Use of the angiotensin receptor blocker (ARB) irbesartan does not appear to reduce mortality rates in patients with heart failure (HF), US research suggests.
The findings, presented at the American Heart Association scientific sessions in New Orleans last week, highlight the need for better treatments for HF patients with preserved left ventricular ejection fraction.
Researchers randomly assigned 4,128 patients, aged 60 and over, to receive 300mg of irbesartan or placebo daily. All had HF and an ejection fraction of at least 45 per cent.
The patients were followed up for 49.5 months, during which time 742 people in the irbesartan group died, compared with 763 deaths in the placebo group. But this difference was not statistically significant.
Lead researcher Dr Barry Massie, from the Veterans Affairs Medical Centre, San Francisco, said that the trial failed to achieve its primary endpoint, a reduction of mortality.
'It had no significant impact on the secondary endpoints of hospitalisation for HF, stroke and MI,' he added.
'It is disappointing that there remains no specific evidencebased therapy for these patients.'
However, the researchers pointed out that the effects of ARBs in the trial may have been decreased by the fact that 25 per cent of patients involved were taking ACE inhibitors and 15 per cent were taking spironolactone, which affect the renin-angiotensin system.
In order for this field to move forward, a better understanding of the mechanisms underlying this syndrome and the potential targets for treatment are required, said Dr Massie.
Dr Margaret Redfield, from the Mayo Clinic in Minnesota, added: 'This was a very impor-tant trial. ARBs are commonly used in HF patients despite a lack of evidence.
'We need more studies to understand what is going on with these patients.'
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