New techniques have made it safer than ever, but early intervention is crucial…

Catheter ablation can be a first-line treatment for many atrial fibrillation (AF) cases, with recent evidence—and major technological advances—changing who should be referred and when, explains cardiologist Professor Rukshen Weerasooriya, a sub-specialist cardiac electrophysiologist at Perth’s Hollywood Private Hospital and founder of CloudHolter.

Yet many patients who would be ideal candidates for the procedure still aren’t being referred.

Ablation can be first-line in many cases

Catheter ablation was once a “last resort” for patients with AF, Professor Weerasooriya says.

“Patients had failed multiple cardioversions, lots of antiarrhythmics, even possibly had toxicity from antiarrhythmics, and only then would they be considered for ablation.”

But this has changed, largely because of the treatment’s comparative effectiveness, as outlined in the latest2023 Cardiac Society of Australia and New Zealand (CSANZ) position statement, Professor Weerasooriya says.

“It is much, much more effective than what I call the unholy trinity of flecainide, sotalol, and amiodarone. The best efficacy for these drugs is 40 to 60% in clinical trials, and most patients who start them just can’t tolerate them in the longer term. So ablation really is far superior to drugs and that’s been proven in multiple RCTs.”

Today’s procedures are much safer

Early on, AF ablations were considered highly dangerous. “And we had to proceed with great caution because it was brand new,” he says. “But now we’re 25 years down the track.”

Pulsed field ablation (PFA) has shifted the paradigm over the last two years, he says.

Unlike radiofrequency ablation and cryoablation, which use thermal energy to destroy tissues, pulsed field ablation uses high-energy electrical pulses that target cardiac cells more selectively, he explains.

“There’s therefore no risk to the oesophagus, no risk to the phrenic nerve and no risk of pulmonary vein stenosis. This has been a big deal for us because those were our main serious complications.”

PFA procedures use a single catheter rather than three and are typically much faster, he says.

“So the time under anaesthetic has really dramatically reduced. And in most public hospitals in Australia now, an AF ablation is a day procedure.”

Who should be considered for ablation?

The CSANZ position statement recommends considering catheter ablation for all patients with symptomatic paroxysmal or persistent AF if antiarrhythmic drug therapy has failed or was not tolerated. It may also be considered for symptomatic patients with long-standing persistent AF in these circumstances.

“You can also consider referring patients who are naive to antiarrhythmic medication for ablation instead of even trying an antiarrhythmic medication,” Professor Weerasooriya says.

Not every patient needs an ablation, he emphasises, noting AF management hinges on whether you want to achieve rate or rhythm control.

“If the patient is minimally symptomatic, it is very reasonable to consider rate control,” he says.

Importantly, patients with AF and reduced left ventricular ejection fraction should be referred urgently regardless of symptom status, as AF-mediated cardiomyopathy is a potentially reversible cause of heart failure.

“This is the one Class 1A indication that applies even to the asymptomatic patient.”

“Catheter ablation will improve the ejection fraction. The only thing that improves ejection fraction more than ablation in these patients is heart transplantation.”

It’s important to refer patients to a cardiac electrophysiologist specifically, he adds.

“You need an electrician and not a plumber.”

When to refer

Professor Weerasooriya cautions against waiting until patients have had multiple cardioversions or medical therapy failures before referring them.

Timing is critical, he says, stressing that earlier intervention leads to better outcomes.

“The golden window for us to treat these patients is that first year of diagnosis.”

AF progresses over time, he explains, with patients moving from paroxysmal to persistent AF and eventually to long-standing persistent AF as structural and electrical remodelling occurs within the atria.

“The further you go down, the harder it is for us to ablate it. The less success rate, the more we have to do.”

“I would certainly encourage that in the first year after diagnosis, at least get an opinion from a cardiac electrophysiologist. We really like to have a discussion with the patient at that paroxysmal stage.”

Managing risk factors

Ablation is not a cure, Professor Weerasooriya emphasises.

“Having a long-term care plan in GP is really important for these patients. It’s not just have an ablation and forget about your AF.”

Management of six modifiable risk factors—hypertension, alcohol intake, obesity, sleep apnoea, physical inactivity and smoking—is a Class 1 recommendation.

“To my mind, these are more important than the procedure,” he says.

Tight blood pressure control is particularly important. “Not only does it prevent AF recurrence and atrial remodelling, it also reduces bleeding risk when they’re on DOAC.”

Patients should be encouraged to reduce their alcohol consumption, preferably to zero but limiting intake to three standard drinks per week is a reasonable goal.

Weight loss is advised for patients with obesity, he adds. “What we found is that 10% body weight loss, if they’re obese to start with, will really buttress the result of our ablation.”

Physical activity is also important, with research showing that patients who participate in structured exercise training are more likely to achieve freedom from AF.

Patients can usually resume sexual activity 1-2 days after the procedure, but should wait 2 weeks before resuming formal exercise in a gym, mainly because of the groin puncture, he advises.

The presence of sleep apnoea should be actively investigated, particularly in patients with obesity. “Look for it. Treat it. Because if you treat sleep apnoea, they’ll do better in the long term.”

Smoking cessation should also be a priority.

Can you stop anticoagulation after AF ablation?

In patients with a CHA₂DS₂-VASc score of 4 or less, very new evidence suggests that it may be reasonable to cease DOAC 12 months after a successful AF ablation, Professor Weerasooriya says. It is a good idea to run a Holter monitor test to exclude silent AF at the 12-month post ablation mark, talk to the cardiac electrophysiologist, and make a shared decision with the patient about whether to stop anticoagulation, he says.

“This is very new evidence that has not yet reached guidelines so an individual approach is called for,” Professor Weerasooriya says.

Potential post-ablation complications

“Early arrhythmia recurrence is very common during the first 1 month post ablation, so we just reassure the patients and treat their arrhythmia as we normally would,” Professor Weerasooriya says.

Some patients may experience a temporary increase in resting heart rate, he notes. “They’ll go up about 10 beats per minute for about three to six months, and it’s because we’ve taken out some of the epicardially located vagal nerves when we ablated. It’ll get better.”

Transient migraine-like symptoms, often with visual aura, are also common in the first two weeks after ablation, he says.

“It’s because of the transeptal puncture that we make, which then heals off. It’s very scary because they’ve been told that stroke is a potential complication, and they’ll often present to ED thinking they’re having a stroke.”

“Vascular and groin complications, false aneurysms and AV fistulas can happen, because we’ve made a big puncture in their vein, we might have accidentally hit the artery, and then we’re anticoagulating them.”

Thromboembolism and late tamponade are rare, he says.

Atrio-oesophageal fistula is also rare—but essential to identify, he adds.

“If a patient is sick with a fever weeks after an AF ablation, get in contact with your electrophysiologist or whoever did that procedure straight away,” he says. “It has an 80% mortality. If we catch it early, there’s stuff we can do, but they tend to be caught late.”

Key takeaways:

• Catheter ablation is a first-line option for many patients with AF
• Pulsed field ablation has made the procedure faster, simpler and safer
• Refer patients early to a sub-specialist cardiac electrophysiologist ideally within the first year of diagnosis
• Patients with AF and reduced ejection fraction should be referred urgently regardless of symptoms
• Direct referral to a cardiac electrophysiologist should be considered where possible
• Management of modifiable risk factors is still essential after ablation and these patients should have a GP initiated chronic disease care plan