Yes Moerk, the creation of SCI (silent cerebral ischemia) is indeed a very important issue. But is is not at all 'Big news' as noted in the title above, and has been one of the biggest focus of current AFIB research increasingly so over the last 5 to 6 years. I've written 4 articles in the AFIB Report myself over the last 2.5 years on this SCI issue sharing multiple large studies and updates on our now very evolved understanding of both the proximal causes and proven steps to greatly reduce SCI creation in the first place ... foremost by restoring durable NSR (normal sinus rhythm) and secondarily by using proper techniques during an AFIB ablation which when done correctly had been shown in multiple modest to larger size well-done studies to reduce SCI creation significantly.
Silent cerebral ischemia (SCI) caused by having AFIB, first and foremost, and that it can be caused to a much lessor degree by an ablation itself in which this large new study on the issue confirms to occur in around 30% of ablations, but to a far lessor degree particularly when state of the art uninterrupted anti-coagulation methods and proper transeptal puncture and sheath/catheter techniques are used during the immediate periprocedural period ... By the way, this is a known issue in nearly every other cardiovascular procedure well that results in access to the left atrium and/or arterial vascular occurs to one degree or another.
SCI is certainly an important issue and yet, our EP blogger friend Dr. John conveyed only half of the message while overlooking the most important key point of this issue that greatly alters what one otherwise without learning and understanding the relationship of AFIB and SCI creation, might then mistakenly interpret the take-home message from this research to point to an anti-ablation conclusion, and this would be a shame with ongoing AFIB being the number one source of long lasting SCI white spots.
The key facts that must be digested to properly understand the true meaning and importance of this issue are:
1. That the single biggest source of SCI is On-going unaddressed AFIB itself, be it paroxysmal and certainly with persistent and long-standing persistent AFIB, and by a Huge margin! Pause for a moment and let that fact sink in .... It is unaddressed AFIB itself in all its forms that is THE number one source responsible for the greatest increase in overall lifetime SCI Burden in the brain, period. The number one and single most important step to preventative an increase in these SCI being created is to establish durable continuous Normal Sinus Rhythm (NSR) by whatever means possible.
The second step is to confirm that your ablationist is fully aware of and uses all the best known procedural methods and practices to reduce the creation of a small number of SCI during an ablation of other left-sided procedure as discussed below which can reduce the odds of creating one to a few new tiny asymptomatic white spots on the brain that are almost often no longer visible by MRI within a few days post ablation.
2. While SCI tiny white spots are asymptomatic individually, the weight of the very strong evidence now is that when allowed to accumulate over time they are anything but asymptomatic leading directly to an increased association with early onset dementia and Alzheimer's.
3. And while the numbers of SCI that on average are generated during cardiovascular procedures including AFIB ablation are typically limited to from one to four white spots on average that almost always, but not in every single instance, vanish from view within 48 to 72 hours (decidedly not so with the accumulated burden of SCI white matter burden that is created by AFIB itself over time).
4. This is a very important issue and luckily those of us that have had ablations with EPs using already in their ablation process what has now long ago been established as the state of the art uninterrupted anticoagulation protocol, combined with using dual ( not single sheath) transeptal puncture to prevent multiple insertions and retractions of the lasso mapping catheter and ablation catheter into and out of the left atrium as a single sheath typically requires ( upping the risk of tiny air bubbles getting into the LA and possibly traveling to the brain as well as several other established procedural steps that have been shown now in multiple studies to dramatically cut the numbers of SCI created to one or two they spots that almost invariably vanish in short order.
Plus ensuring an ACT (activated clotting time) measurement of around 350secs, or slightly higher, is maintained from just before transeptal puncture until all hardware and sheaths are fully removed from the LA and groin which also 'almost' eliminates the risk of true stroke and TIA during the actual ablation itself by those who practice these wise uninterrupted AC methods.
These steps, most all of which were pioneered at Cleveland Clinic and St Davids along with several other top ablation centers like Univ of Penn, Mass General, Mayo and the German group of Deneke and Giata in Italy etc, have shown they conclusively can reduce this risk of ablation-caused SCI to an essentially relatively negligible level, especially compared to AFIB related accumulation of SCI, so just insist on going only to an EP who is fully SCI reduction aware and already practices these protocols as a feature of every ablation they do.
But the last thing you want to do is get the wrong message from this research and go out of your way to avoid an expert ablation process that includes all the known SCI minimizing practices when you are still dealing with AFIB in spite of all efforts to tame it long term via natural or drug means. And thereby likely doom yourself to battling with atrial arrhythmia the rest of your life which would very likely result in a classics case of being 'penny wise and pound foolish' and only help ensure M a far greatly likelihood of accumulating enough SCI burden over time such that it becomes very much symptomatic in the form of early onset cognitive dysfunction, dementia or even full-blown Alzheimer's.
That big picture then is to always keep your focus on reducing your AfIB burden as much as possible while doing everything in your power to restore durable life-long NSR by other means before adding in an expert ablation process.
If you can achieve this one key goal that truly lasts and remains uninterrupted by periodic bouts of arrhythmia via the various life-style risk factor reducing and nutritional electrolyte repletion protocols we urge all afibbers to adopt as life-long good health habits to the degree that your AFIB and overall health dictate is appropriate for you, then it goes without saying that is the holy grail best case outcome any of us can achieve.
But the next best course and outcome which is a close second, and significantly more likely to be the path most of us will have to follow to achieve real long-term freedom from AFIB, as found in our long collective forum and website experience, it for the majority of afibbers to combine the best of both worlds including all the above RFM and electrolyte repletion steps along with an expert ablation process when the RFM proves insufficient to sustain truly lasting uninterrupted NSR.
Dr. John got the story half right in his report on this latest study on SCI and ablations, but overlooked the most important reality that it is ongoing untreated AFIB itself that results in the greatest SCI burden and greatest risk for dementia by a truly huge margin.
In addition, the SCI during ablation issue has become a major research topic the last 5 years and real strides have been made, and will continue to be made toward the goal of refining our understanding and protocols to totally eliminate the creation of SCI during AFIB and most other cardiac procedures open to the arterial blood flow in the heart as well.
An ancient 'lessons of life' Indian Hindu proverb is perfectly suited here: 'it often takes a small thorn to remove a much larger more dangerous thorn and then both can be discarded'.
Shannon
PS the portion of Dr John's review of another study that Moerk posted above is one in which doing two PVI ablations back to back empirically in all paroxysmal patients in this proved to give a bit better 12 to 18 month success rate than just bringing people back in for the follow up ablation only after and only if they became symptomatic. In light of the high level of PV reconnections still experienced by a large majority of EPs out there combined with the greater the effect improving establishing effective transmural results and achieve a more durable full PVI with a follow up ablation.
In this study, the structure is to bring everyone back in after two months post index ablation for a full repeat PVI that may make sense via several mechanisms that I don't have time to spell out in detail here as I'm buried in the next AFIB Report and have to leave early Friday morning for 7 nights to my old home for 38 years of my adult life in Honolulu Hawaii to take care of a laundry list of errands and appointments now.
When I have the time after I get the newsletter out, I'll go into more details and revisit the take home message from this story... But rest assured, when you go to a center that understands how to significantly reduce PV reconnection rates from the first ablation onward and keeps reconnections during or following an index ablation well below 10%, which is what St Davids as a center averages and where Dr Natale's reconnection rates are in the low single digits between 3% to 5% ... and when your EP is well versed in posterior wall Isolation as well and addressing other non-PV triggers during an index ablation, it then makes all the sense in the world to go for a follow up which is really a targeted touch up, only when and if, the afibbers starts to trigger and have episodes again either symptomatic or asymptomatic.
This approach followed by the big centers makes much more sense rather than have everyone come back in after two months following an index ablation to repeat the entire PVI and nothing else. When learning how to consistently reduce reconnection rates and how to properly and consistently achieve durable posterior wall isolation, that is the better overall goal and target young or less experienced EPs should aim for. Start with getting better the first time around. And BTW a repeat PVI will not infrequently lead to partial or complete posterior wall isolation, even if inadvertently.
Shannon
Edited 6 time(s). Last edit at 05/18/2016 11:35PM by Shannon.