Phenotype, Management and Predictors of Outcome in a Large Cohort of Adult Congenital Heart Disease Patients with Heart Failure

Objective: Although heart failure (HF) is the leading cause of premature death in adult congenital heart disease (ACHD), little population-specific data exist. This study reports early experience from a dedicated, sub-specialty adult congenital heart disease-heart failure (ACHD-HF) clinic, aiming to identify risk factors for adverse outcome.

Methods: Between 2012 and 2015, 126 patients (57% male) attended the ACHD-HF clinic. Baseline and follow-up data were analysed and compared across 4 anatomical/physiological subgroups: cyanotic ACHD, Fontan circulation (1V), biventricular circulation with a subaortic right ventricle (2V-RV) and biventricular circulation with a subaortic left ventricle (2V-LV). Predictors of the composite primary outcome: death, transplant or ventricular assist device (VAD) were identified using multivariable Cox proportional hazard models.

Results: Mean age at first visit was 38±13years. Patients were grouped as follows: cyanotic ACHD 10%, 1V 24%, 2V-RV 29% and 2V-LV 37%. During a median follow-up of 1.7 (IQR 0.8-2.9) years, 38 patients (30%) reached the primary outcome. Event-free survival was 89%, 78% and 63% at 1, 2 and 3years. Forty (31.7%) patients experienced 69 HF hospitalisations. Between-group differences were noted for systolic function, valvular regurgitation, pacing prevalence and invasive hemodynamics. Multivariable analysis revealed 2V-RV subgroup (p=0.001), NYHA class (p=0.002) B-type natriuretic peptide >164pg/ml (p=0.003) and sodium <136mmol/L (p=0.036) as independently associated with death, transplant or VAD.

Conclusions: Our young ACHD-HF patients experienced high adverse event rates during a short period of follow-up. The prognostic markers identified will aid clinicians to stratify short-term risk and thereby guide advanced HF management decisions in ACHD.