BP Lowering Useful in CV Risk Management Even at Normal Levels

Megan Brooks

April 30, 2021

Lowering blood pressure with antihypertensive medication protects against future cardiovascular (CV) events even in people with normal or only mildly elevated blood pressure, a large meta-analysis concludes.

Results showed that each 5 mm Hg reduction in systolic blood pressure lowered the relative risk for CV events by about 10% across the full spectrum of baseline blood pressures, regardless of whether or not the individual had cardiovascular disease (CVD) or not.

"The take-home message is that pharmacological blood pressure lowering should be considered as a tool for cardiovascular risk management even when blood pressure is normal or mildly elevated, for primary and secondary prevention of CVD," lead investigator Kazem Rahimi, MD, University of Oxford, United Kingdom, told theheart.org | Medscape Cardiology.

"The advice to patients with normal blood pressure and high CVD risk is that they are likely to benefit from taking one or several antihypertensive medications to reduce their risk of suffering a major cardiovascular event in the future," Rahimi added.

The study was published online this week in The Lancet.

The data, from the Blood Pressure Lowering Treatment Trialists' Collaboration, were first presented at the virtual European Society of Cardiology (ESC) Congress 2020 and reported by theheart.org | Medscape Cardiology at that time.

For this analysis, Rahimi and colleagues looked at individual participant-level data from 48 randomized antihypertensive treatment trials. Participants were divided into seven subgroups based on systolic blood pressure baseline (less than 120, 120-129, 130-139, 140-149, 150-159, 160-169, 170 and above mm Hg).

The analysis included 344,716 patients with ≥1000 patient-years per allocated group.

Over an average 4 years of follow-up, a 5 mm Hg reduction in systolic blood pressure lowered the relative risk for major CV events by about 10%.

The risks for stroke, heart failure, ischemic heart disease, and death from CVD were reduced by 13%, 13%, 8%, and 5%, respectively.

The relative risk reductions were proportional to the intensity of blood pressure-lowering. Neither the presence of CVD nor the level of blood pressure at study entry modified the effect of treatment.

Practice Changing

"This study calls for a change in clinical practice that predominantly confines antihypertensive treatment to people with higher than average blood pressure values," Rahimi and colleagues write.

"On the basis of this study, the decision to prescribe blood pressure medication should not be based simply on a previous diagnosis of cardiovascular disease or an individual's current blood pressure. Rather, blood pressure medication should be viewed as an effective tool for preventing cardiovascular disease when an individual's cardiovascular risk is elevated," they say.

In a linked editorial, Thomas Kahan, MD, PhD, Karolinska Institute, Stockholm, Sweden, notes that the similar relative benefits of treatment in primary and secondary prevention indicate that the CV risk for an individual will be "a major determinant of the absolute benefit of treatment, confirming the importance of risk assessment in individual patients."

"These findings have important implications for clinical practice and suggest that antihypertensive treatment might be considered for any person for whom the absolute risk for a future cardiovascular event is sufficiently high," Kahan writes.

In a Science Media Centre press release, Sir Nilesh Samani, MBChB, MD, medical director for the British Heart Foundation, said this study "again emphasizes the importance of controlling blood pressure as well as possible, to reduce the risk of heart and circulatory diseases."

"The benefits of lowering blood pressure are there whether you have preexisting heart disease or not, and this study shows that lowering blood pressure — even if it is in the normal range — is associated with fewer heart attacks and strokes," Samani commented.

"This doesn't mean we should treat everyone with blood pressure-lowering drugs. If someone already has a low risk of heart disease, a 10% reduction in their blood pressure may only carry a small direct benefit," Samani added. "Ultimately, the decision to treat blood pressure and the target level to aim for is something that requires a conversation between the patient and the doctor. It’s also important to remember that blood pressure can be improved by means other than medication such as exercise and losing weight."

The meta-analysis was funded by the British Heart Foundation, the National Institute for Health Research Oxford Biomedical Research Centre, Oxford Martin School, and UK Research and Innovation. Rahimi has disclosed no relevant financial relationships. Kahan has received research grants to the Karolinska Institute from Amgen, Medtronic, and ReCor Medical. Samani has disclosed no relevant financial relationships.

Lancet. Published online April 29, 2021. Full text, Editorial

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