Heart Failure: All ARBs Aren’t the Same
Study Suggests Higher Death Risk in Losartan Patients
Jan. 11, 2011 -- Blood pressure drugs in the class known as angiotensin II receptor blockers (ARBs) reduce mortality in patients with heart failure, but new research suggests that not all work equally well.
Heart failure patients in Sweden who took the drug candesartan (Atacand) had a lower risk of death than patients who took the drug losartan (Cozaar).
The analysis included more than 30,000 patients enrolled in a Swedish heart failure registry.
At one year, 90% of patients taking candesartan were still alive, compared to 83% of patients taking losartan. After five years, 61% of candesartan patients and 44% of losartan patients were living.
The study appears Jan. 12 in the Journal of the American Medical Association.
No ARB Class Effect
The naturally occurring hormone angiotensin II causes blood vessel walls to constrict and narrow, leading to an increase in blood pressure. ARBs lower blood pressure by blocking the action of angiotensin II.
Although the drugs have never been compared head to head for the treatment of heart failure, there have been suggestions that some ARBs are more effective than others.
In a 2007 study involving patients who were 65 and older, survival rates among patients taking losartan were worse than rates for patients taking other ARBs, including candesartan, irbesartan (Avepro), and valsartan (Diovan).
The findings suggested that the benefits derived by heart failure patients were not due to an ARB class effect.
The newly published study raises more questions about a class effect, but they do not mean that patients taking losartan need to stop taking the drug or switch to another ARB, American Heart Association spokesman Clyde W. Yancy, MD, tells WebMD.
Yancy is chief of cardiology at Chicago’s Northwestern University Feinberg School of Medicine.
“The bottom line is this should not change clinical practice,” he says. “We have seen nothing that raises concerns that this drug or any other angiotensin receptor blocker causes harm.”
Manufacturer: ‘More Study Needed’
In several previous studies examining ARBs in the treatment of heart failure, benefits were limited to patients with compromised heart function, as evidence by reduced left ventricular ejection fraction (LVEF).