Background – Much debate is still going on about the best ablation strategy – via endocardial or epicardial approach – in patients with atrial fibrillation (AF), and evidence gaps exist in current guidelines in this area. More specifically, there are no clear long-term outcome data after failed surgical AF ablation.Methods – Since June 2008, 549 surgical AF ablation procedures through a right minithoracotomy were performed at our institution. From 2008 to 2011, a unipolar radiofrequency device was used (151 patients), whereas from 2011 to 2020 a bipolar radiofrequency device was used (398 patients). Patients were scheduled for surgery on the basis of the following criteria: recurrent episodes of paroxysmal or persistent lone AF refractory to maximally tolerated antiarrhythmic drug dosing and at least one failed cardioversion attempt. Besides the recommended follow-up by the local cardiologist, starting from 2021, surviving patients were asked to undergo assessment of left ventricular function and to complete a questionnaire addressing quality of life and predisposing factors for recurrent AF.Results – At a mean follow-up of 77 months, the rate of AF recurrence was 20.7% (n=114). On multivariate analysis, impaired left ventricular ejection fraction (58 patients, 51%, p=0.002), worsening of European Heart Rhythm Association (EHRA) symptom class (37 patients, 32%, p=0.003) and cognitive decline or depression (23 patients, 20%, p=0.023) during follow-up were found to be significantly associated with AF recurrence.Conclusions – Surgical AF ablation through a right minithoracotomy is safe, but a better outcome could be achieved using a hybrid approach. Patients after initial failed surgical AF ablation show worsening of cardiac function, clinical status and quality of life at follow-up compared to patients with successful AF ablation.