Cryoablation study

This summary was on Medpage Today. The link is below and I've also copied the text. I haven't had a chance to research in depth, but it did sound positive for cryoablation.

[www.medpagetoday.com]



Afib Ablation: Fewer Returns After 'Ice' Than 'Fire'
Secondary FIRE AND ICE analysis favors cryoablation for readmissions
by Nicole Lou
Reporter, MedPage Today/CRTonline.org
Patients with symptomatic paroxysmal atrial fibrillation (afib) have lower rates of rehospitalizations if they get cryoablation instead of radiofrequency (RF) catheter ablation.
The rehospitalization rate was 32.6% with the cryoballoon versus 41.5% with RF ablation (log-rank P=0.01) in secondary findings of the FIRE AND ICE trial reported at the Cardiostim-EuroPace meeting in Nice, France.
Though Karl-Heinz Kuck, MD, PhD, of St. Georg Hospital in Germany, presented improvements in quality-of-life with both treatments over 30 months of follow-up, recipients of cryoablation had fewer:
• Cardiovascular rehospitalizations (23.8% versus 35.9%, log-rank P<0.01)
• Repeat ablations (11.8% versus 17.6%, log-rank P=0.03)
• Direct current cardioversions (3.2% versus 6.4%, log-rank P=0.04)
Patients with no history of direct current cardioversion had fewer cardiovascular rehospitalizations over follow-up (24.7% with cryoballoon versus 31.9% with RF catheter, P<0.01). The odds were borderline for those with prior direct current cardioversion (20.9% versus 48.9%, P=0.05).
"The secondary analyses [of FIRE AND ICE] favor cryoballoon over [RF ablation], with important implications on daily clinical practice," the investigator said.
In a prior report of FIRE AND ICE's primary analysis, Kuck and colleagues showed cryoablation to be non-inferior to RF ablation for the primary efficacy and safety endpoints. The study included 762 patients who were randomized to RF catheter ablation or cryoablation.
"While the learning curve and reproducibility of any technology are very important, what FIRE AND ICE has shown is that, for most operators, cryoballoon may be a safer and more efficient approach for initial treatment of paroxysmal afib," Wilber Su, MD, of Banner-University Medical Center in Phoenix, told MedPage Today.
"Cryoballoon has already become the preferred approach in my practice, both from personal experience as well as patient demand," he added.
Either way, "being comfortable with the technology of choice to maximize procedural safety and outcome is the most critical part of clinical care," concluded Su, who was not part of the trial. "For RF, operator dependence likely may play a bigger role. For cryoballoon, while the outcome may have shown less adverse outcomes compared to that of RF, it is still not zero. Operators needs to make a strong effort to minimize harm with any technology."
The FIRE AND ICE trial was funded by Medtronic.
Kuck disclosed receiving consulting fees and honoraria from Biosense Webster, Edwards Lifesciences, St. Jude Medical; as well as serving on the speaker's bureau of Medtronic.
Su reported receiving research support, speaker's fees, and honoraria from Medtronic and St. Jude Medical.

Doreen

This adds longer follow up data regarding post procedure re-hospitalizations compared to when first reported Fire and Ice trial results. The reduction in burden and reduced hospitalizations is a big deal and probably why cryo is being used more often in place of RFA, for paroxysmal AF. I sitll worry about phrenic nerve injury and PV stenosis, the former being the most devastating and although most PN injury (6%) resolve over weeks, somewhere between 1-2% end up with permanent PN palsy if recollection serves. I would love to understand how Natale's group in Austin decides whether to do cryo or RFA as all their EPs are skilled in RFA for AF.

Hi researcher, Natale's group primarily uses RF because they are highly skilled in it. The good news about cryo
is it's easier and faster for the PVI portion of an ablation, especially for EPs not highly experienced in RF (highly experienced meaning at least 4 to 5 years of hands on RF training in a high volume center,) and still get roughly equivalent PVI only results.

There are A few EPs at St Davids who use cryo when they have a clear early case of paroxysmal AF with few to nine more than 24 HR AFIB episodes ( note longer than 24hr episodes makes likelihood of non-PV triggers being there almost certain which then requires expertise at real time Non-PV focal trigger detection in other areas of left and right atrium that very good ablationist Dr Vivek Reddy of Mt Sinai in NYC said recently at AF symposium in Boston , really is challenging and separates he men for the boys in this field.

Over 75% of all cases at St Davids are non-paroxysmal (persistent and and LSPAF) cases which essentially guarantees Non-PV triggers and a more extended ablation beyond PVI-only protocol for the most robust success rates.

Most Cryo-exclusive operators also do careful patient selection to insure they are not too often surprised by more complex cases than the balloon is designed to handle and beyond their comfort and skill level. And some swap out ablation catheters from Cryo to RF once they have zapped the 4 PVs but that then introduces some added risk of micro air bubbles forming and being released into the left atrium where said microbubblesxcan migrate esadily to the brain or other areas you would not want that to happen, possibly upping the risk for TIA or greater accumulation of tiny silent cerebral emboli which though typically asymptomatic is associated with early onset dementia as it accumulates beyond a certain level.

I suspect risk of that is low, but multiple exchange of catheters and/or sheaths between RA and LA is a practice leasing EPs try to avoid.
Extracting and reinserting a different catheter from right to left atrium after transeptal puncture has been established.

The EU groups who, as a whole, comparatively and collectively address far fewer non-paroxysmal cases than comparable big centers in the US and Asia, quite naturally have gravitated more to Cryo for the noted advantage in time and, if they are less familiar with RF, then also in lower overall risk though as you noted researcher the risk of phrenic nerve and PS injury tend to be are higher in Cryo than RF. Though both can happen too in RF but generally are less common these days in experienced centers.

But the big advantage of those EPs at St Davids , including foremost Dr Natale, who have become proficient in using Natale's 'Gliding catheter' ablation method more than replicates the continuous line ablation lesions that is cryos big claim to fame, while offering more flexibility in modifying the angle and shape of the encircling single continuous lesion or line around the PVs which comes in handy with variable PV anatomy.

Plus you then have the advantage of using that same father for focal Non -PV triggers without having to switch tecnologies in mid stream in the procedure etc.

Other centers that don't focus on nearly as many non-paroxysmal cases my wind up preferring Cryo .. And don't underestimate the allure of being able to do couple extra cases a day in busier center with Cryo due to its greater speed in laying down a PVI.

There is certainly a role for both technologies for given different centers and different target patient bases.

Shannon

Shannon

Shannon, along the same thoughts, Sam Asirvatham of Mayo published recently a review of sub clincal strokes during AF ablation and long procedure time and sheath changes are big contributing factors. I think the article is in the latest "innovations in CRM". As you said the big attractiveness to EPs and centers are shortened procedure times using Cryo and subsequently being able to do more procedures per day. It is a numbers game that works in favor of cryo especially for paroxysmal cases. And then there are the 80% of all ablations done at centers that do less than 25 cases a year - for those that never get good at RFA, cryo may be the way to go but I cringe to think what happens to the folks that are beyond paroxysmal and have no good choices.



Edited 1 time(s). Last edit at 06/22/2016 02:10PM by researcher.

researcher Wrote:
-------------------------------------------------------
> Shannon, along the same thoughts, Sam Asirvatham
> of Mayo published recently a review of sub clincal
> strokes during AF ablation and long procedure time
> and sheath changes are big contributing factors.
> I think the article is in the latest "innovations
> in CRM". As you said the big attractiveness to
> EPs and centers are shortened procedure times
> using Cryo and subsequently being able to do more
> procedures per day. It is a numbers game that
> works in favor of cryo especially for paroxysmal
> cases. And then there are the 80% of all centers
> that do less than 25 cases a year - for those that
> never get good at RFA, cryo may be the way to go
> but I cringe to think what happens to the folks
> that are beyond paroxysmal and have no good
> choices.


Well said researcher ... and your last sentence with emphasis!

One factor is that the vast majority of EPs doing the bulk of 'assigned' ablations, where referring doctors who are all members of the same HMO and forced to refer ablation patients to the local HMO plan participating EP regardless of their experience or track record, is a big reason who over 81% of all Medicare ( and which is no doubt roughly similar for all other private insurance plans too) are largely greenhorns doing under 25 procedures a year!

And keep in mind that Cryo would have huge appeal for this group who do not plan nor ever wish to expand into Non-PV trigger real time EP sleuthing, detection and deciding just which squiggle on the voltage map to ablate. The appeal of just sticking a cryo-balloon inside each PV and pushing the trigger to ablate and then get out of there , not even looking for any more mischief to go after is overwhelmingly compelling for those who want to do ablations but not get themselves too deep in uncharted waters.

As such, such EPs will remain severely limited in the scope of patients they can really help. As long as they are very strict in their patient selection process, they can still get a decent overall track record. But will have to turn away a large number of persistent, LSPAF and even advanced paroxysmal cases to maintain even a half way decent and honest success rate.

Shannon



Edited 1 time(s). Last edit at 06/21/2016 09:24PM by Shannon.

Shannon, We are studying health plans on the exchanges as we speak. Years ago, there were big differences between HMOs and PPOs. Not anymore. In our county Kaiser HMO premiums is about the same if not higher compared to Cigna or Aetna PPO for example. We will have to look closer to see what's going on. I know from my parents experiences that Kaiser is excellent for preventative care and all their centers have been newly built within the last 10 years. I have had two athlete friends switch to Kaiser just to get orthopedic operations as their guy in the county has a word of mouth following and as far as I can tell, the knee and hip operations have been excellent. As for EP ablations, those get funneled to their referral center in Los Angeles. For SF bay area folks, those get funneled to Santa Clara. Kaiser LA is also a teaching facility for UCLA and Santa Clara for Stanford. For Kaiser anyway, they have "centers of excellence" set up for ablation procedures. The other HMO's need to do the same so that ablation procedures are done by skilled EPs doing big volumes. Kaiser LA and Santa Clara are high volume.



Edited 1 time(s). Last edit at 06/22/2016 07:08PM by researcher.

Thanks, Researcher, and Shannon, for following up on the latest studies, and being willing to share your expertise with all of us.

Doreen

You are welcome Doreen,

And keep in the mind too these FIRE and ICE stats are referring to centers that specialist in CRYO especially Karl Hines Kucks center in Germany who largely conducted this study and it is very relevant when viewing the broad base of more typical RF ablationist too ... not elite level RF ablationist.

Still when looking at larger patterns that a person who just gets assigned for an ablation and has neither the insight or instinct to seek out learning about the very best care available in this field, the message of FIRE and ICE is well taken.

But you wont see a elite operator like Natale of Haissaguerre switching to CRYO anytime soon for the bulk of they ablations as its a too limiting tool for their class of patients they typically see. Plus, most important to understands, the skill and experience these Elite level RF ablationist possess with RF technology more than outweighs the relative benefit CRYO can certainly present when comparing a broader cross section of ablationists the average AFIB patient is likely to run across in the typical 'inside the bubble' referral system.

Shannon

And researcher, Ive heard for a while that Kaiser is doing very well and much better across many specialities, especially in California branches of Kaiser but not necessarily outside the state. In Hawaii for example Kaiser is not considered the destination of choice for most procedures there, or at least was decidedly not considered and elite hospital for much of any specialities at least as of 5 years ago.

That may be changing, and I really hope so, with some of the new overhaul you are speaking of if that trend has spread to Hawaii Kaiser too by now, but its been 5 years since I was living in Honolulu and Ive lost touch with those goings on over this time.

I do know that Kaiser has not been considered a prime ablation destination as yet, though there may be some individual operator exceptions in their system by now.

Shannon

Shannon, the problem with cryo balloon that I was afraid of has just been elucidated in the latest issue of EP Lab digest. A spotlight inteview article regarding Banner Health in Arizona. The director of EP said in the interview that they are extending cryo balloon to persistent, long standing persistent and substrate modification. This is a predicable over stretch of the fundamental limitations of balloons. This was what I was afraid of, that centers will make claims just to hold on to all types of AF patients even though they know limitations of their approach. Banner Health gets a black mark for not serving in the best interests of their non-paroxysmal AF patients.

Thanks for the info on Banner Health in Phoenix. sounds like their ablation marketing department in taking some liberties in trying to promote their center as for folks with all types of AFIB. If they try that with Cryo for non-paroxysmal cases, it will only result in big increase in multiple repeat ablation business there. Hopefully, those patients will learn of our website or other good resources to learn to cast a wider net for any follow up procedure they might need.

It's stunning to me the numbers of EPs that still continue on with a PVI only even for more advanced cases where there are clearly a far greater certainty of finding non-PV triggers! Alas the Bart majority of EPs don't want to even look for mischief elsewhere beyond their anatomical inlets pattern.

They will thus doom their patients to less than a 50% to 52% one year success rate which multiple randomized control trials have now confirmed is about the best one year success you can get from persistent and LSPAF mixed class of patients. The problem is compounded by the fact that repeat PVI-only ablations in the non-PAF classes hardly moves the needle forward to higher long term success, if no posterior wall, SVC, no real time detected non-PV triggers including along LA Septal wall, Coronary sinus and LAA as needed, are not ablated in subsequent ablations.

That's why anyone with even advanced paroxysmal cases should absolutely seek out an experienced persistent AF ablstionist who does a large majority of persistent cases as the bulk of their total AFIB ablation caseload. And if you do get just a PVI only index ablation and it fails at a certain point, please do NOT return to the same EP if all they are going to do is try to reconfirm the PVs are sealed with a full repeat PVI and nothing more.

Very quickly you will almost certainly hit the road of greatly diminishing returns on each ablation and the mahouts of such advance cases will be stuck on AAR and OAC drugs for life to manage their perhaps lessor occurring for a while but still progressive AFIB.

It makes far more sense to go to a elite level persistent ablationist from the index procedure forward to insure the greatest long term success from the least amount of total ablation burden and least number of total ablations you will require to achieve real long time freedom from all atrial arrhythmias.

Shannon



Edited 1 time(s). Last edit at 06/27/2016 02:11PM by Shannon.

More info. Their paper below show a long term follow up study, up to 7 years, at a single center where majority cases are done by RF. It does a nice job detailing their experience in comparison to others. Both older and newer versions of cryoballoons are covered. The newer cryo balloons may be too effective in lowering temperatures to the point where phrenic nerve injury risks are elevated compared to older versions. If PN injury is not a concern, then the results are about the same as RF for this center.


[www.jafib.com]