B-blockers as an add-on or combination therapy effective for BP lowering: Study

Findings from the study, published in The Journal of Clinical Hypertension, align with the current hypertension guideline recommendations. The study found that β-blockers (excluding atenolol) are effective in lowering blood pressure as a component of combination antihypertensive therapy or as an add-on to monotherapy.

Despite the same clinical evidence, current hypertension management guidelines differ for using β-blockers. The CHL (Chinese Hypertension League) guidelines recommend β-blockers as one of the first-line antihypertensive drugs. In contrast, the ESH (European Society of Hypertension)/ESC (European Society of Cardiology) and the ISH (International Society of Hypertension) guidelines recommend β-blockers use at any treatment step for cardiovascular disease (CVD) patients. The JSH (Japanese Society of Hypertension) and the AHA (The American Heart Association)/ACC (American College of Cardiology) recommend d β-blockers for resistant hypertension and for CVD patients.

There is emerging evidence from clinical trials that antihypertensive therapy with a β-blocker, except atenolol, may be particularly effective in BP control. Therefore, Qian-Hui Guo from the Shanghai Jiaotong University School of Medicine in Shanghai, China, and colleagues performed a meta-analysis and systematic review of RCTs to assess the effects of β-blockers, other than atenolol as a component of antihypertensive therapy on systolic and diastolic blood pressure in hypertension patients.

For this purpose, the authors searched online databases and identified relevant randomized controlled trials. It included studies comparing BP lowering effects of β-blockers with angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs), or diuretics. A total of 20 studies comprising 5544 participants were included in the analysis.

The study revealed the following findings:

• β-blockers add-on to monotherapy significantly reduced systolic and diastolic blood pressure compared to non-β-blocker monotherapy (weighted mean difference in mm Hg −4.1 and −3.7 respectively).
• These results were consistent across the comparisons with diuretics (systolic pressure, −10.2; diastolic pressure, −5.4), CCBs (systolic pressure, −4.1; diastolic pressure, −2.8), and ACEIs/ARBs (systolic pressure, −2.9; diastolic pressure, −4.2).
• There was no significant difference in blood pressure lowering effects between combinations with and without a β-blocker (systolic pressure, −1.3 mm Hg; diastolic pressure, −.3 mm Hg).
• Metoprolol add-on or combination therapy had a significantly more significant blood pressure reduction than non-β-blocker therapy (systolic pressure, −3.6 mm Hg; diastolic pressure, −2.1 mm Hg).

"Our findings showed that non-atenolol β-blockers as add-ons to several other antihypertensive drugs, such as CCBs, diuretics, and even ACEIs/ARBs, were effective in further blood pressure lowering and that combination therapy with β-blockers equally effective as non-β-blocker combination therapy," the researchers wrote.

"Thus, in line with the current guideline recommendations, β-blockers can and should be used in combination with other classes of antihypertensive drugs at any stage of hypertension treatment," they concluded.

Reference:

Guo QH, Zhu ZM, Feng YQ, Lin JX, Wang JG. Blood pressure lowering effects of β-blockers as add-on or combination therapy: A meta-analysis of randomized controlled trials. J Clin Hypertens (Greenwich). 2023 Feb 8. doi: 10.1111/jch.14616. Epub ahead of print. PMID: 36756690.