Kholeif, Zeyad

Background The purpose of this study was to assess the clinical benefits of guideline‐directed medical therapy (GDMT) for heart failure (HF) in adults with congenital heart disease and HF with reduced ejection fraction. Methods HF with reduced ejection fraction was defined as stage B/C HF and systemic left ventricular ejection fraction <50%. GDMT score was assessed at baseline encounter (baseline GDMT score) and 1‐year follow‐up. GDMT uptitration was calculated as defined as ∆GDMT score from baseline. Cox regression was used to assess the relationship between HF therapy (baseline and ∆GDMT score) and outcomes (HF hospitalization and mortality). Results Of 778 patients (age 44±16, 480 [62%] males), baseline GDMT score was 2 (1, 3) and ∆GDMT score was 0.62 (95% CI, 0.55–0.69). Of 778, only 258 (33%) had GDMT uptitration (∆GDMT score >0). Higher use of GDMT at baseline (adjusted HR per 1 point increase in GDMT score 0.81, 95% CI, 0.74–0.88, P <0.001), and increased use of GDMT over time (adjusted HR for 1 point increase in ∆GDMT score HR 0.70, 95% CI, 0.61–0.79, P <0.001) were associated with lower risk of HF hospitalization. Higher baseline GDMT score (adjusted HR 0.85, 95% CI, 0.76–0.94, P <0.001), and ∆ GDMT score (adjusted HR 0.82, 95% CI, 0.71–0.94, P <0.000) were also associated with lower mortality. Conclusions GDMT use at baseline and GDMT uptitration were associated with improved outcomes and suggest a dose‐dependent relationship between use of GDMT and risk of adverse outcomes. Furthermore, 67% of patients did not receive GDMT uptitration, suggesting suboptimal therapy, and opportunities for improvement.