Short- and Long-Term Risks of Atrial Fibrillation in Surgically Treated Lung Cancer Patients: A Korean Nationwide Study.

[BACKGROUND] To evaluate short- and long-term risks of atrial fibrillation (AF) in patients undergoing surgery for lung cancer (LCA), stratified by treatment modality and time since surgery.

[METHODS] We used the Korean National Health Insurance Service database to analyze 34,519 LCA patients who underwent surgery between 2010 and 2017. We matched them 1:3 with controls from the general population. Competing risk models were used to calculate cause-specific hazard ratios (csHRs) and 95% confidence intervals (CIs) for atrial fibrillation (AF), adjusted for demographic and clinical factors. Landmark analyses were conducted at 1, 3, and 5 years after LCA surgery.

[RESULTS] LCA patients had a higher AF risk than controls (csHR 1.61; 95% CI, 1.53-1.69), peaking within the first year following diagnosis (csHR 4.06; 95% CI, 3.61-4.58), and gradually declining thereafter, though remaining elevated. Patients receiving chemotherapy exhibited sustained elevations in AF risk at 3 years (csHR 1.44; 95% CI, 1.26-1.65) and 5 years (csHR 1.40; 95% CI, 1.18-1.66) after surgery. The risk was heightened in patients receiving both chemotherapy and radiotherapy, with consistently high hazard ratios at 3 years (csHR 2.28; 95% CI, 1.86-2.8) and 5 years (csHR 2.16; 95% CI, 1.65-2.84) after surgery. In contrast, the AF risk in patients undergoing surgery alone was similar to that of the control group after 3 years.

[CONCLUSIONS] AF risk in LCA patients varies by treatment modality and time since surgery. Surveillance strategies should be tailored accordingly.