"We prospectively enrolled 288 AF patients scheduled to undergo initial radiofrequency catheter ablation. Each patient underwent periodontal inflamed surface area (PISA; a quantitative index of periodontal inflammation) measurement.
All eligible patients were recommended to receive periodontal treatment within the blanking period, and 97 consented. "
Published paper link
This could indicate "healthy user bias." Meaning that those who consented to gum treatment are more likely to have done other healthy things (obeyed doctor's instruction & etc).
That being said, I'm a big advocate of proper gum care. This
post in another group outlines various approaches to deal with severe gum disease.