Systolic Hypertension in the Elderly Program (SHEP). Part 8: Electrocardiographic characteristics

Pharmacotherapy for hypertension in adults 60 years or older

BACKGROUND

This is the second substantive update of this review. It was originally published in 1998 and was previously updated in 2009. Elevated blood pressure (known as 'hypertension') increases with age - most rapidly over age 60. Systolic hypertension is more strongly associated with cardiovascular disease than is diastolic hypertension, and it occurs more commonly in older people. It is important to know the benefits and harms of antihypertensive treatment for hypertension in this age group, as well as separately for people 60 to 79 years old and people 80 years or older.

OBJECTIVES

Primary objective• To quantify the effects of antihypertensive drug treatment as compared with placebo or no treatment on all-cause mortality in people 60 years and older with mild to moderate systolic or diastolic hypertensionSecondary objectives• To quantify the effects of antihypertensive drug treatment as compared with placebo or no treatment on cardiovascular-specific morbidity and mortality in people 60 years and older with mild to moderate systolic or diastolic hypertension• To quantify the rate of withdrawal due to adverse effects of antihypertensive drug treatment as compared with placebo or no treatment in people 60 years and older with mild to moderate systolic or diastolic hypertension SEARCH METHODS: The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to 24 November 2017: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We contacted authors of relevant papers regarding further published and unpublished work.

SELECTION CRITERIA

Randomised controlled trials of at least one year's duration comparing antihypertensive drug therapy versus placebo or no treatment and providing morbidity and mortality data for adult patients (≥ 60 years old) with hypertension defined as blood pressure greater than 140/90 mmHg.

DATA COLLECTION AND ANALYSIS

Outcomes assessed were all-cause mortality; cardiovascular morbidity and mortality; cerebrovascular morbidity and mortality; coronary heart disease morbidity and mortality; and withdrawal due to adverse effects. We modified the definition of cardiovascular mortality and morbidity to exclude transient ischaemic attacks when possible.

MAIN RESULTS

This update includes one additional trial (MRC-TMH 1985). Sixteen trials (N = 26,795) in healthy ambulatory adults 60 years or older (mean age 73.4 years) from western industrialised countries with moderate to severe systolic and/or diastolic hypertension (average 182/95 mmHg) met the inclusion criteria. Most of these trials evaluated first-line thiazide diuretic therapy for a mean treatment duration of 3.8 years.Antihypertensive drug treatment reduced all-cause mortality (high-certainty evidence; 11% with control vs 10.0% with treatment; risk ratio (RR) 0.91, 95% confidence interval (CI) 0.85 to 0.97; cardiovascular morbidity and mortality (moderate-certainty evidence; 13.6% with control vs 9.8% with treatment; RR 0.72, 95% CI 0.68 to 0.77; cerebrovascular mortality and morbidity (moderate-certainty evidence; 5.2% with control vs 3.4% with treatment; RR 0.66, 95% CI 0.59 to 0.74; and coronary heart disease mortality and morbidity (moderate-certainty evidence; 4.8% with control vs 3.7% with treatment; RR 0.78, 95% CI 0.69 to 0.88. Withdrawals due to adverse effects were increased with treatment (low-certainty evidence; 5.4% with control vs 15.7% with treatment; RR 2.91, 95% CI 2.56 to 3.30. In the three trials restricted to persons with isolated systolic hypertension, reported benefits were similar.This comprehensive systematic review provides additional evidence that the reduction in mortality observed was due mostly to reduction in the 60- to 79-year-old patient subgroup (high-certainty evidence; RR 0.86, 95% CI 0.79 to 0.95). Although cardiovascular mortality and morbidity was significantly reduced in both subgroups 60 to 79 years old (moderate-certainty evidence; RR 0.71, 95% CI 0.65 to 0.77) and 80 years or older (moderate-certainty evidence; RR 0.75, 95% CI 0.65 to 0.87), the magnitude of absolute risk reduction was probably higher among 60- to 79-year-old patients (3.8% vs 2.9%). The reduction in cardiovascular mortality and morbidity was primarily due to a reduction in cerebrovascular mortality and morbidity.

AUTHORS' CONCLUSIONS

Treating healthy adults 60 years or older with moderate to severe systolic and/or diastolic hypertension with antihypertensive drug therapy reduced all-cause mortality, cardiovascular mortality and morbidity, cerebrovascular mortality and morbidity, and coronary heart disease mortality and morbidity. Most evidence of benefit pertains to a primary prevention population using a thiazide as first-line treatment.

First-line drugs for hypertension

BACKGROUND

This is the first update of a review published in 2009. Sustained moderate to severe elevations in resting blood pressure leads to a critically important clinical question: What class of drug to use first-line? This review attempted to answer that question.

OBJECTIVES

To quantify the mortality and morbidity effects from different first-line antihypertensive drug classes: thiazides (low-dose and high-dose), beta-blockers, calcium channel blockers, ACE inhibitors, angiotensin II receptor blockers (ARB), and alpha-blockers, compared to placebo or no treatment.Secondary objectives: when different antihypertensive drug classes are used as the first-line drug, to quantify the blood pressure lowering effect and the rate of withdrawal due to adverse drug effects, compared to placebo or no treatment.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to November 2017: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We contacted authors of relevant papers regarding further published and unpublished work.

SELECTION CRITERIA

Randomized trials (RCT) of at least one year duration, comparing one of six major drug classes with a placebo or no treatment, in adult patients with blood pressure over 140/90 mmHg at baseline. The majority (over 70%) of the patients in the treatment group were taking the drug class of interest after one year. We included trials with both hypertensive and normotensive patients in this review if the majority (over 70%) of patients had elevated blood pressure, or the trial separately reported outcome data on patients with elevated blood pressure.

DATA COLLECTION AND ANALYSIS

The outcomes assessed were mortality, stroke, coronary heart disease (CHD), total cardiovascular events (CVS), decrease in systolic and diastolic blood pressure, and withdrawals due to adverse drug effects. We used a fixed-effect model to to combine dichotomous outcomes across trials and calculate risk ratio (RR) with 95% confidence interval (CI). We presented blood pressure data as mean difference (MD) with 99% CI.

MAIN RESULTS

The 2017 updated search failed to identify any new trials. The original review identified 24 trials with 28 active treatment arms, including 58,040 patients. We found no RCTs for ARBs or alpha-blockers. These results are mostly applicable to adult patients with moderate to severe primary hypertension. The mean age of participants was 56 years, and mean duration of follow-up was three to five years.High-quality evidence showed that first-line low-dose thiazides reduced mortality (11.0% with control versus 9.8% with treatment; RR 0.89, 95% CI 0.82 to 0.97); total CVS (12.9% with control versus 9.0% with treatment; RR 0.70, 95% CI 0.64 to 0.76), stroke (6.2% with control versus 4.2% with treatment; RR 0.68, 95% CI 0.60 to 0.77), and coronary heart disease (3.9% with control versus 2.8% with treatment; RR 0.72, 95% CI 0.61 to 0.84).Low- to moderate-quality evidence showed that first-line high-dose thiazides reduced stroke (1.9% with control versus 0.9% with treatment; RR 0.47, 95% CI 0.37 to 0.61) and total CVS (5.1% with control versus 3.7% with treatment; RR 0.72, 95% CI 0.63 to 0.82), but did not reduce mortality (3.1% with control versus 2.8% with treatment; RR 0.90, 95% CI 0.76 to 1.05), or coronary heart disease (2.7% with control versus 2.7% with treatment; RR 1.01, 95% CI 0.85 to 1.20).Low- to moderate-quality evidence showed that first-line beta-blockers did not reduce mortality (6.2% with control versus 6.0% with treatment; RR 0.96, 95% CI 0.86 to 1.07) or coronary heart disease (4.4% with control versus 3.9% with treatment; RR 0.90, 95% CI 0.78 to 1.03), but reduced stroke (3.4% with control versus 2.8% with treatment; RR 0.83, 95% CI 0.72 to 0.97) and total CVS (7.6% with control versus 6.8% with treatment; RR 0.89, 95% CI 0.81 to 0.98).Low- to moderate-quality evidence showed that first-line ACE inhibitors reduced mortality (13.6% with control versus 11.3% with treatment; RR 0.83, 95% CI 0.72 to 0.95), stroke (6.0% with control versus 3.9% with treatment; RR 0.65, 95% CI 0.52 to 0.82), coronary heart disease (13.5% with control versus 11.0% with treatment; RR 0.81, 95% CI 0.70 to 0.94), and total CVS (20.1% with control versus 15.3% with treatment; RR 0.76, 95% CI 0.67 to 0.85).Low-quality evidence showed that first-line calcium channel blockers reduced stroke (3.4% with control versus 1.9% with treatment; RR 0.58, 95% CI 0.41 to 0.84) and total CVS (8.0% with control versus 5.7% with treatment; RR 0.71, 95% CI 0.57 to 0.87), but not coronary heart disease (3.1% with control versus 2.4% with treatment; RR 0.77, 95% CI 0.55 to 1.09), or mortality (6.0% with control versus 5.1% with treatment; RR 0.86, 95% CI 0.68 to 1.09).There was low-quality evidence that withdrawals due to adverse effects were increased with first-line low-dose thiazides (5.0% with control versus 11.3% with treatment; RR 2.38, 95% CI 2.06 to 2.75), high-dose thiazides (2.2% with control versus 9.8% with treatment; RR 4.48, 95% CI 3.83 to 5.24), and beta-blockers (3.1% with control versus 14.4% with treatment; RR 4.59, 95% CI 4.11 to 5.13). No data for these outcomes were available for first-line ACE inhibitors or calcium channel blockers. The blood pressure data were not used to assess the effect of the different classes of drugs as the data were heterogeneous, and the number of drugs used in the trials differed.

AUTHORS' CONCLUSIONS

First-line low-dose thiazides reduced all morbidity and mortality outcomes in adult patients with moderate to severe primary hypertension. First-line ACE inhibitors and calcium channel blockers may be similarly effective, but the evidence was of lower quality. First-line high-dose thiazides and first-line beta-blockers were inferior to first-line low-dose thiazides.

Atrial Fibrillation and Isolated Systolic Hypertension

We performed a post hoc analysis of the Systolic Hypertension in the Elderly Program database to assess the incidence of atrial fibrillation in the elderly hypertensive population, its influence on cardiovascular events, and whether antihypertensive treatment can prevent its onset. The Systolic Hypertension in the Elderly Program was a double-blind placebo-controlled trial in 4736 subjects with isolated systolic hypertension aged ≥60 years. Atrial fibrillation was an exclusion criterion from the trial. Participants were randomly assigned to stepped care treatment with chlorthalidone and atenolol (n=2365) or placebo (n=2371). The occurrence of atrial fibrillation and cardiovascular events over 4.7 years as well as the determination of cause of death at 4.7 and 14.3 years were followed. Ninety-eight subjects (2.06%) developed atrial fibrillation over 4.7 years mean follow-up, without significant difference between treated and placebo groups. Atrial fibrillation increased the risk for: total cardiovascular events (RR 1.69; 95% CI 1.21 to 2.36), rapid death (RR 3.29; 95% CI 1.08 to 10.00), total (RR 5.10; 95% CI 3.12 to 8.37) and nonfatal left ventricular failure (RR 5.31; 95% CI 3.09 to 9.13). All-cause and total cardiovascular death were significantly increased in the atrial fibrillation group at 4.7 years (HR 3.44; 95% CI 2.18 to 5.42; HR 2.39; 95% CI 1.05 to 5.43) and 14.3 years follow-up (HR 2.33; 95% CI 1.83 to 2.98; HR 2.21; 95% CI 1.54 to 3.17). Atrial fibrillation increased the risk for total cardiovascular events, rapid death, and left ventricular failure. All-cause mortality and total cardiovascular mortality were significantly increased in hypertensives with atrial fibrillation at 4.7 and 14.3 years follow-up.

Risk factors for stroke and type of stroke in persons with isolated systolic hypertension. Systolic Hypertension in the Elderly Program Cooperative Research Group

BACKGROUND AND PURPOSE

We sought to determine risk factors for stroke and stroke type in persons with isolated systolic hypertension (ISH).

METHODS

We performed proportional hazards analyses of data from the Systolic Hypertension in the Elderly Program, a double-blind, randomized, placebo-controlled trial of 4736 persons aged > or =60 years with ISH (systolic blood pressure, 160 to 219 mm Hg; diastolic blood pressure, <90 mm Hg). One treatment group received chlorthalidone (12.5 to 25 mg/d) with step-up to atenolol (25.0 to 50.0 mg/d) or reserpine (0.05 to 0.10 mg/d), if needed. The other treatment group received matching placebo. The main outcome measures were stroke, stroke or transient ischemic attack [TIA], and stroke types: ischemic (including lacunar, atherosclerotic, and embolic) and hemorrhagic.

RESULTS

During an average follow-up of 4.5 years, 384 strokes or TIAs and 262 strokes (including 217 ischemic, 66 lacunar, 26 atherosclerotic, and 25 embolic strokes) were documented. In multivariate analyses, placebo treatment, older age, smoking, history of diabetes, higher systolic blood pressure, lower HDL cholesterol, and ECG abnormality were significantly associated (P<0.05) with increased incidence of stroke or TIA, stroke, or ischemic stroke. Greater lacunar stroke risk was significantly related to placebo treatment, older age, history of diabetes (relative risk [RR] = 3.03; 95% confidence interval [CI], 1.70 to 5.40), and smoking (RR = 3.04; 95% CI, 1.73 to 5.37). Greater atherosclerotic and embolic stroke risk were significantly related to presence of carotid bruit (RR = 5.75; 95% CI, 2.50 to 13.24) and older age (RR = 1.65 per 5 years; 95% CI, 1.25 to 2.18), respectively.

CONCLUSIONS

In older persons with ISH, history of diabetes and smoking are important risk factors for lacunar stroke, whereas carotid bruit and age are important risk factors for atherosclerotic and embolic stroke, respectively.

Coronary heart disease risk factors in men and women aged 60 years and older: findings from the Systolic Hypertension in the Elderly Program

BACKGROUND

Coronary heart disease (CHD) is the most common cause of death in men and women aged 60 years and older. Although a number of studies support the concept that CHD risk factors that have been defined in younger adults are significantly associated with CHD events in older adults, others do not support this thesis, and further definition of the risk-factor concept in older adults is required.

METHODS AND RESULTS

The Systolic Hypertension in the Elderly Program recruited 4736 persons (mean age, 72 years); 14% were black, and 43% were men. Mean systolic and diastolic blood pressures were 170 and 77 mm Hg, respectively. About 13% of participants were current smokers; 10% had a history of diabetes; 5%, a prior myocardial infarction; 5% angina pectoris; 2.3%, intermittent claudication; and 7%, a carotid bruit. Mean total cholesterol value was 6.11 mmol/L. Mean follow-up was 4.5 years. In multivariate Cox regression analyses for CHD, variables that were significant were baseline total cholesterol value, smoking, history of diabetes, presence of carotid bruit, and treatment group in the trial. Active treatment yielded a 27% reduction in CHD risk. For each 1.03 mmol/L increase in total cholesterol value, there was an increase in risk of about 20%. Current smokers had a 73% increase, diabetics a 121% increase, and those with carotid bruit a 113% increase in CHD risk.

CONCLUSIONS

The results of this study support the concept that CHD risk factors are important in older men and women with isolated systolic hypertension.