Red blood cell distribution width in addition to N-terminal prohormone of B-type natriuretic peptide concentration improves assessment of risk of cardiovascular events in adult patients with congenital heart disease

Abstract

More patients with CHD than control patients have RDW levels>15%.•Great complexity and high NT-pro-BNP concentration predict high RDW levels in CHD.•The combination of RDW and NT-pro-BNP adds value in predicting CHD outcome. Aim To establish predictors of high RDW values in patients with congenital heart disease (CHD), and their relationship with cardiovascular events. Methods: Overall, 561 patients with stable CHD who attended a single outpatient clinic and a matched control population of 2128 patients were studied. Exclusion criteria were renal failure, anaemia, receiving iron therapy and cyanosis. Blood tests included glucose, creatinine, iron, apoferritin, liver enzymes and a complete blood count. C-reactive protein and N-terminal prohormone of B-type natriuretic peptide (NT-pro-BNP) concentrations were also measured in patients with CHD. Major adverse cardiac events (MACE) were defined as cardiovascular/total mortality, arterial thrombotic events, arrhythmias, major bleedings, pulmonary embolism or heart failure needing hospital admission. Results: The median age in patients with CHD was 23 (17–36) years and the median follow-up time was 5.8 (3.2–8.7) years; 103 (4.8%) controls and 40 (7.1%) patients with CHD had an RDW>15% (P=0.032). During follow-up, MACE were reported in 48 patients. CHD of great complexity, cardiovascular risk factors, low haemoglobin concentration and high NT-pro-BNP concentration were risk factors for an RDW>15%. Kaplan-Meier analysis showed a significantly worse cardiovascular outcome in patients with CHD with an RDW>15% (P<0.001). The multivariable survival analysis determined that age, CHD of great complexity, high NT-pro-BNP concentration and an RDW>15% were independent predictive factors for MACE. Conclusion: RDW and NT-pro-BNP concentration are independent analytical predictors of MACE in patients with CHD.