the elderly, are required.

The role of existing and newer calcium channel blockers in the treatment of hypertension

Calcium channel blockers (CCBs), which include both dihydropyridines such as nifedipine and amlodipine and non-dihydropyridines (verapamil and diltiazem), are among the most widely prescribed agents for the management of essential hypertension. Several large outcome risk trials and comprehensive meta-analyses have found that CCBs reduce the cardiovascular morbidity and mortality associated with uncontrolled hypertension, including stroke. CCBs, however, appear less effective than angiotensin-converting enzyme inhibitors and diuretics for preventing heart failure and myocardial infarction. CCBs are among the agents listed as potential first-line therapy, either alone or in combination with other agents in hypertension management guidelines. Furthermore, CCBs are suitable for add-on therapy in combination with diuretics, angiotensin-converting enzyme inhibitors, and angiotensin-II receptor blockers. CCBs may be partially suitable for patients with comorbid Raynaud's syndrome, isolated systolic hypertension (dihydropyridine), or angina pectoris (non-dihydropyridine). The newer inherently long-acting dihydropyridine agents (e.g., lacidipine, lercanidipine), which are not currently available in the United States, appear to have comparable efficacy to older agents of the dihydropyridine class but may have an improved tolerability profile, especially with regard to peripheral edema.

Dihydropyridine calcium channel blockers: basic pharmacological similarities but fundamental therapeutic differences

Recent trials indicate that treatment with calcium channel blockers (CCBs) reduces cardiovascular morbidity and mortality in hypertensive patients (including those with significant coronary artery disease). Since the fundamental mechanism of action of all CCBs is the same, it might be assumed that the findings of these outcome studies can be generalized to all types of CCB. However, in the light of the well-recognized clinical pharmacological differences between the 'rate-limiting' agents, verapamil and diltiazem, and the dihydropyridine group of CCBs, this must be considered to be a misconception. Less well-recognized, and often ignored, are the significant differences between agents within the dihydropyridine group. These differences translate to distinct differences in the therapeutic profiles and may well translate into differences in outcome during long-term treatment. Thus, the differences in pharmacokinetic, pharmacodynamic and therapeutic profiles make it clear that caution should be exercised in assuming that all dihydropyridine CCBs licensed for once-daily administration are equivalent in terms of their durations of action and overall antihypertensive efficacy.

Hypertension in the Elderly

Elderly individuals with hypertension show specific characteristics as a result of advancing arteriosclerosis, a high frequency of isolated systolic hypertension, increased pulse pressure and orthostatic hypotension. The necessity to treat hypertension in the elderly, including isolated systolic hypertension, has been demonstrated in many large-scale intervention trials. Young-old (65-74 years of age) hypertensive patients should be treated the same as nonelderly hypertensive patients. In old-old (75-84 years of age) patients with mild hypertension (140-159/90-99 mm Hg), the recommended target blood pressure (BP) is <140/90 mm Hg. In old-old (75-84 years of age) and oldest-old (> or =85 years of age) patients with systolic BP > or =160 mm Hg, cautious treatment is required. An intermediate target BP of <150 mm Hg is appropriate, followed by a final target BP of <140 mm Hg, if tolerated. Nonmedical therapy, such as salt restriction, exercise and weight reduction, is useful in the elderly. However, individualised management of nonmedical therapy is necessary to avoid deterioration of quality of life resulting from strict management of the patient's lifestyle. Diuretics, calcium channel antagonists, ACE inhibitors and angiotensin II type 1 receptor antagonists have been established as first-line antihypertensive drugs in the elderly. Use of combination therapy helps to achieve target BPs. The starting dose of each drug should be half the usual dose for nonelderly patients, and may be increased at intervals of >4 weeks, with achievement of the target BP in 3-6 months or longer. In hypertensive patients with co-morbid diseases, the target BP should be determined individually and antihypertensive drugs selected bearing in mind the patient's clinical circumstances. Avoiding hypoperfusion of target organs is very important in elderly hypertensive patients. When treating hypertension in elderly patients, the approach should be to identify individual pathophysiological characteristics and lower the BP cautiously and slowly.

Blood Pressure Reduction and Cardiovascular Prevention: An Update Including the 2003-2004 Secondary Prevention Trials

In a meta-analysis published in June 2003, we reported that new and old classes of antihypertensive drugs had similar long-term efficacy and safety. Furthermore, we observed that in clinical trials in hypertensive or high-risk patients gradients in systolic blood pressure (SBP) accounted for most differences in outcome. To test whether our previous conclusions would hold, we updated our quantitative overview with new information from clinical trials published before 2005. To compare new and old antihypertensive drugs, we computed pooled odds ratios from stratified 2 x 2 contingency tables. In a meta-regression analysis, we correlated these odds ratios with corresponding between-group differences in SBP. We then contrasted observed odds ratios with those predicted from gradients in SBP. The main finding of our overview was that reduction in SBP largely explained cardiovascular outcomes in the recently published actively controlled trials in hypertensive patients and in placebo-controlled secondary prevention trials. The published results suggested that dihydropyridine calcium-channel blockers might offer a selective benefit in the prevention of stroke and inhibitors of the renin-angiotensin system in the prevention of heart failure. For prevention of myocardial infarction, the published results were more equivocal, because of the benefit of amlodipine over placebo or valsartan in 2 trials, whereas other placebo-controlled trials of calcium-channel blockers or angiotensin converting enzyme inhibitors did not substantiate the expected benefit with regard to cardiac outcomes. In conclusion, the hypothesis that new antihypertensive drugs might influence cardiovascular prognosis over and beyond their antihypertensive effect remains unproven. Our overview emphasizes the need of tight blood pressure control, but does not allow determining to what extent blood pressure must be lowered for optimal cardiovascular prevention.

The Japanese Trial to Assess Optimal Systolic Blood Pressure in Elderly Hypertensive Patients (JATOS): Protocol, Patient Characteristics, and Blood Pressure during the First 12 Months

The benefits of a systolic blood pressure (BP) below 150-160 mmHg are well established; whether a systolic BP of less than 140 mmHg provides additional benefits remains controversial. This study was designed to compare the 2-year effect of a strict treatment to maintain systolic BP below 140 mmHg (group A) and that of a mild treatment to maintain systolic BP at between 140 and below 160 mmHg (group B). The study design followed the Prospective Randomized Open Blinded End-point (PROBE) study. The subjects were elderly patients (65-85 years old) who consistently had a systolic BP of 160 mmHg or higher. The baseline drug was efonidipine hydrochloride (efonidipine), a long-acting dihydropiridine calcium antagonist. The primary endpoints were stroke, cardiac disease, vascular disease, and renal failure. After a run-in period of 2 to 4 weeks, 2,165 patients were assigned to group A and 2,155 patients to group B. There were no significant differences between the groups in sex, age, baseline BP, or other cardiovascular risk factors. The systolic BP was 7.2 mmHg lower (p < 0.0001) and the diastolic BP 2.4 mmHg lower (p < 0.0001) in group A than in group B after 12 months of treatment. As of this interim analysis, primary endpoints have occurred in 87 patients (stroke in 58 patients, cardiac disease in 27 patients, occlusive arterial disease in 1 patient, and renal failure in 1 patient). Five patients have died of stroke and 2 patients of myocardial infarction. The primary-endpoint-related morbidity rate was 20.9/1,000 patient-years, and the mortality rate was 1.7/1,000 patient-years. Currently available results indicate that this study, one of the largest randomized trials of antihypertensive therapy in elderly patients in Japan, was conducted safely. The final results are expected to provide important and practical information for the management of hypertension in elderly patients.

Calcium antagonists

Calcium antagonists were introduced for the treatment of hypertension in the 1980s. Their use was subsequently expanded to additional disorders, such as angina pectoris, paroxysmal supraventricular tachycardias, hypertrophic cardiomyopathy, Raynaud phenomenon, pulmonary hypertension, diffuse esophageal spasms, and migraine. Calcium antagonists as a group are heterogeneous and include 3 main classes--phenylalkylamines, benzothiazepines, and dihydropyridines--that differ in their molecular structure, sites and modes of action, and effects on various other cardiovascular functions. Calcium antagonists lower blood pressure mainly through vasodilation and reduction of peripheral resistance. They maintain blood flow to vital organs, and are safe in patients with renal impairment. Unlike diuretics and beta-blockers, calcium antagonists do not impair glucose metabolism or lipid profile and may even attenuate the development of arteriosclerotic lesions. In long-term follow-up, patients treated with calcium antagonists had development of less overt diabetes mellitus than those who were treated with diuretics and beta-blockers. Moreover, calcium antagonists are able to reduce left ventricular mass and are effective in improving anginal pain. Recent prospective randomized studies attested to the beneficial effects of calcium antagonists in hypertensive patients. In comparison with placebo, calcium antagonist-based therapy reduced major cardiovascular events and cardiovascular death significantly in elderly hypertensive patients and in diabetic patients. In several comparative studies in hypertensive patients, treatment with calcium antagonists was equally effective as treatment with diuretics, beta-blockers, or angiotensin-converting enzyme inhibitors. From these studies, it seems that a calcium antagonist-based regimen is superior to other regimens in preventing stroke, equivalent in preventing ischemic heart disease, and inferior in preventing congestive heart failure. Calcium antagonists are also safe and effective as first-line or add-on therapy in diabetic hypertensive patients. Heart rate-lowering calcium antagonists (verapamil, diltiazem) may have an edge over the dihydropyridines in post-myocardial infarction patients and in diabetic nephropathy. Thus, calcium antagonists may be safely used in the management of hypertension and angina pectoris.

Systolic blood pressure variability as a risk factor for stroke and cardiovascular mortality in the elderly hypertensive population

OBJECTIVE

To investigate whether baseline systolic blood pressure variability was a risk factor for stroke, cardiovascular mortality or cardiac events during the Syst-Eur trial.

DESIGN

The Syst-Eur study was a randomized, double-blind, placebo-controlled trial, powered to detect differences in stroke rate between participants on active antihypertensive treatment and placebo. Systolic blood pressure variability measurements were made on 744 participants at the start of the trial. Systolic blood pressure variability was calculated over three time frames: 24 h, daytime and night-time. The placebo and active treatment subgroups were analysed separately using an intention-to-treat principle, adjusting for confounding factors using a multiple Cox regression model.

PARTICIPANTS

An elderly hypertensive European population.

MAIN OUTCOME MEASURES

Stroke, cardiac events (fatal and non-fatal heart failure, fatal and non-fatal myocardial infarction and sudden death) and cardiovascular mortality (death attributed to stroke, heart failure, myocardial infarction, sudden death, pulmonary embolus, peripheral vascular disease and aortic dissection).

RESULTS

The risk of stroke increased by 80% (95% confidence interval: 17-176%) for every 5 mmHg increase in night-time systolic blood pressure variability in the placebo group. Risk of cardiovascular mortality and cardiac events was not significantly altered. Daytime variability readings did not predict outcome. Antihypertensive treatment did not affect systolic blood pressure variability over the median 4.4-year follow-up.

CONCLUSION

In the placebo group, but not the active treatment group, increased night-time systolic blood pressure variability on admission to the Syst-Eur trial was an independent risk factor for stroke during the trial.

Prevalence, pathophysiology and treatment of isolated systolic hypertension in the elderly

Isolated systolic hypertension is the predominant type of hypertension in the elderly and is associated with cardiovascular complications such as stroke, coronary heart disease and heart failure. In this review, the role of arterial stiffness, endothelial function, atherosclerosis and oxidative stress in the pathogenesis of isolated systolic hypertension is extensively discussed. Placebo-controlled intervention trials such as the Systolic Hypertension in Europe Trial and the Systolic Hypertension in the Elderly Program have clearly shown that pharmacological treatment of isolated systolic hypertension improves outcome in the elderly. Nevertheless, isolated systolic hypertension remains the major subtype of untreated and uncontrolled hypertension.

Management of hypertension in the very elderly patient

This Hypertension Grand Rounds discusses pharmacological treatment of hypertension in individuals who have survived 9 decades on earth. This rapidly growing group of relatively active and healthy elderly people is at high risk for hypertension, its treatment, and its adverse consequences, including stroke and heart failure. In this age group, the most common abnormality is elevated systolic blood pressure, which is much more predictive of stroke and heart disease death after 53 years of age. With the possible exception of the Antihypertensive and Lipid Lowering to prevent Heart Attack Trial (ALLHAT), recent clinical trials have emphasized the overriding importance of lowering blood pressure rather than the specific agent chosen to begin therapy. In 1999, a metaanalysis of 7 clinical trials that enrolled 1670 subjects >80 years of age indicated that active antihypertensive drug therapy significantly reduced stroke by 34% and heart failure by 39% but was associated with a nonsignificant 6% increase in mortality. The HYpertension in the Very Elderly Trial (HYVET) will enroll 2100 patients >80 years of age and will compare 2 groups randomized to indapamide+/-perindopril versus placebo+/-placebo for incident stroke during 5 years of follow-up. This study should answer lingering questions about whether active antihypertensive therapy is associated with a major and significant reduction in cardiovascular morbidity and mortality in this age group as it clearly does in younger hypertensives. Its choice of a diuretic as initial therapy is consistent with other trials, but chlorthalidone is the drug with the most compelling evidence in large US trials that included very elderly patients.

Clinical experience with perindopril in elderly hypertensive patients: a subgroup analysis of a large community trial

OBJECTIVE

To evaluate the effectiveness and safety of perindopril in a subgroup of 3010 elderly (> or =65 years) hypertensive patients, who participated in a large US general practice-based community trial.

METHODS

All patients received open-label perindopril 4 mg once a day for 6 weeks. After 6 weeks the dosage was either maintained (group I) or increased to 8 mg/day (group II) based on the physician's assessment of blood pressure (BP) response. Patients were then followed for another 6 weeks for a total study duration of 12 weeks.

RESULTS

Demographic and baseline clinical characteristics revealed a higher proportion of women, longer duration of hypertension and higher baseline systolic BP (SBP) among elderly than young (<65 years, n = 7332) hypertensive patients. A clinically relevant BP reduction of similar magnitude was obtained in elderly and young patients with perindopril monotherapy. At week 12, the mean reduction in BP from baseline was 18.4/8.7 mm Hg in the elderly and 17.5/11.3 mm Hg in the young. Elderly patients with hypertension not responding adequately to the 4 mg/day dosage at week 6 had a BP reduction of 6.3/3.6 mm Hg (group II). Up-titration to an 8 mg/day dosage for another 6 weeks gave an additional 8.9/3.5 mm Hg reduction resulting in a total reduction of 15.2/7.1 mm Hg from baseline. A similar magnitude of increase in response to up-titration of perindopril was seen in young patients. BP control (<140/90 mm Hg) on perindopril monotherapy was achieved in 41.4% of elderly and 51.9% of young patients. In both age groups, up-titration to an 8.0 mg/day dosage in group II patients increased BP control by approximately 5-fold at week 12 (28.2% in the elderly and 36.4% in the young). A similar increased response on BP reduction and BP control (<140/90 mm Hg) with up-titration was seen in elderly subgroups of African American and diabetic patients. The 7th Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure recommended target goal of <130/80 mm Hg was achieved with perindopril monotherapy in 15.6% of hypertensive diabetic patients. Perindopril reduced BP effectively and safely in very elderly (> or =75 years) hypertensive patients. Perindopril was well tolerated in elderly patients including high-risk groups. The incidence of cough (7-10%), the most common symptom, was similar in all age groups. The low incidence of postural hypotension (< or =0.2%) observed in the elderly and very elderly further supports the good tolerance and safety profile of the drug. Data analysis from this study suggests that community physicians, in general, are less aggressive in controlling BP in the elderly and more inclined to treat or control diastolic BP than SBP.

CONCLUSION

Perindopril treatment is effective and well tolerated in elderly patients with hypertension.

The case for blood pressure control in risk groups

Hypertension rarely occurs in isolation, and many hypertensives have additional risk factors for cardiovascular disease in addition to elevated blood pressure. Each patient's cardiovascular disease risk profile should be determined individually, and the treatment approach tailored to each case. Cardiovascular disease risk factors and high blood pressure are closely linked, suggesting that the ideal treatment should not only lower blood pressure, but also effectively lower overall risk. This is likely to require more than one drug, and one of the most effective and safe combinations is that of an angiotensin receptor blocker with a diuretic. The completion of one of the most important trials undertaken to explore risk factors and anti-hypertensive treatment, the Valsartan long-term evaluation trial (VALUE), will certainly enhance understanding for the role of combination treatment in high-risk patients, as well as contribute to the design of rational treatments for blood pressure control.

Outcomes in hypertensive patients at high cardiovascular risk treated with regimens based on valsartan or amlodipine: the VALUE randomised trial

BACKGROUND

The Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial was designed to test the hypothesis that for the same blood-pressure control, valsartan would reduce cardiac morbidity and mortality more than amlodipine in hypertensive patients at high cardiovascular risk.

METHODS

15?245 patients, aged 50 years or older with treated or untreated hypertension and high risk of cardiac events participated in a randomised, double-blind, parallel-group comparison of therapy based on valsartan or amlodipine. Duration of treatment was event-driven and the trial lasted until at least 1450 patients had reached a primary endpoint, defined as a composite of cardiac mortality and morbidity. Patients from 31 countries were followed up for a mean of 4.2 years.

FINDINGS

Blood pressure was reduced by both treatments, but the effects of the amlodipine-based regimen were more pronounced, especially in the early period (blood pressure 4.0/2.1 mm Hg lower in amlodipine than valsartan group after 1 month; 1.5/1.3 mm Hg after 1 year; p<0.001 between groups). The primary composite endpoint occurred in 810 patients in the valsartan group (10.6%, 25.5 per 1000 patient-years) and 789 in the amlodipine group (10.4%, 24.7 per 1000 patient-years; hazard ratio 1.04, 95% CI 0.94-1.15, p=0.49).

INTERPRETATION

The main outcome of cardiac disease did not differ between the treatment groups. Unequal reductions in blood pressure might account for differences between the groups in cause-specific outcomes. The findings emphasise the importance of prompt blood-pressure control in hypertensive patients at high cardiovascular risk.

Prevention and treatment of stroke in patients with hypertension

BACKGROUND

Each year, stroke occurs in 30.9 million individuals worldwide and is responsible for approximately 4 million deaths. In the United States, it is the third leading cause of death, occurring with greater frequency than myocardial infarction in patients with hypertension. The greatest burden of stroke, apart from death, is serious long-term physical and mental disability. Stroke survivors often experience physical handicap, depression, and cognitive dysfunction, which together affect their daily functioning, quality of life, and survival. The treatment of stroke is associated with extremely high costs, with stroke-related illnesses responsible for >$49 billion in the United States in 2002. Despite intensive research efforts, few effective treatments are available once stroke has occurred; thus, stroke prevention should be a primary focus for all health care providers.

OBJECTIVE

The purpose of this article was to review the epidemiology and burden of stroke in terms of disability, quality of life, and cost of care, and to summarize the evidence for treatments having therapeutic benefit, with an emphasis on antihypertensive agents.

METHODS

Relevant studies were identified through a MEDLINE search of English-language articles published between 1990 and 2004. The search terms were stroke, epidemiology, economic impact, disability, quality of life, hypertension, drug therapy, and angiotensin II-receptor antagonists. Articles describing major clinical studies, new data, or new mechanisms pertinent to the therapy of stroke were selected for review.

CONCLUSIONS

Identifying and modifying key risk factors is crucial to reducing the morbidity and mortality of stroke. Hypertension is one of the most important risk factors for stroke, and treatment with a variety of antihypertensive agents reduces the risk. Recent evidence suggests that the angiotensin II (ATII)-receptor antagonist losartan may offer advantages beyond blood pressure lowering, including attenuation of the central aortic reflected pressure wave, molecule-specific properties, and neural protective influences on brain ATII type 2 receptors.

Benefits of blood pressure reduction in elderly patients

Hypertension in the elderly is characterized principally by increased systolic blood pressure (SBP). Consequently, isolated systolic hypertension (ISH) is the most common subtype in this population. The major haemodynamic determinant underlying ISH is increased large-artery stiffness. This is expressed as an increase in SBP and decrease in diastolic blood pressure (DBP), leading to widening pulse pressure. Epidemiological studies show that ISH and increased pulse pressure in the elderly constitute independent cardiovascular risk factors and may be more robust in predicting the adverse cardiovascular sequelae of hypertension than elevated DBP alone. Reducing high blood pressure (> 140/90 mmHg), including ISH (SBP > 140 mmHg, DBP < 90 mmHg), with conventional and newer antihypertensive agents significantly reduces the risk of major coronary events, stroke, coronary heart disease and all-cause mortality. Among the elderly population, there appears to be no age threshold beyond which treatment of hypertension, including ISH, should not be considered beneficial. Clinical management has to take into account some specific aspects related to its pathophysiology and the patient characteristics of this population. Although the therapeutic goal is < 140/90 mmHg, a decrease of 20-30 mmHg in SBP, even if the overall goal is not achieved, is associated with improved prognosis.

Lercanidipine vs lacidipine in isolated systolic hypertension

This randomised, double-blind, double-dummy, parallel group, multicentre study compared the efficacy and tolerability of lercanidipine with lacidipine. Elderly patients with isolated systolic hypertension (supine blood pressure >/=160/<95 mmHg) were enrolled and underwent a placebo run-in period of 14-27 days before random allocation to lercanidipine tablets 10 mg once daily (n=111) or lacidipine tablets 2 mg once daily (n=111) for the assessment period (112-160 days). Titration to lercanidipine 20 mg once daily (two 10 mg tablets) or lacidipine 4 mg once daily (two 2 mg tablets) was allowed after 8 weeks, if required. Both treatments decreased supine and standing systolic and diastolic blood pressure between the end of the run-in period and the end of the assessment period (P<0.0001). At the end of the assessment period, the estimated mean treatment difference (95% confidence intervals) in supine systolic blood pressure was -0.81 (-4.45, 2.84) mmHg. These confidence intervals were within the limits specified for equivalence, that is, (-5, 5) mmHg. Ambulatory blood pressure monitoring showed that the antihypertensive effects of both drugs lasted for the full 24-h dosing period and followed a circadian pattern. Both treatments were well tolerated with a low incidence of adverse drug reactions and a low withdrawal rate. Significantly fewer patients withdrew from treatment with lercanidipine (P=0.015). Neither treatment had any clinically significant effect on pulse rate or cardiac conduction. In conclusion, both treatments were equally effective in controlling supine systolic blood pressure in patients with isolated systolic hypertension.

Comparison of the effects on 24-h ambulatory blood pressure of valsartan and amlodipine, alone or in combination with a low-dose diuretic, in elderly patients with isolated systolic hypertension (Val-syst Study)

OBJECTIVE

The aim of this study was to compare the time-effect profiles of a once-daily administration of valsartan and amlodipine, each given alone or in combination with hydrochlorothiazide, in terms of ambulatory blood pressure (BP) and heart rate in elderly patients with isolated systolic hypertension.

METHODS

One hundred and sixty-four elderly outpatients with systolic hypertension received valsartan 80 mg (n=79) or amlodipine 5 mg (n=85) once daily for eight weeks, after which the patients with poorly controlled office BP were up-titrated to valsartan 160 mg or amlodipine 10 mg once daily. If their office systolic BP was still >140 mmHg after eight weeks at these doses, 12.5 mg hydrochlorothiazide was added for a further eight weeks. The hourly BP decreases in all of the patients were calculated on the basis of 24-h ambulatory recordings made after the placebo period and at the end of active treatment. The trough/peak ratio and smoothness index were calculated in the responders.

RESULTS

Both the valsartan- and amlodipine-based treatments effectively lowered mean 24-h, daytime and night-time systolic ambulatory BP (all p<0.001) without any significant differences between the two regimens. Ambulatory heart rate decreased in the subjects on valsartan and slightly increased in those on amlodipine (the differences in 24-h and daytime heart rate were significant (p=0.008 and 0.002 respectively). Among the 138 responders, the valsartan-based treatment had a greater anti-hypertensive effect during the daytime hours (p=0.02), a difference that was also significant for average 24-h BP (p=0.02). The mean systolic BP trough/peak ratio was 0.56 in the patients on valsartan, and 0.77 in those on amlodipine (NS). The smoothness index was respectively 1.70 and 1.58 (NS).

CONCLUSIONS

The present results show that both the valsartan- and amlodipine-based treatments lead to a similar long-term reduction in 24-h systolic BP. However, in treatment responders, valsartan has a greater anti-hypertensive effect during the daytime.

Treatment and blood pressure control in isolated systolic hypertension vs diastolic hypertension in primary care

Cross-sectional surveys on prevalence, treatment and control of hypertension could not satisfactorily distinguish between diastolic hypertension and isolated systolic hypertension because the definition of hypertension included patients under pharmacological treatment. We assessed the situation in the two types of hypertension in general practice in Belgium, based on current blood pressure (BP) measurements and on BP prior to the initiation of drug therapy. Participating physicians enrolled the first 15 at least 55-year-old men visiting the surgery, measured their BP and recorded data on medical history including pretreatment BP, drug utilization, cardiovascular risk factors and target organ damage. Diastolic hypertension was defined as diastolic BP> or =90 mmHg, irrespective of systolic BP, and isolated systolic hypertension as systolic BP > or =140 mmHg and diastolic BP < 90 mmHg. Among 3761 evaluable patients, 74% were hypertensive. Among the 1533 hypertensive patients in whom blood pressure was known prior to treatment (n=965) or who were untreated at the study visit (n=568), 1164 had diastolic hypertension and 369 isolated systolic hypertension. The prevalence of antihypertensive treatment was, respectively, 75 and 25% (P<0.001) in these two types of hypertension. The odds of being treated were independently determined by type of hypertension, severity of hypertension and level of risk (P<0.001). BP was controlled in 25% of all patients with diastolic hypertension and in 13% of all patients with isolated systolic hypertension (P<0.001). About half of the treated patients with systolic hypertension were on a diuretic and/or a calcium-channel blocker. In conclusion, isolated systolic hypertension is less frequently treated than diastolic hypertension, overall BP control is poor and actual drug therapy diverges from recommendations based on placebo-controlled intervention trials.

Perindopril-based blood pressure lowering in individuals with cerebrovascular disease

OBJECTIVE

To assess the consistency of the benefits of blood pressure lowering on secondary stroke risk by age, sex and geographic region of recruitment.

DESIGN

Randomized, placebo-controlled trial. Participants were randomized to the angiotensin-converting enzyme (ACE) inhibitor perindopril (plus the diuretic indapamide if not indicated or contraindicated) or to placebo(s) over a mean follow-up of 3.9 years. Main analyses used Cox proportional hazards models on an intention-to-treat basis. Subgroup results were standardized for the proportion (42%) taking single-drug therapy.

SETTING

A total of 172 centres in Asia, Australia, New Zealand and Europe.

PARTICIPANTS

Patients (n = 6105) with a history of stroke or transient ischaemic attack, of whom 50% were aged over 65 years at baseline, 30% were women and 39% were from Asia.

MAIN OUTCOME MEASURES

Stroke, coronary heart disease and major vascular events.

RESULTS

Overall, treatment reduced stroke by 28% [95% confidence interval (CI) 17-38%] and major vascular events by 26% (16-44%), with separately significant reductions across subgroups defined by age (< or > or = 65 years), sex and region (Asia or not). Treatment was safe and well tolerated, and the absolute benefits were large; 5 years' treatment would be expected to avert at least one major vascular event among every 20 patients in all age, sex and region subgroups. There was some evidence of particularly large benefits among younger participants and those from Asia.

CONCLUSIONS

Blood pressure lowering reduces secondary stroke risk, with large absolute benefits across groups defined by age, sex and geographic region.

Trials in isolated systolic hypertension: an update

Isolated systolic hypertension (ISH) has proved to be a powerful predisposing factor for cardiovascular diseases in the elderly. Recent placebo-controlled interventional trials such as the Systolic Hypertension in the Elderly Program, the Systolic Hypertension in Europe, and the Systolic Hypertension in China showed that the lowering of systolic blood pressure using a diuretic- or a calcium antagonist-based treatment is associated with a decrease in cardiovascular events. Antihypertensive therapy was found especially effective in preventing stroke in the elderly with ISH. A slowing in the progression of dementia was observed in patients randomized to a calcium antagonist-based treatment. Patients at high cardiovascular risk such as those with diabetes benefited the most from treatment. In another trial performed in patients with left ventricular hypertrophy (Losartan Intervention For Endpoint Reduction), a subset of patients had ISH. In those patients, an angiotensin II antagonist-based treatment was superior to a b-blocker-based treatment in preventing cardiovascular complications. The experience accumulated in patients with ISH showed that combination therapy is often required to control blood pressure. Overall, the evidence available today indicates that pharmacologic treatment of ISH markedly improves the outcome of elderly patients.

Impact of the high-risk and mass strategies on hypertension control and stroke mortality in primary health care

Stroke has been the second leading cause of death in Taiwan in recent years. Following a 6-month pilot study in Yu-Chi in 1993, a 3.5-year hypertension control programme was performed to examine the effectiveness of combined high-risk and mass strategies in a rural community with limited medical resources. All Yu-Chi residents aged 40 years and older were invited to participate in the programme. The high-risk strategies included hypertension screening, home visits, and follow-up for the hypertensives. The mass strategies included health education and village-based campaigns. Changes over time in the participants' hypertension knowledge, behaviour, and blood pressure control status were evaluated. A comparison of the stroke mortality between the intervention community and a neighbourhood reference community before and after the intervention programme was performed. A total of 4977 residents were screened and 3761 completed the first and second rescreening. The hypertension knowledge and behaviour scores in the hypertensives significantly improved, systolic and diastolic blood pressure and waist-to-hip ratio significantly reduced, and the rates of hypertension treatment and control increased significantly at 1 and 3.5 years after intervention. In contrast, blood pressure levels increased significantly in the normotensives. Between 1994 and 1997, stroke mortality rate decreased by 39.9 and 4.8% in the intervention and reference communities, respectively. The results indicated that the community-based hypertension control programme was effective. The immediate decline in stroke mortality appeared to be mostly related to the high-risk strategies.

Fosinopril and amlodipine in the treatment of isolated systolic hypertension

The aim of this study was to assess the therapeutic effects of fosinopril (F) and amlodipine (A) on regulation and circadian rhythm of blood pressure, and to evaluate left ventricle mass index (LVMI) in patients over 60 years of age with isolated systolic hypertension, after three months of administration period. After one-week placebo run-in period, 60 patients were randomized into two groups, each including 30 patients, to receive either fosinopril or amlodipine for three months. Clinical, echocardiographic examinations and 24h ambulatory blood pressure measurements were performed at baseline, and after 3 months of therapy. The goal blood pressure was ? 140/90 mmHg. It was accomplished in more than two thirds of cases (F 76.6%, and A 79.9%), with lower drug doses needed in the group treated with F. In 13 patients goal values were not accomplished, therefore the therapy was prolonged for one additional month, with combination of two drugs. In 10 of these patients (76.9%), adequate regulation of blood pressure was achieved. Both fosinopril and amlodipine efficiently control blood pressure by once-a-day administration, both significantly influencing its circadian rhythm and resulting in regression of myocardial hyperthrophy. Adequate control of blood pressure and beneficial effects on circadian rhythm of blood pressure are achieved with lower doses of fosinopril.

Use of Calcium Channel Antagonists for the Treatment of Hypertension in the Elderly

Systolic blood pressure and pulse pressure increase continuously throughout adult life and the prevalence of arterial hypertension rises accordingly, reaching 53-78% among those aged 65-74 years. Estimates of the prevalence of isolated systolic hypertension in the elderly range from 34-65%, with more women than men affected. It has been shown that within all age groups a difference in usual systolic blood pressure of 20 mm Hg or a difference in usual diastolic blood pressure of 10 mm Hg is associated with an approximately 2-fold difference in the risk of dying from stroke or ischaemic heart disease. Intervention trials using predominantly diuretics and/or beta-adrenoceptor antagonists have proven the efficacy and tolerability of antihypertensive treatment in elderly patients. For many years there have been ongoing discussions about the safety of calcium channel antagonists, especially in patients with diabetes mellitus. However, according to a recently published large prospective, randomised, double-blind, controlled clinical trial with more than 33,000 patients enrolled, no indications for increased total mortality, cancer rate or gastrointestinal bleeding for participants on amlodipine, a long-acting dihydropyridine calcium channel antagonist, were found. With calcium channel antagonists, protective effects against cardiovascular disease have been proven in large trials with elderly patients, particularly against stroke. There is good evidence to suggest that calcium channel antagonists may be superior to other antihypertensive agents in diabetic patients with isolated systolic hypertension. These agents are well tolerated and probably delay the progression of dementia. The lack of adverse metabolic effects that, in the case of a diuretic-based regimen, may have important long-term implications concerning cardiovascular risk, make calcium channel antagonists an attractive choice when antihypertensive treatment decisions need to be made in a predominantly overweight or obese elderly population.

The Use of Calcium Antagonists in the Therapy of Hypertension in the Elderly

Calcium antagonists (calcium channel blockers) are widely used in the treatment of hypertension and other cardiovascular diseases. The results of a large number of clinical trials have demonstrated that calcium antagonists are as efficacious as other classes of antihypertensive agents in decreasing blood pressure in the elderly patients. Large clinical trials have shown the effectiveness of calcium antagonists (with long duration of action) in reducing cardiovascular and cerebrovascular morbidity and mortality in elderly hypertensive patients. The calcium antagonists are a chemically, pharmacologically and therapeutically heterogeneous group of agents. Among themselves, they differ in vasoselectivity, effect on cardiac conduction, sympathetic activation, adverse effect profile, ability to protect against target organ damage, suitability for patients with co-morbid conditions, and pharmacodynamic characteristics. The calcium antagonists can be used as single agents or in combination with other antihypertensive drugs. These drugs should not be used as first-line drugs in treating high blood pressure in patients with heart failure, since drugs in other classes provide more benefits. The dihydropyridine calcium antagonists should not be used in post-myocardial infarction patients or in patients with unstable angina; however, non-dihydropyridines may be used in such patients. The adverse effects of dihydropyridines include peripheral and ankle edema, flushing and headache. The short-acting preparations of the older calcium antagonists are no longer used, because of the potential for adverse cardiovascular outcome.

Hydralazine for treatment of severe hypertension in pregnancy: meta-analysis

OBJECTIVE

To review outcomes in randomised controlled trials comparing hydralazine against other antihypertensives for severe hypertension in pregnancy.

STUDY DESIGN

Meta-analysis of randomised controlled trials (published between 1966 and September 2002) of short acting antihypertensives for severe hypertension in pregnancy. Independent data abstraction by two reviewers. Data were entered into RevMan software for analysis (fixed effects model, relative risk and 95% confidence interval); in a secondary analysis, risk difference was also calculated.

RESULTS

Of 21 trials (893 women), eight compared hydralazine with nifedipine and five with labetalol. Hydralazine was associated with a trend towards less persistent severe hypertension than labetalol (relative risk 0.29 (95% confidence interval 0.08 to 1.04); two trials), but more severe hypertension than nifedipine or isradipine (1.41 (0.95 to 2.09); four trials); there was significant heterogeneity in outcome between trials and differences in methodological quality. Hydralazine was associated with more maternal hypotension (3.29 (1.50 to 7.23); 13 trials); more caesarean sections (1.30 (1.08 to 1.59); 14 trials); more placental abruption (4.17 (1.19 to 14.28); five trials); more maternal oliguria (4.00 (1.22 to 12.50); three trials); more adverse effects on fetal heart rate (2.04 (1.32 to 3.16); 12 trials); and more low Apgar scores at one minute (2.70 (1.27 to 5.88); three trials). For all but Apgar scores, analysis by risk difference showed heterogeneity between trials. Hydralazine was associated with more maternal side effects (1.50 (1.16 to 1.94); 12 trials) and with less neonatal bradycardia than labetalol (risk difference -0.24 (-0.42 to -0.06); three trials).

CONCLUSIONS

The results are not robust enough to guide clinical practice, but they do not support use of hydralazine as first line for treatment of severe hypertension in pregnancy. Adequately powered clinical trials are needed, with a comparison of labetalol and nifedipine showing the most promise.

Hydralazine for treatment of severe hypertension in pregnancy: meta-analysis

OBJECTIVE

To review outcomes in randomised controlled trials comparing hydralazine against other antihypertensives for severe hypertension in pregnancy.

STUDY DESIGN

Meta-analysis of randomised controlled trials (published between 1966 and September 2002) of short acting antihypertensives for severe hypertension in pregnancy. Independent data abstraction by two reviewers. Data were entered into RevMan software for analysis (fixed effects model, relative risk and 95% confidence interval); in a secondary analysis, risk difference was also calculated.

RESULTS

Of 21 trials (893 women), eight compared hydralazine with nifedipine and five with labetalol. Hydralazine was associated with a trend towards less persistent severe hypertension than labetalol (relative risk 0.29 (95% confidence interval 0.08 to 1.04); two trials), but more severe hypertension than nifedipine or isradipine (1.41 (0.95 to 2.09); four trials); there was significant heterogeneity in outcome between trials and differences in methodological quality. Hydralazine was associated with more maternal hypotension (3.29 (1.50 to 7.23); 13 trials); more caesarean sections (1.30 (1.08 to 1.59); 14 trials); more placental abruption (4.17 (1.19 to 14.28); five trials); more maternal oliguria (4.00 (1.22 to 12.50); three trials); more adverse effects on fetal heart rate (2.04 (1.32 to 3.16); 12 trials); and more low Apgar scores at one minute (2.70 (1.27 to 5.88); three trials). For all but Apgar scores, analysis by risk difference showed heterogeneity between trials. Hydralazine was associated with more maternal side effects (1.50 (1.16 to 1.94); 12 trials) and with less neonatal bradycardia than labetalol (risk difference -0.24 (-0.42 to -0.06); three trials).

CONCLUSIONS

The results are not robust enough to guide clinical practice, but they do not support use of hydralazine as first line for treatment of severe hypertension in pregnancy. Adequately powered clinical trials are needed, with a comparison of labetalol and nifedipine showing the most promise.

Current treatment of patients with hypertension: therapeutic implications of INSIGHT

When planning treatment for patients with hypertension, current guidelines emphasise the importance of risk stratification, based on blood pressure, the presence of end-organ damage and other cardiovascular risk factors. Because the beneficial effect of antihypertensive therapy seems to be linked to the degree of blood pressure reduction, guidelines recommend reducing blood pressure below 140/90mm Hg, with a lower target in patients who are young or who have diabetes mellitus (with or without nephropathy) or non-diabetic nephropathy. Blood pressure reduction can be achieved with several classes of drugs, including diuretics, beta-blockers, ACE inhibitors, angiotensin II antagonists and calcium channel antagonists. Calcium channel antagonists have been shown to reduce the risk of stroke and major cardiovascular events. However, it is still controversial whether different treatment regimens based on different drug classes can offer advantages beyond similar degrees of blood pressure control in preventing cardiovascular morbidity and mortality. The International Nifedipine GITS Study: Intervention as a Goal in Hypertension Treatment (INSIGHT) was a controlled clinical trial aimed at comparing the efficacy of a long-acting calcium channel antagonist, nifedipine gastrointestinal-transport-system (GITS), versus co-amilozide, a combination of the diuretics hydrochlorothiazide (HCTZ) and amiloride, on morbidity and mortality in high-risk hypertensive patients. Nifedipine GITS and HCTZ/amiloride were equally effective at reducing blood pressure and the risk of primary outcomes (a composite of death from any cardiovascular or cerebrovascular cause, non-fatal stroke, myocardial infarction and heart failure). Results from other studies indicate that there may be greater benefits for stroke and smaller benefits for coronary artery disease with calcium channel antagonist-based regimens than with diuretic or beta-blocker-based regimens. However, there is at present insufficient evidence to recommend a specific drug choice based on patient risk profile. Thus, the choice of antihypertensive drug(s) should be according to efficacy and tolerability. In addition to the reductions in cardiovascular risk, two substudies of INSIGHT showed that nifedipine GITS was able to prevent the progression of intima media thickness in the common carotid artery and slow the progression of coronary calcification. The clinical significance of this effect in the prevention of cardiovascular events still remains to be established.

The Differences Between ACE Inhibitor-Treated and Calcium Channel Blocker-Treated Hypertensive Patients

Large-scale outcome trials have demonstrated that blood pressure reduction with angiotensin-converting enzyme (ACE) inhibitors or calcium channel blockers (CCBs) is associated with reduced cardiovascular complications in hypertension. Comparative trials against conventional drugs and between ACE inhibitors and CCBs have failed to reveal conclusive differences in cause-specific outcomes. Studies in high-risk patients suggest that ACE inhibitors are superior to CCBs and other drugs in protection against cardiovascular events and renal disease. Very long-term prospectively collected observational data from the Glasgow Blood Pressure Clinic and the UK General Practice Research Database strongly support an advantage of ACE inhibitors over CCBs for cardiovascular morbidity and mortality. Considering all the available information, it can be concluded that the use of CCBs in the routine therapy of hypertension cannot be recommended while wider use of ACE inhibitors, along with low-dose diuretics and beta blockers, appears justified.