Thorac cardiovasc Surg 2014; 62(07): 547-553
DOI: 10.1055/s-0034-1372334
Original Basic Science
Georg Thieme Verlag KG Stuttgart · New York

Body Mass Index Affects Connexin43 Remodeling in Patients with Atrial Fibrillation

Susanne Rothe
1  Clinic for Cardiac Surgery, Heart Centre Leipzig, University Leipzig, Leipzig, Germany
,
Andrea Busch
1  Clinic for Cardiac Surgery, Heart Centre Leipzig, University Leipzig, Leipzig, Germany
,
Hartmuth Bittner
2  Department of Transplantation, Florida Hospital, Orlando, Florida, United States
,
Martin Kostelka
1  Clinic for Cardiac Surgery, Heart Centre Leipzig, University Leipzig, Leipzig, Germany
,
Pascal Maria Dohmen
1  Clinic for Cardiac Surgery, Heart Centre Leipzig, University Leipzig, Leipzig, Germany
,
Friedrich-Wilhelm Mohr
1  Clinic for Cardiac Surgery, Heart Centre Leipzig, University Leipzig, Leipzig, Germany
,
Stefan Dhein
1  Clinic for Cardiac Surgery, Heart Centre Leipzig, University Leipzig, Leipzig, Germany
› Author Affiliations
Further Information

Publication History

13 December 2013

25 January 2014

Publication Date:
08 April 2014 (online)

Abstract

Background Increased body mass index (BMI) is often found to be a risk factor for cardiac disease. However, it is unclear whether BMI also affects the gap junction remodeling process in atrial fibrillation (AF). The aim of the study was to see if BMI can influence the connexin43 (Cx43) distribution in patients with sinus rhythm (SR) and AF.

Methods We investigated a total of 51 white Caucasian patients of both gender (mean age: 69 years, 30% diabetes mellitus, ejection fraction [EF] > 50%) with SR or AF, with either BMI < 27 or ≥ 27 undergoing cardiac surgery for mitral valve repair, aortic valve repair, or coronary heart disease. We obtained human right atrial tissue for immunohistochemistry and investigated the CX43-positive polar and lateral membrane length in the different BMI (BMI < 27, BMI ≥ 27) and rhythm groups (SR or AF).

Results In lean SR patients, Cx43 (BMI < 27) was found mainly at the cell poles while only 2% of the lateral membrane stained positive for Cx43. In obese SR patients (BMI > 27), 6.7 ± 0.7% of the lateral membrane was positive (p < 0.05). In AF generally, there was significantly more lateral Cx43 staining, which was significantly enhanced in obese AF patients. In lean AF patients, lateral Cx43 positivity increased to 14 ± 1% (p < 0.05), while in BMI > 27 AF patients, this was significantly enhanced to 22 ± 2% (p < 0.05). The BMI effect was independent from left atrial diameter, EF, and comorbidity.

Conclusions Enhanced BMI is associated with increased remodeling effects of AF on irregular Cx43 distribution.