Thursday, August 17, 2006

Yet another analysis of the ALLHAT trial

The idealized world of the medical student as he learns about randomized clinical trials (RCT) is one in which something like this is visualized. Let's do a RCT to find out which is the best way to treat hypertension and then we will have evidence based medicine directing our rational,quality filled medical care.. Well, the ALLHAT trial could be thought of as just such a undertaking so now we should know,right?

With trials of this scope and complexity a large amount of data is generated and rather than a simple black and white answer emerging there are often multiple conclusions all of which do not agree. Such is how this been with ALLHAT. The most recent analysis of this controversial BP trial is from Dr. Frans Leenen from the Ottawa heart Institute.

Here are some of his findings:

Calcium channel blockers(CCBs) were not associated with more coronary artery disease events but were blamed for more episodes of heart failure. Ace inhibitors (ACEi), on the other hand appeared to be more likely to cause stroke,gi bleeding, peripheral artery disease and angina and ( here is a surprise) angio-edema.

Rather than the simple "well that settles it" that was hoped for in ALLHAT, we have arguments and counter-arguments presented,editorials supporting the results and the BP recommendations (JNCVI) largely based on ALLHAT and editorials arguing that the trial was poorly designed and bears no resemblance to the way BP is really treated (i.e. did not compare realistic choices for BP meds) .

We have gone back and forth with CCBs as well. Are they harmful? Are they as good as any other BP treatment ( which is suggested by Leenen's article)? Not only do trial results seem to differ , various analyses in regard to the same trial differ.I doubt if the recent analysis by Leenen will settle much of anything.

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