The risk is even worse if the drugs are taken in combination with others, such as thiazides, calcium antagonists or renin-angiotensin system (RAS) inhibitors.
The heart patient taking the drugs was almost twice as likely to suffer a major 'cardiovascular event' such as a heart attack, including a fatal attack, compared with the patient who wasn't taking those types of drugs.
The drugs' dangers were uncovered by researchers who looked at the outcomes for 55,320 patients with high blood pressure who were having surgery for something other than a cardiovascular condition.
Of these, 14,644 patients were taking beta-blockers and the rest had been prescribed other antihypertensive medications.
In a 30-day follow-up, researchers from the University of Copenhagen found that the risk of an adverse event was even higher in men who were 70 years of age or older and who were undergoing surgery for an acute problem.
(Source: JAMA Internal Medicine, 2015' 1: doi: 10.1001/jamainternmed.2015.5346)