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

BACKGROUND

Previous meta-analysis of outcome trials in hypertension have not specifically focused on isolated systolic hypertension or they have explained treatment benefit mainly in function of the achieved diastolic blood pressure reduction. We therefore undertook a quantitative overview of the trials to further evaluate the risks associated with systolic blood pressure in treated and untreated older patients with isolated systolic hypertension

METHODS

Patients were 60 years old or more. Systolic blood pressure was 160 mm Hg or greater and diastolic blood pressure was less than 95 mm Hg. We used non-parametric methods and Cox regression to model the risks associated with blood pressure and to correct for regression dilution bias. We calculated pooled effects of treatment from stratified 2 x 2 contingency tables after application of Zelen's test of heterogeneity.

FINDINGS

In eight trials 15 693 patients with isolated systolic hypertension were followed up for 3.8 years (median). After correction for regression dilution bias, sex, age, and diastolic blood pressure, the relative hazard rates associated with a 10 mm Hg higher initial systolic blood pressure were 1.26 (p=0.0001) for total mortality, 1.22 (p=0.02) for stroke, but only 1.07 (p=0.37) for coronary events. Independent of systolic blood pressure, diastolic blood pressure was inversely correlated with total mortality, highlighting the role of pulse pressure as risk factor. Active treatment reduced total mortality by 13% (95% CI 2-22, p=0.02), cardiovascular mortality by 18%, all cardiovascular complications by 26%, stroke by 30%, and coronary events by 23%. The number of patients to treat for 5 years to prevent one major cardiovascular event was lower in men (18 vs 38), at or above age 70 (19 vs 39), and in patients with previous cardiovascular complications (16 vs 37).

INTERPRETATION

Drug treatment is justified in older patients with isolated systolic hypertension whose systolic blood pressure is 160 mm Hg or higher. Absolute benefit is larger in men, in patients aged 70 or more and in those with previous cardiovascular complications or wider pulse pressure. Treatment prevented stroke more effectively than coronary events. However, the absence of a relation between coronary events and systolic blood pressure in untreated patients suggests that the coronary protection may have been underestimated.

Randomised trial of treatment of hypertension in elderly patients in primary care

A randomised trial of the treatment of hypertension in 884 patients aged 60 to 79 years at the onset showed a reduction of 18/11 mm Hg in blood pressure over a mean follow up period of 4.4 years. The principal antihypertensive agents were atenolol and bendrofluazide. There was a reduction in the rate of fatal stroke in the treatment group to 30% of that in the control group (95% confidence interval 11-84%, p less than 0.025). The rate of all strokes (fatal and non-fatal) in the treatment group was 58% of that in the control group (95% confidence interval 35-96%, p less than 0.03). The incidence of myocardial infarction and total mortality was unaffected by treatment. Questionnaires completed by the patients and their relatives failed to identify any differences in symptoms that were likely to be due to treatment.

Antihypertensive drugs in very old people: a subgroup meta-analysis of randomised controlled trials. INDANA Group

BACKGROUND

Beneficial clinical effects of treatment with antihypertensive drugs have been shown in middle-aged patients and in those hypertensive patients over 60 years old, but whether treatment is beneficial in patients over 80 years old is not known.

METHODS

We collected data from all participants aged 80 years and over in randomised controlled trials of antihypertensive drugs through direct contact with study investigators. Our primary outcome was fatal and non-fatal stroke. Secondary outcomes were death from all causes, cardiovascular death, fatal and non-fatal major coronary and cardiovascular events, and heart failure.

FINDINGS

There were 57 strokes and 34 deaths among 874 actively treated patients, compared with 77 strokes and 28 stroke deaths among 796 controls, representing 1 non-fatal stroke prevented for about 100 patients treated each year. The meta-analysis of data from 1670 participants aged 80 years or older suggested that treatment prevented 34% (95% CI 8-52) of strokes. Rates of major cardiovascular events and heart failure were significantly decreased, by 22% and 39%, respectively. However, there was no treatment benefit for cardiovascular death, and a non-significant 6% (-5 to 18) relative excess of death from all causes.

INTERPRETATIONS

The inconclusive findings for mortality contrast with the benefit of treatment for non-fatal events. Results of a large-scale specific trial are needed for definite conclusion that antihypertensive treatment is beneficial in very elderly hypertensive patients. Meanwhile, an age threshold beyond which hypertension should not be treated cannot be justified.

Effect of antihypertensive drug treatment on cardiovascular outcomes in women and men. A meta-analysis of individual patient data from randomized, controlled trials. The INDANA Investigators

BACKGROUND

Trials of drug therapy for hypertension have shown that such therapy has a clear overall benefit in preventing cardiovascular disease. Although these trials have included slightly more women than men, it is still not clear whether treatment benefit is similar for both sexes.

OBJECTIVE

To quantify the average treatment effect in both sexes and to determine whether available data show significant differences in treatment effect between women and men.

DESIGN

Subgroup meta-analysis of individual patient data according to sex. Analysis was based on seven trials from the INDANA (INdividual Data ANalysis of Antihypertensive intervention trials) database and was adjusted for possible confounders.

PATIENTS

20,802 women and 19,975 men recruited between 1972 and 1990.

INTERVENTIONS

Primarily beta-blockers and thiazide diuretics.

RESULTS

In women, treatment effect was statistically significant for stroke (fatal strokes and all strokes) and for major cardiovascular events. In men, it was statistically significant for all categories of events (total and specific mortality, all coronary events, all strokes, and major cardiovascular events). The odds ratios for any category of event did not differ significantly between men and women. In absolute terms, the benefit in women was seen primarily for strokes; in men, treatment prevented as many coronary events as strokes. Graphical analyses suggest that these results could be completely explained by the difference in untreated risk.

CONCLUSIONS

In terms of relative risk, treatment benefit did not differ between women and men. The absolute risk reduction attributable to treatment seemed to depend on untreated risk. These findings underline the need to predict accurately the untreated cardiovascular risk of an individual person in order to rationalize and individualize antihypertensive treatment.

Effects of "natural oestrogen" replacement therapy on menopausal symptoms and blood clotting

In a double-blind study on the value of equine ("natural") oestrogens 30 patients presenting with menopausal symptoms in a group practice were monitored for possible adverse effects on blood clotting, weight, and blood pressure. The women were randomly allocated to two groups and given either three months' hormone treatment followed by three months' placebo or vice versa. An appreciable amelioration of all symptoms on placebo made it difficult to asses the genuine value of oestrogen treatment during the period of study. Both groups made a dramatic clinical improvement during the first three months. Nevertheless, the symptoms of the 15 women who received oestrogen first returned after the cross-over to placebo without any suggestion of a placebo response. In contrast, the other group who took placebo first did not deteriorate after changing to oestrogen. The menopausal index and the karyopyknotic index were not reliable guides to the need for oestrogen treatment. Hot flushes, however, were proportionately reduced on oestrogen and they seemed to be more readily eliminated in individual cases by oestrogen. The results of blood clotting studies indicated that natural oestrogen administration raised the levels of the extrinsic clotting factors VII and X and accelerated the prothrombin time. The findings were similar to those observed after three months synthetic oestrogen administration with oral contraception. Long-term studies and epidemiological surveys of the clinical incidence of thrombotic and other sequelae are needed before large-scale oestrogen replacement treatment can be recommended.

Effect of antihypertensive treatment in patients having already suffered from stroke. Gathering the evidence. The INDANA (INdividual Data ANalysis of Antihypertensive intervention trials) Project Collaborators

BACKGROUND AND PURPOSE

Drug treatment of high blood pressure has been shown to reduce the associated cardiovascular risk. Stroke represents the type of event more strongly linked with high blood pressure, responsible for a high rate of death or invalidity, and with the highest proportion of events that can be avoided by treatment. Hypertensive patients with a history of cerebrovascular accident are at particularly high risk of recurrence. Specific trials of blood pressure lowering drugs in stroke survivors showed inconclusive results in the past.

METHODS

We performed a meta-analysis using all available randomized controlled clinical trials assessing the effect of blood pressure lowering drugs on clinical outcomes (recurrence of stroke, coronary events, cause-specific, and overall mortality) in patients with prior stroke or transient ischemic attack.

RESULTS

We identified 9 trials, including a total of 6752 patients: 2 trials included 551 hypertensive stroke survivors; 6 trials of hypertensive patients included a small proportion of stroke survivors (536 patients); 1 trial included stroke survivors, whether hypertensive or not (5665 patients). The recurrence of stroke, fatal and nonfatal, was significantly reduced in active groups compared with control groups consistently across the different sources of data (relative risk of 0.72, 95% confidence interval: 0.61 to 0.85). There was no evidence that this intervention induced serious adverse effect.

CONCLUSIONS

Blood pressure lowering drug interventions reduced the risk of stroke recurrence in stroke survivors. Available data did not allow to verify whether such benefit depends on initial blood pressure level. More data are needed before considering antihypertensive therapy in normotensive patients at high cerebrovascular risk.

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.

Can we improve compliance with long-term HRT?

In order to increase awareness of strategies to prevent osteoporosis and heart disease we designed a clinic offering education and screening to all women aged 40-60 years on our practice list of 8600 patients, starting in January 1988. Screening and supervision of HRT users occurred at a weekly clinic run by the doctor and nurse. Audit in August 1991 showed that there were 260 present users of HRT (20%) of our population of 1322 women aged 40-60 years. Seventy-eight percent had taken HRT for over a year and 15% for more than 5 years. Ex-users totalled 117, of whom 52% had taken HRT for over a year and 14% for over 5 years. Examination of the clinic registers and responses to postal questionnaires showed that 681 (51.5%) of patients attended the health education clinic. Of the clinic attenders, 25% took HRT compared with 10.8% of non-attenders. Compliance with long-term therapy measured by audit of repeat prescriptions varied between 84% and 92% over a period of 5 years. Reasons for stopping treatment were anxiety over possible side-effects, especially breast cancer and dislike of bleeding.

Menopause research: the Korpilampi workshop

A workshop on menopause research focused on three topics: (1) problems and issues in the definition of menopausal status: (2) problems and issues in cross-cultural research: (3) the contributions which research in the behavioural sciences can make to clinical research and practice. Among the conclusions reached by the workshop was the recommendation that researchers should adopt a standard definition of menopause based on the cessation on menses. Yet, while standard definitions are essential to scientific comparison, it is also important to determine how women decide on their own status, particularly when working cross-culturally.

Conjugated equine oestrogens and blood clotting: a follow-up report

A follow-up study of blood clotting and platelet aggregation was performed on 21 women who had received long-term hormone replacement treatment with conjugated equine oestrogens. The prothrombin time and factor VII and X values were significantly accelerated after three months, but there was no further increase with continual administration for 18 months. After 12 to 18 months' treatment, however, thrombin-induced platelet aggregation (Chandler's tube) was also significantly accelerated, which suggested a widening spectrum of effect. No overall acceleration of "intrinsic" clotting (partial thromboplastin time and thromboelastography) was found during the study, but the relatively small numbers may have been responsible. Further efforts are therefore required to find formulations and doses of oestrogens which, while relieving menopausal symptoms, cause less acceleration of blood clotting and platelet aggregation.

A study of the effectiveness of propranolol in menopausal hot flushes

A prospective, double-blind, randomized comparison of propranolol, 40 mg three times daily, and matching placebo showed propranolol to be no more effective than placebo in controlling hot flushes in a group of 25 perimenopausal women. Other menopausal symptoms, such as insomnia and palpitations, were equally unaffected. However, a very close correlation was found between the daily atmospheric temperature and the number of flushes occurring in the group.

The Hypertension in the Very Elderly Trial (HYVET). Rationale, methodology and comparison with previous trials

The Hypertension in the Very Elderly Trial (HYVET) is a multicentre, open, randomised, controlled trial. The aim of this trial is to investigate the effect of active treatment on stroke incidence in hypertensive patients over the age of 80 years. Secondary end-points include total cardiovascular mortality and morbidity. Entry criteria include a sustained sitting systolic blood pressure of 160 to 219mm Hg plus a sustained sitting diastolic pressure of 95 to 109mm Hg. Also required is a standing systolic blood pressure of at least 140mm Hg. Patients must give their informed consent, and be free of congestive heart failure requiring treatment, gout, renal failure or a recent cerebral haemorrhage. Patients are to be randomised to 3 groups-(i) no treatment; (ii) treatment with a diuretic [bendroflumethiazide (bendrofluazide)]; or (iii) treatment with an angiotensin converting enzyme (ACE) inhibitor (lisinopril). Starting dosage for bendroflumethiazide and lisinopril is 2.5 mg/day. In order to achieve goal sitting systolic and diastolic blood pressures (< 150/80 mm Hg), a doubling of the dosage is allowed. Furthermore, slow release diltiazem (120 mg/day increasing to 240 mg/day if required) may be added to the medication of the actively treated groups. These drugs have been chosen as inexpensive and appropriate representatives of their therapeutic classes. 700 patients in each group (a total of 2100) will be sufficient to detect a 40% difference in cerebrovascular events between no treatment and active treatment (alpha = 0.01, 1-beta = 0.90). These numbers will also detect a difference in total mortality of 25% and in cardiovascular mortality of 35%. The pilot phase of the trial has been started with support from the British Heart Foundation. Centres which are interested in taking part should contact C.J. Bulpitt or any of the other authors.

Hormonal and non-hormonal interventions for menopausal symptoms

Recent cohort studies confirm that only flushes, night sweats and vaginal dryness are provenly associated with ovarian failure. Experiments nave demonstrated that these symptoms and insomnia associated with nocturnal vasomotor symptoms are more effectively controlled by oestrogen than placebo. Hormonal interventions include a variety of oestrogen or oestrogen/progestogen regimes. Non-hormonal treatments of flushes include exercise, paced respiration and psychotherapy. After the menopause vaginal atrophy and some urinary symptoms respond to local oestrogen and vaginal dryness in also prevented by lubricants. Libido is not increased by oestrogen therapy but may be improved by testosterone. Depression is common in middle-aged women but is not specifically associated with the hormonal changes occurring at the menopause. Oestrogen therapy may improve and stabilise mood during the peri-menopause but there is no firm evidence that it is effective for depression after the menopause. Arthralgia is not a symptom specific to menopause and experimental evidence concerning the role of oestrogen in the treatment of rheumatoid arthritis is inconclusive. Cognitive function is not related to menopause and measures such as stopping smoking, exercise and maintaining body weight may be partly effective in preventing menopausal symptoms.

Identification of risk factors in hypertensive patients: contribution of randomized controlled trials through an individual patient database

BACKGROUND

Predicting individual risk is needed to target preventive interventions toward people with the highest probability of benefit over a given time period. We assessed which prognostic factors should be used in predicting risk for hypertensive patients and in searching for treatment modifiers.

METHODS AND RESULTS

Data from 24 390 hypertensive participants who constituted the control groups from 8 controlled trials (1726 deaths over 5 years) were analyzed in multivariate survival models. Outcomes were coronary heart disease death, stroke death, and cardiovascular death. We explored systematically the heterogeneity of results between trials. Left ventricular hypertrophy was electrocardiographically confirmed to be a powerful risk factor and should be included in risk scoring. Height, glomerular filtration rate, and serum uric acid deserve further exploration. Body mass index and heart rate were not confirmed as independent cardiovascular risk factors in this population. The association between male sex and coronary heart disease death was significantly stronger in British cohorts. The lack of prognostic value of diastolic blood pressure was explained by an interaction with age, with a positive association before 65 years and a negative association thereafter. Previous antihypertensive treatment was a significant risk factor.

CONCLUSIONS

Clinical trials provide valuable information for risk prediction. Carefully exploring the heterogeneity among trials is a way to assess the generalizability of findings. This approach, if systematically performed, should increase the ability to identify risk modifiers and to predict individual therapeutic benefit.

A double-blind cross-over study of piperazine oestrone sulphate and placebo with coagulation studies

A double-blind trial of piperazine oestrone sulphate was performed over a period of 14 months on 55 menopausal women complaining of depressiona and hot flushes. Depression was not affected but the hot flushes were significantly lessened by the oestrogen treatment. After three months of piperazine oestrone sulphate there were no significant accelerations of prothrombin time or increases in factors VII or X but, after six months, there was an acceleration in the prothrombin time. After 14 months those who received piperazine oestrone sulphate for the first six months showed a significant increase in alpha 1-antitrypsin and factor VIIR:AG. Oestrone piperazine sulphate appears to produce less marked changes in coagulation than oestrogen-containing oral contraceptives or conjugated equine oestrogens.