Postoperative pericardial effusion, pericardiotomy and atrial fibrillation: an explanatory analysis of the PALACS trial.

TitlePostoperative pericardial effusion, pericardiotomy and atrial fibrillation: an explanatory analysis of the PALACS trial.
Publication TypeJournal Article
Year of Publication2023
AuthorsRong LQ, Di Franco A, Rahouma M, Dimagli A, Chan J, Lopes AJ, Kim J, Sanna T, Devereux RB, Delgado V, Weinsaft JW, Crea F, Alexander JH, Gillinov M, J DiMaio M, Pryor KO, Girardi L, Gaudino M
JournalAm Heart J
Date Published2023 Mar 17

BACKGROUND: In the Posterior left pericardiotomy for the prevention of atrial fibrillation after cardiac surgery (PALACS) trial, posterior pericardiotomy was associated with a significant reduction in postoperative atrial fibrillation (POAF) after cardiac surgery. We aimed to investigate the mechanisms underlying this effect.

METHODS: We included PALACS patients with available echocardiographic data (n=387/420, 92%). We tested the hypotheses that the reduction in POAF with the intervention was associated with 1) a reduction in postoperative pericardial effusion and/or 2) an effect on left atrial size and function. Spline and multivariable logistic regression analyses were used.

RESULTS: Most patients (n=307, 79%) had postoperative pericardial effusions (anterior 68%, postero-lateral 51.9%). The incidence of postero-lateral effusion was significantly lower in patients undergoing pericardiotomy (37% vs 67%; p<0.001). The median size of anterior effusion was comparable between patients with and without POAF (5.0 [IQR 3.0-7.0] vs 5.0 [IQR 3.0-7.5] mm; p=0.42), but there was a non-significant trend towards larger postero-lateral effusion in the POAF group (5.0 [IQR 3.0-9.0] vs 4.0 [IQR 3.0-6.4] mm; p=0.06). There was a non-linear association between postero-lateral effusion and POAF at a cut-off at 10 mm (OR 2.70; 95%CI 1.13, 6.47; p=0.03) that was confirmed in multivariable analysis (OR 3.5, 95%CI 1.17, 10.58; p=0.02). Left atrial dimension and function did not change significantly after posterior pericardiotomy.

CONCLUSIONS: Reduction in postero-lateral pericardial effusion is a plausible mechanism for the effect of posterior pericardiotomy in reducing POAF. Measures to reduce postoperative pericardial effusion are a promising approach to prevent POAF.

Alternate JournalAm Heart J
PubMed ID36934978