Triangular posterior pericardiectomy and postoperative outcomes after coronary artery bypass grafting

Postoperative atrial fibrillation (POAF) and pericardial effusion remain common complications after coronary artery bypass grafting (CABG).

Posterior pericardiotomy has been proposed to reduce these events, but long-term data remain limited. We evaluated the impact of triangular posterior pericardiectomy (TPP) on early and 12-month outcomes after CABG using unsupervised taxonomic analysis of postoperative responses. This retrospective study included 489 patients undergoing CABG with cardiopulmonary bypass between 2017 and 2023. Patients underwent standard surgery (no pericardiectomy, n = 347) or triangular posterior pericardiectomy (n = 142). Unsupervised taxonomic classification based on a pentad of clinical responses-CRP dynamics (day 4-day 1 difference), pericardial fluid on day 6, postoperative drainage volume, POAF, and atrial fibrillation during 12-month follow-up-was used to identify phenotypes. Comparative analyses were performed using statistical tests.

Four phenotypes were identified. Phenotype 4 (n = 50), with the highest prevalence of TPP (92%), showed the lowest inflammatory response, absence of pericardial effusion, the lowest drainage volume (≈950 mL), and no POAF or atrial fibrillation during 12-month follow-up. Phenotypes with lower TPP prevalence showed higher CRP levels, greater drainage volumes (≈1200 mL), presence of pericardial effusion, and increased POAF incidence (cohort incidence 35%). TPP was not associated with increased pleural complications.

Unsupervised phenotypic analysis suggests triangular posterior pericardiectomy is associated with a favorable postoperative profile characterized by reduced inflammation, minimal pericardial effusion, lower drainage, and absence of early and late atrial fibrillation after CABG.