Evaluation of the Adult Congenital Heart Surgery Mortality Score at Two European Centers

Background: The adult congenital heart surgery (ACHS) score was derived from The Society of Thoracic Surgeons Congenital Heart Surgery Database. The score was validated with data for 1,603 operations and reached a good predictive power. We sought to evaluate its predictive power for 1,654 operations performed in two European centers. Methods: Data of all consecutive patients aged 18 years or more who underwent surgery for congenital heart disease between 2004 and 2013 at center 1 (n = 830) and between 2005 and 2016 at center 2 (n = 824) were collected. Mortality was defined as hospital mortality or mortality within 30 days after surgery. The discriminatory power of the ACHS score was assessed using the area under the receiver-operating characteristics curve (c-index). Results: During the examined 13-year period, 1,639 operations of 43 different procedural groups were eligible for scoring. The most frequent procedures were closure of atrial septal defect (n = 175, 10.7%), repair of partial anomalous pulmonary venous connection (n = 117, 7.1%), and aortic valve replacement (n = 112, 6.8%). Hospital mortality was 3.1%. The procedures with the highest mortality were heart transplantation (3 of 11, 27.3%), mitral valve replacement (9 of 39, 23.1%), and systemic venous stenosis repair (2 of 9, 22.2%). The c-index for the ACHS mortality score was 0.760 (0.750 in center 1 and 0.772 in center 2). Conclusions: The ACHS score reached similar, good predictive power in two different centers. The score is a useful tool to analyze surgical outcomes and to support individual decision making.