Monday, March 14, 2011

THE RETURN OF AN OLD PROBLEM. ARBs AND AMIs?

I think the whole of the cardiology community is divided on this issue. Does ARB increase the incidence of AMIs? I remember, in the early 2000, there was a lot of debate about the earlier ARBs and AMIs and then On-Target came out , and showed that there was no increase risk. That was left that way.
Now, last summer, the early results of ROADMAP ( Randomised Olmesartan and Diabetes Microalbuminuria Prevention ). This trial involving 4447 patients with diabetes and at least one coronary risk factor, was randomised to placebo, or olmesartan at 40 mg daily, and followed up for 3.2 years. The early results released last summer, showed that Olmesartan did delay the onset of microalbuminuria, in this subset of patients, but it also showed an increase incidence of cardiac events. This prompted the FDA to ask for more information. Well, 9 months later, the ROADMAP has appeared in print in NEJM, March 10th issue, and the FDA has still not issued any statement, making one wondering what is happening. The ROADMAP, actually showed that there was a 23% delay in the onset of microalbuminuria. But this is severly offset by 15 cardiovascular events in the treatment arm, compared to 3 CVS events in the placebo arm. This is worrying.
There was also an earlier study, a smaller one to, studying the use of olmesartan to prevent microalbuminuria. That study of about 500 patients also showed a slight increase in cardiac events, while reducing the incidence of microalbuminuria.
Now, we are really confused? Does ARBs have an increase in cardiac risk? Is it the effective of BP to low normal levels ( the J curve effect ), that is causing the problem? Or are ARBs atherogenic, and also triggering events?
I do use alot of ARBs and so I am also a little concern. I searched the literature and consulted ( via email ) opinions from experts. They are also divided. Looks like we need more data, or a clinical trial looking specifically at this problem. It is an important issue to resolve, because ARB is otherwise a good drug.
I suppose, if we follow ROADMAP long enough, we may also get a better idea.

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