Skip to main content Accessibility help

The assessment of complexity in congenital cardiac surgery based on objective data

  • David R. Clarke (a1), Francois Lacour-Gayet (a1), Jeffrey Phillip Jacobs (a2), Marshall L. Jacobs (a3), Bohdan Maruszewski (a4), Christian Pizarro (a5), Fred H. Edwards (a6) and Constantine Mavroudis (a7)...

When designed in 2000, the Aristotle Complexity Score was entirely based on subjective probability. This approach, based on the opinion of experts, was considered a good solution due to the limited amount of data available. In 2008, the next generation of the complexity score will be based on observed data available from over 100,000 congenital cardiac operations currently gathered in the congenital cardiac surgery databases of the Society of Thoracic Surgeons and the European Association for Cardio-Thoracic Surgery.

A mortality score is created based on 70,000 surgeries harvested in the congenital databases of The Society of Thoracic Surgeons and The European Association for Cardio-Thoracic Surgery. It is derived from 118 congenital cardiovascular operations, representing 91% of the operations and including 97% of the patients. This Mortality Index of the new Aristotle Complexity Score could further be stratified into 5 levels with minimal within-group variation and maximal between-group variation, and may contribute to the planned unification of the Aristotle Complexity Score with the Risk Adjustment for Congenital Heart Surgery system.

Similarly, a score quantifying morbidity risk is created. Due to the progress of congenital cardiac surgery, the mortality is today reduced to an average of 4%. No instrument currently exists to measure the quality of care delivered to the survivors representing 96% of the patients. An objective assessment of morbidity was needed. The Morbidity Index, based on 50,000 operations gathered in the congenital databases of The Society of Thoracic Surgeons and The European Association for Cardio-Thoracic Surgery, is derived from 117 congenital cardiovascular operations representing 90% of the operations and including 95% of the patients. This morbidity indicator is calculated on an algorithm based on length of stay in the hospital and time on the ventilator.

The mortality and morbidity indicators will be part of the next generation of the complexity score, which will be named the Aristotle Average Complexity Score. It will be based on the sum of mortality, morbidity, and subjective technical difficulty. The introduction of objective data in assessment of mortality and morbidity in congenital cardiac surgery is a significant step forward, which should allow a better evaluation of the complexity of the operations performed by a given centre or surgeon.

Corresponding author
Correspondence to: Francois Lacour-Gayet, MD, Professor of Surgery, University of Colorado School of Medicine, The Children’s Hospital in Denver, 13123 E. 16th Avenue. Aurora. CO80045, United States of America. Tel: +1 720 777 3376; Fax: +1 720 777 7271; E-mail:
Hide All
1.O’Brien, SM, Jacobs, JP, Clarke, DR, et al. Accuracy of the Aristotle Basic Complexity Score for classifying the mortality and morbidity potential of congenital heart surgery procedures. Ann Thorac Surg 2007; 84: 20272037. PMID: 18036930.
2.Jenkins, KJ, Gauvreau, K. Center-specific differences in mortality: preliminary analyses using the Risk Adjustment in Congenital Heart Surgery (RACHS-1) method. J Thorac Cardiovasc Surg 2002; 124: 97104.
3.Edwards, FH, Grover, FL, Shroyer, LW, Schwartz, M, Bero, J. The Society of Thoracic Surgeons National Cardiac Surgery Database: Current risk assessment. Ann Thorac Surg 1997; 63: 903908.
4.Welke, KF, Shen, I, Ungerleider, RM. Current assessment of mortality rates in congenital cardiac surgery. Ann Thorac Surg 2006; 82: 164171.
5.Lacour-Gayet, FG, Clarke, DR, Jacobs, JP, et al. and the Aristotle Committee. The Aristotle Score: a complexity-adjusted method to evaluate surgical results. Eur J Cardiothorac Surg 2004; 25: 911924.
6.Lacour-Gayet, F, Jacobs, ML, Jacobs, JP, Mavroudis, C. The need for an objective evaluation of morbidity in congenital heart surgery. Ann Thorac Surg 2007 ; 84: 12.
7.Jacobs, JP, Jacobs, ML, Mavroudis, C, et al. What is operative morbidity? Defining complications in a surgical registry database: a report from the STS Congenital Database Task Force and the Joint EACTS-STS Congenital Database Committee. Ann Thorac Surg 2007; 84: 14161421.
8.Lacour-Gayet, FG, Jacobs, JP, Clarke, DR. Evaluation of quality of care in congenital heart surgery: contribution of the Aristotle Complexity Score. Adv Pediatr 2007; 54: 6783. PMID: 17918467.
9. [], accessed January 7, 2008.
10.Benavidez, OJ, Gauvreau, K, Del Nido, P, Bacha, E, Jenkins, KJ. Complications and risk factors for mortality during congenital heart surgery admissions. Ann Thorac Surg 2007; 84: 147155.
11.Shahian, DM, Edwards, FH, Ferraris, VA, et al. Quality measurement in adult cardiac surgery: Part 1 – Conceptual framework and measure selection. Ann Thorac Surg 2007; 83: S3S12.
12.O’Brien, SM, Shahian, DM, DeLong, ER, et al. Quality measurement in adult cardiac surgery: Part 2 – Statistical considerations in composite measure scoring and provider rating. Ann Thorac Surg 2007; 83: S13S26.
13.To err is human. Building a safer health system. Institute of Medicine. National Academy Press; 2006.
14.Performance management. Accelerating improvement. Institute of Medicine. National Academy Press; 2006.
15.Mavroudis, C, Jacobs, JP (eds). International Congenital Heart Surgery Nomenclature and Database Project. Ann Thorac Surg 2000; 69 (Suppl 1): 1372.
16.Welke, KF, Peterson, ED, Vaughan-Sarrazin, MS, et al. Comparison of cardiac surgery volumes and mortality rates between the Society of Thoracic Surgeons and Medicare Databases from 1993 through 2001. Ann Thorac Surg 2007; 84: 15381546.
17.Jacobs, JP, Lacour-Gayet, FG, Jacobs, ML, et al. Initial application in the STS congenital database of complexity adjustment to evaluate surgical case mix and results. Ann Thorac Surg 2005; 79: 16351649.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Cardiology in the Young
  • ISSN: 1047-9511
  • EISSN: 1467-1107
  • URL: /core/journals/cardiology-in-the-young
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed