Beta blockers have a role in younger hypertensive patients
Beta blockers have been dropped out of major guidelines as first-line therapy for hypertension but there may be exceptions to this rule, says a cardiologist.
The Joint National Committee (JNC) 8 and National Institute for Health and Care Excellence (NICE) guidelines removed the recommendation of beta blockers as first-line therapy for the management of hypertension, said consultant cardiologist Professor Imran Zainal Abidin, of the Faculty of Medicine, University of Malaya. The removal is supported by a Cochrane meta-analysis but as the pathophysiology of essential hypertension differs in elderly and younger patients, age should be factored in when interpreting study findings and guideline recommendations. [Cochrane Database Syst Rev 2017;(1):CD002003, BMJ 2009;338:b1665. Doi:10.1136/bmj.b1665]
The elderly are more prone to have isolated systolic hypertension whereas younger patients usually have diastolic hypertension with or without elevated systolic pressure, he said. Hypertension in younger patients is associated with obesity and increased sympathetic nerve activity. Moreover, high plasma norepinephrine levels have been linked to higher CV risk, said Imran. Similarly, high resting heart rates—a surrogate for high sympathetic nerve activity—can be predictive of premature all-cause death, coronary heart disease and CV events in younger hypertensives.
In this younger group, antihypertensives that can increase sympathetic nerve activity such as diuretics, dihydropyridine calcium blockers and angiotensin receptor blockers do not decrease and may even increase the risk of myocardial infarction. As such, they are inappropriate first-line agents in younger hypertensive patients and this should be highlighted in recommendations by all guidelines, said Imran.
Additionally, the type of beta blocker used in most studies that found the antihypertensive class lacking in protection against stroke and CV outcomes was atenolol. Thus, there is insufficient evidence to expand that verdict to all the drugs in the class, he noted.
Moreover, there is evidence that shows beta blockers are effective in reducing composite death, stroke and myocardial infarction in patients less than 60 years old. [CMAJ 2006;174(12):1737–1742] Further elaborating, Imran said there was a 35 to 50 percent reduction in the risk of myocardial infarction (beta blockers vs placebo or diuretics) and 50 to 55 percent reduction in stroke risk (vs placebo), in non-smoking men.
Besides younger patients, beta blockers are also an appropriate antihypertensive agent for patients with essential hypertension and concomitant ischaemic heart disease, heart failure, obstructive cardiomyopathy, aortic dissection or certain cardiac arrhythmias, said Imran. This class of antihypertensives may also be useful for patients with hyperkinetic circulation—palpitations, tachycardia and anxiety, migraine headaches and essential tremors.
Imran was speaking at the Malaysian Society of Hypertension’s (MSH) 15th Annual Scientific Meeting, held recently in Kuala Lumpur.