CABANA: No Outcomes Profit In First Massive Trial Of AF Ablation


(Up to date)

Catheter ablation for atrial fibrillation (AF) produced no vital enchancment in scientific outcomes in a big and vital new scientific trial. CABANA is the primary and lengthy anticipated randomized managed trial of AF ablation within the greater than two decade lengthy historical past of the process.

The outcomes will possible spark an intense controversy within the medical and cardiology neighborhood, since AF ablation has develop into a worthwhile income middle in lots of cardiology practices.  The preliminary response from leaders of the EP neighborhood has been to interpret the trial as supporting present scientific observe, however scientific trial consultants exterior the EP neighborhood have reached far harsher conclusions. The response to CABANA is probably going so as to add gasoline to the continuing debate raised by a collection of trials, together with COURAGE, ORBITA, and ISCHEMIA, over a number of the basic practices in scientific cardiology.

The Catheter ABlation vs ANtiarrhythmic Drug Remedy in Atrial Fibrillation (CABANA) trial, sponsored by the NIH with extra assist from trade, randomized 2,204 sufferers with AF to catheter ablation or drug remedy. The outcomes had been introduced by Douglas Packer (Mayo Clinic) on the annual assembly of the Coronary heart Rhythm Society (HRS) in Boston on Thursday.

There was no vital distinction between the 2 arms within the main endpoint of the trial (the composite of all-cause mortality, disabling stroke, severe bleeding, or cardiac arrest), which occurred in 9.2% of sufferers within the drug group and eight% of sufferers within the ablation group (hazard ratio Zero.86, CI Zero.65-1.15, p =Zero.303). There have been additionally no vital variations within the particular person parts of the first endpoint.

Packer sought solace in optimistic findings from some secondary analyses of the trial. One secondary final result, the speed of demise or CV hospitalization, was considerably lowered from 58.1% to 51.7% (HR0.83, CI Zero.74-Zero.93, p=Zero.001). As anticipated, ablation was additionally related to a major discount in recurrence of AF (HR Zero.53, CI Zero.46-Zero.61, p

Regardless of the impartial discovering of the primary intention-to-treat (ITT) evaluation, the EP neighborhood discovered assist within the per protocol evaluation. In the course of the course of the trial 9.2% of sufferers randomized to ablation didn’t endure ablation whereas 27.5% of sufferers randomized to drug remedy ended up present process ablation. The per protocol evaluation due to this fact in contrast the 1307 sufferers who underwent ablation with the 897 sufferers who acquired drug remedy. On this evaluation the composite main final result was lowered from 10.9% within the drug group to 7% within the ablation group (HR Zero.67, CI Zero.50-Zero.89, p=Zero.006). All trigger mortality was lowered on this per protocol evaluation from 7.5% to four.four%.

Packer concluded that “ablation is an appropriate therapy technique for treating AF with low opposed occasion charges even in increased danger sufferers.” Eric Prystowsky, the trial discussant at HRS, stated that the outcomes set up ablation as a primary line different to drug remedy.

At a information convention Packer defended the per protocol evaluation. “You may’t get profit from a remedy for those who don’t get the remedy,” he stated.

However a distinct cardiology trial professional with the final title of Packer, Milton Packer (Baylor Well being),  warned in opposition to efforts to spin the trial utilizing the per protocol evaluation. “When investigators are dissatisfied within the outcomes of a trial, there’s an comprehensible temptation to investigate the information to seek out one thing which may look optimistic.  One method is doing a ‘per-protocol’ evaluation, however (even when prespecified) such an method is inherently biased, as a result of it violates the intention-to-treat precept.  Why would you design a randomized trial if you will analyze it in a manner that’s inconsistent with randomization?  We don’t carry out or settle for ‘per-protocol’ analyses in trials of drug remedy, and we don’t settle for them as proof for efficacy for trials of system remedy. The frustration within the outcomes of the CABANA trial is especially putting, since this was an unblinded trial, and thus, was biased towards ablation remedy.”

At an HRS information convention Douglas Packer additionally stated that ablation improved high quality of life, however acknowledged in response to a query that this knowledge received’t be introduced till the European Society of Cardiology assembly on the finish of the summer time.

The response of the EP neighborhood is demonstrated by the next trade on Twitter, through which electrophysiologists try to make use of the complexity of the trial to attempt to ignore or brush apart the failure of the first endpoint:


Harlan Krumholz (Yale College) stated that CABANA will gasoline a “lengthy debate, because it has simply the kind of ambiguous end result that may be interpreted by way of no matter prior perception you had. I take it as a push towards ablation, particularly for youthful sufferers – however the outcomes aren’t definitive. Can’t we discover a manner on this nation to take an vital subject like this and run a collection of trials and produce a physique of proof – in as near real-time as attainable? For now, evidently these therapies each stay cheap – how we talk this end result to sufferers is the following problem.”

Sanjay Kaul (Cedars Sinai) stated that “the ITT evaluation is the one evaluation that preserves the benefit of randomization.” Subsequently, “essentially the most dependable inference is that CABANA did not validate the speculation that the therapy technique of percutaneous left atrial catheter ablation for the aim of eliminating atrial fibrillation (AF) is superior to present state-of-the-art pharmacologic remedy.” Kaul concluded that it’s “time to noticeably take into account a sham-controlled trial for ablation!”

Milton Packer stated that “I’m certain that the outcomes of CABANA are profoundly disappointing for the investigators and for the EP neighborhood…. The trial did not yield any dependable proof that ablation is healthier than no ablation with respect to vital scientific outcomes. The CABANA investigators conclude that catheter ablation is an appropriate therapy for atrial fibrillation, however we already knew that BEFORE the trial. Here’s what is new,” Packer stated. “The EP neighborhood can not declare that ablation achieves something besides making the ECG look higher.”

Packer agreed with Kaul concerning the want for a sham-controlled trial. “It’s time to do a sham-controlled trial of ablation, alongside the strains of the ORBITA design for PCI.  Till such a trial is finished, the EP neighborhood carries the burden of proof to display that ablation is helpful and in whom.  Let’s see in the event that they step as much as the plate and do the correct factor.  However any perception that CABANA demonstrates the efficacy of ablation remedy will not be evidence-based medication.  It merely represents a excessive stage of self-deception.”


Including extra feedback from William Boden and Sanjay Kaul:

William Boden:

I imagine it was none apart from Eric Prystowsky who as soon as famously quoted that “there isn’t a structural cardiac situation for which a tool or procedural intervention doesn’t exist”. Whereas this has definitely been a self-fulfilling prophecy for the previous 2+ many years, right here we see but once more within the CABANA trial the place the ITT evaluation of a big, potential RCT has failed to point out a conclusive final result for the first endpoint or definitive proof of profit for the process past secondary endpoint analyses.

But, if historical past has taught us something, it’s that the outcomes of unfavorable/impartial trials which might be disliked by the people who do these procedures will very possible do little to alter observe or dampen the keenness for recommending procedures like AF ablations and a continued “enterprise as regular” method to administration. Maybe sometime we’ll evolve past the present observe of “selective” evidence-based medication: that’s, embrace what you want, and dismiss/discard what you dislike.

Sanjay Kaul:

Looks as if the EP neighborhood (not not like the interventional neighborhood) is extremely motivated to resolve the ‘cognitive dissonance’ provoked by the null outcomes of the CABANA trial.

Why do the ‘proceduralists’ at all times at all times give you lame excuses in protection of their failed procedures in contrast with medical remedy?


Within the battle between revenue-based medication vs evidence-based medication, remuneration at all times wins…


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