2021 PALACS TRIAL M Posterior left pericardiotomy for the prevention of postoperative atrial fibrillation after cardiac surgery Randomized, parallel, stratified, single-centre study Objective: To evaluate posterior left pericardiotomy compared with no intervention among patients undergoing open heart surgery 420 patients Patients 18 years of age,undergoing elective interventions on the coronary arteries, aortic valve or ascending aorta, or a combination of these & no h/o atrial fibrillation or other arrhythmias or contraindications to the experimental intervention Posterior left pericardiotomy (n = 212) No intervention (n = 208) PRIMARY OUTCOME 18 Postoperative atrial fibrillation % OR 0.44; 95% CI, 0-27 to 0-70; P=0.0005 SECONDARY OUTCOME Major adverse events % Pericardial effusion % RR 0.58; 95% CI, 0-37 to 0.91; P=0.46 Conclusion: Among patients undergoing open heart surgery for CABG, aortic valve replacement, and/or aortic repair, posterior left pericardiotomy was beneficial. Pericardiotomy was associated with a significant reduction in postoperative atrial fibrillation, without increasing the incidence of complications.. M Gaudino et al. The Lancet, 398(10316), 2075-2083