PARIS — Catheter ablation has been placed front and center in the latest guidelines for the management of supraventricular tachycardia (SVT) from the European Society of Cardiology (ESC). The guidelines also refine the use of drug therapy for the condition and make important recommendations for pregnant women.
Moreover, the guidelines have dropped a whole host of medications that were once considered part of standard care for managing this family of arrhythmic conditions.
The last time the ESC produced guidelines on the management of SVT was in 2003.
Demosthenes G. Katritsis, MD, PhD, Department of Cardiology, Hygeia Hospital, Athens, Greece, who co-chaired the guidelines task force, told theheart.org | Medscape Cardiology that, with the accumulation of knowledge over the years, it was the "proper time" to update the recommendations.
Compared with the previous version, the 2019 guidelines contain several refinements to the strength of recommendations around the use of medications to treat SVT. In addition, many drugs have been dropped all together.
Katritsis explained that what has changed is that "we have learned how to use the drugs safely," pointing out that, "with the notable exception of β- blockers and perhaps calcium channel blockers," most drugs used to treat SVTs are proarrhythmic.
"What I mean is that they may exert antiarrhythmic action but at the same time they may promote other arrhythmias," he said. "That's why you see with some of them, for example, sotalol or quinidine in the past, that we have experienced increased mortality with their use, rather than decreased mortality."
Katritsis said that "we have become wiser now," highlighting that "a lot of the main points of our guideline are that we never recommend long-term therapy with drugs, except β-blockers or calcium channel blockers."
Perhaps one notable feature of the guidelines, which were presented here at the ESC Congress 2019 and published in the European Heart Journal, is that they do not contain reference to many novel drugs since the 2003 version.
However, Katritsis pointed out that there is a new indication for ivabradine, and "we have established the value of ibutilide and dofetilide in converting atrial flutter."
The guidelines also mention the calcium channel blocker etripamil (Milestone Pharmaceuticals). "If this proves in extended trials to be useful, it will be a great step forward," Katritsis said. "We do not recommend it yet, though, because we think that the evidence is not convincing enough to qualify for a guideline."
For him, however, one of the major changes concerns catheter ablation because of the impressive outcomes achieved with the technique, with success rates of up to 100%.
"This means, practically, that whenever you are dealing with SVT, regardless of whether it's reentrant or a focal arrhythmia, you have to offer the patient the possibility of catheter ablation because it eradicates it, and this doesn't happen very often."
Crucially, this can be achieved with "old-fashioned, conventional ablation without mapping or sophisticated new techniques," Katritsis emphasized, meaning that it should be available for most patients with conventional SVT.
While the epidemiological evidence for SVT is limited, the estimated prevalence in the general population is 2.25 per 1000 persons, at an incidence of 2.5 per 100,000 person-years.
Women face double the risk for SVT of that seen in men, and individuals aged 65 years and older have a fivefold greater risk for the condition than younger people.
Although SVT, which comes in a wide variety of forms, is in itself not life-threatening, it is a lifelong condition that affects the function of the heart and can lead to an increased risk for stroke and reduced quality of life.
To examine the latest evidence and update the guidelines to reflect modern management, the task force, which was co-chaired by Josep Brugada, MD, PhD, Hospital Sant Joan de Déu, University of Barcelona, Spain, conducted a literature review.
As well as looking at the outcomes, they took into account patient-specific modifiers, comorbidities, and issues around patient acceptance, as well the frequency of follow-up and cost-effectiveness.
With 16 years having passed since the last set of recommendations, many drugs that were previously included were no longer considered, such as:
Sotalol and lidocaine for the acute management of wide QRS tachycardias;
Procainamide, sotalol, and digoxin for acute focal atrial flutter;
Amiodarone, sotalol, and disopyramide for chronic atrial tachycardia; and
Digitalis for acute atrial flutter.
In addition, amiodarone, sotalol, flecainide, propafenone, and the "pill-in-the pocket" approach have been dropped from the therapy of chronic atrioventricular nodal re-entrant tachycardia (AVNRT) for the 2019 guidelines.
In many cases, the review also led to refinements in the strength of recommendation.
For example, the strength of recommendation was increased from IIb to IIa for β-blockers in the acute management of narrow-QRS tachycardias and for atrioventricular re-entrant tachycardia (AVRT), as well as for verapamil for SVT in pregnancy and adenosine in the acute management of wide-QRS tachycardia.
On the other hand, the recommendation was reduced from I to IIa or IIb in the 2019 guidelines for verapamil and diltiazem for the acute management of narrow-QRS tachycardias and for procainamide and amiodarone in the acute management of wide-QRS tachycardias.
The same change was made for β-blockers in the therapy for inappropriate sinus tachycardia, acute and chronic focal atrial tachycardia, acute atrial flutter, and chronic AVNRT.
The recommendation was also reduced from I to IIa for verapamil and diltiazem in the management of chronic focal atrial tachycardia, acute atrial flutter, and chronic AVNRT.
The task force also made a series of novel recommendations for 2019.
These include a class I recommendation for ibutilide or dofetilide for the conversion of atrial flutter and high-rate atrial pacing for the termination of atrial flutter in the presence of an implanted pacemaker or defibrillator.
The task force also gave a class IIa recommendation to consider using ivabradine alone or in combination with a β-blocker in symptomatic patients with inappropriate sinus tachycardia.
Anticoagulation should also be considered in patients with atrial flutter without atrial tachycardia, although the recommendation is again IIa and the recommendations acknowledge that "the threshold for initiation is not established."
In pregnancy, the guidelines recommend for the first time that all anti-arrhythmic drugs be avoided during the first trimester (class I), while β-1–selective blockers (not atenolol) or verapamil should be considered to prevent SVT in women without Wolff-Parkinson-White (WPW) syndrome (IIa).
Pregnant women with WPW syndrome but without ischemic or structural heart disease should be considered for flecainide or propafenone to prevent SVT, the task force recommends (class IIa).
The biggest changes between the 2003 and 2019 guidelines, however, center on the use of catheter ablation.
In a series of recommendations on the technique, the guidelines state that catheter ablation is recommended in high-risk patients with asymptomatic SVT (class I).
It may also be considered in patients with asymptomatic pre-excitation and low-risk accessory pathway at invasive or noninvasive risk stratification (IIb), and in those with asymptomatic pre-excitation and left ventricular dysfunction due to electrical dyssynchrony (IIa).
If a tachycardia that is responsible for tachycardiomyopathy cannot be ablated or controlled by drugs, then atrioventricular nodal ablation with subsequent biventricular or His-bundle pacing is recommended (class I).
Despite all these firm recommendations, the task force acknowledges many gaps remain in the evidence for the management of SVT, not least of which is that the exact circuit of AVNRT (the most common regular arrhythmia in humans) is still unresolved.
Moreover, the genetics of SVT have not been thoroughly investigated and, despite evidence for familial forms of AVNRT, AVRT, sinus tachycardia, and atrial tachycardia, the data are "scarce," they note.
Questions also remain over the distinction between triggered activity and enhanced automaticity, the proper management of asymptomatic pre-excitation and strict catheter ablation indications, and the propagation of re-entrant circuits.
No funding sources were declared. Brugada declares speaker fees, honoraria, consultancy, advisory board fees, investigator, or committee member, et cetera, from Livanova, Boston Scientific, St Jude Medical, Biotronik. Katritsis declares royalty fees from Oxford University Press and research funding from Medtronic and Boston Scientific. Full disclosures for all authors can be found on the ESC website.
European Society of Cardiology (ESC) Congress 2019. Released August 31, 2019.
Eur Heart J. Published online August 31, 2019. Full text
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Cite this: New ESC Guideline on SVT Management: Catheter Ablation Key - Medscape - Sep 02, 2019.