Sorry this took most of the week to get out. (There was a good reason.)
Better late than never I suppose.
On Day 3 of the 2013 American College of Cardiology meeting, I woke up well rested and inspired to squeeze in as much learning as possible. The first order of business was putting the final touches on the athletes and atrial fibrillation piece. (The big question was whether to keep the line about love?)
My THO assignment for the final day was to find something useful to say about catheter ablation of atrial fibrillation. This is, after all, how I make a living. Stay tuned for that post; itâ€™s coming soon over at Trials and Fibrillations.
The morning started nicely. I’m in the Starbuck’s across from the convention center waiting for an Americano when I notice a young cardiologist staring at my badge. This is how it goes at national meetings; people look at name badges first, then faces, then back to the badge. The young stranger speaks: “You are the guy from theHeart.org…I read your column…It’s good, and I especially liked your take on the Watchman.” Truth: That felt pretty amazing. Writers are no different than any other profession–we love compliments.
Now let’s get to the talks:
My first session reviewed much of the recent data on catheter ablation of AF. Dr. Sanjay Narayan (San Diego) and Douglas Packer (Mayo) are both excellent speakers. Dr. Narayan, the pioneer of using Focal Impulse and Rotor Modulation (FIRM) as an AF ablation strategy, gave an elegant explanation of FIRM ablationâ€”a (potential) paradigm changer. Dr. Packer was tasked with reviewing the long-term data in support AF ablation. He titled his talk: Are anti-arrhythmic drugs (AAD) that bad? Is ablation that good? Dr. Packer emphasized the AFFIRM lesson: rhythm control strategies, using anti-arrhythmic drugs (efficacy 30%), do not prevent stroke. The question now is this: Ablation is definitely better than AADs for lowering AF burden and symptoms; so will it follow that ablation will reduce the risk of stroke? (Again, stay tuned to theHeart.org for my next post on this question.)
As the lead investigator for the CABANA trial, Dr. Packer used this opportunity to explain how much we will learn when two groups of AF patients are randomized to either drugs or ablation. A final note on his presentations: one has to wonder how much time goes into finding and choreographing his wonderfully humorous cartoon slides. His last slide, which depicts a video of a cat poking at a copy machine, illustrates nicely the potential pitfalls of looking too closely at every nuance of AF ablation.
Right across the hallway, Dr. Edward Gerstenfeld (UCSF) spoke on the role of AF ablation as primary treatment (before a trial of drugs). As we get better at AF ablation, moving it up the decision tree makes sense. Itâ€™s an especially relevant topic for athletes with AF, as this group tends to tolerate medications poorly.
In bullet form, here are a few of Dr Gerstenfeld’s most salient points:
- There is now 100% agreement that PV isolation forms the core of AF ablation. (This point comes up later.)
- Joint European and North American guidelines give primary ablation a IIa level recommendation (General agreement that the treatment is reasonable and the level of evidence is moderate.)
- Studies that look at rhythm control drugs have not been held to the same threshold of failure that has ablation. An AF ablation is considered to have failed for only a 30 second run of AF. That’s an awfully tough standard. He also noted that we tend to give AADs a free ride. A patient does not have to sign a consent form before taking a potentially risky drug.
- The MANTRA-PAF trial, published recently in the NEJM, was held up as a negative study of primary ablation. The problem was that the ablation protocol used has been abandoned due to its known inferiority. This is not a knock on the investigators, because at the time they did not know their ablation strategy would prove to be suboptimal.
Dr. Gerstenfeld left us with a nice quote: â€œIf you see an AF doctor and they say they can do an ablation tomorrow, you should go somewhere elseâ€¦Rarely is there downside to waiting for an ablation, or trying a drug in the interim.â€ (BTW: I tell you this stuff so you donâ€™t think I am making stuff up on the blog.)
Itâ€™s still mid-morning on Day 3 when I switched over and went to a general session on implantable devices:
On the Front Lines: Managing ICDs.
The first of two talks during the session came from Dr. Andrew Epstein (Philadelphia). He spoke on recent updates to ICD guidelines. He made three major points:
- On the controversial 90-day waiting period in newly-diagnosed CHFâ€”Dr Epstein made it clear that the practice of waiting 90 days before implanting an ICD is well supported by the evidence. His slide-set (available to cardiosource members) outlines the references. At least in my mind, the strongest case for waiting comes from a review of the Kaplan-Meier survival curves in the SCD-HeFT trial. Basically, the primary prevention ICD, compared to standard medical treatment, did not confer a survival advantage until at least a year had passed. What’s more, Dr Epstein reminds us that there is much to do during this initial time. Namely, it is a great opportunity to maximize medical therapy of left ventricular dysfunction. In many cases intensive medical treatment along with a tincture of time results in improvement of LV dysfunction. (I felt like starting a standing ovation at this point.)
- ON CRT and QRS: CRT does not benefit patients with a narrow QRS. In the MADIT-CRT trial, a subset analysis showed a trend towards harm in patients with non-LBBB. The benefit from CRT therapy will be greatest in patients with typical LBBB and the wider the QRS the more likely the benefit.
- 2013 Appropriate Use Statement for Cardiac Devices: Dr Epstein told the audience that he did not like the new appropriate use document–even though he was one of the writers. He suggested it might obfuscate matters on ICD criteria. The problem: clinicians who implant devices now have four guiding documents: 1.) The ACC/HRS guidelines 2.)The Appropriate Use statement 3.) The CMS National Coverage Decision 4) The DOJ investigation. Dr Epstein agreed that given the differences in each of these â€˜consensusâ€™ statements it would be tough to come up with a unifying theme. He told the audience to stay tuned for more clarity.
Choosing the primary prevention patient most likely to benefit from an ICD:
Dr. Epstein gave a great presentation on ICDs, but the next one in the series was even better. Dr. Phillip Cuculich (St. Louis) focused his 20 minute talk on choosing patients for primary prevention ICDs. It was right out of the Dr. Lynne Warner Stevenson school of common sense. Dr. Cuculich emphasized that rational ICD implantation meant finding the sweet spot of patients sick enough to be at risk for sudden death but not so sick they would die of something else. He went over a number of the risk scores for death after ICD implantation. The point is simple: as co-morbid diseases accumulate, say COPD, peripheral vascular disease, dementia, advanced heart failure and kidney disease, the mortality with an ICD becomes equal to that without one. Increasing co-morbidity raises an already elevated NNT (numbers needed to treat) or save one life with an ICD. The only well-validated risk predictor for future sudden death is ejection fraction–but clearly not all patients with an EF <35% benefit from an ICD.
Other important take-home messages from Dr Cuculich:
- Focus on the Numbers Needed to treat (NNT);
- The best candidates for primary prevention ICDs have high arrhythmia risk, long longevity and low chance of arrhythmia.
- Pay attention to pre-ICD demographics as these factors speak to the risk of death with, versus the risk of death without the ICD.
- One particular area of research in St Louis involves the use of vests of ECG electrodes. Currently, a standard ECG takes a 12-lead view of the heart; the St Louis research ECGs incorporate 250 electrodes. Their hypothesis is that better characterizing the QRS, with notches and the like, may be predictive of future arrhythmia.
Later in the day, I went to session entitled: Does my dynamic 83 year-old heart failure patient need an ICD? Dr. Rachel Lampert (Yale) did an excellent job reviewing the literature on ICD benefits in the elderly. It turns out, as it so often does in the elderly, that no hard and fast rules exist. Clinical judgement and shared decision-making come to the fore.
In the same session was an excellent survey of how and when to incorporate palliative care into the care of patients with advanced heart disease. Dr Sarah Goodlin (Utah) offered a number of helpful hints for cardiologists:
- Palliative care should be delivered concurrently with cardiology care.
- There is no place for handoffs to palliative care. Cardiologists should stay engaged at end of life.
- Use the patientâ€™s name; express empathy; touch and listen;
- And alwaysâ€¦hope for the best but plan for the worst.
We cardiologists could learn a ton from palliative care doctors.
At what age and at what level of frailty does anticoagulation risk exceed benefit?
Dr. Elaine Hylek (Lexington Mass) gave a nice overview on this important and common clinical scenario. Itâ€™s all about balancing risk. She emphasized that AF-related stroke in the elderly confers an especially high mortalityâ€”up to 24% 30-day mortality in one study. The HAS-BLED scoring system, which incorporates age, hypertension, abnormal renal/liver function, previous bleeding, labile INR, and other drugs, especially the NSAID group, can help sort out bleeding risk.
Dr Hylek spent some extra time on the issue of fall risk. Citing a famous trial published in the American Journal of Medicine (2005) where researchers compared a cohort of 18,261 low fall risk patients v. 1,245 high fall risk elderly patients.Â The authors found the risk of ICH in the high fall risk patient was 2.8% while the risk of ischemic stroke was 13.7%. The take home message is one that most clinicians know well: the frail elderly are much more at risk for stroke than ICH.
That’s a wrap for this year’s ACC. Three days went by very quickly.