Heart failure therapy in congenitally corrected transposition of the great arteries: effect on right ventricular function and survival

Abstract Background and Aims The aim of the study was to assess the effect of guideline-directed medical therapy (GDMT) on cardiac function, neurohormonal activation, and mortality in adults with congenitally corrected transposition of the great arteries (cc-TGA) presenting with systemic right ventricular (RV) systolic dysfunction. The study hypothesis was that GDMT use (assessed using the GDMT score) was associated with improved cardiac function (higher RV free wall strain [RVFWS]), less neurohormonal activation (lower N-terminal pro-B-type natriuretic peptide [NT-proBNP] levels), and lower mortality. Methods GDMT score, RVFWS, and NT-proBNP levels were assessed at baseline and 1-year follow-up. GDMT uptitration was assessed using ΔGDMT (GDMT at 1-year minus GDMT at baseline). Improvements in RV systolic function and neurohormonal activation were defined as a relative increase in RVFWS of >20% and a relative decrease in NT-proBNP levels of >20%, respectively. Results Of 213 patients (age 43 ± 15 years; 54% male), baseline GDMT score was 1.97 ± 1.27, and ΔGDMT score was 0.74 ± 0.39. Baseline RVFWS was −18 ± 5%; 25% had improved RV systolic function. Baseline NT-proBNP was 369 (142, 1004) pg/mL; 56% had improved neurohormonal activation. Higher baseline GDMT score and ΔGDMT score were associated with improvement in RV systolic function and neurohormonal activation. Overall, 34 (16%) patients died, and higher baseline GDMT score and ΔGDMT score were associated with a lower risk of mortality and of the composite adverse event endpoint (heart failure hospitalization, death, and heart transplantation). Clinical benefits of GDMT use were observed only in patients with moderate/severe RV systolic dysfunction, and not in patients with mild RV systolic dysfunction. Conclusions GDMT use was associated with improved outcomes in patients with moderate/severe RV systolic dysfunction.