After Two Years A-Fib Free, What Causes ‘Very Late Recurrence’ in Post-Ablation Patients?

Even though catheter ablation is remarkably successful in restoring most paroxysmal A-Fib patients to normal sinus rhythm, a small number of these patients do have relapses (recurrences) sometimes many years out.

The main objective of this study was to understand why Atrial Fibrillation relapses years after successful electrical isolation of the pulmonary veins (PVs) in paroxysmal patients and whether the presence of comorbidities influence recurrence.

These are the questions Dr Andrea Natale and his colleagues at the Texas Cardiac Arrhythmia Institute were looking to answer.

Study Parameters

In this observational study, researchers at Texas Cardiac Arrhythmia Institute looked at 1,633 of their paroxysmal patients who had been A-Fib free for two years after their first or second catheter ablations, then suffered recurrences years later  (i.e., Very late recurrent).

The patients were divided into two groups based on the presence or absence of comorbidities (presence of two or more diseases). The groups were:

Group 1: 692 patients with no comorbidities
Group 2: 941 patients with comorbidities

A-Fib and Common Comorbidities

The Group 2 patients had one or more of the following illnesses/conditions (comorbidities):

• Moderate to severe sleep apnea
• Diabetes mellitus
• Body mass index 30 kg/m² or higher (obese)
• Hypertension treated with multiple anti-hypertensive agents
• Low left ventricular ejection fraction (lower than 45%; normal is 50% to 75%)

Quality of Previous Ablations

The patients who experienced recurrences had been previously well ablated (one or two procedures.) Standard ablation procedures included PVI plus isolation of the left atrial posterior wall and the Superior Vena Cava (SVC):

• Their pulmonary veins were completely isolated of all PV potentials as confirmed by entrance and/or exit block. The electrical isolation was extended to the posterior wall contained between the PVs.
• Posterior wall isolation was performed using multiple ablation points covering the whole posterior wall.
• The SVC was mapped and isolated circumferentially in all patients. The atrial myocardial sleeves extend into the SVC for up to 2 to 5 cm. thus harboring ectopic pacing cells that provide the substrate for atrial arrhythmia. The Superior Vena Cava (SVC) is a known source on non-PV triggers.

Patient Follow‐up

Follow‐up was performed at 1, 3, 6, and 12 months with office visits, cardiology evaluation, 12‐lead electrocardiogram (ECG) and 7‐day Holter monitoring at 1, 6, and 12 months. After 1 year, patients were followed up annually with a 7‐day Holter and were asked to check their pulse regularly to monitor rate.

Ablation success was defined as absence of arrhythmia off antiarrhythmic drugs.

Ten-Year Recurrence Findings

At 10 years of follow-up, median time to recurrence was 7.4 years. The recurrence rate among the study patients was:

• Group 1 patients: 31.1% experienced recurrence (215 of 692)
• Group 2 patients: 51% experienced recurrence (480 of 941)

Redo Ablations

Patients with recurrence of their A-Fib, underwent a ‘re-do’ ablation:

• 201 in Group 1 patients
• 456 in Group 2 patients

Ablations targets at re-do:

• 561 patients received isolation of the Left Atrial Appendage (LAA) and Coronary Sinus (CS); 96 patients received left atrial lines and flutter ablation; 9 patients received re‐isolation of PVs;
• PV reconnection was not noted in any of the patients with two prior procedures. The SVC was found to be permanently isolated in 642 (97.7%) and no reconnection of posterior wall in 611 (93%) cases.

Top: Representative images showing a patient’s lesion sets during initial ablation. Bottom: 5 years later during the same patient’s re-do ablation.

Two-Year Results After Redo Ablation

At 2 years, 91.1% (134) of Group 1 and 94.4% (391) of Group 2 remained arrhythmia free! These patients received left atrial appendage (LAA) and Coronary Sinus (CS) isolation.

Of those who received left atrial lines and flutter ablation, results were poor with around 7% arrhythmia free.

Study Conclusions

The main objective of this study was to understand why Atrial Fibrillation relapses years after successful PV catheter ablation in paroxysmal patients and whether the presence or absence of comorbidities influence very late recurrences.

Despite permanent pulmonary vein isolation (PVI), very late recurrence was primarily driven by non‐pulmonary vein triggers especially from the left atrial appendage and coronary sinus. Ablation of these triggers resulted in high success rate (regardless of the comorbidity profile.)

The median time to recurrence was significantly shorter in patients with cardiovascular comorbidities.

Editor’s Comments

These study results are remarkable! The study findings reinforce the crucial role of non-PV triggers in the relapse of A-Fib. Knowing how comorbidities shorten the timeline to A-Fib recurrence can motivate patients to improve their overall health.

If You’re Having an Ablation or Re-do Ablation: Besides isolating the Pulmonary Veins, talk with your doctor about mapping and isolating non-PV triggers i.e., from the Left Atrial Appendage (LAA) and Coronary Sinus (CS).

How can You Avoid Recurrence? Get rid of comorbidities. Even after the establishment of sinus rhythm, comorbidities contribute to the progression of A-Fib and its recurrence.

While patients in Group 2 (with comorbidities) were able to be cured and restored to sinus rhythm just as well as patients without comorbidities, recurrence occurred sooner (5.6 years versus 7.4 years).

To postpone or avoid recurrence of your A-Fib, do what you can to get healthier. Lose weight if needed, get treatment if you have sleep apnea, address hypertension issues, manage your diabetes, stop smoking, moderate your  consumption of alcohol.

Why Does A-Fib Sometimes Recur Many Years Later? We can only speculate. Perhaps the evolution or development of A-Fib silently continues during the years of being A-Fib free. Is it age-related? Does genetics play a role? Obviously more research needs to be done in this area.

Last Thoughts: Have researchers like Dr. Andrea Natale discovered how to cure even the most difficult A-Fib cases? Isolating the LAA and the CS seems to be the key.

Are we close to a time where even the most difficult cases of A-Fib can be cured by the right EPs using the right ablation techniques at the right time?

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