The more expensive angiotensin-receptor blocker (ARB) candesartan fared better for heart failure patients compared with losartan, but cost may drive people toward the latter, according to a study published in the Jan. 12 issue of the Journal of the American Medical Association.
“For heart failure, it is known that these types of drugs—ARBs—reduce the combination of mortality and hospitalization and they are used mainly in patients who cannot tolerate ACE inhibitors,” senior author Lars H. Lund, MD, PhD, told Cardiovascular Business News. “But they [ARBs] also are used with other ACE inhibitors, so they are good and established drugs, but it is not known which are preferred or if there are any differences between them.”
Lund and his colleagues from the department of cardiology at the South Hospital in Stockholm, Sweden, compared the rates of all-cause mortality in heart failure (HF) patients who were administered ARBs, either candesartan (Atacand, AstraZeneca) or losartan (Cozaar, Merck) to better understand the makeup of the two drugs.
Researchers used the Swedish Heart Failure Registry to look at the results of 30,254 patients registered at 62 hospitals and 60 outpatient clinics between 2000 and 2009. Of those patients, 2,639 patients were treated with candesartan and 2,500 were treated with losartan.
Study patients had a mean age of 74 and 39 percent were women, and the study’s primary outcome was all-cause mortality at one and five years. Patients who were given candesartan were healthier but had a lower left ventricular ejection fraction (LVEF) compared with those administered losartan.
The researchers found that patients who were administered candesartan had a 90 percent one-year survival rate compared to 83 percent of patients who received losartan. Five-year survival rates were reported to be 61 and 44 percent, respectively.
One complication of the research, said Lund, is that losartan recently went off patent and is now almost 10-fold cheaper than candesartan. “At the time of this study, people were already moving away from candesarton in favor of losartan because of the cost difference.”
The study will cause two very different reactions, Lund said. Some will say that every patient should be switched to candesartan despite its high cost, while others will say that mandating this huge cost difference is not yet justified by the current findings.
“It will be interesting to watch the conversation pan out, and I don’t know which reaction will dominate,” Lund offered.
Last June, a Lancet Oncology study reported that certain types of ARBs—in particular losartan, candesartan and telmisartan (Micardis, Boehringer Ingelheim)—may increase the risk of cancer in patients. While the current study did not look at this issue, subsequent studies have shown that there should not be too much concern with the increased cancer risk linked to ARBs, Lund said.
“I think the consensus is that ARBs are not harmful,” said Lund. However, he did note that a recent study found when ACE inhibitors were administered with ARBs, a potential risk of cancer was found, but said more studies are needed to prove these findings.
“While we expected a small difference between the outcomes of candesartan and losartan, our study showed a much larger difference than some studies comparing ARBs and placebo,” Lund concluded.
“Ideally, different ARB agents should be tested against each other in randomized-controlled trials. It would also be important and perhaps more feasible to confirm our findings in other large HF registries,” he said