Key messages
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In people who have mildly elevated blood pressure but do not have cardiovascular disease (e.g. heart attacks) or other related health risks (e.g. diabetes), blood pressure-lowering medications may not reduce the risk of death or the risk of developing major cardiovascular (heart and blood vessel) disease.
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Blood pressure-lowering medications may lower the risk of stroke, but may also increase the risk of unwanted effects that result in study withdrawal.
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Additional research is needed to understand the effects of blood pressure-lowering medications in people with mildly elevated blood pressure without cardiovascular disease or other health-related risks (e.g. diabetes).
What is hypertension?
Hypertension is consistently high blood pressure.
How is hypertension treated?
Depending on the severity of an individual's hypertension and other medical conditions they may have, hypertension can be treated with a healthy lifestyle including diet and regular physical activity. Medications are also commonly prescribed.
What did we want to find out?
We wanted to know the benefits and risks of medications that lower blood pressure prescribed in people who have mild hypertension (systolic blood pressure 140 to 159 mmHg, diastolic blood pressure 90 to 99 mmHg) and did not have major cardiovascular (heart and blood vessel) diseases or other related health risks.
What did we do?
We searched for studies of blood pressure-lowering medications in people with mild hypertension to find out if they lower the risk of death and major cardiovascular diseases (including stroke and heart attacks). We also looked at the risk of unwanted effects. We compared and summarized the results of the studies and rated our confidence in the evidence based on factors such as study methods and sizes.
What did we find?
We included five studies involving a total of 9124 people, 4593 who received blood pressure-lowering medications and 4531 who received placebo (dummy treatment) or no treatment. We found that medications may not lower the risk of death or major cardiovascular diseases. Blood pressure-lowering medications may lower the risk of stroke, but may also increase the risk of unwanted effects that result in study withdrawal.
Main results
The benefit of a lower risk of stroke with blood pressure medications for people with mild hypertension and no other heart conditions or conditions that increase their risk of cardiovascular disease needs to be weighed against the unwanted effects of these medications.
What are the limitations of the evidence?
We have little confidence in the evidence because the studies did not cover all the people we were interested in; the studies were very small; and there were not enough studies to be certain about the results. One of the studies that showed a reduced risk of stroke looked at people with kidney disease, so it may not be applicable to all people with mild hypertension. Only one study reported on unwanted effects of the medications.
How up-to-date is the evidence?
The evidence is current to June 2024.
Read the full abstract
People with no previous cardiovascular events or cardiovascular disease represent a primary prevention population. The benefits and harms of treating mild hypertension in primary prevention patients are not known at present. This review examines the existing randomised controlled trial (RCT) evidence.
Objectives
To reassess the efficacy and risks of initiating antihypertensive pharmacotherapy in adults with untreated mild hypertension and no pre-existing cardiovascular disease. The primary objective was to reassess the risk of all-cause mortality and total cardiovascular events (defined as fatal and non-fatal strokes, myocardial infarction, and congestive heart failure). The secondary objectives were to reassess the risk of stroke (fatal and non-fatal), coronary heart disease (fatal and non-fatal myocardial infarction and sudden cardiac death), and WDAEs.
Search strategy
We searched the Cochrane Hypertension Specialised Register, CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform from inception to June 2024.
Selection criteria
RCTs of at least 1 year duration.
Data collection and analysis
The outcomes assessed were mortality, stroke, coronary heart disease (CHD), total cardiovascular events (CVS), and withdrawals due to adverse effects.
Main results
Of 11 RCTs identified 4 were included in this review, with 8,912 participants. Treatment for 4 to 5 years with antihypertensive drugs as compared to placebo did not reduce total mortality (RR 0.85, 95% CI 0.63, 1.15). In 7,080 participants treatment with antihypertensive drugs as compared to placebo did not reduce coronary heart disease (RR 1.12, 95% CI 0.80, 1.57), stroke (RR 0.51, 95% CI 0.24, 1.08), or total cardiovascular events (RR 0.97, 95% CI 0.72, 1.32). Withdrawals due to adverse effects were increased by drug therapy (RR 4.80, 95%CI 4.14, 5.57), Absolute risk increase (ARI) 9%.
Authors' conclusions
In people with untreated mild hypertension and no pre-existing cardiovascular disease, initiation of antihypertensive monotherapy or step-up therapy may not reduce all-cause mortality, total cardiovascular events, or coronary heart disease compared to those who received placebo or no treatment. There may be a reduction in stroke, but possibly also an increase in WDAEs.
Funding
CIHR Grant to the Hypertension Review Group and British Columbia Ministry of Health Grant to the Therapeutics Initiative.
Registration
Protocol (2007): doi.org/10.1002/14651858.CD006742.
Original review (2012): doi.org/10.1002/14651858.CD006742.pub2.
