Key messages
The evidence identified in this review does not support lower blood pressure goals over standard goals in people with high blood pressure (also known as hypertension) and heart or vascular (blood vessels and circulatory system) problems
More new trials are needed to examine this question
What is high blood pressure?
Hypertension (high blood pressure) is a long-term condition that increases the risk of health problems such as heart attack, stroke, or kidney disease.
How is high blood pressure treated?
Many people with heart or vascular problems also have high blood pressure. Some clinical guidelines recommend a lower blood pressure goal (135/85 mmHg or lower) for people with high blood pressure and previous heart or vascular problems than for with those without (140 mmHg to 160 mmHg or less systolic (pressure when heart pumps blood around the body) and 90 mmHg to 100 mmHg diastolic or less (pressure when heart rests between beats) are standard blood pressure goals). It is unclear whether lower goals lead to overall health benefits.
What did we want to find out?
We wanted to find out if lower blood pressure goals are better than standard blood pressure goals for people with high blood pressure who also have heart or vascular problems.
What did we do?
We searched for studies that compared lower blood pressure targets to standard blood pressure targets in people with high blood pressure and a history of cardiovascular disease (heart disease, angina, stroke, vascular disease). Studies had to talk about results such as deaths or other events caused by diseases of the heart or the blood vessels, such as heart attack, stroke, or heart failure. Studies could also talk about other types of health-related side effects. We only chose randomized studies (where people were randomly put into one of two or more treatment groups) with 50 or more people in each group and that lasted at least six months.
What did we find?
In this update, we found one new study giving a total of seven studies with 9595 people included in the review. We found little to no difference in total numbers of deaths, or heart or vascular deaths between lower and standard blood pressure goals. There was also little to no difference for the total number of heart or vascular problems and total serious harms, but the evidence was less certain.
What are the limitations of the evidence?
Based on uncertainty and limited information, we found more people dropped out of the trials because of medicine-related harms in the lower blood pressure target group and no overall health benefit among people in the lower target group.
How up to date is this evidence?
This is the third update of a review first published in 2017. The evidence is up to date to January 2022.
We found there is probably little to no difference in total mortality and cardiovascular mortality between people with hypertension and cardiovascular disease treated to a lower compared to a standard blood pressure target. There may also be little to no difference in serious adverse events or total cardiovascular events. This suggests that no net health benefit is derived from a lower systolic blood pressure target. We found very limited evidence on withdrawals due to adverse effects, which led to high uncertainty. At present, evidence is insufficient to justify lower blood pressure targets (135/85 mmHg or less) in people with hypertension and established cardiovascular disease. Several trials are still ongoing, which may provide an important input to this topic in the near future.
This is the third update of the review first published in 2017.
Hypertension is a prominent preventable cause of premature morbidity and mortality. People with hypertension and established cardiovascular disease are at particularly high risk, so reducing blood pressure to below standard targets may be beneficial. This strategy could reduce cardiovascular mortality and morbidity but could also increase adverse events. The optimal blood pressure target in people with hypertension and established cardiovascular disease remains unknown.
To determine if lower blood pressure targets (systolic/diastolic 135/85 mmHg or less) are associated with reduction in mortality and morbidity compared with standard blood pressure targets (140 mmHg to 160mmHg/90 mmHg to 100 mmHg or less) in the treatment of people with hypertension and a history of cardiovascular disease (myocardial infarction, angina, stroke, peripheral vascular occlusive disease).
For this updated review, we used standard, extensive Cochrane search methods. The latest search date was January 2022. We applied no language restrictions.
We included randomized controlled trials (RCTs) with more than 50 participants per group that provided at least six months' follow-up. Trial reports had to present data for at least one primary outcome (total mortality, serious adverse events, total cardiovascular events, cardiovascular mortality). Eligible interventions involved lower targets for systolic/diastolic blood pressure (135/85 mmHg or less) compared with standard targets for blood pressure (140 mmHg to 160 mmHg/90 mmHg to 100 mmHg or less).
Participants were adults with documented hypertension and adults receiving treatment for hypertension with a cardiovascular history for myocardial infarction, stroke, chronic peripheral vascular occlusive disease, or angina pectoris.
We used standard Cochrane methods. We used GRADE to assess the certainty of the evidence.
We included seven RCTs that involved 9595 participants. Mean follow-up was 3.7 years (range 1.0 to 4.7 years). Six of seven RCTs provided individual participant data. None of the included studies was blinded to participants or clinicians because of the need to titrate antihypertensive drugs to reach a specific blood pressure goal. However, an independent committee blinded to group allocation assessed clinical events in all trials. Hence, we assessed all trials at high risk of performance bias and low risk of detection bias. We also considered other issues, such as early termination of studies and subgroups of participants not predefined, to downgrade the certainty of the evidence.
We found there is probably little to no difference in total mortality (risk ratio (RR) 1.05, 95% confidence interval (CI) 0.91 to 1.23; 7 studies, 9595 participants; moderate-certainty evidence) or cardiovascular mortality (RR 1.03, 95% CI 0.82 to 1.29; 6 studies, 9484 participants; moderate-certainty evidence). Similarly, we found there may be little to no differences in serious adverse events (RR 1.01, 95% CI 0.94 to 1.08; 7 studies, 9595 participants; low-certainty evidence) or total cardiovascular events (including myocardial infarction, stroke, sudden death, hospitalization, or death from congestive heart failure (CHF)) (RR 0.89, 95% CI 0.80 to 1.00; 7 studies, 9595 participants; low-certainty evidence). The evidence was very uncertain about withdrawals due to adverse effects. However, studies suggest more participants may withdraw due to adverse effects in the lower target group (RR 8.16, 95% CI 2.06 to 32.28; 3 studies, 801 participants; very low-certainty evidence). Systolic and diastolic blood pressure readings were lower in the lower target group (systolic: mean difference (MD) –8.77 mmHg, 95% CI –12.82 to –4.73; 7 studies, 8657 participants; diastolic: MD –4.50 mmHg, 95% CI –6.35 to –2.65; 6 studies, 8546 participants). More drugs were needed in the lower target group (MD 0.56, 95% CI 0.16 to 0.96; 5 studies, 7910 participants), but blood pressure targets at one year were achieved more frequently in the standard target group (RR 1.20, 95% CI 1.17 to 1.23; 7 studies, 8699 participants).