Postoperative Atrial Fibrillation in Patients Undergoing Cardiac Surgery.

Introduction Atrial fibrillation (AF) is the most common arrhythmia occurring after cardiac surgery. It can lead to hemodynamic instability and significantly increase the risk of thromboembolic events. Aim The primary aim of this study was to assess the incidence of AF in patients undergoing cardiac surgery during the first postoperative week. The secondary aim was to investigate the influence of preoperative, intraoperative, and postoperative factors on the development of postoperative AF (POAF). Materials and methods This study included 140 patients of all ages and both sexes who underwent cardiac surgery and were admitted to the ICU of the General Hospital of Athens "Ippokrateio." All participants had no prior history of AF but developed a POAF episode lasting more than 30 seconds within the first postoperative week. Data were collected from the patients' medical records. Results Among the 140 patients, 42.9% developed POAF. The incidence of POAF was significantly higher in patients who were taking diuretics (62.2% vs. 33.7%; p = 0.001) and in those who underwent mitral valve replacement (64.3% vs. 37.5%; p = 0.010). POAF was also associated with lower ejection fraction (p = 0.003), higher preoperative CRP levels (p < 0.001), longer duration of intubation (p = 0.015), longer cross-clamp time (p = 0.016), and extended ICU stay (p = 0.005). Furthermore, postoperative hemoglobin (p = 0.050) and hematocrit (p = 0.044) levels were significantly lower in POAF cases, while postoperative CRP levels were significantly higher (p < 0.001). Conclusions POAF is associated with multiple risk factors, including mitral valve surgery, prolonged ICU stay, low ejection fraction, extended cross-clamp time, and longer ventilation duration. Additionally, the use of diuretics and elevated CRP levels were significantly linked to the occurrence of POAF.