Predicting 15-Year Mortality in Adults With Congenital Heart Disease Using Disease Severity and Functional Indices

Abstract

BackgroundDisease severity and functional indices are widely used for risk stratification of patients with congenital heart disease (CHD). The predictive value of these classification systems for assessing long-term mortality is unknown. We aimed to determine and compare the predictive value of disease severity and functional indices for 15-year mortality in adults with CHD. MethodsBetween 2000 and 2002, we categorized 629 patients with CHD (median age, 24 years; 60% were men) on 5 indices: disease complexity scores based on criteria of Task Force 1 of the 32nd Bethesda Conference; Disease Severity Index; New York Heart Association functional class; Ability Index; and Congenital Heart Disease Functional Index (CHDFI). Harrell’s concordance statistics index (C-index) was calculated for each classification system through Cox hazard regression analysis to evaluate their performance on predicting all-cause and cardiac mortality over the subsequent 15 years. ResultsOver the 15-year follow-up period, 40 patients died, resulting in a mortality rate of 4.56 per 1000 person-years. The CHDFI showed the highest discrimination ability for all-cause mortality (C-index = 0.74; P < 0.001) and cardiac mortality (C-index = 0.76; P < 0.001). The C-index for the other classifications ranged from 0.58 to 0.71 for all-cause mortality and 0.55 to 0.67 for cardiac mortality. The CHDFI showed statistical superiority toward the Disease Severity Index (P < 0.01). ConclusionsThese results suggest that the Task Force 1 of the 32nd Bethesda Conference, New York Heart Association functional class, Ability Index, and CHDFI could aid in predicting long-term mortality. The CHDFI demonstrated the highest discrimination ability and emphasizes the importance to integrate both anatomic and physiological variables to predict long-term mortality.