Cardiovascular Journal of Africa: Vol 25 No 6 (November/December 2014)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 6, November/December 2014 282 AFRICA
De novo atrial fibrillation post cardiac surgery:
the Durban experience
Ebrahim Mansoor
Abstract
Atrial fibrillation (AF) is the most common complication
post cardiac surgery and results in elevated morbidity and
mortality rates and healthcare costs. A pilot, retrospective
study of the medical records of all adult patients develop-
ing de novo AF post surgery was undertaken at the cardiac
surgical unit in Durban between 2009 and 2012. We aimed to
describe the local experience of AF with a view to suggesting
an adapted local treatment policy in relation to previously
published data. Fifty-nine patients developed AF during the
study period. AF occurred predominantly three or more days
post surgery. Thirty-five patients required cardioversion and
amiodarone to restore sinus rhythm. Return to the general
ward (RGW) was 4.6 days longer than the institutional norm.
Liberal peri-operative β-blocker and statin use is currently
preferred to a formal prophylaxis strategy. Randomised,
controlled trials are required to evaluate measures curbing
prolonged length of stay and morbidity burdens imposed by
AF on the local resource-constrained environment.
Keywords: cardiac surgery, atrial fibrillation, arrhythmia, cardio-
version, amiodarone, β-blocker
Submitted 5/6/14, accepted 28/10/14
Cardiovasc J Afr 2014; 25: 282–287
DOI: 10.5830/CVJA-2014-067
Atrial fibrillation (AF) is the most common arrhythmia after
cardiac surgery. This complication constitutes significant
morbidity and mortality rates for the cardiac surgical patient.1
Consequential increase in length of stay (LOS), partly on the
basis of thromboembolic events, incurs a financial burden on
health institutions.
Although the entity of de novo AF post cardiac surgery has
been intensely studied globally, a grave paucity of data exists
from the developing world. The aim of this study was to describe
the South African experience of de novo AF post cardiac surgery
with special emphasis on the issues pertaining to a resource-
limited setting.
Methods
A retrospective uni-centre audit of a prospectively collated
database between December 2009 and February 2012 was
undertaken at the Department of Cardiothoracic Surgery,
Inkosi Albert Luthuli Central Hospital (IALCH) in Durban,
South Africa. All adult patients who developed de novo AF
post coronary and valve surgery were included in the study.
Paediatric patients and patients with chronic pre-operative AF
were excluded from the cohort.
Data was extracted from patients’ medical records. Atrial
fibrillation was defined as an arrhythmia with irregular
irregularity and absent P waves. Diagnosis of AF was confirmed
on telemetry and 12-lead electrocardiogram (ECG). AF was
managed as per the European Association of Cardiothoracic
Surgeons (EACTS) 2006 guideline. 2 Selective deviations from the
guideline were on a patient-specific basis upon consultation with
the Department of Cardiology.
The following parameters were evaluated: demographics: age,
gender, race; type of surgery: coronary, valve or combinations
thereof; risk factors for AF (among others hereunder listed):
pre-operative withdrawal of β-blockers, prior cardiac surgery,
body mass index (BMI), smoking (within six months prior to
surgery); nature of surgery: emergency or elective; co-morbidities:
hypertension, diabetes mellitus; time of AF presentation: < 24
hours, 24–48 hours and > 48 hours post surgery; medication:
pre-operative use of statins and β-blockers; treatment of AF:
none, i.e. spontaneously resolved, electrical cardioversion,
amiodarone use, or a combination of cardioversion and
amiodarone; pre-operative echocardiographic parameters: left
ventricular diastolic dimension (LVD), left atrial size (LA),
ejection fraction (EF).
Return to the general ward (RGW) is a surrogate concept
introduced to quantify LOS and cost burden imposed by
the development of AF in the post-operative period. The
institutional norm is two days, one day in the intensive care unit
(ICU) and another in the high-care ward, after which time the
patient returns to the general cardiac surgical ward.
In addition to the above, follow-up information available at
the time of data presentation was analysed, particularly the time
from surgery, β -blocker use and maintenance of sinus rhythm
were recorded. The study was approved by the Biomedical
Research Ethics Committee (BREC) at the University of
KwaZulu-Natal (BE296/13).
Results
Fifty-nine patients developed de novo AF after cardiac surgery
in the index cohort during the study period. Considering the
total of 997 adult patients who underwent surgical intervention
for coronary or valve-related pathology in this period, the
institutional AF rate was 5.9%. The number of patients
developing AF per surgical procedure is shown in Table 1.
Thirty-three patients (55.9%) had coronary artery surgery,
either alone or in combination with valve surgery. All six patients
who underwent combination valve and coronary surgery had
aortic valve replacements. Off-pump coronary surgery consisted
Department of General Surgery, in association with the
Department of Cardiothoracic Surgery, University of
KwaZulu-Natal, Durban, South Africa
Dr Ebrahim Mansoor, MB ChB,