Postoperative atrial fibrillation (POAF) after isolated coronary revascularization is the most frequent rhythm disorder after cardiac surgery, with a reported incidence between 10% and 40%, associated with hemodynamic instability, increased morbidity and mortality. The aim of this study was to identify significant preoperative predictors for non-valvular POAF in patients undergoing on-pump and off-pump coronary artery surgery.Design and method:
Retrospective study included 226 consecutive patients revascularized at Clinic of Cardiac Surgery, Clinical Center of Serbia, between September and December 2014. Patients were divided in two groups: on-pump (N: 176) and off-pump (N: 50). In both groups, we investigated the association of preoperative factors (gender, age, body mass index [BMI], type of coronary artery disease [CAD], left ventricular systolic function, preoperative angina pectoris [AP] and myocardial infarction [MI], preoperative size of the left atrium and left ventricle, degree of mitral regurgitation [MR], arterial hypertension, diabetes, hyperlipidemia, chronic lung disease, preoperative transient ischemic attack or cerebrovascular insult, peripheral arterial disease and smoking) with the occurrence of non-valvular POAF, using the Logistic regression analysis. Exclusion criteria were severe MR and preoperative AF.Results:
The incidence of POAF was 23.45% (on-pump: 22.2%, off-pump: 28%; p > 0.05). There were statistically significant differences between two study groups considering: type of CAD (X2 = 5,030; p = 0,026), left ventricular systolic function (X2 = 12,896; p < 0,001), preoperative MI (X2 = 6,668; p = 0,010), preoperative size of the left atrium (X2 = 13,046; p < 0,001) and left ventricle (EDD: t = 3,439; p = 0,001, ESD: t = 3,162; p = 0,002) and presence of diabetes mellitus (X2 = 6,841; p = 0,009). In the off-pump group, an independent preoperative predictor of POAF was preoperative size of left atrium (OR 34.000; 95% CI 1.479–781.787; p: 0.027). We found that patients with very enlarged left atrium (>5 cm) had significantly higher risk of POAF. Paradoxically, an independent inverse relationship of preoperative arterial hypertension and the risk of POAF was documented in the on-pump group (OR 0.088; 95% CI 0.009–0.874; p: 0.038), most likely due to the more frequent preoperative use of beta-blockers in patients with a history of hypertension.Conclusions:
Independent preoperative predictors for POAF are preoperative size of left atrium in off-pump and arterial hypertension in on-pump revascularized patients.