The most common outcomes used to assess performance of a cardiac surgical unit are mortality and length of post operative stay in hospital. The table below shows the mortality rates and post operative stays of patients operated on in 2002 and 2003. It is broken down into type of procedure.
|Mortality||Merdian length of post-operative stay|
|All patients||5.72%||9 days|
|1st time CABG (elective)||0.9%||8 days|
|1st time CABG (all patients)||4.3%||8 days|
|Redo CABG||5.66%||9 days|
CABG + valve
Valve + other
One of the first points to note from the above table is the mortality rate in the Professor Eoin O'Malley department of cardio-thoracic surgery at the Mater Misericordiae Hospital for patients undergoing elective 1st time CABG procedures in 2002 and 2003 was 0.9%. In the UK in 2001 this figure was 1.4%.
For all patients undergoing 1st time CABG procedures the mortality rate is 4.3% and 75% of these patients were in the emergency/urgent category, which is 250% greater than cardio-thoracic units in the UK (30% of patients were emergency/urgent) and 140% greater than patients operated on in St James Hospital (53% of patients were emergency/urgent).
Risk stratification (Euroscore www.euroscore.org) involves assigning a score to patients depending on the different risks attached to them upon presentation for surgery. Items such as patient age, gender, presence of other diseases such as respiratory or renal disease, actual heart function and recent heart attack to name a few are all components in calculating the risk of the patient.
Risk stratification analysis of these 1st time CABG patients showed that the average risk (Euroscore) was 4. In the UK the average risk is 3 and almost 66% of patients there have a risk in the 0-3 range compared to 49% at the Mater.
51% of 1st time CABG patients in the Mater have a risk greater than 4 (Euroscore) compared to 33% of patients in the cardio-thoracic units in the UK and almost 18% of Mater patients have a risk greater than 7 (Euroscore) compared to 6% in the UK.
The risk stratification data reflects the severity of illness being referred to and operated upon at the National Centre of cardio-thoracic surgery at the Mater compared to our colleagues in the UK.
The other common outcome used is the duration of post operative stay. As seen in the table above the median length of stay of all patients in 2002 and 2003 was 9 days.
1st time CABG patients have a median stay of 8 days and more complicated procedures such as valve surgery, combination of CABG and valve surgery and other surgery such as aortic surgery result in a longer post operative stay.