COMMENTARY

Nov 6, 2020 This Week in Cardiology Podcast

John M. Mandrola, MD

Disclosures

November 06, 2020

Please note that the text below is not a full transcript and has not been copyedited. For more insight and commentary on these stories, subscribe to the This Week in Cardiology podcast.

In This Week’s Podcast

For the week ending November 6, 2020, John Mandrola, MD comments on the following news and features stories.

COVID

For 6 months, I’ve started the podcast with COVID notes. It’s still bad, though there are some tiny hints of positive news. Belgium, one of the harder hit European countries, announced this week that their hospitals will not likely be overwhelmed.

Here in the US, cases continue to rise, but whether it is due to testing people who are less ill or lower-risk or a better understanding of treatment, or all of the above, I cannot yet see that deaths have risen. It’s been 30 days since case numbers rose. Here at my hospital in a medium-sized US city, we have seen a modest rise in hospital admissions, but hardly any rise in ICU admissions or patients on ventilators. An intensivist says that there are definitely more cases on the wards but thankfully not yet in the ICUs. This could change in the next week or two, so we shall see.

AF Ablation

JAMA published a randomized clinical trial (RCT) in the atrial fibrillation (AF) ablation space. RCTs should always be celebrated; they are hard to do, and I salute the authors of the VENUS trial, specifically Dr. Miguel Valderrabanno from Houston Methodist Debakey.

I am a reluctant and cautious AF ablation doctor. When we do this inelegant procedure, we ought to have the data for the best approaches. The VENUS trial asked the question as to whether ethanol ablation of the Vein of Marshall (VOM) improves outcomes over more standard AF ablation in patients with persistent AF.

Ethanol ablation of the VOM is a nifty procedure in which pure ethanol is injected into the VOM and results in ablation of the peri-mitral area anterior to the left pulmonary veins and on the ridge between the appendage and veins. This is a difficult area to ablate. In VENUS, 50% of patients had had persistent AF for more than 2 years, and 90% had had it for more than 6 months. This is a tough group because the duration of AF inversely correlates with successful restoration of sinus rhythm.

VENUS was conducted in 12 centers in the US and Canada, with roughly 340 patients randomly assigned to standard catheter ablation or catheter ablation with ethanol VOM. The primary endpoint was freedom from AF or atrial tachycardia for more than 30 seconds after a single procedure without antiarrhythmic drugs at 6 and 12 months.

The main results:

  • 49.2% (91/185) in the catheter ablation + VOM group were free of AF

  • 38% (60/158) in the standard catheter ablation

  • P = .04

AF burden was skewed; about 10% of patients in both arms had extremely high burden AF, but 78% had AF burden of 0 in VOM group, and 68% had AF burden of 0 in the standard group. The difference made statistical significance at P=.03. The key caveat is that this statistic included multiple procedures and/or antiarrhythmic drugs. However, in the supplement, the percent AF burden at 12 months overall did not differ.

So, should this procedure be added to the procedure? I would say a hard no. And my 4 criticisms of VENUS are not personal; it was a good trial.

  1. The primary outcome could not be ascertained in 27 patients because of lack of monitoring data. And only about half of the patients had implantable loop recorder monitoring. Recall that the p value for the primary outcome was.04 and thus a couple of events either way could have easily tipped the results to non-significant.

  2. AF burden is arguably a better measure of AF ablation success and if you look at overall AF burden there was not even a signal of benefit.

  3. The comparator group was treated very aggressively. Even though the STAR AF2 RCT found no benefit to ablation outside of standard pulmonary vein isolation (PVI), 95% of patients in both groups received ablation beyond standard PVI. Thus, this was really a trial comparing massive left atrial ablation vs really massive left atrial ablation. I am not sure why AF operators don’t stick to the evidence at hand.

  4. Which brings me to the complication rates in these 66-year-old patients. In a trial of 340 patients there were seven neuro events including three strokes; seven pericardial effusions; eleven patients had groin complications; and seven had pneumonias.

While the differences between groups in complications were not much different, the most important finding from this paper may be that overly aggressive non-evidence-based ablation outside the pulmonary vein is hazardous.

Five Practices to Avoid in Pediatric Cardiology

The American Academy of Pediatrics is on a hot streak. Earlier this year they recommended opening schools for in-person learning. More recently, they announced recommendations as part of the Choosing Wisely campaign after reviewing evidence pertaining to practices common during pediatric visit.

  • Do not routinely do an ECG for sports participation.

  • Do not do routinely do an ECG before ADHD therapy.

  • Do not routinely do an echocardiogram for syncope or chest pain.

  • Do not get troponin levels for chest pain.

Thank goodness this last one came up, for it is another reason to remind my listeners that troponins should not be ordered unless you suspect the patient is having an acute coronary syndrome due to plaque rupture. Since kids don’t have plaque rupture or type I MI, measuring troponin only risks bringing on further testing. Keep in mind friends that the athletic literature has multiple studies showing that prolonged vigorous exercise can increase troponin.

Heart Failure Performance Measures

The American College of Cardiology/American Heart Association (ACC/AHA) has published a new revision of the AHA/ACC heart failure performance measures. Journalist Richard Mark Kirkner has full coverage but I am highlighting some things I like and others I don’t like.

First off, one of the smartest guys on Twitter is the senior author; kudos to Boback Ziaeian.

I liked the focus on symptom and activity assessment. I always ask what patients can do. Do you go to the grocery? Do you walk the dog? What is that cane for or walker for?

I liked the emphasis on magnetic resonance angiography (MRA) and checking labs. MRA’s seem really wise to me, but hyperkalemia is a worry.

I liked the addition of angiotensin receptor neprilysin inhibitor (ARNI) drugs. I am not sure it is much better than full dose RAS inhibition; nonetheless, it deserves to be added.

I liked the addition of cardiac resynchronization therapy (CRT) but we all know that CRT is helpful. Here is what should have been added and focused: CRT implant is not enough. CRT needs to be assessed after implant to make sure it is working. A doctor treating patients with heart failure needs to recognize or even document that CRT is happening. An ECG shows adequate resynchronization.

A couple other thing perplex me about HF recommendations. Why allow oodles of ACEs and ARBs when only a handful have been studied? You must assume there is a class effect. Losartan for instance has no RCT-level evidence. If there is a class effect with ACE/ARB why isn’t there one with beta blockers? Why do you specifically include only bisoprolol, carvedilol, and metoprolol XL for performance measures within beta blockers?

Another problem I have with this addition tof performance measures is the emphasis on increasing doses. If we are only enforcing these measures in young, male, ambulatory patients like those enrolled in the trials, I’d say fine. But what happens in the real world is that, because there is a financial incentive to label everyone with as much disease as possible, clinicians will be nudged to advance meds in older, more frail adults who would never have been enrolled in trials.

I know Boback and his co-authors will say all you have to do is document all this. And that is true. But I would have liked the issue of bedside translation of the trials to be front and center. Finally, another thing that bothers me about the beta blocker recommendation is that a ton of patients with heart failure with reduced ejection fraction (HFrEF) have AF. Why is there no accommodation for the fact that very strong evidence from individual level patient meta-analyses suggest that when there is AF, beta blockers don’t reduce death—they don’t harm patients with HFrEF, it’s just that there is no benefit. At minimum, let us use short-acting beta-blockers when there is both AF and heart failure.

AHA Annual Meeting

Next Friday, I will have a full AHA preview as the meeting starts Friday November 13. The podcast comes out Friday afternoon, so next Friday morning the first two late-breaking sessions will occur before the podcast. Here are some quick highlights of that session

The first trial involves a novel oral agent called omecamtiv mecarbil, which is a cardiac myosin activator that has been shown to improve parameters of systolic function. GALACTIC-HF is an RCT of 8000 patients with HFrEF that compared omecamtiv mecarbil with placebo. We learned by press release early in October that the myosin activator met its primary endpoint of cardiovascular (CV) death and heart failure events. Alas, the drug did not reduce the key secondary endpoint of CV death.

There are two studies looking at replacement of vital minerals. The VITAL Rhythm study is a substudy of VITAL, a huge RCT that compared vitamin D and omega-3 fatty acids and reported no reduction of CV events or cancer incidence. VITAL-Rhythm will look at whether or not vitamin D or omega-3s will reduce AF incidence over 7 years.

The second trial of note is the AFFIRM-AHF trial looking at ferric carboxymaltose in iron deficient patients with acute heart failure. The study narrowly missed statistical significance on the primary endpoint but sit down for this, and I am not making it up, a press release had this sentence: “a pre-specified sensitivity analysis considering the impact of the COVID-19 pandemic, revealed a statistically significant difference in favor of the [infusion].” This trial could win the spin award of 2020.

The second late-breaking sessions will feature two RCTs on the polypill. And a report from the Swedish CArdioPulmonary BioImage Study which is a large population-based cohort used to predict coronary artery disease in the general population.

The big story of the 5-day meeting comes in the fourth late-breaking session on Sunday. This is the Samson, “n of 1” trial, from the Imperial College London group of Darrell Francis. Samson may answer one of the most important questions in primary practice and cardiology: Do statins really cause more side effects than placebo? Or is it all a nocebo effect.

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