Letters to the Editor / European Journal of Cardio-Thoracic Surgery
Reply to Chhabra et al. George Drossosa,*, Charilaos-Panagiotis Koutsogiannidisa, Konstantinos Diplarisa and Fotini Ampatzidoub a Department of Cardiothoracic Surgery, General Hospital ‘G. Papanikolaou’, Thessaloniki, Greece Cardiac Surgery Intensive Care Unit, General Hospital ‘G. Papanikolaou’, Thessaloniki, Greece
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data about the right ventricular myocardial performance index of patients and the incidence of undiagnosed asymptomatic paroxysmal atrial fibrillation preoperatively. We agree that atrial fibrillation pathophysiology is complex. However, increasing evidence supports its association with inflammation. Epicardial adipose tissue is considered to be proinflammatory and according to our findings, it may represent risk factor for postoperative atrial fibrillation, because of its inflammatory properties. Larger prospective studies may confirm the association of these results or not.
Received 23 April 2014; accepted 26 April 2014
Chhabra and associates made some potentially valid points regarding pericardial fat and its association with atrial fibrillation [1]. We thank him for the interest in our recent research [2]. The main shortcoming of our work is the small sample size. Well-known, traditional risk factors and comorbidities (hypertension, diabetes, body mass index, myocardial infarction, cross-clamp time) did not reach statistical significance, mainly due to the small sample size, which has been discussed in our manuscript. Indeed, Batal et al. have reported the association between atrial fibrillation and pericardial fat located between the left atrium and the oesophagus (in general population and not after cardiac operation), which has been cited in our article [3]. In our study, we have only calculated the total volume of pericardial fat and not a potential effect of its distribution. We also read with interest White’s prospective AFIST-III study. In this paper, anterior fat pad maintenance did not reduce postoperative atrial fibrillation incidence through a mechanism of preservation of parasympathetic tone. Our findings suggested that pericardial fat might represent a novel risk factor for postoperative atrial fibrillation, likely mediated by its inflammatory properties [4]. We were also expecting correlation between body mass index and pericardial fat volumes. According to literature, it may not be very surprising that there is lack of such an association. In a review, Iacobellis et al. reported conflicting results regarding the association between total epicardial fat weight and body mass index in hypertrophied and non-hypertrophied hearts. In addition, they suggested that pericardial fat is more closely related to visceral than total fat [5]. Epicardial adipose tissue is a form of visceral adipose tissue. Bonora et al. reported that subcutaneous, but not visceral adipose tissue, is correlated with simple anthropometric measurements (body mass index, waist circumference) [6]. In the ‘Study Limitations’ of our paper, we reported that the role of statins in postoperative atrial fibrillation has not been analysed. Also, we did not have
REFERENCES [1] Chhabra L, Kluger J, Flynn AW, Spodick DH. Pericardial fat and postoperative atrial fibrillation after coronary artery bypass surgery. Eur J Cardiothorac Surg 2015;47:584. [2] Drossos G, Koutsogiannidis CP, Ananiadou O, Kapsas G, Ampatzidou F, Madesis A et al. Pericardial fat is strongly associated with atrial fibrillation after coronary artery bypass graft surgery. Eur J Cardiothorac Surg 2014;46: 1014–20. [3] Batal O, Schoenhagen P, Shao M, Ayyad AE, Van Wagoner DR, Halliburton SS et al. Left atrial epicardial adiposity and atrial fibrillation. Circ Arrhythm Electrophysiol 2010;3:230–36. [4] Mazurek T, Zhang L, Zalewski A, Mannion JD, Diehl JT, Arafat H et al. Human epicardial adipose tissue is a source of inflammatory mediators. Circulation 2003;108:2460–66. [5] Iacobellis G, Corradi D, Sharma AM. Epicardial adipose tissue: anatomic, biomolecular and clinical relationships with the heart. Nat Clin Pract Cardiovasc Med 2005;2:536–43. [6] Bonora E, Micciolo R, Ghiatas AA, Lancaster JL, Alyassin A, Muggeo M et al. Is it possible to derive a reliable estimate of human visceral and subcutaneous abdominal adipose tissue from simple anthropometric measurements? Metabolism 1995;44:1617–25. * Corresponding author. Department of Cardiothoracic Surgery, General Hospital ‘G. Papanikolaou’, Exohi, 57010 Thessaloniki, Greece. Tel: +302313307661;+302-3133076612; fax: +302-313307667; e-mail: drogevan@ otenet.gr (G. Drossos). doi:10.1093/ejcts/ezu221 Advance Access publication 28 May 2014
LETTERS TO THE EDITOR
Keywords: Postoperative atrial fibrillation • Coronary artery bypass surgery • Pericardial fat
Reply to Chhabra et al. George Drossosa,*, Charilaos-Panagiotis Koutsogiannidisa, Konstantinos Diplarisa and Fotini Ampatzidoub a Department of Cardiothoracic Surgery, General Hospital ‘G. Papanikolaou’, Thessaloniki, Greece Cardiac Surgery Intensive Care Unit, General Hospital ‘G. Papanikolaou’, Thessaloniki, Greece
b
585
data about the right ventricular myocardial performance index of patients and the incidence of undiagnosed asymptomatic paroxysmal atrial fibrillation preoperatively. We agree that atrial fibrillation pathophysiology is complex. However, increasing evidence supports its association with inflammation. Epicardial adipose tissue is considered to be proinflammatory and according to our findings, it may represent risk factor for postoperative atrial fibrillation, because of its inflammatory properties. Larger prospective studies may confirm the association of these results or not.
Received 23 April 2014; accepted 26 April 2014
Chhabra and associates made some potentially valid points regarding pericardial fat and its association with atrial fibrillation [1]. We thank him for the interest in our recent research [2]. The main shortcoming of our work is the small sample size. Well-known, traditional risk factors and comorbidities (hypertension, diabetes, body mass index, myocardial infarction, cross-clamp time) did not reach statistical significance, mainly due to the small sample size, which has been discussed in our manuscript. Indeed, Batal et al. have reported the association between atrial fibrillation and pericardial fat located between the left atrium and the oesophagus (in general population and not after cardiac operation), which has been cited in our article [3]. In our study, we have only calculated the total volume of pericardial fat and not a potential effect of its distribution. We also read with interest White’s prospective AFIST-III study. In this paper, anterior fat pad maintenance did not reduce postoperative atrial fibrillation incidence through a mechanism of preservation of parasympathetic tone. Our findings suggested that pericardial fat might represent a novel risk factor for postoperative atrial fibrillation, likely mediated by its inflammatory properties [4]. We were also expecting correlation between body mass index and pericardial fat volumes. According to literature, it may not be very surprising that there is lack of such an association. In a review, Iacobellis et al. reported conflicting results regarding the association between total epicardial fat weight and body mass index in hypertrophied and non-hypertrophied hearts. In addition, they suggested that pericardial fat is more closely related to visceral than total fat [5]. Epicardial adipose tissue is a form of visceral adipose tissue. Bonora et al. reported that subcutaneous, but not visceral adipose tissue, is correlated with simple anthropometric measurements (body mass index, waist circumference) [6]. In the ‘Study Limitations’ of our paper, we reported that the role of statins in postoperative atrial fibrillation has not been analysed. Also, we did not have
REFERENCES [1] Chhabra L, Kluger J, Flynn AW, Spodick DH. Pericardial fat and postoperative atrial fibrillation after coronary artery bypass surgery. Eur J Cardiothorac Surg 2015;47:584. [2] Drossos G, Koutsogiannidis CP, Ananiadou O, Kapsas G, Ampatzidou F, Madesis A et al. Pericardial fat is strongly associated with atrial fibrillation after coronary artery bypass graft surgery. Eur J Cardiothorac Surg 2014;46: 1014–20. [3] Batal O, Schoenhagen P, Shao M, Ayyad AE, Van Wagoner DR, Halliburton SS et al. Left atrial epicardial adiposity and atrial fibrillation. Circ Arrhythm Electrophysiol 2010;3:230–36. [4] Mazurek T, Zhang L, Zalewski A, Mannion JD, Diehl JT, Arafat H et al. Human epicardial adipose tissue is a source of inflammatory mediators. Circulation 2003;108:2460–66. [5] Iacobellis G, Corradi D, Sharma AM. Epicardial adipose tissue: anatomic, biomolecular and clinical relationships with the heart. Nat Clin Pract Cardiovasc Med 2005;2:536–43. [6] Bonora E, Micciolo R, Ghiatas AA, Lancaster JL, Alyassin A, Muggeo M et al. Is it possible to derive a reliable estimate of human visceral and subcutaneous abdominal adipose tissue from simple anthropometric measurements? Metabolism 1995;44:1617–25. * Corresponding author. Department of Cardiothoracic Surgery, General Hospital ‘G. Papanikolaou’, Exohi, 57010 Thessaloniki, Greece. Tel: +302313307661;+302-3133076612; fax: +302-313307667; e-mail: drogevan@ otenet.gr (G. Drossos). doi:10.1093/ejcts/ezu221 Advance Access publication 28 May 2014
LETTERS TO THE EDITOR
Keywords: Postoperative atrial fibrillation • Coronary artery bypass surgery • Pericardial fat
