Tuesday, June 08, 2010

When Atrial Fibrillation Recurs

... as told this morning in the Washington Post:
"I was amazed at how quiet my heart was," says Currier, a 69-year-old resident of Springfield. But the benefits of the treatment, called catheter ablation, didn't last. Soon her heartbeat became erratic again, forcing her to ask: What should I do?

That's the dilemma facing more than 2.2 million Americans who have atrial fibrillation, the most common heart arrhythmia and one of the most vexing to control. While treatments ranging from medication to surgery are proliferating -- and often are marketed aggressively by hospitals -- no one can say with certainty which will work best for any individual patient. And each treatment has side effects, some of them serious.

"We don't have great evidence to help patients and doctors make a fundamental choice among the treatment options, which differ dramatically," says Steven Pearson, president of the Institute for Clinical and Economic Review, which evaluates medical treatments and is affiliated with Harvard Medical School.

That makes A-fib, as it's commonly called, a top candidate for comparative effectiveness research, say Pearson and other experts. Congress set aside $1.1 billion last year for this type of research, which involves head-to-head testing of drugs and treatments to determine which work best, and for which types of patients. Advocates say such research will improve health care and help get costs under control.

More information about A-fib therapies, for instance, would allow doctors to customize treatment for specific patients, says Harold Sox, a prominent internist who headed an Institute of Medicine committee advising Congress on how to spend the comparative effectiveness research funds. The committee issued a report recommending that atrial fibrillation should be a top candidate for such funding when it is given out by the government in the coming months.
So I found it interesting that while the above article alluded to, but did not mention by name, the multi-center, prospectively randomized pivotal trial ongoing now called the CABANA trial (Catheter ABlation versus ANtiarrhythmic drug therapy for Atrial fibrillation). So far, only 46 patients of nearly 3000 patients needed to complete the study have been enrolled. It is anticipated that over 140 centers around the world will participate.

Yet despite the widespread prevalence of atrial fibrillation, the study has been slow to enroll. We should ask ourselves "why?"

Let me count he ways.

First, is the public and referring doctors are not aware of the study and the pivotal trial is just getting underway. (This morning's article should help a bit.)

But there are other issues...

... like the media and other doctors' pre-conceived understanding of the procedure - "I-hear-that-ablation-stuff-is 90-98% effective, so just go in there and get your afib ablated and you'll be fixed" attitude. Patients have seen the glowing early results of catheter ablation, touted by some early on with "85 percent" success rates (which, quite frankly, are hogwash, unless we count people who continue to take antiarrhythmic drugs following their ablation - hardly a comparison of the two approaches).

But other early trials that only looked only at the time to first afib recurrence have had glowing press coverage as well, potentially biasing recruitment efforts for the CABANA trial.

Finally, there's the complexity of recruiting patients. Patient's usually prefer a "guick-fix" and many might be less inclined to participate in the CABANA trial's five-year duration. Also, gathering the vast quantities of information required for such a comprehensive evaluation of these two widely-disparate treatment approaches involves numerous medication, heart rhythm, and patient evaluations throughout the study's course. When one tries to capture every single warfarin medication adjustment or palpitation on event recorder, the manpower needs and time required to complete such a "comparative effectiveness research" trial in the era of manpower constraints being imposed on hospital systems limits enthusiasm for conducting such large trials. Are we to assume doctors who are already taxed with ever-growing clinical responsibilities can easily pick up the slack? That's why centers with higher research nurse-to-doctor ratios will be the centers most likely to recruit faster.

Which leads other less well-endowed medical centers to wonder if the results of these types of trials will really reflect "real-world" clinical medicine.

Probably not.

But when you don't have much else to go on, and the money for research is increasingly showered on large health care systems, it might be the best we can do as a country. What this might mean to smaller, more rural health care delivery as the government applies the results of this trial across the nation remains to be seen.


Disclaimer: I am the principle investigator for CABANA trial at our institution and yes, we have one research nurse dedicated to this trial.


Keith said...

All very good points that you make. What we need to do is direct some of the resources going into industry toward these types of studies, to determine the true effectiveness of these procedures and devices. It seems that there are too many conflicts of interest to depend on relaible and unbiased research from the private sector, which is why I think comparitive effectiveness research sponsored and paid by goverment is a must.

Much as our lack of oversight in the financial services area has led to the current catastrophic results, we must be certain that new and expensive treatments actually do what they are touted to do and do it much more effectively than less costly approaches. Lack of adequate oversight in the medical and pharmaceutical indutries will create the same sorts of negative effects on our economy in the long run if we do not provide adequate checks and balances. We have now seen too many examples of pharmaceutical companies withholding post marketing data unfavorable to their drug or device companies ignoring the defects in their devices, such as the lead fracture problems with the guidant pacemakers. Fines have not been a detterant since they often turn out to be less than the profit made off the defective device or drug. So legal costs and fines simply become a cost of doing buisiness. Over on Health Care Renewal blog, they point out that Pfizer has had three separate corporate integrity agreements that they have signed for separate incidents of malfeaseance, but keep exhibiting the same bad behavior. Maybe we need to have compaines compare ther new drug or device to the current standard of care rather than to placebo!

You make very good points about most of these procedures being done in less than real world settings. But then again, maybe this is a procedure that should not be routinely performed in a community hospital. Maybe we should have referral centers that are very adept at doing these and frequently perform them. We need to move away from the mindset of every hospital performing every complicated procedure. Not every hospital can possibly perform all these tasks and do them well. But since some procedures and techniques are basically overpriced (or more profitable), struggling smaller institutions feel they need to engage in these to feed the monster and to some degree subsidize the less profitable of money losing aspects of health care. It all comes back to the tilt in reimbursement toward procedures driving our unsustainable system of health care. When I finally see a hospital advertising its excellent psychiatric/endorinolgic/rheumatologic/infectious disease or other more cognitively driven field of health care, then I will know that health care has fundamentally changed for the better.

DrWes said...


It seems that there are too many conflicts of interest to depend on relaible and unbiased research from the private sector, which is why I think comparitive effectiveness research sponsored and paid by goverment is a must.

This study is only supported by the government to the tune of, at most, 40%. Government (a la TAXPAYERS) does not have the money for these trials and has had to turn to industry (in this case, Boston Scientific and St. Jude) for funding. This is the ruse of CER that has been bestowed on the public. I find it ironic that the great Comparative Effectiveness Governmental Gods have forgotted that these trials take LOTS of money to find differences in MORTALITY between varying treatment arms, and ONLY with industry's money will they be able to afford to continue this approach.

How much will industry want or be able to participate in these trials when the government continues to demand multi-billion- dollar excise taxes from industry in their "pay-to-play" plan going forward. These costs are then passed on to patients via their insurers.

Will small companies have any chance in hell of competing to bring lower prices to the instruments used in our field?

I think not.

So now we jump through all of these hoops to end up at the same conclusion: the costs for consumables and the procedure will not decline, only the number of those eligible for the therapy will be limited to those capable of traveling to "certified" centers.

CER basically becomes a very expensive and politically-savvy way to ration care that further removes the physician and patient from the decision process.

Unknown said...

In your original post, you mention it puzzling that The Washington Post failed to mention the CABANA trial and that perhaps a lack of awareness of the ongoing trial contributed, in part, to slow enrollment. The first time I heard of CABANA was from a single-line mention in an article authored by John Camm back in 2006 (Nat Clin Pract Cardiovasc Med. 2006;3:345). In your opinion, what has taken so long for this study to actually be initiated? Surely, it can’t be as simple as the red tape involved in initiating a government-supported study?

DrWes said...


In your opinion, what has taken so long for this study to actually be initiated? Surely, it can’t be as simple as the red tape involved in initiating a government-supported study?

This is a VERY complicated trial and costs a minor fortune. Funding of such trials is ALWAYS challenging to arrange - in this case St. Jude Medical and Bard stepped up WITH the NIH to help fund the trial. International logistical issues with this large trial were also complicated to put in place. From conversations with Dr. Doug Packer (the national PI) this study was the culmination of five years of very hard and dedicated work by many.

Unknown said...

Thank you for your prompt reply. Next question: do you know of any progress to the number of patients enrolled over the course of the last month since the Post article? I'm curious to learn whether exposure (on a consumer level) to the problem actually amounts to more referrals and/or greater enrollment. In the end, time will tell, I suppose.