Myocardial Protective Effect of Antegrade Cardioplegic Cardiac Arrest Versus Ventricular Fibrillation During Cardiopulmonary Bypass on Immediate Postoperative and Mid-Term Left Ventricular Function in Right Ventricular Outflow Tract Surgery

The objective of this study is to examine the myocardial protective effect of antegrade cardioplegic cardiac arrest (ACC) versus ventricular fibrillation (VF) on short-term and mid-term left ventricular (LV) function in right ventricular outflow tract (RVOT) surgery. RVOT operations conducted from January 2006 to December 2015 were reviewed. The numbers of cases using ACC and VF were 71 and 49, respectively. Postoperative mortality and morbidity were compared between the two groups. Before and after propensity score matching, left ventricular ejection fraction (LVEF) and left ventricular end-systolic/end-diastolic diameter (LVESD/LVEDD) in echocardiography were measured immediately after operation and at mid-term follow-up between postoperative 6 and 24 months. There was no perioperative mortality or cerebrovascular accident. There was no statistically significant difference in the incidence of ventricular and atrial arrhythmia. In the overall patient group, LVESD was significantly decreased in the ACC group compared to the VF group immediately after operation (-0.65 +/- 3.55 mm vs. 2.99 +/- 4.98 mm, P=0.001). Mid-term follow-up data demonstrated that LVEF at midterm was higher in the ACC group than in the VF group (64.80%+/- 7.40% vs. 60.24%+/- 7.93%, P=0.022). However, the increased amount compared to preoperative value was not statistically significant (1.94%+/- 12.65% vs. -2.94%+/- 9.41%, P=0.059). After propensity score matching, the LVEF was significantly improved in the ACC group compared to the VF group at the mid-term follow-up (6.16%+/- 6.77% vs. -5.41%+/- 9.05%, P=0.001). Multiple linear regression model demonstrated that lower preoperative LVEF, ACC rather than VF, and exclusion of RVOT reconstruction procedure were positive prognostic factors for the improvement of LVEF at mid-term follow up. The results of this study suggest that myocardial protection using ACC is safe and may be more beneficial in LV function recovery up to the mid-term follow-up after pulmonary valve replacement and other RVOT procedures.