CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 7, August 2013
248
AFRICA
another hospital, who has considerable experience in assessing
patients’ hospital records. The cause of death of each patient was
identified and a decision was made to define the death as cardiac
or non-cardiac related. Also, as in the FIASCO study, deaths
were further classified into three categories: (1) non-preventable,
(2) preventable (technical error), and (3) preventable (system
error), in order to determine the cause of death.
10
Results
Between 2002 and 2007, 3 729 patients underwent on-pump
CABG surgery at our hospital and 2 570 (69%) of them were
identified as having an additive EuroSCORE
≤
2. They were
categorised as a low-risk group according to the EuroSCORE
definition.
2,3
There were 24 early mortalities (defined as occurring
within 30 days of the CABG operation) in the study group and
therefore mortality was found to be 0.93% (24 out of 2 570). The
deaths were further classified as cardiac and non-cardiac, and
according to this division, nine (37.5%) of the deaths were found
to have cardiac causes, whereas 15 (62.5%) were considered to
have a non-cardiac cause.
As in the FIASCO study, when deaths were classified into
non-preventable, preventable (technical error) or preventable
(system error),
10
11 (45.8%) of the deaths were considered
to be preventable and 13 (54.2%) were non-preventable, a
categorisation which both internal and external reviewers agreed
upon. The details of patient deaths are summarised in Table 1.
All patients in this group received left internal mammary artery
grafts for revascularisation of the left anterior descending artery.
Other grafts were obtained from veins, and on average each
patient received 2.9
±
0.7 bypass grafts.
Among those 13 patients (54.2%) who were categorised as
suffering unpreventable deaths, seven patients were diagnosed
with a stroke, two had sepsis due to mediastinitis, one had
pulmonary emboli (PE) without prominent deep-vein thrombosis,
and another had respiratory insufficiency postoperatively. One
patient had sudden cardiac arrest after discharge, and the
last patient died due to ischaemic heart disease and possible
poor distal run-off, causing a hypotensive cardiopulmonary
failure in the ward that was not responsive to cardiopulmonary
resuscitation. This patient was weaned off bypass with the help
of intra-aortic balloon pump (IABP), but unfortunately died on
the sixth day after the operation.
The patient who died of PE had been re-admitted to the
intensive care unit (ICU) with sudden sharp chest pains and
respiratory insufficiency six days after surgery. The sudden
onset of symptoms and a chest X-ray suggested PE. The patient
succumbed to respiratory failure 11 days after surgery. The other
patient who died of respiratory failure had chronic obstructive
pulmonary disease (COPD). After the operation, mechanical
TABLE 1. SUMMARY OF THE CAUSE OF DEATHAND POSSIBLE IDENTIFIED PROBLEMS IN LOW-RISK CABG OPERATIONS
No Age Gender Cause of death
Cardiac
death Preventable Identified problem
1 56 Male Cardiac arrest in the ICU, peri-operative MI
Yes Yes – technical Haematoma of LIMA, occlusion of graft
2 64 Male Cardiac arrest in the ICU, peri-operative MI
Yes Yes – technical Dissection of LIMA, occlusion of graft
3 63 Male Cardiac arrest in the ward, peri-operative MI
Yes Yes – technical Haematoma of LIMA, occlusion of graft
4 58 Male Cardiac arrest in the ICU, peri-operative MI
Yes Yes – technical Dissection of LIMA, occlusion of graft
5 59 Female Cardiac arrest in the ICU, peri-operative MI
Yes Yes – technical Haematoma of LIMA, occlusion of graft
6 54 Male Ventricular fibrillation after CABG × 3 in ICU,
2 saphenous vein occlusions
Yes Yes – technical Surgical technical error of anastomosis?
7 57 Female Renal failure (excessive blood transfusion)
2 800 mm
3
drainage, late revision surgery
No Yes – system System error
8 61 Male Renal failure ( excessive blood transfusion) 3 650 mm
3
drainage, no revision
No Yes – system System error
9 53 Male Pneumothorax-related respiratory insufficiency in ward
No Yes – system System error, unable to transfer to ICU on time
10 67 Male Development of LCOS in ICU stay
Yes
Yes – system System error, early discharge from ICU
11 65 Male Stroke, pre-operative normal sinus rhythm and
postoperative atrial fibrillation-related cerebral infarct
and emboli due to intracardiac thrombi
No Yes – system System error, lack of cardioversion on time
12 55 Male Stroke
No
No
13 57 Male Stroke
No
No
14 46 Male Stroke
No
No
15 54 Male Stroke
No
No
16 53 Female Stroke
No
No
17 59 Female Stroke
No
No
18 68 Male Stroke
No
No
19 58 Male Mediastinitis
No
No
20 58 Female Mediastinitis
No
No
21 55 Male Pulmonary emboli
No
No
22 54 Male Respiratory failure, bullous lung disease
No
No
23 54 Male Ischaemic heart disease, poor distal run-off
Yes
No
24 61 Male Sudden cardiac death after discharge
Yes
No
Possible late tamponade?
CABG: coronary artery bypass grafting, MI: myocardial infarction, ICU: intensive care unit, LIMA: left internal mammarian artery, LCOS: low-cardiac
output syndrome.
