Inflammation, Atrial Fibrillation and Cardiac Surgery: Current Medical and Invasive Approaches for the Treatment of Atrial Fibrillation

Atrial fibrillation (AF) is a cardiac dysrhythmia commonly seen in clinical practice especially after cardiac surgery. It is associated with increased morbidity and mortality for the patients. The pathogenesis of AF is not exactly understood yet, but there is growing data about the relationship between AF and inflammation. Cardiac surgery itself is a big source for inflammation. It causes major surgical trauma, ischemia/reperfusion injury, hypothermia, low arterial pressure, and the equipment of cardiopulmonary bypass makes a large foreign surface thus it activates inflammatory response. There is a large number of data about the treatment options of AF and there are also strategies, which are related to reduction of inflammatory activation during cardiopulmonary bypass. In order to review the relationship between cardiac surgery, inflammation, AF and treatment strategies in patients with AF, we conducted a search through Pubmed for articles in English using the keywords: "atrial fibrillation, cardiac surgery, inflammation, medical therapy, surgical therapy, ablation therapy" from January 2012 to present. We also searched separately for each alternative treatment modality on Pubmed. To identify further articles, we also looked into related citations in review articles and commentaries. We searched thoroughly the guidelines published by the European Society of Cardiology (2016), and the American Heart Association/American College of Cardiology/Heart Rhythm Surgery (2014). Many studies concluded that inflammation contributes in the occurrence of AF. Inflammatory markers, such as CRP, interleukins and complements have high sensitivity and specificity for prediction of AF whether the patient having cardiac surgery or not. Beta-blockers, diltiazem and amiodarone are the most commonly used drugs for rate control in AF following surgery. Although there are some new therapeutic approaches to reduce postoperative inflammatory activation, such as the use of vitamins, fatty acids, statins, or technical improvements to cardiopulmonary bypass unit like miniaturized bypass circuits, heparin coating of the circuits, leukocyte filters, or various surgical approaches like off-pump coronary bypass surgery, we still need more effective strategies to reduce both postoperative inflammation and postoperative AF risk after cardiac surgery. Today we use more advanced invasive and surgical treatment strategies for AF although we need far more advanced technics to reduce perioperative inflammatory activation, which actually causes AF.