Risk Factors for Atrial fibrillation Following a Cardiac Surgery

Background: Atrial fibrillation (AF) following cardiac surgery is common and has clinical impact on morbidity. The preoperative and intraoperative risk factors are still not well defined. The objective of the study is to examine preoperative and intraoperative risk factors for AF following cardiac surgery.

Methods: Retrospective analysis of database of cardiac surgeries during 2017-2019 in Poriya medical center. Patients who were not in sinus rhythm before surgery were excluded. Preoperative factors and intraoperative factors (pump time, aortic clamp time, and minimum pH) were recorded.

Results:

208 patients were included in the analysis. Overall AF following cardiac surgery was detected in 50 (24%) patients. Of 175 patients who did not have history of AF before surgery 27 (15.5%) had post-operative AF. In the 33 patients with previous AF, AF following surgery was noted in 27 (70%).

Patients with AF following surgery were older (66.2±8.0 vs. 60.7± 11.4 years, p=0.002), treated more with anti-arrhythmic drugs (18.9% vs 4.5, p=0.001), and had higher rates of history of pre-operative AF (46% Vs 6.3%, p=0.0001), cerebral vascular accidents (14% vs 4.4%, p=0.019), prior valve replacement (10% vs 1.9%, p=0.009) compared to patients without AF following surgery. Aortic clamp time tended to be longer among patients with AF following surgery (116.7±52.0 vs 101.7±50.2 min, p=0.07). In multivariate cox regression analysis, age (HR 1.04, CI 1.01-1.07, P=0.006) and history of preoperative AF (HR 6.01, CI 3.42-10.57, P<0.001) were predictors of AF following cardiac surgery. The probability of being free of AF following surgery was 80% among patients without history of AF compared to 30% in patients with previous AF history (p<0.001).

Conclusion: Preoperative AF and age and were predictors of AF following cardiac surgery.