Proving the Value of Comparative Trials

Failed the stress test? Suffering from persistent angina? Got partially blocked arteries? Aggressive drug therapy will reduce your risk of suffering a heart attack as much as inserting a stent to prop up clogged arteries, according to a new study released yesterday by the New England Journal of Medicine.

The Veterans Administration study received well-deserved front page coverage in the morning papers (see the New York Times coverage here and the Washington Post story here). The bottom line is that patients who get the expensive, invasive procedure (angioplasty involves sticking a catheter into your thigh and snaking it up to the arteries around your heart to insert the stent) actually have slightly worse results, although the difference was not statistically significant.

There could be enormous financial benefits to the health care system if the implications of this study are widely followed. Many of the drugs used in the trial are available as cheap generics. They used aspirin for blood-thinning, for instance, except for those patients with aspirin intolerance, who then received Plavix. An angioplasty/stent operation, on the other hand, costs up to $50,000.

But don't count on patients necessarily hearing about this study when they get routed to a cardiologist after complaining of chest pain. "I don't think this is going to cause any huge paradigm shift," Gregory J. Dehmer, president of the Society for Cardiovascular Angiography and Interventions, told the Post. "This study was limited to a fairly select group of patients with very stable symptoms."

Not really. Perhaps the most shocking statistic in the study was that fully 20 percent of patients in both groups suffered heart attacks or died within five years of entering the trial (the study enrolled patients between 1999 and 2004). Sadly, while both groups were encouraged to stop smoking, lose weight and exercise regularly, neither group reported a significant reduction in body mass index.

While most of the physicians who conducted the trial had extensive financial ties to drug manufacturers, the trial itself received only unrestricted grants from those commercial interests and the grants went to the VA. The U.S. and Canadian governments provided the bulk of support for the trial.

So what's the takeaway lesson for health care policymakers? For years, trials funded by stent manufacturers have suggested that the invasive procedure should be standard of care for patients with early symptoms of heart disease. Only a well-constructed comparative clinical trial could show that this isn't necessarily the case.

Alas, such trials invariably take a long time and come out long after a train filled with commercially-driven medical interventions has left the station. This trial shows conclusively that the government needs to allocate several billion dollars a year to fund numerous comparative trials on a range of medical interventions. And the Food and Drug Administration should make manufacturers carry out such tests as a routine part of their products' initial approval process. That way, patients and their insurers won't have to wait five or ten years to learn the relative worth of competing medical interventions.

Posted by gooznews at March 27, 2007 07:35 AM