Aim: 1. Defining the independent predictors for new-onset post-operative atrial fibrillation (POAF) in patients (pts) undergoing aortic valve replacement (AVR) and their adjusted value for calculation of a preoperative risk score.
2. Assessment of the independent prognostic value of the LV diastolic dysfunction and left atrium (LA) dilatation for POAF development in these pts.
3. Identifying the predictors for recurrent atrial fibrillation (AF) and their implications for postoperative course in AVR pts.
Material and method: Prospective study on 802 pts who underwent AVR for aortic stenosis (456pts) or aortic regurgitation (AR) (346pts). Patients were evaluated clinically and by echocardiography (including TDI) preoperatively and postoperatively at 10, 20 and 30 days. All were in sinus rhythm without history of AF.
Statistical analysis used SYSTAT and SPSS programs for regression analysis and for relative risks and correlation coefficient calculations. Multivariable analyses were adjusted for age and gender including left ventricular ejection fraction (LVEF)≤35%, restrictive LV diastolic filling pattern (LVDFP), renal insufficiency and logistic EuroSCORE ≥20%
Results: POAF occurred in 320 of 862 patients (39.9%).
1. Regression analysis identified as independent predictors for POAF: restrictive LVDFP (RR=23.42), preoperative AR (RR=10.31), LA dimension index >30mm/m2 (RR=13.92), advanced age (RR for 10-year increase=2.09), LVEF≤35%, LV endsystolic diameter (LVESD)>55mm, higher body mass index, NYHA class III/IV, comorbidities
2. The presence of a restrictive LVDFP increased the POAF risk by 23.42 fold and the rate of POAF increased exponentially with diastolic dysfunction severity (p<0.001)
3. Predictors of recurrent POAF (occurred at 44,69% of POAF pts) included restrictive LVDFP, age >75years, LA dimension index >30mm/m2, LV end-systolic volume (LVESV) >85cm3, bicaval venous cannulation, moderate mitral regurgitation (MR), severe pulmonary hypertension (PHT).
Conclusions: 1. The independent predictors for POAF initiation after AVR were: restrictive LVDFP, preoperative AR, advanced age, LVESD >55mm, LVEF ≤35%, obesity, NYHA class III/IV and comorbidities
2. Restrictive LVDFP and LA dilatation has a powerful independent and incremental predisposing value for the initiation of POAF after AVR and their evaluation may be very useful during risk stratification of patients undergoing cardiac surgery
3. The only independent predictors for recurrent POAF after AVR were: restrictive LVDFP, older age, LA dimension index>30mm/m2, LVESV>85cm3, bicaval venous cannulation, moderate MR, severe PHT.