PRAGUE-12: Surgical Ablation of A-fib During Cardiac Surgery Has Long-term Stroke Benefit

SAN FRANCISCO, CA—Until now, adding surgical ablation of A-fib to cardiac surgery has been shown to increase the chances of sinus rhythm without an impact on clinical outcomes. But new data from the PRAGUE-12 trial indicate that long-term stroke rates are improved as well.

After 5 years of follow-up, a composite of CV death, stroke, severe bleeding, or hospitalization for worsening heart failure occurred less frequently in patients who had concomitant ablation, although the difference fell shy of statistical significance when accounting for competing risks (42.6% vs 61.6%; subhazard ratio 0.69; 95% CI 0.47-1.02).

All of the components of that endpoint were numerically less frequent in the ablation arm of the trial, but only the difference in stroke was statistically significant (5.6% vs 14.1%; SHR 0.32; 95% CI 0.12-0.84).

Pavel Osmancik, MD, PhD (Charles University and University Hospital Kralovske Vinohrady, Prague, Czech Republic), presented the results at the Heart Rhythm Society 2019 Scientific Sessions earlier this month. They were published simultaneously online in Heart Rhythm.

“Additional long-term follow-up is needed to see the full benefits of surgical ablation,” Osmancik said during his presentation at the meeting.

Commenting for TCTMD, cardiac surgeon A. Marc Gillinov, MD (Cleveland Clinic, OH), said these findings are important because most studies of surgical ablation of A-fib have had short-term follow-up, which is problematic.

“The surgical ablation of atrial fibrillation has not gained widespread acceptance among surgeons,” he explained. “Less than half of patients who have A-fib who go to the operating room for some kind of cardiac surgical procedure get an ablation, and I think one of the reasons that it hasn’t gained as much traction as it should is that surgeons haven’t been convinced that it actually improves outcomes.

“This study is the first one that’s really long term,” Gillinov continued. “It’s a randomized controlled trial—those are rare in surgery—and it shows that at 5 years the people who had ablation are better across the board. Most notably, they have fewer strokes, which of course is the big thing.”

A Common Problem

A-fib is found in about one out of every 10 patients who undergo cardiac surgery for CAD or valve disease, Osmancik noted. More than 20 randomized trials have shown that concomitant surgical ablation of A-fib is safe and increases the chances of sinus rhythm over the short term in these patients. But, Osmancik pointed out, these trials—which have been limited by small sample sizes and a short length of follow-up (none longer than 2 years)—have not demonstrated a benefit in terms of clinical outcomes.

Included in that group of trials is PRAGUE-12, which—as reported in the European Heart Journal in 2012—showed that adding surgical ablation to CABG, valve surgery, or a combination of the two procedures increased rates of sinus rhythm at 1 year, with no increase in perioperative complications or impact on clinical outcomes.

Long-term follow-up was planned as part of the original study. Of the 224 patients randomized, 207 were available for 5-year follow-up analysis. The mean age of these patients was 70.5, and 60.4% were men. The indication for surgery was CAD in 26.6%, valve disease in 45.9%, and a combination in 27.5%.

The patients who received concomitant ablation and those who did not were generally well matched at baseline, except for higher rates of CAD on coronary angiography (65.7% vs 50.9%) and a history of MI (36.4% vs 19.4%) in those who were not ablated.

Through 5 years of follow-up, the addition of ablation increased the rate of freedom from A-fib (29.6% vs 11.1%), translating into a significant reduction in recurrence in the fully adjusted model (SHR 0.44; 95% CI 0.31-0.62).

The only clinical outcome reduced by concomitant surgical ablation was stroke. Osmancik said that finding could not be explained by differential rates of oral anticoagulation during follow-up. He and his co-authors note in their paper that the improvement in stroke risk is likely related to better maintenance of sinus rhythm or to the use of left atrial appendage resection as part of the ablation procedure.

Gillinov speculated that it was likely the latter, “given that their rhythm results were not spectacular.”

He noted, however, that the surgeons performing ablation in the trial “didn’t do a full lesion set characteristic of a maze procedure, and it’s likely that the results in terms of rhythm would be superior today with a full lesion set.”

Even so, Gillinov indicated that the results are persuasive. “I think the findings will convince more people to add ablation because they demonstrate that it’s good for patients,” he said.