Failing systemic right ventricle: to treat or not to treat

Congenital heart diseases (CHD) are a heterogeneous group of conditions that afflict an increasing number of adults. On some occasions, the singularities of the anatomy and physiology are a real challenge for the treating cardiologist. Such is the case of patients with congenitally corrected transposition of the great arteries (ccTGA) and those with transposition of the great arteries (TGA) repaired with the atrial switch procedure, in which a morphologically right ventricle (RV) sustains the systemic circulation. Although there are case reports of asymptomatic elderly patients being diagnosed with previously undetected ccTGA, these are exceptions. The systemic right ventricle (SRV) usually experiences a progressive decline in the systolic function ultimately leading to death or heart transplantation in most cases. Available drug strategies for the treatment of the failing left ventricle (LV) in acquired heart disease are commonly used in the SRV dysfunction, but such approach is not based on scientific evidence. Several studies have unsuccessfully tried to prove a net benefit from the use of beta blockers or agents targeting the renin-angiotensin-aldosterone system (RAAS) in patients with biventricular circulation and an SRV. Even a few randomised controlled trials (RCT), the top method in the hierarchy of scientific evidence, have failed in this purpose.1 There are different reasons that could explain this lack of success, the most important being the small sample size of all the studies. The largest RCT2 only included 88 patients (44 randomised to valsartan and 44 to placebo). Considering that the Survival And Ventricular Enlargement …