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Home > ABOUT US > Clinical Outcomes > Heart Surgeries

Heart Surgeries


A variety of heart surgeries are performed by qualified and skilled surgeons in the National University Hospital.


This site provides an overview of the volume and types of common adult heart surgeries and clinical outcomes of the patient population who underwent heart surgeries performed at the National University Hospital (NUH) from 2003-'05 and 2006-'08.


The total number of heart surgeries performed in NUH has increased by 5.2% during the 3-year period of 2006-'08, as compared to 2003-'05 (from 1536 to 1615). The percentage of elective or urgent procedures has increased (73.6 to 84.6%), while that of emergency operations decreased from 26.4% to 15.4%.

Urgent - Urgent procedures are usually performed within 24 hours in order to minimize the chance of further clinical worsening of patient's condition.
Emergency - These are operations that would have to be conducted without delay.


The main types of heart surgeries performed in 2003-'05 and 2006-'08 are:


  • Isolated coronary artery-bypass graft surgery or CABG also known as Heart Bypass Operation
    2003-'05
    79.1%
    2006-'08
    77.4%


  • Isolated heart valve surgery
    2003-'05
      12.2%
    2006-'08
      10.7%


  • A combination of these two operations
    2003-'05
      6.1%
    2006-'08
      4.8%


  • Others - refers to less common heart operations such as surgical repair of defect in the inner walls of the heart etc
    2003-'05
      4.3%
    2006-'08
      5.4%


The proportion of heart surgeries performed under elective or urgent situation and on an emergency basis is tabulated in Table A for reference.


Over fifteen per cent of the cardiac surgeries (all types and CABG) were performed under emergency situations to prevent the patient's heart condition from deteriorating.


Table A: Distribution by Types of Heart Surgeries and Urgency (2006-'08)



Electives + Urgent Emergency* (a) Total (b)
Isolated CABG 1075 203 (15.8%) 1278
Isolated Valve 157 15 (8.7%) 172
CABG + Valve 73 5 (6.4%) 78
Others 61 26 (29.9%) 87
Total 1366 249 (15.4%) 1615

*Depicts percentage of the total surgeries for each category (a/b*100)



Demographic Profile of Heart Surgery Patients in NUH


Men constituted more than three quarters of the patients (77.5%) who underwent heart surgeries. Majority (84%) who underwent heart surgeries were above 50 years of age.



How Long You Are Expected to Stay in Hospital after Heart Surgery: Length of Stay (LOS))


Median LOS is 9 days for all types of surgeries and isolated CABG (heart bypass), but you may be expected stay 2 days longer if the surgery is performed under emergency situations. The 90th percentile stay is around 22 days for all types of surgeries and 21 days for isolated CABG (heart bypass).



Survival* Rates after Heart Surgery


Different survival rates are observed for different types of heart surgeries


Chart 1 - Actual and Predicted Survival Rates for All Types of Heart Surgeries


*Survival after heart surgery is defined as "no deaths within 30 days of surgery or within the same hospital admission (as the heart surgery)".
Survival rate is computed as number of heart surgery patients who survived over total number of heart surgeries performed.


Table B - Survival Rates for Elective + Urgent vs. Emergency for All Types of Heart Surgeries



Electives + Urgent Emergency Total
Survival Rate 97% 89.2% 95.8%


Survival rate is better when patients are operated under elective + urgent situation as compared to that of emergency situation. The number of high-risk group patients in emergency surgeries is more than twice compared to elective + urgent surgeries (73.5% vs. 27.7%, respectively).
Overall, comparing the two three-year periods, there are more high-risk patients in 2006-'08 (29.1% and 34.8% in 2003-'05 and 2006-'08, respectively).


Table C - Risk-adjusted Survival Rates for All Types of Heart Surgeries (2006-'08, N=1615)



All Types of Heart Surgeries
Euroscore
Risk Groups
% Patients in
Risk Groups
Actual
Survival Rate
Predicted
Survival Rate
Low Risk 28.9% 98.9% 98.7% (98.7-98.7)
Medium Risk 36.3% 98.5% 96.9% (96.8-97.0)
High Risk 34.8% 90.4% 85.1% (83.9-86.2)
Total Number
of Patients
1615 95.8% 93.3% (92.8-93.8)


Chart 2 - Survival* Rates for Coronary Artery Bypass Graft Surgery (Heart Bypass)


*Survival after heart surgery is defined as "no deaths within 30 days of surgery or within the same hospital admission (as the heart surgery)".
Survival rate is computed as number of heart surgery patients who survived over total number of heart surgeries performed.


Table D - Difference in the Survival Rate for Emergency Vs. Elective + Urgent for isolated CABG (2006-'08)



Electives + Urgent Emergency Total
Survival Rate 98.1% 92.1% 97.2%


For isolated CABG, survival rate is also better when patients are operated under elective + urgent situation as compared to that of emergency situation. The number of high-risk group patients in emergency surgeries is more than twice compared to that of elective + urgent surgeries (73.4% vs. 25.6%, respectively).
There were more high-risk patients who underwent isolated CABG in 2006-'08 (27.1% vs. 33.2%, in 2003-'05 and 2006-'08, respectively).


Table E - Risk-Adjusted Survival Rates for CABG Surgeries (2006-'08)


Coronary Artery Bypass Surgeries
Euroscore
Risk Groups
% Patients in
Risk Groups
Actual
Survival Rate
Predicted
Survival Rate
Low Risk 32.8% 99.3% 98.7% (98.7-98.8)
Medium Risk 34.0% 98.8% 97.0% (96.9-97.1)
High Risk 33.2% 93.4% 85.3% (84.0-86.6)
Total Number
of Patients
1278 95.8% 93.7% (93.1-94.2)



Conclusion


Despite the increase in the number of heart surgeries performed and the number of patients in the high-risk group, the survival rates have improved over the years. This suggests that NUH continually strives to give the best quality of healthcare delivery to its patients.



Data source: NUHS CTVS Database

Information is correct as at November 2009