[De novo atrial fibrillation following aortic valve replacement surgery]

Objetives: The present study aimed to explore the risk factors associated with de novo atrial fibrillation following isolated aortic valve replacement surgery and its prevalence in a high volume cardiothoracic surgery center.

This is a cross-sectional retrospective observational study including all patients submitted to isolated aortic valve replacement surgery during 2014 and the corresponding data. Patients with previous history of atrial fibrillation, endocarditis or aortic valve prosthesis were excluded. The statistical analysis was conducted according to the type of variables concerned.

One hundred and seventy-three patients were included and 45.1% had de novo atrial fibrillation, with a median occurrence on 2.4 ±1.5 days of the postoperative period. Age was significantly associated with the arrhythmia (p=0.028). Atrial fibrillation patients had a significantly lower minimum of postoperative creatinine clearance (p=0.026) and a higher postoperative plasmatic C-reactive protein peak (p=0.025). Arrhythmic patients had a median time of hospital stay significantly superior to those who did not develop atrial fibrillation (p=0.008). Hospital mortality was low and similar between groups (3%, p=0.796).

This study confirms the high prevalence of atrial fibrillation following aortic valve replacement surgery. The increased C-reactive protein and decreased creatinine clearance reinforce the importance of inflammation in its pathophysiology. The longer hospital stay in these patients also contributes to the importance of atrial fibrillation prevention and risk stratification.