How well can blood pressure be controlled? Progress report on the Systolic Hypertension in Europe Follow-Up Study (Syst-Eur 2)

BACKGROUND: The randomised, double-blind, placebo-controlled Systolic Hypertension in Europe trial (Syst-Eur 1) proved that blood pressure (BP) lowering therapy starting with nitrendipine reduces the risk of cardiovascular complications in elderly patients with isolated systolic hypertension. In an attempt to confirm the safety of long-term antihypertensive therapy based on a dihydropyridine, the Syst-Eur patients remained in open follow-up after the end of Syst-Eur 1. This paper presents the second progress report of this follow-up study (Syst-Eur 2). It describes BP control and adherence to study medications. METHODS: After the end of Syst-Eur 1 all patients, treated either actively or with placebo, were invited either to continue or to start antihypertensive treatment with the same drugs as previously used in the active treatment arm. In order to reach the target BP (sitting SBP <150 mmHg), the first line agent, nitrendipine, could be associated with enalapril and/or hydrochlorothiazide. RESULTS: Of the 3787 eligible patients, 3516 (93%) entered Syst-Eur 2. At the last available visit, 72% of the patients were taking nitrendipine. SBP/DBP at entry in Syst-Eur 2 averaged 160/83 mmHg in the former placebo group and 151/80 mmHg in the former active-treatment group. At the last follow-up visit SBP/DBP in the patients previously randomised to placebo or active treatment had decreased by 16/5 mmHg and 7/5 mmHg, respectively. The target BP was reached by 74% of the patients. CONCLUSION: Substantial reductions in systolic BP may be achieved in older patients with isolated systolic hypertension with a treatment strategy starting with the dihydropyridine calcium-channel blocker, nitrendipine, with the possible addition of enalapril and/or hydrochlorothiazide

Quality control of the blood pressure phenotype in the European Project on Genes in Hypertension

OBJECTIVES: In the European Project on Genes in Hypertension (EPOGH) standardized epidemiological methods were used to determine complex phenotypes consisting of blood pressure (BP) in combination with other traits. In this report, we present the quality control of one of the BP phenotypes. METHODS: In seven European countries eight different research groups recruited random samples of nuclear families. Trained observers measured the BP five times consecutively with the participants in the seated position at each of two separate home visits, 1 to 3 weeks apart, according to the guidelines of the British Hypertension Society. Quality assurance and quality control of this BP phenotype were implemented according to detailed instructions defined in the protocol of the EPOGH study. RESULTS: On 31 August 2001, BP measurements of 2476 subjects were available for analysis. Fewer BP readings than the five planned per visit occurred in one of the eight centres, but only in 0.4% of the home visits. Across centres the relative frequency of identical consecutive readings for systolic or diastolic blood pressure varied from 0 to 6%. The occurrence of odd readings ranged from 0 to 0.1%. Of the 49,488 systolic and diastolic BP readings, 24.0% ended on a zero (expected 20%). In most EPOGH centres there was a progressive decline in the BP from the first to the second home visit. Overall, these decreases averaged 2.36 mmHg [95% confidence interval (CI): 1.98-2.74, P < 0.001] for systolic BP and 1.74 mmHg (95% CI: 1.46-2.02, P < 0.001) for diastolic BP. CONCLUSIONS: Quality assurance and control should be planned at the design stage of a project involving BP measurement and implemented from its very beginnings until the end. The procedures of quality assurance set up in the EPOGH study for the BP measurements resulted in a well-defined BP phenotype, which was consistent across centres.status: publishe

Withdrawal from treatment in the Syst-Eur Trial.

OBJECTIVE: To investigate the reasons for withdrawal from double-blind randomized trials, and the reasons for changing treatment within a randomized therapeutic group. DESIGN: The Syst-Eur trial, in which 4695 older patients with systolic hypertension were randomized to active or placebo treatment. METHODS: The reasons for withdrawal from the trial were examined, both for patient-initiated and investigator-initiated withdrawals. In addition, the reasons for stopping the first-line treatment (nitrendipine), the second-line treatments (enalapril and hydrochlorothiazide) and the corresponding placebos, were determined. RESULTS: A total of 135 patients (6%) were withdrawn by the investigators from placebo treatment because their blood pressure was too high, and, similarly, 36 (1.6%) through patient initiation. The corresponding results for the actively treated patients were 14 (0.6%) and 7 (0.3%). Very few patients were withdrawn from the trial because of the adverse effects of treatment. However, 39 (4%) stopped taking active nitrendipine because of ankle oedema, compared with 4 (0.5%) on placebo. Similarly, 28 versus three stopped due to flushing. Forty-one (10%) stopped taking enalapril because of cough, against eight (2%) for enalapril placebo. In all, 15.0% stopped active nitrendipine, 20.2% enalapril and 6.3% hydrochlorothiazide, versus placebo 7.1, 9.1 and 5.1%. CONCLUSIONS: The numbers withdrawn from the trial for adverse treatment consequences were small in comparison to the cardiovascular benefits. Nevertheless the numbers stopping individual treatments were higher than expected

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.status: publishe

Prognostic Significance of Renal Function in Elderly Patients with Isolated Systolic Hypertension: Results from the Syst-Eur Trial

Several reports suggest that markers of renal function such as serum creatinine, serum uric acid, and urinary excretion of protein may be related to cardiovascular complications and mortality. This study analyzed the data from the Syst-Eur trial, which was a randomized, placebo-controlled, double-blind intervention trial in elderly patients with isolated systolic hypertension. The purpose was to evaluate whether serum levels of creatinine and uric acid and urinary protein excretion at entry are related to subsequent morbidity and mortality. Incidence rates of total mortality, cardiovascular mortality, stroke (fatal as well as nonfatal), coronary events, and all cardiovascular endpoints were calculated for each quintile of serum creatinine or serum uric acid or for each category of protein excretion (none, trace, and overt). Crude and adjusted relative hazard rates were also determined for each 20 micro M increase in serum creatinine, each 50 micro M increase in serum uric acid, and for each protein excretion category. Even when adjusted for age, gender, and various other covariates, serum creatinine was significantly associated with a worse prognosis. There was an U-shaped relationship between serum uric acid and total mortality, but otherwise no obvious relationships were detected between serum uric acid levels and complications when appropriate adjustments were made for confounding variables. Proteinuria at entry was a significant predictor of total mortality and all cardiovascular endpoints. It is concluded that higher levels of serum creatinine and trace or overt proteinuria are associated with an increased number of cardiovascular events and with a higher mortality in patients with isolated systolic hypertension.status: publishe

Prognostic significance of renal function in elderly patients with isolated systolic hypertension: results from the Syst-Eur trial

Several reports suggest that markers of renal function such as serum creatinine, serum uric acid, and urinary excretion of protein may be related to cardiovascular complications and mortality. This study analyzed the data from the Syst-Eur trial, which was a randomized, placebo-controlled, double-blind intervention trial in elderly patients with isolated systolic hypertension. The purpose was to evaluate whether serum levels of creatinine and uric acid and urinary protein excretion at entry are related to subsequent morbidity and mortality. Incidence rates of total mortality, cardiovascular mortality, stroke (fatal as well as nonfatal), coronary events, and all cardiovascular endpoints were calculated for each quintile of serum creatinine or serum uric acid or for each category of protein excretion (none, trace, and overt). Crude and adjusted relative hazard rates were also determined for each 20 micro M increase in serum creatinine, each 50 micro M increase in serum uric acid, and for each protein excretion category. Even when adjusted for age, gender, and various other covariates, serum creatinine was significantly associated with a worse prognosis. There was an U-shaped relationship between serum uric acid and total mortality, but otherwise no obvious relationships were detected between serum uric acid levels and complications when appropriate adjustments were made for confounding variables. Proteinuria at entry was a significant predictor of total mortality and all cardiovascular endpoints. It is concluded that higher levels of serum creatinine and trace or overt proteinuria are associated with an increased number of cardiovascular events and with a higher mortality in patients with isolated systolic hypertension.status: publishe

Predictive value of clinic and ambulatory heart rate for mortality in elderly subjects with systolic hypertension

OBJECTIVE: To examine the association of clinic and ambulatory heart rate with total, cardiovascular, and noncardiovascular death in a cohort of elderly subjects with isolated systolic hypertension from the Systolic Hypertension in Europe Trial. METHODS: A total of 4682 patients participated, whose untreated blood pressure on conventional measurement at baseline was 160 to 219 mm Hg systolic and lower than 95 mm Hg diastolic. Clinic heart rate was the mean of 6 readings during 3 visits. Ambulatory heart rate was recorded with a portable intermittent technique in 807 subjects. RESULTS: Raised baseline clinic heart rate was positively associated with a worse prognosis for total, cardiovascular, and noncardiovascular mortality among the 2293 men and women taking placebo. Subjects with heart rates higher than 79 beats/min (bpm) (top quintile) had a 1.89 times greater risk of mortality than subjects with heart rate lower than or equal to 79 bpm (95% confidence interval, 1.33-2.68 bpm). In a Cox regression analysis, predictors of time to death were heart rate (P<.001), age (P<.001), serum creatinine level (P =.001), presence of diabetes (P =.002), previous cardiovascular disease (P =.01), triglyceride readings (P =.02), smoking (P =.04), and elevated systolic blood pressure (P =.05), while total cholesterol level was found to be nonsignificant in the model. In the ambulatory monitoring subgroup, clinic and ambulatory heart rates predicted noncardiovascular but not cardiovascular mortality. However, in a Cox regression analysis in which clinic and ambulatory heart rates were included, a significant association with noncardiovascular mortality was found only for clinic heart rate (P =.004). In the active treatment group, the weak predictive power of clinic heart rate for mortality disappeared after adjustment for confounders. CONCLUSIONS: In untreated older patients with isolated systolic hypertension, a clinic heart rate greater than 79 bpm was a significant predictor of all-cause, cardiovascular, and noncardiovascular mortality. Ambulatory heart rate did not add prognostic information to that provided by clinic heart rate.status: publishe

Effects of immediate versus delayed antihypertensive therapy on outcome in the Systolic Hypertension in Europe Trial.

BACKGROUND: To assess the impact of immediate versus delayed antihypertensive treatment on the outcome of older patients with isolated systolic hypertension, we extended the double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) trial by an open-label follow-up study lasting 4 years. METHODS: The Syst-Eur trial included 4695 randomized patients with minimum age of 60 years and an untreated blood pressure of 160-219 mmHg systolic and below 95 mmHg diastolic. The double-blind trial ended after a median follow-up of 2.0 years (range 1-97 months). Of 4409 patients still alive, 3517 received open-label treatment consisting of nitrendipine (10-40 mg daily) with the possible addition of enalapril (5-20 mg daily), hydrochlorothiazide (12.5-25 mg daily), or both add-on drugs. Non-participants (n = 892) were also followed up. RESULTS: Median follow-up increased to 6.1 years. Systolic pressure decreased to below 150 mmHg (target level) in 2628 participants (75.0%). During the 4-year open-label follow-up, stroke and cardiovascular complications occurred at similar frequencies in patients formerly randomized to placebo and those continuing active treatment. These rates were similar to those previously observed in the active-treatment group during the double-blind trial. Considering the total follow-up of 4695 randomized patients, immediate compared with delayed antihypertensive treatment reduced the occurrence of stroke and cardiovascular complications by 28% (P = 0.01) and 15% (P = 0.03), respectively, with a similar tendency for total mortality (13%, P = 0.09). In 492 diabetic patients, the corresponding estimates of long-term benefit (P < 0.02) were 60, 51 and 38%, respectively. CONCLUSIONS: Antihypertensive treatment can achieve blood pressure control in most older patients with isolated systolic hypertension. Immediate compared with delayed treatment prevented 17 strokes or 25 major cardiovascular events per 1000 patients followed up for 6 years. These findings underscore the necessity of early treatment of isolated systolic hypertension

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 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