To Örebro University

Atrial fibrillation (AF) is associated with an increased risk of stroke, heart failure, and cardiovascular death. Ablation therapy can reduce AF symptoms, arrhythmia burden and mortality, and is performed endovascularly or surgically. Coronary revascularization involve surgical or endovascular techniques. New-onset AF is more commonly reported following surgery, but systematic heart rhythm monitoring strategies are rare. This thesis aimed to investigate the short- and long-term outcomes of totally endoscopic surgical ablation, as well as the short- and long-term incidence, risk factors, and burden of AF after cardiac revascularization.

Study I was a randomized controlled trial comparing totally endoscopic epicardial box lesion ablation of the left atrium to medical therapy in patients with long-standing persistent AF (LSPAF). At 1 year, 80% of ablated patients were in sinus rhythm (SR) without the need for antiarrhythmic drugs. Ablation improved physical working capacity, left ventricular systolic function, and self-reported quality of life.

Studies II, III, and IV were prospective cohort studies conducted in a real-world population of patients undergoing coronary artery bypass graft (CABG) or per-cutaneous coronary intervention (PCI). A systematic in-hospital and outpatient arrhythmia detection strategy was employed to determine the short-term (30-day) and long-term (24-month) cumulative incidence of new-onset AF. New-onset AF was common after CABG, with most events occurring within the first 30 days, whereas it was rare after PCI, with an even distribution over the 24 months. Undergoing CABG was a significant risk factor for developing new-onset AF. For patients who underwent CABG and developed postoperative AF, the arrhythmia burden was low during the first postoperative year.

Study V was a retrospective cohort study investigating the long-term rhythm out-come of the patients from Study I. At a mean follow-up of 9 years, most patients were in AF. The mean time for freedom from AF after totally endoscopic box lesion ablation for LSPAF was 23 months.