There's a long standing convention that placebo controlled clinical trials are allowed for drugs (generally), but not for procedures. Particularly procedures which are considered standard or only-option. Among such are stents in cardiac care. I recall, long ago, reports that stents caused clots, which sometimes escaped into the bloodstream and caused great harm.
Early difficulties with coronary stents included a risk of early thrombosis (clotting) resulting in occlusion of the stent. Coating stainless steel stents with other substances such as platinum or gold did not eliminate this problem. High-pressure balloon expansion of the stent to ensure its full apposition to the arterial wall, combined with drug therapy using aspirin and another inhibitor of platelet aggregation (usually ticlopidine or clopidogrel) nearly eliminated this risk of early stent thrombosis.
So, this week Gina Kolata reports that stents aren't so useful for one of its major uses.
Then the subjects had a procedure: a real or fake insertion of a stent. This is one of the few studies in cardiology in which a sham procedure was given to controls who were then compared to patients receiving the actual treatment.
But...
When the researchers tested the patients six weeks later, both groups said they had less chest pain, and they did better than before on treadmill tests.
But there was no real difference between the patients, the researchers found. Those who got the sham procedure did just as well as those who got stents.
Oooooops!!! Read the whole piece, and see how little data (well, none, really) supported using stents in this way.
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