Cardiovascular Journal of Africa: Vol 28 No 2 (March/April 2017)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 2, March/April 2017 104 AFRICA
Relationship between Vitamin D and the development of
atrial fibrillation after on-pump coronary artery bypass
graft surgery
Levent Cerit, Hatice Kemal, Kamil Gulsen, Barcin Ozcem, Zeynep Cerit, Hamza Duygu
Abstract
Background: Vitamin D deficiency is associated with many
diverse cardiovascular disorders, such as hypertension, heart
failure, stroke, coronary artery disease and atrial fibrillation.
The relationship between Vitamin D and the development
of atrial fibrillation after coronary artery bypass surgery
(CABG) has not been studied. Therefore, we assessed the
relationship between Vitamin D and the development of post-
operative atrial fibrillation (POAF) after CABG.
Methods: Medical records of consecutive patients who under-
went CABG surgery were retrospectively reviewed for the
development of atrial fibrillation in the postoperative period.
Vitamin D, other biochemical parameters, and clinical and
echocardiographic parameters were evaluated in all patients.
The independent variables for the development of postopera-
tive atrial fibrillation were defined and their predictive values
were measured.
Results: The study group consisted of 128 patients, of whom
41 (32%) developed POAF. Age, diabetes mellitus, chronic
obstructive pulmonary disease, history of transient ischaemic
attack/stroke, heart failure, left atrial diameter, platelet:large-
cell ratio, and creatinine, urea, uric acid, calcium and potassi-
um levels were identified as important variables for the devel-
opment of POAF. However, with logistic regression analysis,
chronic obstructive pulmonary disease (OR: 28.737, 95% CI:
0.836–16.118, p < 0.001), heart failure (OR: 15.430, 95% CI:
0.989–7.649, p = 0.006), diabetes mellitus (OR: 11.486, 95%
CI: 0.734–11.060, p = 0.001) and left atrial diameter (OR:
1.245, 95% CI: 0.086–6.431, p = 0.011) appeared as independ-
ent variables predicting the development of POAF.
Conclusion: In our study, although there was a significant nega-
tive correlation between Vitamin D and left atrial diameter,
Vitamin D level was not an independent predictor for POAF.
Keywords: atrial fibrillation, Vitamin D, coronary artery bypass
graft surgery
Submitted 24/3/16, accepted 18/5/16
Published online 2/8/16
Cardiovasc J Afr 2017; 28: 104–107
DOI: 10.5830/CVJA-2016-064
Atrial fibrillation (AF) is the most common arrhythmia occurring
after coronary artery bypass graft (CABG) surgery and is seen
in approximately 15 to 30% of patients. The occurence of
postoperative atrial fibrillation (POAF) is associated with
increased morbidity and mortality rates, longer hospital stay and
a two- to three-fold increase in incidence of postoperative stroke.
Older age, obesity, hypertension (HT), prior AF and cognestive
heart failure are associated with a higher risk for POAF.1
Vitamin D is transformed in the liver and kidneys to calcidiol
and calcitriol, respectively, and affects specific target tissues
via Vitamin D receptors (VDRs). Calcitriol, the active form of
Vitamin D, binds to VDRs in the intestines, bones and kidneys
to increase calcium absorption from the intestines, promoting
calcium deposition in the bones. VDRs are found in other tissues,
including the brain, cardiomyocytes, vascular smooth muscle
cells, endothelial cells, pancreatic beta-cells, skeletal muscle,
the prostate, colon, macrophages and skin, exerting several
pleiotropic effects. Vitamin D utilises a direct effect relating to
atherosclerosis, such as modulating endothelial function and
influencing vascular smooth muscle proliferation and migration.2,3
To our knowledge, the relationship between Vitamin D and
POAF has not been studied before. Therefore, we assessed the
relationship between Vitamin D and the development of POAF.
Methods
The study group consisted of 128 consecutive patients who
underwent on-pump CABG surgery. The data of the patients
were retrospectively analysed for AF in the postoperative period
until discharge. The study was approved by the local ethics
committee.
The patients were monitored using a heart-rhythm monitor
in the intensive care unit. In addition, daily electrocardiographic
recordings were obtained during the hospital stay, both in the
intensive care unit and the regular ward. New-onset postoperative
AF (as classified by the Society of Thoracic Surgeons) was
defined as AF or atrial flutter occurring in the postoperative
period and requiring medical treatment (beta-blocker, calcium
channel blocker, amiodarone, anticoagulants and cardioversion).
Patients who developed AF in the postoperative period up to
discharge were included in the POAF group.
Patients’ data, including age, gender, history of HT, chronic
kidney disease, diabetes mellitus (DM), heart failure (HF),
chronic obstructive pulmonary disease (COPD), congenital
heart disease, valvular heart disease, liver disease, stroke, thyroid
disease, pre-operative drug use (beta-blockers and statins), and
echocardiographic variables such as ejection fraction (EF),
left atrial diameter, and presence of valvular disease were
retrospectively retrieved from the medical charts and included
in the analysis.
Near East University, Nicosia, Cyprus
Levent Cerit, MD,
Hatice Kemal, MD
Kamil Gulsen, MD
Barcin Ozcem, MD
Zeynep Cerit, MD
Hamza Duygu, MD