Beta blockers in patients with heart failure

Researchers in the Archives of Internal Medicine 2004 did an overview of randomised beta blocker trials in patients with heart failure which attempts to quantify the risks of adverse effects.
They searched Medline from 1966 to 2002 and identified 9 trials in over 14,000 patients followed up from 6 to 24 months and combined the results to calculate estimates of risks associated with therapy. Beta blocker therapy was associated with significant absolute annual increases in risks of:

• Hypotension , Dizziness and Bradycardia.

The team note that these absolute increases in risk were small, and overall fewer patients were withdrawn from beta-blocker therapy than from placebo. There was no significant absolute risk of fatigue associated with therapy. The risk of depression and sexual dysfunction were not assessed.

Beta-blocker therapy was associated with a reduction in:

• All-cause withdrawal of medication , All-cause mortality, Heart failure hospitalisations and Worsening HF.

The authors hope that these data will alleviate concerns about prescribing beta-blockers to patients with heart failure.

The article observes that Beta blocker therapy should only be started in a stable patient in the absence of cardiogenic shock.
• The more severe the heart failure and the lower the BP, the smaller should be the initial dose of the beta-blocker.
• In patients with severe heart failure and low blood pressure, the titration of the dose of beta blocker should also be slower.

Furthermore, in patients with severe clinical heart failure (particularly III-B or IV), there may be a deterioration in the signs and symptoms of heart failure during initiation and titration of beta blocker. These potential problems should be discussed with the patient, and it should be emphasised that this initial deterioration is quite common, that these symptoms will resolve and cardiac function and prognosis improve with continued therapy.