Impaired cardiac autophagy in patients developing postoperative atrial fibrillation

Garcia, L.; Verdejo H.E.; Kuzmicic J.; Zalaquett R.; Gonzalez S.; Lavandero S.; Corbalan, R

Abstract

Objectives: Postoperative atrial fibrillation (POAF) is a common complication after on-pump heart surgery. Several histologic abnormalities, such as interstitial fibrosis and vacuolization, have been described in atrial samples from patients developing POAF. This ultrastructural remodeling has been associated with the establishment of a proarrhythmic substrate. We studied whether atrial autophagy is activated in patients who develop POAF. Methods: A total of 170 patients in sinus rhythm who had undergone elective coronary artery bypass grafting were included. Systemic inflammatory markers were measured at baseline and 72 hours after surgery. During the procedure, samples of the right atrial appendages were obtained for evaluation of remodeling by light and electron microscopy. Protein ubiquitination and autophagy-related LC3B processing were assessed by Western blot. Results: Of these patients, 22% developed POAF. The level of high-sensitivity C-reactive protein, fibrosis, inflammation, myxoid degeneration, and ubiquitin-aggregates in the atria did not differ between patients with and without POAF. Electron microphotographs of those with POAF showed a significant accumulation of autophagic vesicles and lipofuscin deposits. Total protein ubiquitination was similar in the patients with and without POAF, but LC3B processing was markedly reduced in those with POAF, suggesting a selective impairment in autophagic flow. Conclusions: This study provides novel evidence that ultrastructural atrial remodeling characterized by an impaired cardiac autophagy is present in patients developing POAF after coronary artery bypass surgery. © 2012 by The American Association for Thoracic Surgery.

Más información

Título según WOS: Impaired cardiac autophagy in patients developing postoperative atrial fibrillation
Título según SCOPUS: Impaired cardiac autophagy in patients developing postoperative atrial fibrillation
Título de la Revista: JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
Volumen: 143
Número: 2
Editorial: MOSBY-ELSEVIER
Fecha de publicación: 2012
Página de inicio: 451
Página final: U485
Idioma: English
URL: http://www.scopus.com/inward/record.url?eid=2-s2.0-84855849355&partnerID=40&md5=ae5836efb9852ace4f728f432fe9072a
DOI:

10.1016/j.jtcvs.2011.07.056

Notas: ISI, SCOPUS