By Chris Berrie
MILAN, Italy -- June 18, 2008 -- The beta-blocker bisoprolol and the angiotensin-converting enzyme inhibitor (ACEI) enalapril have similar efficacies as monotherapies in elderly patients with mild-to-moderate chronic heart failure (HF), although significantly worsening HF is seen with bisoprolol, according to the multicentre, prospective, randomised Cardiac Insufficiency Bisoprolol Study (CIBIS) 3 trial.
The trial was presented here in a poster presentation on June 16 at the Heart Failure 2008 (HF2008) Congress.
Standard optimal treatment for HF involves a combination of an ACEI and a beta-blocker, although in clinical practice, some patients might only tolerate one of these therapies. According to European guideline recommendations, this treatment starts with the ACEI and the beta-blocker is added later.
"In practice, it is not always possible to have both drugs, so most patients, in fact, end up with an angiotensin-converting enzyme inhibitor but not a beta-blocker," indicated researcher Daniela Dobre, MD, Department of Clinical Pharmacology, University Medical Centre Gröningen, Gröningen, Netherlands.
Indeed, with elderly patients in particular, tolerance problems can lead many patients to not receive a beta-blocker at all, or to only receive lower doses than recommended.
To assess the clinical effects and safety profiles of initial monotherapy with bisoprolol versus enalapril in elderly patients with mild to moderate HF, the CIBIS 3 trial studied 1,010 patients 65 years or older with mild to moderate HF were randomised to monotherapy with bisoprolol (n = 505) or enalapril (n = 505) for 6 months.
The study's primary outcome was a combined endpoint of all-cause mortality or hospitalisation; secondary endpoints were each individual endpoint, as well as cause of death and safety.
For the composite primary endpoint, the impact of the 2 drugs were not significantly different, with rates of all-cause mortality or hospitalisation of 22% for bisoprolol and 21% for enalapril (hazard ratio, 1.02; 95% confidence interval, 0.8-1.3; P = .9).
Also similar in the 2 treatment arms were rates of nonsudden death (3% vs 3%; P = .9), unclassified death (0.2% vs 0.2%; P = .9), all-cause hospitalisation (20% vs 18%; P = .6), and cardiovascular hospitalisation (12% vs 10%; P = .3).
Although there were no safety concerns with either agent, there was a trend in favour of bisoprolol for all-cause mortality (5% vs 6%; P = .2) and sudden death (2% vs 3%; P = .1). However, more patients in the bisoprolol arm had significantly worsening HF that required hospitalisation or that occurred in hospital (9% vs 5%; P = .03).
Dr. Dobre said, "The idea is that, indeed, in some patients [a beta-blocker] may provide benefit, according to indications for some patients with heart failure, but physicians have to be aware that under this medication the patient should be titrated very carefully and monitored very closely."
Funding for this study was provided by Merck & Co.
[Presentation title: Clinical Effects of Initial 6-Months Monotherapy With Bisoprolol Versus Enalapril in the Treatment of Patients With Mild to Moderate Chronic Heart Failure. Data From the CIBIS 3 Trial. Abstract P666]
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