Cerebrovascular events after perioperative paroxysmal atrial fibrillation in patients undergoing aortic valve replacement

BACKGROUND: Postoperative atrial fibrillation (POAF) is common after aortic valve replacement (AVR). However, the long-term risk of cerebrovascular ischemic events (CVA) associated with POAF in this scenario is not known. The study objective was to look at the long-term risk of stroke in patients undergoing AVR with POAF compared to those with no POAF, particularly in patients having a bioprosthetic valve and not discharged on anticoagulation. We also looked at the risk of peri-operative stroke and long-term mortality. METHODS: A retrospective study of 831 patients undergoing AVR were followed up for a median of 6.5 years. The primary outcome was the occurrence of CVA after discharge, comparing those with to those without POAF, after excluding patients with a past history of atrial fibrillation (AF). They were divided into two cohorts, those having bioprosthetic valves (without oral anticoagulation), and those with a mechanical valve (with oral anticoagulation). Other outcomes studied were the incidence of early perioperative CVA comparing patients with a history of AF to those with no history, and long-term mortality in the different cohorts. RESULTS: There was no increased risk of long-term stroke in patients with POAF when compared to those without POAF, neither in bioprosthetic valves (adjusted HR 1.14; CI 95% 0.46-2.83, P=0.78)-nor in mechanical valves (adjusted HR 1.41; CI 95% 0.55-3.65, P=0.48). Patients with a history of AF had an increased risk of perioperative stroke (OR 1.5; CI 95% 1.3-13.8, P=0.01). CONCLUSIONS: Patients undergoing bioprosthetic AVR who develop POAF are not at an increased risk of stroke despite not being on any oral anticoagulation.